Bunga Rampai Biologi: Juli 2009

Selasa, 21 Juli 2009

Ecology

Ecology
From Wikipedia, the free encyclopedia
Jump to: navigation, search
This article needs additional citations for verification.
Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (May 2007)
For other uses, see Ecology (disambiguation).

The science of ecology includes everything from global processes (above), the study of various marine and terrestrial habitats (middle) to individual interspecific interactions like predation and pollination (below).

Ecology (from Greek: οἶκος, oikos, "house"; -λογία, -logia, "study of") is the interdisciplinary scientific study of the distribution and abundance of organisms and their interactions with their environment.[1] The environment of an organism includes all external factors, including abiotic ones such as climate and geology, and biotic factors, including members of the same species (conspecifics) and other species that share a habitat.[2] If the general life science of biology is viewed as a hierarchy of levels of organization, from molecular processes, to cells, tissues and organs, and finally to the individual, the population and the ecosystem, then the study of the latter three levels belongs within the purview of ecology.

Examples of objects of ecological study include: Population processes, including reproductive behavior, mortality, bioenergetics and migrations, interspecific interactions such as predation, competition, parasitism and mutualism, plant and animal community structures and their function and resilience, and biogeochemical cycling. Because of its vast scope, ecological science is often closely related to other disciplines. Thus, molecular ecology addresses ecological questions using tools from genetics, paleoecology uses tools from archeology, and theoretical ecologists use often highly complex mathematical models to explore how ecosystems and their elements function.

Aside from pure scientific inquiry, ecology is also a highly applied science. Much of natural resource management, such as forestry, fisheries, wildlife management and habitat conservation is directly related to ecological sciences and many problems in agriculture, urban development and public health are informed by ecological considerations.

The term "ecology" has also been appropriated for philosophical ideologies like social ecology and deep ecology and is sometimes used as a synonym for the natural environment or environmentalism. Likewise "ecological" is often taken in the sense of environmentally friendly.
Contents
[hide]

* 1 Historical roots of ecology
* 2 Scope
o 2.1 Disciplines
* 3 Fundamental principles
o 3.1 Levels of organization
o 3.2 Biosphere
o 3.3 Ecosystem
o 3.4 Dynamics and stability
o 3.5 Spatial relationships and subdivisions of land
o 3.6 Ecosystem productivity
o 3.7 Ecological crisis
* 4 See also
o 4.1 Lists
* 5 Notes
* 6 References
* 7 External links

[edit] Historical roots of ecology
Main article: History of ecology

Ernst Haeckel (left) and Eugenius Warming (right), two early founders of ecology.

Ecology as a scientific discipline is relatively young, reaching prominence mostly in the second half of the 20th century. However, systematic ecological studies can trace roots to ancient times, with Aristotle and Theophrastus, for example, making early observations on animal migrations and plant biogeography respectively. Several notable 19th century scientists such as Alexander Humboldt (1769 – 1859), Charles Darwin (1809 – 1882), Alfred Russel Wallace (1823 – 1913) and Karl Möbius (1825 – 1908) made many important contributions, from laying down the foundation of biogeography to identifying an interacting groups of organisms as a functionally connected community (biocoenosis).

The term "ecology" itself (German: Oekologie) was first coined by the German biologist Ernst Haeckel in 1866, who defined it as "the comprehensive science of the relationship of the organism to the environment."[3] The first significant textbook on the subject (together with the first university course) was written by the Danish botanist, Eugenius Warming. For this early work, Warming is sometimes identified as the founder of ecology.[4]

[edit] Scope

Ecology is usually considered as a branch of biology, the general science that studies living organisms. It is associated with the highest levels of biological organization, including the individual organism, the population, the ecological community, the ecosystem and the biosphere as a whole. When referring to the study of a single species, a distinction is often made between its "ecology" and its "biology". For example, "polar bear biology" might include the study of the polar bear's physiology, morphology, pathology and ontogeny, whereas "polar bear ecology" would include a study of its prey species, its population and metapopulation status, distribution, dependence on environmental conditions, etc.

Because of its focus on the interrelations between organisms and their environment, ecology is a multidisciplinary science that draws on many other branches, including geology and geography, meteorology, soil science, genetics, chemistry, physics, mathematics and statistics. Due to its breadth of scope, ecology is considered by some to be a holistic science, one that over-arches older disciplines such as biology which in this view become sub-disciplines contributing to ecological knowledge. It has been argued that the mechanistic models which have driven the development of most other sciences are inappropriate for unraveling the complex interactions in most ecosystems, and that progress in ecology is better served by a central paradigm driven by information theory and complexity theory.[5]

Ecology is also a highly applied science, especially with respect to issues of natural resource management. Efforts related to wildlife conservation, habitat management, mitigation of ecological impacts of environmental pollution, ecosystem restoration, species reintroductions, fisheries, forestry and game management are often the direct domain of applied ecology. Urban development, agricultural and public health issues are also often informed by ecological perspectives and analysis.

[edit] Disciplines
Main article: Ecology (disciplines)

Ecology is a broad discipline comprising many sub-disciplines. A common, broad classification, moving from lowest to highest complexity, where complexity is defined as the number of entities and processes in the system under study, is:

* Ecophysiology examines how the physiological functions of organisms influence the way they interact with the environment, both biotic and abiotic.
* Behavioral ecology examines the roles of behavior in enabling an animal to adapt to its environment.
* Population ecology studies the dynamics of populations of a single species.
* Community ecology (or synecology) focuses on the interactions between species within an ecological community.
* Ecosystem ecology studies the flows of energy and matter through the biotic and abiotic components of ecosystems.
* Systems ecology is an interdisciplinary field focusing on the study, development, and organization of ecological systems from a holistic perspective.
* Landscape ecology examines processes and relationship in a spatially explicit manner, often across multiple ecosystems or very large geographic areas.
* Evolutionary ecology studies ecology in a way that explicitly considers the evolutionary histories of species and their interactions.
* Political ecology connects politics and economy to problems of environmental control and ecological change.

Ecology can also be sub-divided according to the species of interest into fields such as animal ecology, plant ecology, insect ecology, and so on. Another frequent method of subdivision is by biome studied, e.g., Arctic ecology (or polar ecology), tropical ecology, desert ecology, marine ecology, etc. The primary technique used for investigation is often used to subdivide the discipline into groups such as chemical ecology, molecular ecology, field ecology, quantitative ecology, theoretical ecology, and so forth.

Subdivisions of ecology are not mutually exclusive; indeed, very few exist in isolation. Many of them overlap, complement and inform each other. For example, the population ecology of an organism is a consequence of its behavioral ecology and intimately tied to its community ecology. Methods from molecular ecology might inform the study of the population, and all kinds of data are modeled and analyzed using quantitative ecology techniques, often motivated by basic results in theoretical ecology.

[edit] Fundamental principles

[edit] Levels of organization
Some of the biodiversity of a coral reef

Ecology can be studied at a wide range of levels, from large to small scale. These levels of ecological organization, as well as an example of a question ecologists would ask at each level, include:

* Biosphere: " What role does concentration of atmospheric carbon dioxide play in the regulation of global temperature?"
* Region: "How has geological history influenced regional diversity within certain groups of organisms?"
* Landscape: "How do vegetated corridors affect the rate of movement by mammals among isolated fragments?"
* Ecosystem: "How does fire affect nutrient availability in grassland ecosystems?"
* Community: "How does disturbance influence the number of mammal species in African grasslands?"
* Interactions: "What evolutionary benefit do zebras gain by allowing birds to remove parasites?"
* Population: "What factors control zebra populations?"
* Individual Organism: "How do zebras regulate internal water balance?"
o These levels range from broadest to most specific.[6]

[edit] Biosphere
Main articles: Biosphere, Biodiversity, and Unified neutral theory of biodiversity

For modern ecologists, ecology can be studied at several levels: population level (individuals of the same species in the same or similar environment), biocoenosis level (or community of species), ecosystem level, and biosphere level.

The outer layer of the planet Earth can be divided into several compartments: the hydrosphere (or sphere of water), the lithosphere (or sphere of soils and rocks), and the atmosphere (or sphere of the air). The biosphere (or sphere of life), sometimes described as "the fourth envelope," is all living matter on the planet or that portion of the planet occupied by life. It reaches well into the other three spheres, although there are no permanent inhabitants of the atmosphere. Relative to the volume of the Earth, the biosphere is only the very thin surface layer that extends from 11,000 meters below sea level to 15,000 meters above.
Earth's oceans
(World Ocean)

* Arctic Ocean
* Atlantic Ocean
* Indian Ocean
* Pacific Ocean
* Southern Ocean

It is thought that life first developed in the hydrosphere, at shallow depths, in the photic zone. (Recently, though, a competing theory has emerged, that life originated around hydrothermal vents in the deeper ocean. See Origin of life.) Multicellular organisms then appeared and colonized benthic zones. Photosynthetic organisms gradually produced the chemically unstable oxygen-rich atmosphere that characterizes our planet. Terrestrial life developed later, protected from UV rays by the ozone layer. Diversification of terrestrial species is thought to be increased by the continents drifting apart, or alternately, colliding. Biodiversity is expressed at the ecological level (ecosystem), population level (intraspecific diversity), species level (specific diversity), and genetic level.

The biosphere contains great quantities of elements such as carbon, nitrogen, hydrogen, and oxygen. Other elements, such as phosphorus, calcium, and potassium, are also essential to life, yet are present in smaller amounts. At the ecosystem and biosphere levels, there is a continual recycling of all these elements, which alternate between the mineral and organic states.

Although there is a slight input of geothermal energy, the bulk of the functioning of the ecosystem is based on the input of solar energy. Plants and photosynthetic microorganisms convert light into chemical energy by the process of photosynthesis, which creates glucose (a simple sugar) and releases free oxygen. Glucose thus becomes the secondary energy source that drives the ecosystem. Some of this glucose is used directly by other organisms for energy. Other sugar molecules can be converted to molecules such as amino acids. Plants use some of this sugar, concentrated in nectar, to entice pollinators to aid them in reproduction.

Cellular respiration is the process by which organisms (like mammals) break the glucose back down into its constituents, water and carbon dioxide, thus regaining the stored energy the sun originally gave to the plants. The proportion of photosynthetic activity of plants and other photosynthesizers to the respiration of other organisms determines the specific composition of the Earth's atmosphere, particularly its oxygen level. Global air currents mix the atmosphere and maintain nearly the same balance of elements in areas of intense biological activity and areas of slight biological activity.

Water is also exchanged between the hydrosphere, lithosphere, atmosphere, and biosphere in regular cycles. The oceans are large tanks that store water, ensure thermal and climatic stability, and facilitate the transport of chemical elements thanks to large oceanic currents.

For a better understanding of how the biosphere works, and various dysfunctions related to human activity, American scientists attempted to simulate the biosphere in a small-scale model, called Biosphere II.

[edit] Ecosystem
Main article: Ecosystem
The Daintree Rainforest in Queensland, Australia is an example of a forest ecosystem.

A central principle of ecology is that each living organism has an ongoing and continual relationship with every other element that makes up its environment. The sum total of interacting living organisms (the biocoenosis) and their non-living environment (the biotope) in an area is termed an ecosystem. Studies of ecosystems usually focus on the movement of energy and matter through the system.

Almost all ecosystems run on energy captured from the sun by primary producers via photosynthesis. This energy then flows through the food chains to primary consumers (herbivores who eat and digest the plants), and on to secondary and tertiary consumers (either carnivores or omnivores). Energy is lost to living organisms when it is used by the organisms to do work, or is lost as waste heat.

Matter is incorporated into living organisms by the primary producers. Photosynthetic plants fix carbon from carbon dioxide and nitrogen from atmospheric nitrogen or nitrates present in the soil to produce amino acids. Much of the carbon and nitrogen contained in ecosystems is created by such plants, and is then consumed by secondary and tertiary consumers and incorporated into themselves. Nutrients are usually returned to the ecosystem via decomposition. The entire movement of chemicals in an ecosystem is termed a biogeochemical cycle, and includes the carbon and nitrogen cycle.

Ecosystems of any size can be studied; for example, a rock and the plant life growing on it might be considered an ecosystem. This rock might be within a plain, with many such rocks, small grass, and grazing animals -- also an ecosystem. This plain might be in the tundra, which is also an ecosystem (although once they are of this size, they are generally termed ecozones or biomes). In fact, the entire terrestrial surface of the earth, all the matter which composes it, the air that is directly above it, and all the living organisms living within it can be considered as one, large ecosystem.

Ecosystems can be roughly divided into terrestrial ecosystems (including forest ecosystems, steppes, savannas, and so on), freshwater ecosystems (lakes, ponds and rivers), and marine ecosystems, depending on the dominant biotope.

[edit] Dynamics and stability
Main articles: Biogeochemistry, Homeostasis, and Population dynamics
Much attention has been given to preserving the natural characteristics of Hopetoun Falls, Australia, while allowing ample access for visitors.

Ecological factors that affect dynamic change in a population or species in a given ecology or environment are usually divided into two groups: abiotic and biotic.

Abiotic factors are geological, geographical, hydrological, and climatological parameters. A biotope is an environmentally uniform region characterized by a particular set of abiotic ecological factors. Specific abiotic factors include:

* Water, which is at the same time an essential element to life and a milieu
* Air, which provides oxygen, nitrogen, and carbon dioxide to living species and allows the dissemination of pollen and spores
* Soil, at the same time a source of nutriment and physical support
o Soil pH, salinity, nitrogen and phosphorus content, ability to retain water, and density are all influential
* Temperature, which should not exceed certain extremes, even if tolerance to heat is significant for some species
* Light, which provides energy to the ecosystem through photosynthesis
* Natural disasters can also be considered abiotic

Biocenose, or community, is a group of populations of plants, animals, microorganisms. Each population is the result of procreations between individuals of the same species and cohabitation in a given place and for a given time. When a population consists of an insufficient number of individuals, that population is threatened with extinction; the extinction of a species can approach when all biocenoses composed of individuals of the species are in decline. In small populations, consanguinity (inbreeding) can result in reduced genetic diversity, which can further weaken the biocenose.

Biotic ecological factors also influence biocenose viability; these factors are considered as either intraspecific or interspecific relations.

Intraspecific relations are those that are established between individuals of the same species, forming a population. They are relations of cooperation or competition, with division of the territory, and sometimes organization in hierarchical societies.

An antlion lies in wait under its pit trap, built in dry dust under a building, awaiting unwary insects that fall in. Many pest insects are partly or wholly controlled by other insect predators.

Interspecific relations—interactions between different species—are numerous, and usually described according to their beneficial, detrimental, or neutral effect (for example, mutualism (relation ++) or competition (relation --). The most significant relation is the relation of predation (to eat or to be eaten), which leads to the essential concepts in ecology of food chains (for example, the grass is consumed by the herbivore, itself consumed by a carnivore, itself consumed by a carnivore of larger size). A high predator to prey ratio can have a negative influence on both the predator and prey biocenoses in that low availability of food and high death rate prior to sexual maturity can decrease (or prevent the increase of) populations of each, respectively. Selective hunting of species by humans that leads to population decline is one example of a high predator to prey ratio in action. Other interspecific relations include parasitism, infectious disease, and competition for limited resources, which can occur when two species share the same ecological niche.

The existing interactions between the various living beings go along with a permanent mixing of mineral and organic substances, absorbed by organisms for their growth, their maintenance, and their reproduction, to be finally rejected as waste. These permanent recycling of the elements (in particular carbon, oxygen, and nitrogen) as well as the water are called biogeochemical cycles. They guarantee a durable stability of the biosphere (at least when unchecked human influence and extreme weather or geological phenomena are left aside). This self-regulation, supported by negative feedback controls, ensures the perenniality of the ecosystems. It is shown by the very stable concentrations of most elements of each compartment. This is referred to as homeostasis. The ecosystem also tends to evolve to a state of ideal balance, called the climax, which is reached after a succession of events (for example a pond can become a peat bog).

[edit] Spatial relationships and subdivisions of land
Main articles: Biome and ecozone

Ecosystems are not isolated from each other, but are interrelated. For example, water may circulate between ecosystems by means of a river or ocean current. Water itself, as a liquid medium, even defines ecosystems. Some species, such as salmon or freshwater eels, move between marine systems and fresh-water systems. These relationships between the ecosystems lead to the concept of a biome.

A biome is a homogeneous ecological formation that exists over a large region, such as tundra or steppes. The biosphere comprises all of the Earth's biomes -- the entirety of places where life is possible -- from the highest mountains to the depths of the oceans.

Biomes correspond rather well to subdivisions distributed along the latitudes, from the equator towards the poles, with differences based on the physical environment (for example, oceans or mountain ranges) and the climate. Their variation is generally related to the distribution of species according to their ability to tolerate temperature, dryness, or both. For example, one may find photosynthetic algae only in the photic part of the ocean (where light penetrates), whereas conifers are mostly found in mountains.

Though this is a simplification of a more complicated scheme, latitude and altitude approximate a good representation of the distribution of biodiversity within the biosphere. Very generally, the richness of biodiversity (as well for animal as for plant species) is decreasing most rapidly near the equator and less rapidly as one approach the poles.

The biosphere may also be divided into ecozones, which are very well defined today and primarily follow the continental borders. The ecozones are themselves divided into ecoregions, though there is not agreement on their limits.

[edit] Ecosystem productivity

In an ecosystem, the connections between species are generally related to their role in the food chain. There are three categories of organisms:
The leaf is the primary site of photosynthesis in plants.

* Producers or Autotrophs -- Usually plants or cyanobacteria that are capable of photosynthesis but could be other organisms such as the bacteria near ocean vents that are capable of chemosynthesis.
* Consumers or Heterotrophs -- Animals, which can be primary consumers (herbivorous), or secondary or tertiary consumers (carnivorous and omnivores).
* Decomposers or Detritivores -- Bacteria, fungi, and insects which degrade organic matter of all types and restore nutrients to the environment. The producers will then consume the nutrients, completing the cycle.

These relations form sequences, in which each individual consumes the preceding one and is consumed by the one following, in what are called food chains or food networks. In a food network, there will be fewer organisms at each level as one follows the links of the network up the chain, forming a pyramid.

These concepts lead to the idea of biomass (the total living matter in an ecosystem), primary productivity (the increase in organic compounds), and secondary productivity (the living matter produced by consumers and the decomposers in a given time).
An ecological pyramid

These last two ideas are key, since they make it possible to evaluate the carrying capacity -- the number of organisms that can be supported by a given ecosystem. In any food network, the energy contained in the level of the producers is not completely transferred to the consumers. The higher up the chain, the more energy and resources are lost. Thus, from a purely energy and nutrient point of view, it is more efficient for humans to be primary consumers (to subsist from vegetables, grains, legumes, fruit, etc.) than to be secondary consumers (consuming herbivores, omnivores, or their products) and still more so than as a tertiary consumer (consuming carnivores, omnivores, or their products). An ecosystem is unstable when the carrying capacity is overrun.

The total productivity of ecosystems is sometimes estimated by comparing three types of land-based ecosystems and the total of aquatic ecosystems. Slightly over half of primary production is estimated to occur on land, and the rest in the ocean.

* The forests (1/3 of the Earth's land area) contain dense biomasses and are very productive.
* Savannas, meadows, and marshes (1/3 of the Earth's land area) contain less dense biomasses, but are productive. These ecosystems represent the major part of what humans depend on for food.
* Extreme ecosystems in the areas with more extreme climates -- deserts and semi-deserts, tundra, alpine meadows, and steppes -- (1/3 of the Earth's land area) have very sparse biomasses and low productivity
* Finally, the marine and fresh water ecosystems (3/4 of Earth's surface) contain very sparse biomasses (apart from the coastal zones).

Ecosystems differ in biomass (grams carbon per square meter) and productivity (grams carbon per square meter per day), and direct comparisons of biomass and productivity may not be valid. An ecosystem such as that found in taiga may be high in biomass, but slow growing and thus low in productivity. Ecosystems are often compared on the basis of their turnover (production ratio) or turnover time which is the reciprocal of turnover.

Humanity's actions over the last few centuries have seriously reduced the amount of the Earth covered by forests (deforestation), and have increased agro-ecosystems. In recent decades, an increase in the areas occupied by extreme ecosystems has occurred, such as desertification.

[edit] Ecological crisis
Main article: Ecological crisis
The retreat of Aletsch Glacier in the Swiss Alps (situation in 1979, 1991 and 2002), due to global warming.

Generally, an ecological crisis occurs with the loss of adaptive capacity when the resilience of an environment or of a species or a population evolves in a way unfavourable to coping with perturbations that interfere with that ecosystem, landscape or species survival (Note: The concept of resilience is not universally accepted in ecology, and moreso represents a contingent within the field that take a holist view of the environment. There are also many ecologists that take a reductionistic perspective and that believe that the environment, at base, is indeterministic). It may be that the environment quality degrades compared to the species needs, after a change in an abiotic ecological factor (for example, an increase of temperature, less significant rainfalls)[citation needed]. It may be that the environment becomes unfavourable for the survival of a species (or a population) due to an increased pressure of predation (for example overfishing). Lastly, it may be that the situation becomes unfavourable to the quality of life of the species (or the population) due to a rise in the number of individuals (overpopulation).

Ecological crises vary in length and severity, occurring within a few months or taking as long as a few million years. They can also be of natural or anthropic origin. They may relate to one unique species or to many species, as in an Extinction event. Lastly, an ecological crisis may be local (as an oil spill) or global (a rise in the sea level due to global warming).

According to its degree of endemism, a local crisis will have more or less significant consequences, from the death of many individuals to the total extinction of a species. Whatever its origin, disappearance of one or several species often will involve a rupture in the food chain, further impacting the survival of other species.

In the case of a global crisis, the consequences can be much more significant; some extinction events showed the disappearance of more than 90% of existing species at that time. However, it should be noted that the disappearance of certain species, such as the dinosaurs, by freeing an ecological niche, allowed the development and the diversification of the mammals. An ecological crisis thus paradoxically favoured biodiversity.

Sometimes, an ecological crisis can be a specific and reversible phenomenon at the ecosystem scale. But more generally, the crises impact will last. Indeed, it rather is a connected series of events, that occur till a final point. From this stage, no return to the previous stable state is possible, and a new stable state will be set up gradually (see homeorhesy).

Lastly, if an ecological crisis can cause extinction, it can also more simply reduce the quality of life of the remaining individuals. Thus, even if the diversity of the human population is sometimes considered threatened (see in particular indigenous people), few people envision human disappearance at short span. However, epidemic diseases, famines, impact on health of reduction of air quality, food crises, reduction of living space, accumulation of toxic or non degradable wastes, threats on keystone species (great apes, panda, whales) are also factors influencing the well-being of people.

Due to the increases in technology and a rapidly increasing population, humans have more influence on their own environment than any other ecosystem engineer.

[edit] See also
Environment portal
Ecology portal
Earth sciences portal
Sustainable development portal
Bachalpsee in the Swiss Alps; generally mountainous areas are less affected by human activity.

* Acoustic ecology
* Agroecology
* Biodiversity
* Biotope
* Climate
* Conservation movement
* Earth science
* Ecohydrology
* Ecological economics
* Ecological Forecasting
* Ecology movement
* Ecology of contexts
* Ecosystem
* Ecosystem model
* Ecotope
* ELDIS, a database on ecological aspects of economical development.
* Environment
* Forest farming
* Forest gardening
* Habitat conservation
* Human ecology
* Knowledge ecology
* Landscape ecology
* Landscape limnology
* Natural capital
* Natural resource
* Natural resource management
* Nature
* Sustainability
* Sustainable development

[edit] Lists

* Index of biology articles
* Glossary of ecology
* List of ecologists
* List of important publications in biology#Ecology
* Outline of biology
* Outline of ecology

[edit] Notes

1. ^ Begon, M.; Townsend, C. R., Harper, J. L. (2006). Ecology: From individuals to ecosystems. (4th ed.). Blackwell. ISBN 1405111178.
2. ^ Campbell, Neil A.; Brad Williamson; Robin J. Heyden (2006). Biology: Exploring Life. Boston, Massachusetts: Pearson Prentice Hall. ISBN 0-13-250882-6. http://www.phschool.com/el_marketing.html.
3. ^ Frodin, D.G. (2001). Guide to Standard Floras of the World. Cambridge: Cambridge University Press. pp. 72. ISBN 0-521-79077-8. http://books.google.com/books?id=aMjXCF4rmDUC&printsec=frontcover&dq=qjIyUKx2VnKAYDw2zTZA9n6hkuk#PPA72,M1. "[ecology is] a term first introduced by Haeckel in 1866 as Ökologie and which came into English in 1873"
4. ^ Goodland, R.J. (1975) The tropical origin of ecology: Eugen Warming’s jubilee. Oikos 26, 240-245.
5. ^ R. Ulanowicz, Ecology: The Ascendent Perspective, Columbia (1997)
6. ^ Ecology: Concepts & Applications. Fourth Edition Manuel C. Molles Jr. U of New Mexico. 2008 McGraw Hill Publishing. ISBN 978-0-07-305082-9

[edit] References

* Campbell, Neil A.; Brad Williamson; Robin J. Heyden (2006). Biology: Exploring Life. Boston, Massachusetts: Pearson Prentice Hall. ISBN 0132508826. http://www.phschool.com/el_marketing.html.
* Haeckel, E. (1866) General Morphology of Organisms; General Outlines of the Science of Organic Forms based on Mechanical Principles through the Theory of Descent as reformed by Charles Darwin. Berlin
* Odum, E. P. (1971) General Principles of Ecology, Third Edition W. B. Suanders Company. pp 17-20
* Warming, E. (1909) Oecology of Plants - an introduction to the study of plant-communities. Clarendon Press, Oxford.

[edit] External links
Search Wikimedia Commons Wikimedia Commons has media related to: Ecology
Search Wikiversity At Wikiversity you can learn more and teach others about Ecology at:
The Department of Ecology
Search Wikibooks Wikibooks has more on the topic of
Ecology
Search Wiktionary Look up ecology in Wiktionary, the free dictionary.

* stanford.edu/entries/ecology/ Ecology (Stanford Encyclopedia of Philosophy)
* Science Aid: Ecology High School (GCSE, Alevel) Ecology.
* Ecology Journals List of scientific journals related to Ecology
* Ecology Dictionary - Explanation of Ecological Terms

[show]
v • d • e
The Dynamic Earth
Continents
Africa • Antarctica • Asia • Europe • North America • Oceania • South America
Oceans
Arctic Ocean • Atlantic Ocean • Indian Ocean • Pacific Ocean • Southern Ocean
Dynamic Earth
Earth science • Geological history of Earth • History of Earth • Geology • Plate tectonics • Structure of the Earth
Natural Environment
Biome · Ecology · Ecosystem · Nature · Wilderness
Related Articles
Earth Day · Geology of solar terrestrial planets · Solar System · World
Category · Portal
[show]
v • d • e
Major subfields of biology
Anatomy · Astrobiology · Biochemistry · Biophysics · Bioinformatics · Biostatistics · Botany · Cell biology · Chronobiology · Conservation biology · Developmental biology · Ecology · Epidemiology · Evolutionary biology · Genetics · Genomics · Human biology · Immunology · Marine biology · Mathematical biology · Microbiology · Molecular biology · Neuroscience · Nutrition · Origin of life · Paleontology · Parasitology · Pathology · Physiology · Systems biology · Taxonomy · Zoology
[show]
v • d • e
Fields within the natural sciences

Astronomy · Biology · Chemistry · Earth science · Physics
[show]
v • d • e
Elements of Nature
Universe
Space · Time · Matter · Energy
Earth
Earth science · Geology · History of the Earth · Geological history of Earth · Structure of the Earth · Plate tectonics
Weather
Earth's atmosphere · Climate
Environment
Ecology · Ecosystem · Wilderness
Life
Biosphere · Origin of life · Life on Earth · Plants · Animals · Microbe · Virus · Protista · Flora · Fungi · Fauna · Evolutionary history of life · Biology
Category · Portal
[show]
v • d • e
Botany
Subdisciplines of botany
Ethnobotany · Paleobotany · Plant anatomy · Plant ecology · Plant evo-devo · Plant morphology · Plant physiology

Plants
Evolutionary history of plants · Algae · Bryophyte · Pteridophyte · Gymnosperm · Angiosperm
Plant parts
Flower · Fruit · Leaf · Meristem · Root · Stem · Stoma · Vascular tissue · Wood
Plant cells
Cell wall · Chlorophyll · Chloroplast · Photosynthesis · Plant hormone · Plastid · Transpiration
Plant life cycles
Gametophyte · Plant sexuality · Pollen · Pollination · Seed · Spore · Sporophyte
Plant taxonomy
Botanical name · Botanical nomenclature · Herbarium · IAPT · ICBN · Species Plantarum
Category · Portal
Retrieved from "http://en.wikipedia.org/wiki/Ecology"
Categories: Ecology | Biology | Greek loanwords
Hidden categories: Articles needing additional references from May 2007 | Articles containing Greek language text | Articles containing German language text | All articles with unsourced statements | Articles with unsourced statements from December 2008
Views

* Article
* Discussion
* Edit this page
* History

Personal tools

* Log in / create account

Navigation

* Main page
* Contents
* Featured content
* Current events
* Random article

Search

Interaction

* About Wikipedia
* Community portal
* Recent changes
* Contact Wikipedia
* Donate to Wikipedia
* Help

Toolbox

* What links here
* Related changes
* Upload file
* Special pages
* Printable version
* Permanent link
* Cite this page

Languages

* Afrikaans
* Alemannisch
* العربية
* Aragonés
* Asturianu
* Bân-lâm-gú
* Беларуская
* Bosanski
* Български
* Català
* Чӑвашла
* Cebuano
* Česky
* Cymraeg
* Dansk
* Deutsch
* ދިވެހިބަސް
* Eesti
* Ελληνικά
* Español
* Esperanto
* Euskara
* فارسی
* Français
* Furlan
* Gaeilge
* Gaelg
* Gàidhlig
* Galego
* 한국어
* Hawai`i
* हिन्दी
* Hrvatski
* Ido
* Bahasa Indonesia
* Interlingua
* Íslenska
* Italiano
* עברית
* Basa Jawa
* ქართული
* Кыргызча
* Kreyòl ayisyen
* Ladino
* Latina
* Lëtzebuergesch
* Lietuvių
* Lumbaart
* Magyar
* Македонски
* Malagasy
* Māori
* Bahasa Melayu
* Монгол
* Nederlands
* 日本語
* Norfuk / Pitkern
* ‪Norsk (bokmål)‬
* ‪Norsk (nynorsk)‬
* Nouormand
* Novial
* Occitan
* پښتو
* Polski
* Português
* Română
* Runa Simi
* Русский
* Саха тыла
* Scots
* Shqip
* Simple English
* Slovenčina
* Slovenščina
* Српски / Srpski
* Srpskohrvatski / Српскохрватски
* Basa Sunda
* Suomi
* Svenska
* Tagalog
* தமிழ்
* తెలుగు
* ไทย
* Тоҷикӣ
* Türkçe
* Türkmençe
* Українська
* اردو
* Tiếng Việt
* Žemaitėška
* 中文

Powered by MediaWiki
Wikimedia Foundation

* This page was last modified on 21 July 2009 at 15:37.
* Text is available under the Creative Commons Attribution/Share-Alike License; additional terms may apply. See Terms of Use for details.
Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization.
* Privacy policy
* About Wikipedia
* Disclaimers

Budidaya Jamur Merang

Prospek Cerah Budidaya Jamur Merang
BurukTerbaik
Ditulis Oleh Muridun
07-05-2008,
Halaman 1 dari 5
Sebut saja sate jamur, jamur goreng tepung, sup jamur, pepes jamur, keripik jamur, dan banyak jenis makanan olahan lain dari jamur, kini menjadi daftar menu utama di restoran-restoran yang menyediakan menu khusus vegetarian. Di restoran dan rumah makan umum pun, menu serbajamur kini semakin banyak ditemui.

Jamur disukai tak hanya karena rasanya yang lezat. Jamur, juga dipercaya kaya manfaat. Dibanding dengan daging, jamur memang punya nilai plus tersendiri. Jika daging erat dengan masalah lemak atau kandungan kolesterol, jamur sebaliknya: bebas kolesterol serta kaya serat vitamin dan mineral. Karenanya, jamur dipercaya mampu mengobati berbagai penyakit. Jamur merang, misalnya berguna bagi penderita diabetes dan penyakit kekurangan darah, bahkan dapat mengobati kanker.

Sesuai dengan namanya, umumnya jamur ini tumbuh pada merang atau jerami padi. Jamur merang dapat dengan mudah kita temui di tumpukan jerami sehabis masa panen padi. Seusai masa panen, jamur merang akan sulit ditemui. Namun dengan cara pembudidayaan modern, kita dapat menikmati jamur merang kapan saja. Tidak tergantung musim.

Pembudiyaan jamur merang secara modern, membutuhkan tempat khusus yang diset sebagai tempat tumbuh jamur. Kumbung (rumah jamur) yang telah dilengkapi media tumbuh dan telah diatur temperaturnya merupakan tempat terbaik untuk kembang biak jamur merang.

Kumbung dapat dibuat dengan rangka besi, kayu atau bambu, serta dinding dan atap plastik. Di bagian luar kumbung ini dipasang lagi atap, dan dinding yang terbuat dari anyaman bambu, nipah ataupun kain yang dapat ditutup dan buka, untuk mengatur cahaya matahari yang masuk. Kumbung juga harus dilengkapi jendela untuk mengatur sirkulasi udara. Di dalam kumbung, dibuat dua deret rak (bedengan) bertingkat, sebagai tempat meletakkan media tumbuh.

Media tumbuh yang dibutuhkan merupakan hasil pengomposan jerami dan campuran limbah kapas dengan perbandingan 2:1, ditambah 1-2 % kapur. Jerami dibasahi air, kemudian ditimbun bersama kapur di lantai, lalu ditutup plastik polibag selama 5 hari. Pada hari kelima, timbunan itu dibuka, dibalik, dan ditambahi bekatul, kemudian diletakkan di bedengan. Bedengan itu kemudian ditutup polibag selama 4 hari untuk menjalai proses fermentasi. Sebelum digunakan, bahan ditambah lagi dengan limbah kapas dan biji-bijian seperti kacang hijau, beras, jagung, kedelai, atau biji kapuk.

Setelah siap, media tumbuh diletakkan di rak-rak bedengan di dalam kumbung. Agar terhindar dari serangan bakteri, ngengat, ataupun jamur lain, kumbung dan media tanam harus disterilkan. Sterilisasi dilakukan dengan proses pasteurisasi, yakni pemanasan kompos dan ruangan rumah jamur dengan uap panas hingga temperatur 70 derajat celcius selama 5-7 jam. Suhu kompos dipertahankan 70 derajat selama 2-3 jam.

Pemanasan kumbung ini dilakukan dengan menghidupkan generator uap yang telah dihubungkan dengan ruangan dalam kumbung. Generator uap dapat dibuat sederhana, menggunakan drum-drum bekas yang diisi air, serta dipanaskan menggunakan kayu bakar. Uap yang dihasilkan disalurkan ke dalam kumbung.

Setelah pasteurisasi, udara segar dibiarkan masuk untuk menurunkan suhu hingga mencapai 32-35 derajat celcius. Saat inilah bibit boleh mulai ditanam.

Bibit jamur merang biasanya diperoleh dari penjual bibit. Tidak mudah membuat biakan bibit jamur sendiri, kalaupun bisa, kualitasnya tidak selalu bagus. Bibit ditebarkan di seluruh permukaan jerami yang telah dikomposkan. Setelah itu, jendela dan pintu kumbung ditutup selama tiga hari. Suhu dijaga dalam kisaran 32-38 derajat celcius. Bibit jamur memerlukan suhu yang agak panas untuk menumbuhkan miselium (benang-benang jamur).

Sirkulasi udara harus dijaga. Selain itu, perhatikan pula media tumbuh, jangan sampai jerami kering. Bila perlu, semprotkan air yang telah dicampur sedikit urea.

Pada hari ke 8-12 setelah peletakan bibit, jamur merang sudah siap dipanen. Jamur merang biasanya diminati saat kuncupnya belum mekar, masih berbentuk bulat dengan warna putih kecoklatan. Bila kuncup telah mekar, meski masih bisa dimakan, namun nilai ekonomisnya akan turun.

Saat ini, jamur merang kualitas bagus dapat dijual dengan harga cukup tinggi, 9.000-10.000 perkilogram. Dari setiap kandang berukuran 4 x 8 meter berisi sepuluh rak bedengan, dapat dipanen 25-40 kilogram jamur. Setiap hari selama masa panen yang berlangsung 15-17 hari.

Muridun, petani jamur di Desa Rowosari Kecamatan Limpung, Batang.

Home Budaya Wisata Kampus Politik Kuliner Agama Berita Tips Pewarta
©2008 SuaraWarga - Suara Merdeka CyberNews Groups
Groups

Budidaya Jamur Merang

Prospek Cerah Budidaya Jamur Merang PDF Cetak E-mail
Penilaian Pembaca: / 87
BurukTerbaik
Ditulis Oleh Muridun
07-05-2008,
Halaman 1 dari 5
Sebut saja sate jamur, jamur goreng tepung, sup jamur, pepes jamur, keripik jamur, dan banyak jenis makanan olahan lain dari jamur, kini menjadi daftar menu utama di restoran-restoran yang menyediakan menu khusus vegetarian. Di restoran dan rumah makan umum pun, menu serbajamur kini semakin banyak ditemui.

Jamur disukai tak hanya karena rasanya yang lezat. Jamur, juga dipercaya kaya manfaat. Dibanding dengan daging, jamur memang punya nilai plus tersendiri. Jika daging erat dengan masalah lemak atau kandungan kolesterol, jamur sebaliknya: bebas kolesterol serta kaya serat vitamin dan mineral. Karenanya, jamur dipercaya mampu mengobati berbagai penyakit. Jamur merang, misalnya berguna bagi penderita diabetes dan penyakit kekurangan darah, bahkan dapat mengobati kanker.

Sesuai dengan namanya, umumnya jamur ini tumbuh pada merang atau jerami padi. Jamur merang dapat dengan mudah kita temui di tumpukan jerami sehabis masa panen padi. Seusai masa panen, jamur merang akan sulit ditemui. Namun dengan cara pembudidayaan modern, kita dapat menikmati jamur merang kapan saja. Tidak tergantung musim.

Pembudiyaan jamur merang secara modern, membutuhkan tempat khusus yang diset sebagai tempat tumbuh jamur. Kumbung (rumah jamur) yang telah dilengkapi media tumbuh dan telah diatur temperaturnya merupakan tempat terbaik untuk kembang biak jamur merang.

Kumbung dapat dibuat dengan rangka besi, kayu atau bambu, serta dinding dan atap plastik. Di bagian luar kumbung ini dipasang lagi atap, dan dinding yang terbuat dari anyaman bambu, nipah ataupun kain yang dapat ditutup dan buka, untuk mengatur cahaya matahari yang masuk. Kumbung juga harus dilengkapi jendela untuk mengatur sirkulasi udara. Di dalam kumbung, dibuat dua deret rak (bedengan) bertingkat, sebagai tempat meletakkan media tumbuh.

Media tumbuh yang dibutuhkan merupakan hasil pengomposan jerami dan campuran limbah kapas dengan perbandingan 2:1, ditambah 1-2 % kapur. Jerami dibasahi air, kemudian ditimbun bersama kapur di lantai, lalu ditutup plastik polibag selama 5 hari. Pada hari kelima, timbunan itu dibuka, dibalik, dan ditambahi bekatul, kemudian diletakkan di bedengan. Bedengan itu kemudian ditutup polibag selama 4 hari untuk menjalai proses fermentasi. Sebelum digunakan, bahan ditambah lagi dengan limbah kapas dan biji-bijian seperti kacang hijau, beras, jagung, kedelai, atau biji kapuk.

Setelah siap, media tumbuh diletakkan di rak-rak bedengan di dalam kumbung. Agar terhindar dari serangan bakteri, ngengat, ataupun jamur lain, kumbung dan media tanam harus disterilkan. Sterilisasi dilakukan dengan proses pasteurisasi, yakni pemanasan kompos dan ruangan rumah jamur dengan uap panas hingga temperatur 70 derajat celcius selama 5-7 jam. Suhu kompos dipertahankan 70 derajat selama 2-3 jam.

Pemanasan kumbung ini dilakukan dengan menghidupkan generator uap yang telah dihubungkan dengan ruangan dalam kumbung. Generator uap dapat dibuat sederhana, menggunakan drum-drum bekas yang diisi air, serta dipanaskan menggunakan kayu bakar. Uap yang dihasilkan disalurkan ke dalam kumbung.

Setelah pasteurisasi, udara segar dibiarkan masuk untuk menurunkan suhu hingga mencapai 32-35 derajat celcius. Saat inilah bibit boleh mulai ditanam.

Bibit jamur merang biasanya diperoleh dari penjual bibit. Tidak mudah membuat biakan bibit jamur sendiri, kalaupun bisa, kualitasnya tidak selalu bagus. Bibit ditebarkan di seluruh permukaan jerami yang telah dikomposkan. Setelah itu, jendela dan pintu kumbung ditutup selama tiga hari. Suhu dijaga dalam kisaran 32-38 derajat celcius. Bibit jamur memerlukan suhu yang agak panas untuk menumbuhkan miselium (benang-benang jamur).

Sirkulasi udara harus dijaga. Selain itu, perhatikan pula media tumbuh, jangan sampai jerami kering. Bila perlu, semprotkan air yang telah dicampur sedikit urea.

Pada hari ke 8-12 setelah peletakan bibit, jamur merang sudah siap dipanen. Jamur merang biasanya diminati saat kuncupnya belum mekar, masih berbentuk bulat dengan warna putih kecoklatan. Bila kuncup telah mekar, meski masih bisa dimakan, namun nilai ekonomisnya akan turun.

Saat ini, jamur merang kualitas bagus dapat dijual dengan harga cukup tinggi, 9.000-10.000 perkilogram. Dari setiap kandang berukuran 4 x 8 meter berisi sepuluh rak bedengan, dapat dipanen 25-40 kilogram jamur. Setiap hari selama masa panen yang berlangsung 15-17 hari.

Muridun, petani jamur di Desa Rowosari Kecamatan Limpung, Batang.

Home Budaya Wisata Kampus Politik Kuliner Agama Berita Tips Pewarta
©2008 SuaraWarga - Suara Merdeka CyberNews Groups
Groups

Biodiversity

Biodiversity
From Wikipedia, the free encyclopedia
Jump to: navigation, search
Some of the biodiversity of a coral reef
Rainforests are an example of biodiversity on the planet, and typically possess a great deal of species biodiversity. This is the Gambia River in Senegal's Niokolokoba National Park.

Biodiversity is the variation of life forms within a given ecosystem, biome, or for the entire Earth. Biodiversity is often used as a measure of the health of biological systems. The biodiversity found on Earth today consists of many millions of distinct biological species, which is the product of nearly 3.5 billion years of evolution.[1][2]
Contents
[hide]

* 1 Etymology
* 2 Definitions
* 3 Measurement
* 4 Distribution
* 5 Evolution
* 6 Human benefits
o 6.1 Agriculture
o 6.2 Human health
o 6.3 Business and Industry
o 6.4 Other ecological services
o 6.5 Leisure, cultural and aesthetic value
* 7 Number of species
* 8 Threats
o 8.1 Destruction of habitat
o 8.2 Exotic species
o 8.3 Genetic pollution
o 8.4 Hybridization and genetics
o 8.5 Climate Change
* 9 Conserving biodiversity
* 10 Judicial status
* 11 Analytical limits
o 11.1 Taxonomic and size bias
* 12 Definition
* 13 See also
* 14 References
* 15 Further reading
* 16 External links
o 16.1 Documents
o 16.2 Tools
o 16.3 Resources

[edit] Etymology

Biodiversity is a portmanteau word, from biology and diversity, originating from and used interchangeably with "biological diversity." This term was used first by wildlife scientist and conservationist Raymond F. Dasmann in a lay book[3] advocating nature conservation. The term was not widely adopted for more than a decade, when in the 1980s it and "biodiversity" came into common usage in science and environmental policy. Use of the term by Thomas Lovejoy in the Forward to the book[4] credited with launching the field of conservation biology introduced the term along with "conservation biology" to the scientific community. Until then the term "natural diversity" was used in conservation science circles, including by The Science Division of The Nature Conservancy in an important 1975 study, "The Preservation of Natural Diversity." By the early 1980s TNC's Science program and its head Robert E. Jenkins, Lovejoy, and other leading conservation scientists at the time in America advocated the use of "biological diversity" to embrace the object of biological conservation.

The term's contracted form biodiversity may have been coined by W.G. Rosen in 1985 while planning the National Forum on Biological Diversity organized by the National Research Council (NRC) which was to be held in 1986, and first appeared in a publication in 1988 when entomologist E. O. Wilson used it as the title of the proceedings[5] of that forum.[6]

Since this period both terms and the concept have achieved widespread use among biologists, environmentalists, political leaders, and concerned citizens worldwide. The term is sometimes used to equate to a concern for the natural environment and nature conservation. This use has coincided with the expansion of concern over extinction observed in the last decades of the 20th century.

A similar concept in use in the United States, besides natural diversity, is the term "natural heritage." It pre-dates both terms though it is a less scientific term and more easily comprehended in some ways by the wider audience interested in conservation. "Natural Heritage" was used when Jimmy Carter set up the Georgia Heritage Trust while he was governor of Georgia; Carter's trust dealt with both natural and cultural heritage. It would appear that Carter picked the term up from Lyndon Johnson, who used it in a 1966 Message to Congress. "Natural Heritage" was picked up by the Science Division of the US Nature Conservancy when, under Jenkins, it launched in 1974 the network of State Natural Heritage Programs. When this network was extended outside the USA, the term "Conservation Data Center" was suggested by Guillermo Mann and came to be preferred.

[edit] Definitions
A Sampling of fungi collected during summer 2008 in Northern Saskatchewan mixed woods, near LaRonge is an example regarding the species diversity of fungi. In this photo, there are also leaf lichens and mosses.

Biologists most often define "biological diversity" or "biodiversity" as the "totality of genes, species, and ecosystems of a region". An advantage of this definition is that it seems to describe most circumstances and present a unified view of the traditional three levels at which biological variety has been identified:

* genetic diversity
* species diversity
* ecosystem diversity

This multilevel conception is consistent with the early use of "biological diversity" in Washington. D.C. and international conservation organizations in the late 1960s through 1970's, by Raymond F. Dasmann who apparently coined the term and Thomas E. Lovejoy who later introduced it to the wider conservation and science communities. An explicit definition consistent with this interpretation was first given in a paper by Bruce A. Wilcox commissioned by the International Union for the Conservation of Nature and Natural Resources (IUCN) for the 1982 World National Parks Conference in Bali [7] The definition Wilcox gave is "Biological diversity is the variety of life forms...at all levels of biological systems (i.e., molecular, organismic, population, species and ecosystem)..." Subsequently, the 1992 United Nations Earth Summit in Rio de Janeiro defined "biological diversity" as "the variability among living organisms from all sources, including, 'inter alia', terrestrial, marine, and other aquatic ecosystems, and the ecological complexes of which they are part: this includes diversity within species, between species and of ecosystems". This is, in fact, the closest thing to a single legally accepted definition of biodiversity, since it is the definition adopted by the United Nations Convention on Biological Diversity.

The current textbook definition of "biodiversity" is "variation of life at all levels of biological organization".[8]

For geneticists, biodiversity is the diversity of genes and organisms. They study processes such as mutations, gene exchanges, and genome dynamics that occur at the DNA level and generate evolution. Consistent with this, along with the above definition the Wilcox paper stated "genes are the ultimate source of biological organization at all levels of biological systems..."

[edit] Measurement
Image:Splitsection.svg
It has been suggested that some content from this article or section be split into a separate article entitled Measurement of biodiversity. (Discuss)
Polar bears on the sea ice of the Arctic Ocean, near the north pole.

A variety of objective measures have been created in order to empirically measure biodiversity. Each measure of biodiversity relates to a particular use of the data. For practical conservationists, measurements should include a quantification of values that are commonly-shared among locally affected organisms, including humans. For others, a more economically defensible definition should allow the ensuring of continued possibilities for both adaptation and future use by humans, assuring environmental sustainability.

As a consequence, biologists argue that this measure is likely to be associated with the variety of genes. Since it cannot always be said which genes are more likely to prove beneficial, the best choice for conservation is to assure the persistence of as many genes as possible. For ecologists, this latter approach is sometimes considered too restrictive, as it prohibits ecological succession.

Biodiversity is usually plotted as taxonomic richness of a geographic area, with some reference to a temporal scale. Whittaker[9] described three common metrics used to measure species-level biodiversity, encompassing attention to species richness or species evenness:

* Species richness - the least sophisticated of the indices available.
* Simpson index
* Shannon-Wiener index

Recently, another new index has been invented called the Mean Species Abundance Index (MSA); this index calculates the trend in population size of a cross section of the species. It does this in line with the CBD 2010 indicator for species abundance.[10]

There are three other indices which are used by ecologists:

* Alpha diversity refers to diversity within a particular area, community or ecosystem, and is measured by counting the number of taxa within the ecosystem (usually species)
* Beta diversity is species diversity between ecosystems; this involves comparing the number of taxa that are unique to each of the ecosystems.
* Gamma diversity is a measurement of the overall diversity for different ecosystems within a region.

[edit] Distribution
A conifer forest in the Swiss Alps (National Park).

Selection bias continues to bedevil modern estimates of biodiversity. In 1768 Rev. Gilbert White succinctly observed of his Selborne, Hampshire "all nature is so full, that that district produces the most variety which is the most examined."[11]

Nevertheless, biodiversity is not distributed evenly on Earth. It is consistently richer in the tropics and in other localized regions such as the Cape Floristic Province. As one approaches polar regions one generally finds fewer species. Flora and fauna diversity depends on climate, altitude, soils and the presence of other species. In the year 2006 large numbers of the Earth's species were formally classified as rare or endangered or threatened species; moreover, many scientists have estimated that there are millions more species actually endangered which have not yet been formally recognized. About 40 percent of the 40,177 species assessed using the IUCN Red List criteria, are now listed as threatened species with extinction - a total of 16,119 species.[12]

Even though biodiversity declines from the equator to the poles in terrestrial ecoregions, whether this is so in aquatic ecosystems is still a hypothesis to be tested, especially in marine ecosystems where causes of this phenomenon are unclear.[13] In addition, particularly in marine ecosystems, there are several well stated cases where diversity in higher latitudes actually increases. Therefore, the lack of information on biodiversity of Tropics and Polar Regions prevents scientific conclusions on the distribution of the world’s aquatic biodiversity.

A biodiversity hotspot is a region with a high level of endemic species. These biodiversity hotspots were first identified by Dr. Norman Myers in two articles in the scientific journal The Environmentalist.[14][15] Dense human habitation tends to occur near hotspots. Most hotspots are located in the tropics and most of them are forests.

Brazil's Atlantic Forest is considered a hotspot of biodiversity and contains roughly 20,000 plant species, 1350 vertebrates, and millions of insects, about half of which occur nowhere else in the world. The island of Madagascar including the unique Madagascar dry deciduous forests and lowland rainforests possess a very high ratio of species endemism and biodiversity, since the island separated from mainland Africa 65 million years ago, most of the species and ecosystems have evolved independently producing unique species different from those in other parts of Africa.

Many regions of high biodiversity (as well as high endemism) arise from very specialized habitats which require unusual adaptation mechanisms. For example the peat bogs of Northern Europe.

[edit] Evolution
Apparent marine fossil diversity during the Phanerozoic Eon

Biodiversity found on Earth today is the result of 4 billion years of evolution. The origin of life has not been definitely established by science, however some evidence suggests that life may already have been well-established a few hundred million years after the formation of the Earth. Until approximately 600 million years ago, all life consisted of archaea, bacteria, protozoans and similar single-celled organisms.

The history of biodiversity during the Phanerozoic (the last 540 million years), starts with rapid growth during the Cambrian explosion—a period during which nearly every phylum of multicellular organisms first appeared. Over the next 400 million years or so, global diversity showed little overall trend, but was marked by periodic, massive losses of diversity classified as mass extinction events.

The apparent biodiversity shown in the fossil record suggests that the last few million years include the period of greatest biodiversity in the Earth's history. However, not all scientists support this view, since there is considerable uncertainty as to how strongly the fossil record is biased by the greater availability and preservation of recent geologic sections. Some (e.g. Alroy et al. 2001) argue that, corrected for sampling artifacts, modern biodiversity is not much different from biodiversity 300 million years ago.[16] Estimates of the present global macroscopic species diversity vary from 2 million to 100 million species, with a best estimate of somewhere near 13–14 million, the vast majority of them arthropods.[17]

Most biologists agree however that the period since the emergence of humans is part of a new mass extinction, the Holocene extinction event, caused primarily by the impact humans are having on the environment. It has been argued that the present rate of extinction is sufficient to eliminate most species on the planet Earth within 100 years.[18]

New species are regularly discovered (on average between 5–10,000 new species each year, most of them insects) and many, though discovered, are not yet classified (estimates are that nearly 90% of all arthropods are not yet classified).[17] Most of the terrestrial diversity is found in tropical forests.

[edit] Human benefits
Summer field in Belgium (Hamois).

Biodiversity also supports a number of natural ecosystem processes and services. Some ecosystem services that benefit society are air quality, climate (both global CO2 sequestration and local), water purification, disease control, biological pest control, pollination and prevention of erosion. Biodiversity is also believed to create stability in ecosystems, allowing these ecosystems to continue providing services in the face of disturbances.

Non-material benefits that are obtained from ecosystems include spiritual and aesthetic values, knowledge systems and the value of education. Biodiversity is also central to an ecocentric philosophy.

[edit] Agriculture

The economic value of the reservoir of genetic traits present in wild varieties and traditionally grown landraces is extremely important in improving crop performance. Important crops, such as the potato and coffee, are often derived from only a few genetic strains. Improvements in crop plants over the last 250 years have been largely due to harnessing the genetic diversity present in wild and domestic crop plants. Interbreeding crops strains with different beneficial traits has resulted in more than doubling crop production in the last 50 years as a result of the Green Revolution.

Crop diversity is also necessary to help the system recover when the dominant crop type is attacked by a disease:

* The Irish potato blight of 1846, which was a major factor in the deaths of a million people and migration of another million, was the result of planting only two potato varieties, both of which were vulnerable.
* When rice grassy stunt virus struck rice fields from Indonesia to India in the 1970s. 6273 varieties were tested for resistance.[19] One was found to be resistant, an Indian variety, known to science only since 1966.[19] This variety formed a hybrid with other varieties and is now widely grown.[19]
* Coffee rust attacked coffee plantations in Sri Lanka, Brazil, and Central America in 1970. A resistant variety was found in Ethiopia.[20]

Although the diseases are themselves a form of biodiversity.

Monoculture, the lack of biodiversity, was a contributing factor to several agricultural disasters in history, including the Irish Potato Famine, the European wine industry collapse in the late 1800s, and the US Southern Corn Leaf Blight epidemic of 1970.[21] See also: Agricultural biodiversity

Higher biodiversity also controls the spread of certain diseases as pathogens will need to adapt to infect different species.
Amazon Rainforest in Brazil

Biodiversity provides food for humans. Although about 80 percent of our food supply comes from just 20 kinds of plants, humans use at least 40,000 species of plants and animals a day. Many people around the world depend on these species for their food, shelter, and clothing. There is untapped potential for increasing the range of food products suitable for human consumption, provided that the high present extinction rate can be stopped.[18]

[edit] Human health

The relevance of biodiversity to human health is becoming a major international political issue, as scientific evidence builds on the global health implications of biodiversity loss.[22][23][24] This issue is closely linked with the issue of climate change, as many of the anticipated health risks of climate change are associated with changes in biodiversity (e.g. changes in populations and distribution of disease vectors, scarcity of fresh water, impacts on agricultural biodiversity and food resources etc). Some of the health issues influenced by biodiversity include dietary health and nutrition security, infectious diseases, medical science and medicinal resources, social and psychological health, and spiritual well-being. Biodiversity is also known to have an important role in reducing disaster risk, and in post-disaster relief and recovery efforts.[25][26]

One of the key health issues associated with biodiversity is that of drug discovery and the availability of medicinal resources. A significant proportion of drugs are derived, directly or indirectly, from biological sources; Chivian and Bernstein report that at least 50% of the pharmaceutical compounds on the market in the US are derived from natural compounds found in plants, animals, and microorganisms, while about 80% of the world population depends on medicines from nature (used in either modern or traditional medical practice) for primary healthcare.[23] Moreover, only a tiny proportion of the total diversity of wild species has been investigated for potential sources of new drugs. Through the field of bionics, considerable technological advancement has occurred which would not have without a rich biodiversity. It has been argued, based on evidence from market analysis and biodiversity science, that the decline in output from the pharmaceutical sector since the mid-1980s can be attributed to a move away from natural product exploration ("bioprospecting") in favour of R&D programmes based on genomics and synthetic chemistry, neither of which have yielded the expected product outputs; meanwhile, there is evidence that natural product chemistry can provide the basis for innovation which can yield significant economic and health benefits.[27][28] Marine ecosystems are of particular interest in this regard,[29] however unregulated and inappropriate bioprospecting can be considered a form of over-exploitation which has the potential to degrade ecosystems and increase biodiversity loss, as well as impacting on the rights of the communities and states from which the resources are taken.[30][31][32]

[edit] Business and Industry

A wide range of industrial materials are derived directly from biological resources. These include building materials, fibers, dyes, resirubber and oil. There is enormous potential for further research into sustainably utilizing materials from a wider diversity of organisms. In addition, biodivesity and the ecosystem goods and services it provides are considered to be fundamental to healthy economic systems. The degree to which biodiversity supports business varies between regions and between economic sectors, however the importance of biodiversity to issues of resource security (water quantity and quality, timber, paper and fibre, food and medicinal resources etc) are increasingly recognized as universal.[33][34][35] As a result, the loss of biodiversity is increasingly recognized as a significant risk factor in business development and a threat to long term economic sustainability. A number of case studies recently compiled by the World Resources Institute demonstrate some of these risks as identified by specific industries.[36]
Eagle Creek, Oregon hiking

[edit] Other ecological services
See also: Ecological effects of biodiversity

Biodiversity provides many ecosystem services that are often not readily visible. It plays a part in regulating the chemistry of our atmosphere and water supply. Biodiversity is directly involved in water purification, recycling nutrients and providing fertile soils. Experiments with controlled environments have shown that humans cannot easily build ecosystems to support human needs; for example insect pollination cannot be mimicked by human-made construction, and that activity alone represents tens of billions of dollars in ecosystem services per annum to humankind.

The stability of ecosystems is also related to biodiversity, with higher biodiversity producing greater stability over time, reducing the chance that ecosystem services will be disrupted as a result of disturbances such as extreme weather events or human exploitation.

[edit] Leisure, cultural and aesthetic value

Many people derive value from biodiversity through leisure activities such as hiking, birdwatching or natural history study. Biodiversity has inspired musicians, painters, sculptors, writers and other artists. Many cultural groups view themselves as an integral part of the natural world and show respect for other living organisms.

Popular activities such as gardening, caring for aquariums and collecting butterflies are all strongly dependent on biodiversity. The number of species involved in such pursuits is in the tens of thousands, though the great majority do not enter mainstream commercialism.

The relationships between the original natural areas of these often 'exotic' animals and plants and commercial collectors, suppliers, breeders, propagators and those who promote their understanding and enjoyment are complex and poorly understood. It seems clear, however, that the general public responds well to exposure to rare and unusual organisms—they recognize their inherent value at some level. A family outing to the botanical garden or zoo is as much an aesthetic or cultural experience as it is an educational one.

Philosophically it could be argued that biodiversity has intrinsic aesthetic and spiritual value to mankind in and of itself. This idea can be used as a counterweight to the notion that tropical forests and other ecological realms are only worthy of conservation because they may contain medicines or useful products.

An interesting point is that evolved DNA embodies knowledge,[37] and therefore destroying a species resembles burning a book, with the caveat that the book is of uncertain depth and importance and may in fact be best used as fuel.

[edit] Number of species

As a general guide, the numbers of identified modern species as of 2004 can be broken down as follows:[38]

* 287,655 plants, including:
o 15,000 mosses,
o 13,025 ferns,
o 980 gymnosperms,
o 199,350 dicotyledons,
o 59,300 monocotyledons;
* 74,000–120,000 fungi;[39]
* 10,000 lichens;

* 1,250,000 animals, including:
o 1,190,200 invertebrates:
+ 950,000 insects,
+ 70,000 mollusks,
+ 40,000 crustaceans,
+ 130,200 others;
o 58,808 vertebrates:
+ 29,300 fish,
+ 5,743 amphibians,
+ 8,240 reptiles,
+ 10,234 birds, (9799 extant as of 2006)
+ 5,416 mammals.

However the total number of species for some phyla may be much higher:

* 10–30 million insects;[40]
* 5–10 million bacteria;[41]
* 1.5 million fungi;[39]
* ~1 million mites[42]

Threats
Loss of old growth forest in the United States; 1620, 1850, and 1920 maps:
From William B. Greeley's, The Relation of Geography to Timber Supply, Economic Geography, 1925, vol. 1, p. 1–11. Source of "Today" map: compiled by George Draffan from roadless area map in The Big Outside: A Descriptive Inventory of the Big Wilderness Areas of the United States, by Dave Foreman and Howie Wolke (Harmony Books, 1992). These maps represent only virgin forest lost. Some regrowth has occurred but not to the age, size or extent of 1620 due to population increases and food cultivation.

During the last century, erosion of biodiversity has been increasingly observed. Some studies show that about one eighth of known plant species are threatened with extinction.[43] Some estimates put the loss at up to 140,000 species per year (based on Species-area theory) and subject to discussion.[44] This figure indicates unsustainable ecological practices, because only a small number of species come into being each year. Almost all scientists acknowledge [43] that the rate of species loss is greater now than at any time in human history, with extinctions occurring at rates hundreds of times higher than background extinction rates.

The factors that threaten biodiversity have been variously categorized. Jared Diamond describes an "Evil Quartet" of habitat destruction, overkill, introduced species, and secondary extensions. Edward O. Wilson prefers the acronym HIPPO, standing for Habitat destruction, Invasive species, Pollution, Human OverPopulation, and Overharvesting.[45][46] The most authoritative classification in use today is that of IUCN’s Classification of Direct Threats[47] adopted by most major international conservation organizations such as the US Nature Conservancy, the World Wildlife Fund, Conservation International, and Birdlife International.

[edit] Destruction of habitat
Main article: Habitat destruction

Most of the species extinctions from 1000 AD to 2000 AD are due to human activities, in particular destruction of plant and animal habitats. Raised rates of extinction are being driven by human consumption of organic resources, especially related to tropical forest destruction.[48] While most of the species that are becoming extinct are not food species, their biomass is converted into human food when their habitat is transformed into pasture, cropland, and orchards. It is estimated that more than a third of the Earth's biomass[49] is tied up in only the few species that represent humans, livestock and crops. Because an ecosystem decreases in stability as its species are made extinct, these studies warn that the global ecosystem is destined for collapse if it is further reduced in complexity. Factors contributing to loss of biodiversity are: overpopulation, deforestation, pollution (air pollution, water pollution, soil contamination) and global warming or climate change, driven by human activity. These factors, while all stemming from overpopulation, produce a cumulative impact upon biodiversity.

There are systematic relationships between the area of a habitat and the number of species it can support, with greater sensitivity to reduction in habitat area for species of larger body size and for those living at lower latitudes or in forests or oceans.[50] Some characterize loss of biodiversity not as ecosystem degradation but by conversion to trivial standardized ecosystems (e.g., monoculture following deforestation). In some countries lack of property rights or access regulation to biotic resources necessarily leads to biodiversity loss (degradation costs having to be supported by the community).

A September 14, 2007 study conducted by the National Science Foundation found that biodiversity and genetic diversity are dependent upon each other—that diversity within a species is necessary to maintain diversity among species, and vice versa. According to the lead researcher in the study, Dr. Richard Lankau, "If any one type is removed from the system, the cycle can break down, and the community becomes dominated by a single species."[51]

At present, the most threathened ecosystems are those found in fresh water. The marking of fresh water ecosystems as the ecosystems most under threat was done by the Millennium Ecosystem Assessment 2005, and was confirmed again by the project "Freshwater Animal Diversity Assessment", organised by the biodiversity platform, and the French Institut de recherche pour le développement (MNHNP).[52]

[edit] Exotic species
Main article: Introduced species

The rich diversity of unique species across many parts of the world exist only because they are separated by barriers, particularly large rivers, seas, oceans, mountains and deserts from other species of other land masses, particularly the highly fecund, ultra-competitive, generalist "super-species". These are barriers that couldn't have been easily crossed by natural processes, except through continental drift. However, humans have invented transportation with the ability to bring into contact species that they've never met in their evolutionary history; also, this is done on a time scale of days, unlike the centuries that historically have accompanied major animal migrations.

The widespread introduction of exotic species by humans is a potent threat to biodiversity. When exotic species are introduced to ecosystems and establish self-sustaining populations, the endemic species in that ecosystem that have not evolved to cope with the exotic species may not survive. The exotic organisms may be either predators, parasites, or simply aggressive species that deprive indigenous species of nutrients, water and light. These invasive species often have features, due to their evolutionary background and new environment, that make them highly competitive; able to become well-established and spread quickly, reducing the effective habitat of endemic species.

As a consequence of the above, if humans continue to combine species from different ecoregions, there is the potential that the world's ecosystems will end up dominated by relatively a few, aggressive, cosmopolitan "super-species". In 2004, an international team of scientists estimated that 10 percent of species would become extinct by 2050 because of global warming.[53] “We need to limit climate change or we wind up with a lot of species in trouble, possibly extinct,” said Dr. Lee Hannah, a co-author of the paper and chief climate change biologist at the Center for Applied Biodiversity Science at Conservation International.

[edit] Genetic pollution
Main article: Genetic pollution

Purebred naturally evolved region specific wild species can be threatened with extinction[54] through the process of genetic pollution i.e. uncontrolled hybridization, introgression and genetic swamping which leads to homogenization or replacement of local genotypes as a result of either a numerical and/or fitness advantage of introduced plant or animal.[55] Nonnative species can bring about a form of extinction of native plants and animals by hybridization and introgression either through purposeful introduction by humans or through habitat modification, bringing previously isolated species into contact. These phenomena can be especially detrimental for rare species coming into contact with more abundant ones. The abundant species can interbreed with the rarer, swamping the entire gene pool and creating hybrids, thus driving the entire native stock to complete extinction. Attention has to be focused on the extent of this under appreciated problem that is not always apparent from morphological (outward appearance) observations alone. Some degree of gene flow may be a normal, evolutionarily constructive, process, and all constellations of genes and genotypes cannot be preserved. However, hybridization with or without introgression may, nevertheless, threaten a rare species' existence.[56][57]

[edit] Hybridization and genetics
See also: Food Security

In agriculture and animal husbandry, the green revolution popularized the use of conventional hybridization to increase yield by creating "high-yielding varieties". Often the handful of hybridized breeds originated in developed countries and were further hybridized with local varieties in the rest of the developing world to create high yield strains resistant to local climate and diseases. Local governments and industry have been pushing hybridization which has resulted in several of the indigenous breeds becoming extinct or threatened. Disuse because of unprofitability and uncontrolled intentional and unintentional cross-pollination and crossbreeding (genetic pollution), formerly huge gene pools of various wild and indigenous breeds have collapsed causing widespread genetic erosion and genetic pollution. This has resulted in loss of genetic diversity and biodiversity as a whole.[58]

A genetically modified organism (GMO) is an organism whose genetic material has been altered using the genetic engineering techniques generally known as recombinant DNA technology. Genetically Modified (GM) crops today have become a common source for genetic pollution, not only of wild varieties but also of other domesticated varieties derived from relatively natural hybridization.[59][60][61][62][63]

Genetic erosion coupled with genetic pollution may be destroying unique genotypes, thereby creating a hidden crisis which could result in a severe threat to our food security. Diverse genetic material could cease to exist which would impact our ability to further hybridize food crops and livestock against more resistant diseases and climatic changes.[58]

[edit] Climate Change
Main article: Effect of Climate Change on Plant Biodiversity

The recent phenomenon of global warming is also considered to be a major threat to global biodiversity.[citation needed] For example coral reefs -which are biodiversity hotspots- will be lost in 20 to 40 years if global warming continues at the current trend.[64]

[edit] Conserving biodiversity
Main article: Conservation biology
A schematic image illustrating the relationship between biodiversity, ecosystem services, human well-being, and poverty.[65] The illustration shows where conservation action, strategies and plans can influence the drivers of the current biodiversity crisis at local, regional, to global scales.

Conservation biology matured in the mid- 20th century as ecologists, naturalists, and other scientists began to collectively research and address issues pertaining to global declines in biodiversity.[66][67][68] The conservation ethic differs from the preservationist ethic, historically lead by John Muir, who advocate for protected areas devoid of human exploitation or interference for profit.[67] The conservation ethic advocates for wise stewardship and management of natural resource production for the purpose of protecting and sustaining biodiversity in species, ecosystems, the evolutionary process, and human culture and society.[66][68][69][70] Conservation biologists are concerned with the trends in biodiversity being reported in this era, which has been labeled by science as the Holocene extinction period, also known as the sixth mass extinction.[71] Rates of decline in biodiversity in this sixth mass extinction exceeds the five previous extinction spasms recorded in the fossil record.[71][72][73][74][75] In response to the extinction crisis, the research of conservation biologists is being organized into strategic plans that include principles, guidelines, and tools for the purpose of protecting biodiversity.[66][76][77] Conservation biology is a crisis orientated discipline and it is multi-disciplinary, including ecological, social, education, and other scientific disciplines outside of biology. Conservation biologists work in both the field and office, in government, universities, non-profit organizations and in industry.[66][68] The conservation of biological diversity is a global priority in strategic conservation plans that are designed to engage public policy and concerns affecting local, regional and global scales of communities, ecosystems, and cultures.[78] Conserving biodiversity and action plans identify ways of sustaining human well-being and global economics, including natural capital, market capital, and ecosystem services.[79][80] One of the strategies involves placing a monetary value on biodiversity through biodiversity banking, of which one example is the Australian Native Vegetation Management Framework.

[edit] Judicial status

Biodiversity is beginning to be evaluated and its evolution analysed (through observations, inventories, conservation...) as well as being taken into account in political and judicial decisions:

* The relationship between law and ecosystems is very ancient and has consequences for biodiversity. It is related to property rights, both private and public. It can define protection for threatened ecosystems, but also some rights and duties (for example, fishing rights, hunting rights).
* Law regarding species is a more recent issue. It defines species that must be protected because they may be threatened by extinction. The U.S. Endangered Species Act is an example of an attempt to address the "law and species" issue.
* Laws regarding gene pools are only about a century old[citation needed]. While the genetic approach is not new (domestication, plant traditional selection methods), progress made in the genetic field in the past 20 years have led to a tightening of laws in this field. With the new technologies of genetic analysis and genetic engineering, people are going through gene patenting, processes patenting, and a totally new concept of genetic resources.[81] A very hot debate today seeks to define whether the resource is the gene, the organism itself, or its DNA.

The 1972 UNESCO convention established that biological resources, such as plants, were the common heritage of mankind. These rules probably inspired the creation of great public banks of genetic resources, located outside the source-countries.

New global agreements (e.g.Convention on Biological Diversity), now give sovereign national rights over biological resources (not property). The idea of static conservation of biodiversity is disappearing and being replaced by the idea of dynamic conservation, through the notion of resource and innovation.

The new agreements commit countries to conserve biodiversity, develop resources for sustainability and share the benefits resulting from their use. Under new rules, it is expected that bioprospecting or collection of natural products has to be allowed by the biodiversity-rich country, in exchange for a share of the benefits.

Sovereignty principles can rely upon what is better known as Access and Benefit Sharing Agreements (ABAs). The Convention on Biodiversity spirit implies a prior informed consent between the source country and the collector, to establish which resource will be used and for what, and to settle on a fair agreement on benefit sharing. Bioprospecting can become a type of biopiracy when those principles are not respected.

Uniform approval for use of biodiversity as a legal standard has not been achieved, however. At least one legal commentator has argued that biodiversity should not be used as a legal standard, arguing that the multiple layers of scientific uncertainty inherent in the concept of biodiversity will cause administrative waste and increase litigation without promoting preservation goals. See Fred Bosselman, A Dozen Biodiversity Puzzles, 12 N.Y.U. Environmental Law Journal 364 (2004)

[edit] Analytical limits

[edit] Taxonomic and size bias

Less than 1% of all species that have been described have been studied beyond simply noting its existence.[82] Biodiversity researcher Sean Nee points out that the vast majority of Earth's biodiversity is microbial, and that contemporary biodiversity physics is "firmly fixated on the visible world" (Nee uses "visible" as a synonym for macroscopic).[83] For example, microbial life is very much more metabolically and environmentally diverse than multicellular life (see extremophile). Nee has stated: "On the tree of life, based on analyses of small-subunit ribosomal RNA, visible life consists of barely noticeable twigs.

The size bias is not restricted to consideration of microbes. Entomologist Nigel Stork states that "to a first approximation, all multicellular species on Earth are insects".[84] Even in insects, however, the extinction rate is high and indicative of the general trend of the sixth greatest extinction period that human society is faced with.[85][86] Moreover, there are species co-extinctions, such as plants and beetles, where the extinction or decline in one is reciprocated in the other.[87]

[edit] Definition

1.Biodiversity is the variety of life: the different plants, animals and micro-organisms, their genes and the ecosystems of which they are a part. It is home to more than one million species of plants and animals, many of which are found nowhere else in the world. (From http://www.environment.gov.au/biodiversity/)

2. “Biodiversity” is often defined as the variety of all forms of life, from genes to species, through to the broad scale of ecosystems (for a list of variants on this simple definition see Gaston 1996). "

[edit] See also
Earth sciences portal
Ecology portal
Environment portal
Biology portal
Sustainable Development portal

* 2010 Biodiversity Indicators Partnership
* Adaptation
* Agroecological restoration
* Amazonian forest
* Applied ecology
* Ecological economics
* Extinction
* Biocomplexity
* Biogeography
* Bioinformatics
* BioWeb
* Canadian Biodiversity Information Network
* Conservation Biology
* Conservation Commons
* Conservation ethic
* Convention on Biological Diversity
* Diversity index
* Ecology
* Forest farming
* Ewens sampling formula
* Gene pool
* Genetic pollution
* Genetic erosion
* Global 200
* Global warming
* Green Revolution
* GBIF
* Habitat fragmentation
* Habitat conservation
* Holistic management
* Ongoing mass extinction of species
* IUCN
* International Day for Biological Diversity
* Intermediate Disturbance Hypothesis
* International Institute of Tropical Agriculture
* International Treaty on Plant Genetic Resources for Food and Agriculture
* LifeWatch
* List of biodiversity databases
* List of environmental issues
* List of environmental topics
* Living Planet Index
* Megadiverse countries
* Millennium Ecosystem Assessment
* Millennium Seed Bank Project
* Monoculture
* Mutation
* National Biodiversity Network
* Natural environment
* Nature
* NatureServe
* Reconciliation ecology
* rECOrd (Local Biological Records Centre)
* Satoyama
* Seedbank
* Sustainability
* Sustainable forest management
* Unified neutral theory of biodiversity
* United States environmental law
* Wildlife preserve
* World Conservation Monitoring Centre
* World Conservation Union
* World Forestry Congress
* World Network of Biosphere Reserves

[edit] References

1. ^ Chapman, A.D. (September 2005). "Numbers of Living Species in Australia and the World". Australian Biological Resources Study. http://www.environment.gov.au/biodiversity/abrs/publications/other/species-numbers/01-introduction.html. Retrieved on 2009-04-23.
2. ^ "Determing the genomic infrastructure of evolution and diversity through comparative genome analysis". National Institute of Informatics. 2009. http://www.nii.ac.jp/index.php?action=pages_view_main&page_id=495&lang=english. Retrieved on 2009-04-23.
3. ^ Dasmann, R. F. 1968. A Different Kind of Country. MacMillan Company, New York. ISBN 0020728107.
4. ^ M. E. Soulé and B. A. Wilcox. 1980. Conservation Biology: An Evolutionary-Ecological Perspective. Sinauer Associates. Sunderland, Massachusetts.
5. ^ Edward O.Wilson, editor, Frances M.Peter, associate editor, Biodiversity, National Academy Press, March 1988 ISBN 0-309-03783-2 ; ISBN 0-309-03739-5 (pbk.), online edition
6. ^ Global Biodiversity Assessment. UNEP, 1995, Annex 6, Glossary. ISBN 0-521-56481-6, used as source by "Biodiversity", Glossary of terms related to the CBD, Belgian Clearing-House Mechanism. Retrieved 2006-04-26.
7. ^ Wilcox, Bruce A. 1984. In situ conservation of genetic resources: determinants of minimum area requirements. In National Parks, Conservation and Development, Proceedings of the World Congress on National Parks,, J.A. McNeely and K.R. Miller, Smithsonian Institution Press, pp. 18-30.
8. ^ Kevin J. Gaston & John I. Spicer. 2004. "Biodiversity: an introduction", Blackwell Publishing. 2nd Ed., ISBN 1-4051-1857-1(pbk.)
9. ^ Whittaker, R.H., Evolution and measurement of species diversity, Taxon, 21, 213–251 (1972)
10. ^ MSA Index (page 4)
11. ^ White, The Natural History of Selborne, letter xx 8 October 1768.
12. ^ "Endangered Species List Expands to 16,000". http://news.nationalgeographic.com/news/2006/05/0502_060502_endangered.html. Retrieved on 2007-11-13.
13. ^ "Moustakas, A. & I. Karakassis. How diverse is aquatic biodiversity research?, Aquatic Ecology, 39, 367-375" (PDF). http://www.springerlink.com/content/p2q719335u606034/fulltext.pdf.
14. ^ Myers N. (1988), "Threatened biotas: 'hot spots' in tropical forests", Environmentalist, 8, 187–208.
15. ^ Myers N. (1990), "The biodiversity challenge: expanded hot-spots analysis", Environmentalist, 10, 243–256.
16. ^ J. Alroy, C.R. et al.2001. Effect of sampling standardization on estimates of Phanerozonic marine diversification. Proceedings of the National Academy of Science, USA 98: 6261–6266
17. ^ a b "Mapping the web of life". Unep.org. http://www.unep.org/ourplanet/imgversn/85/heywood.html. Retrieved on 2009-06-21.
18. ^ a b Edward O. Wilson (2002). The Future of Life. New York: Alfred A. Knopf.
19. ^ a b c "Rice Grassy Stunt Virus". Lumrix.net. http://www.lumrix.net/health/Rice_grassy_stunt_virus.html. Retrieved on 2009-06-21.
20. ^ GM Wahl, BR de Saint Vincent and ML DeRose, Effect of chromosomal position on amplification of transfected genes in animal cells, Nature 307:516–520
21. ^ "Southern Corn Leaf Blight". http://cropdisease.cropsci.uiuc.edu/corn/southerncornleafblight.html. Retrieved on 2007-11-13.
22. ^ Reports of the 1st and 2nd International Conferences on Health and Biodiversity. See also: Website of the UN COHAB Initiative
23. ^ a b Chivian E. & Bernstein A. (eds), 2008. Sustaining Life: How Human Health Depends on Biodiversity
24. ^ Corvalan C. et al., 2005 Ecosystems and Human Well-being: Health Synthesis. A report of the Millennium Ecosystem Assessment
25. ^ "COHAB Initiative: Biodiversity and Human Health - the issues". Cohabnet.org. http://www.cohabnet.org/en_issues.htm. Retrieved on 2009-06-21.
26. ^ World Wildlife Fund (WWF): "Arguments for Protection" website[dead link]
27. ^ Harvey L., 2008. Natural products in drug discovery. Drug Discovery Today
28. ^ Hawkins E.S. & Reich M.R., 1992 Japanese-originated pharmaceutical products in the United States from 1960 to 1989: an assessment of innovation. Clin Pharmacol Ther. 51:1-11
29. ^ Roopesh J. et al., 2008 Marine organisms: Potential Source for Drug Discovery Current Science, Vol. 94, No. 3, 10 Feb 2008
30. ^ Bioprospecting: Effects on Environment and Development
31. ^ Home (2005-07-16). "Looking for new compounds in sea is endangering ecosystem". Bmj.com. doi:10.1136/bmj.330.7504.1350-d. http://www.bmj.com/cgi/content/extract/330/7504/1350-d. Retrieved on 2009-06-21.
32. ^ "COHAB Initiative - on Natural Products and Medicinal Resources". Cohabnet.org. http://www.cohabnet.org/en_issue4.htm. Retrieved on 2009-06-21.
33. ^ IUCN, WRI, WBCSD, Earthwatch Inst. 2007 Business and Ecosystems: Ecosystem Challenges and Business Implications
34. ^ Millennium Ecosystem Assessment 2005 Ecosystems and Human Well-being: Opportunities and Challenges for Business and Industry
35. ^ "Business and Biodiversity webpage of the U.N. Convention on Biological Diversity". Cbd.int. http://www.cbd.int/business. Retrieved on 2009-06-21.
36. ^ WRI Corporate Ecosystem Services Review. See also: Examples of Ecosystem-Service Based Risks, Opportunities and Strategies
37. ^ Popper, Karl (1972). Objective Knowledge. Oxford: Clarendon Press. pp. 288-289.
38. ^ 2007 IUCN Red List – Summary Statistics for Globally Threatened Species[dead link]
39. ^ a b David L. Hawksworth, "The magnitude of fungal diversity: the 1•5 million species estimate revisited" Mycological Research (2001), 105: 1422–1432 Cambridge University Press [1]
40. ^ "Encyclopedia Smithsonian: Numbers of Insects". Si.edu. http://www.si.edu/Encyclopedia_SI/nmnh/buginfo/bugnos.htm. Retrieved on 2009-06-21.
41. ^ Proceedings of the National Academy of Sciences, Census of Marine Life (CoML) [2]
42. ^ "Acari at University of Michigan Museum of Zoology Web Page". Insects.ummz.lsa.umich.edu. 2003-11-10. http://insects.ummz.lsa.umich.edu/ACARI/index.html. Retrieved on 2009-06-21.
43. ^ a b "Reid Reversing loss of Biodiversity". Ag.arizona.edu. http://ag.arizona.edu/OALS/ALN/aln37/reid.html. Retrieved on 2009-06-21.
44. ^ S.L. Pimm, G.J. Russell, J.L. Gittleman and T.M. Brooks, The Future of Biodiversity, Science 269: 347–350 (1995)
45. ^ Jim Chen (2003). "Across the Apocalypse on Horseback: Imperfect Legal Responses to Biodiversity Loss". The Jurisdynamics of Environmental Protection: Change and the Pragmatic. Environmental Law Institute. p. 197. ISBN 1585760714.
46. ^ "Hippo dilemma". Windows on the Wild: Science and Sustainabiliy. New Africa Books. 2005. ISBN 1869283805.
47. ^ IUCN's Classification of Direct Threats
48. ^ Paul Ehrlich and Anne Ehrlich, Extinction, Random House, New York (1981) ISBN 0-394-51312-6
49. ^ "Astrobio paper on biomass Distribution". Astrobio.net. 2002-03-15. http://www.astrobio.net/news/modules.php?op=modload&name=News&file=article&sid=307&mode=thread&order=0&thold=0. Retrieved on 2009-06-21.
50. ^ Drakare S, Lennon J.L., Hillebrand H., 2006 The imprint of the geographical, evolutionary and ecological context on species-area relationships Ecology Letters 9 (2), 215–227
51. ^ "Study: Loss Of Genetic Diversity Threatens Species Diversity". Enn.com. 2007-09-26. http://www.enn.com/animals/article/23391. Retrieved on 2009-06-21.
52. ^ Science Connection 22 (July 2008)
53. ^ "Guardian.co.uk". Guardian. http://www.guardian.co.uk/science/2004/jan/08/biodiversity.sciencenews. Retrieved on 2009-06-21.
54. ^ Hybridization and Introgression; Extinctions; from "The evolutionary impact of invasive species; by H. A. Mooney and E. E. Cleland" Proc Natl Acad Sci U S A. 2001 May 8; 98(10): 5446–5451. doi:10.1073/pnas.091093398. Proc Natl Acad Sci U S A, v.98(10); May 8, 2001, The National Academy of Sciences. PMID 33232
55. ^ "Glossary: definitions from the following publication: Aubry, C., R. Shoal and V. Erickson. 2005. Grass cultivars: their origins, development, and use on national forests and grasslands in the Pacific Northwest. USDA Forest Service. 44 pages, plus appendices.; Native Seed Network (NSN), Institute for Applied Ecology, 563 SW Jefferson Ave, Corvallis, OR 97333, USA". Nativeseednetwork.org. http://www.nativeseednetwork.org/article_view?id=13. Retrieved on 2009-06-21.
56. ^ Extinction by hybridization and introgression; by Judith M. Rhymer, Department of Wildlife Ecology, University of Maine, Orono, Maine 04469, USA; and Daniel Simberloff, Department of Biological Science, Florida State University, Tallahassee, Florida 32306, USA; Annual Review of Ecology and Systematics, November 1996, Vol. 27, Pages 83–109 (doi: 10.1146/annurev.ecolsys.27.1.83), [3]
57. ^ Genetic Pollution from Farm Forestry using eucalypt species and hybrids; A report for the RIRDC/L&WA/FWPRDC; Joint Venture Agroforestry Program; by Brad M. Potts, Robert C. Barbour, Andrew B. Hingston; September 2001; RIRDC Publication No 01/114; RIRDC Project No CPF - 3A; ISBN 0642583366; ISSN 1440-6845; Australian Government, Rural Industrial Research and Development Corporation[dead link]
58. ^ a b “Genetic Pollution: The Great Genetic Scandal”; Devinder Sharma can be contacted at: 7 Triveni Apartments, A-6 Paschim Vihar, New Delhi-110 063, India. Email: dsharma@ndf.vsnl.net.in. Centre for alternative agricultural media (CAAM). [4]
59. ^ Pollan, Michael (2001-12-09). "The year in ideas: A TO Z.; Genetic Pollution; By Michael Pollan, The New York Times, December 9, 2001". New York Times. http://query.nytimes.com/gst/fullpage.html?res=9C01E6DE143CF93AA35751C1A9679C8B63. Retrieved on 2009-06-21.
60. ^ "Dangerous Liaisons? When Cultivated Plants Mate with Their Wild Relatives; by Norman C. Ellstrand; The Johns Hopkins University Press, 2003; 268 pp. hardcover, $ 65; ISBN 0-8018-7405-X. Book Reviewed in: Hybrids abounding; Nature Biotechnology 22, 29–30 (2004) doi:10.1038/nbt0104-29; Reviewed by: Steven H Strauss & Stephen P DiFazio; 1 Steve Strauss is in the Department of Forest Science, Oregon State University, Corvallis, Oregon 97331-5752, USA. steve.strauss@oregonstate.edu; 2 Steve DiFazio is at Oak Ridge National Laboratory, Bldg. 1059, PO Box 2008, Oak Ridge, Tennessee 37831-6422 USA. difazios@ornl.gov". Nature.com. 2004-01-01. doi:10.1038/nbt0104-29. http://www.nature.com/nbt/journal/v22/n1/full/nbt0104-29.html. Retrieved on 2009-06-21.
61. ^ "“Genetic pollution: Uncontrolled spread of genetic information (frequently referring to transgenes) into the genomes of organisms in which such genes are not present in nature.” Zaid, A. et al. 1999. Glossary of biotechnology and genetic engineering. FAO Research and Technology Paper No. 7. ISBN 92-5-104369-8". Fao.org. http://www.fao.org/DOCREP/003/X3910E/X3910E00.htm. Retrieved on 2009-06-21.
62. ^ “Genetic pollution: Uncontrolled escape of genetic information (frequently referring to products of genetic engineering) into the genomes of organisms in the environment where those genes never existed before.” Searchable Biotechnology Dictionary. University of Minnesota., [5]
63. ^ "“Genetic pollution: Living organisms can also be defined as pollutants, when a non-indigenous species (plant or animal) enters a habitat and modifies the existing equilibrium among the organisms of the affected ecosystem (sea, lake, river). Non-indigenous, including transgenic species (GMOs), may bring about a particular version of pollution in the vegetable kingdom: so-called genetic pollution. This term refers to the uncontrolled diffusion of genes (or transgenes) into genomes of plants of the same type or even unrelated species where such genes are not present in nature. For example, a grass modified to resist herbicides could pollinate conventional grass many miles away, creating weeds immune to the most widely used weed-killer, with obvious consequences for crops. Genetic pollution is at the basis of the debate on the use of GMOs in agriculture.” The many facets of pollution; Bologna University web site for Science Communication. The Webweavers: Last modified Tue, 20 Jul 2005". Scienzagiovane.unibo.it. http://www.scienzagiovane.unibo.it/English/pollution/2-facets.html. Retrieved on 2009-06-21.
64. ^ Saturday, June 20, 2009 (2008-12-10). "Coral reefs to be destroyed in 20-40 years". Mnn.com. http://www.mnn.com/earth-matters/wilderness-resources/stories/15-of-coral-reefs-already-lost-much-more-feared. Retrieved on 2009-06-21.
65. ^ Millennium Ecosystem Assessment (2005). Ecosystems and Human Well-being: Biodiversity Synthesis. World Resources Institute, Washington, DC.[6]
66. ^ a b c d M. E. Soule. (1986). What is conservation Biology? BioScience, 35(11): 727-734
67. ^ a b P. Davis. (1996). Museums and the Natural Environment. Leicester University Press.
68. ^ a b c F. van Dyke. (2008). Conservation Biology: Foundations, Concepts, Applications, 2nd ed.. Springer Verlag. pp. 478. ISBN 978-1-4020-6890-4 (hc).
69. ^ Hunter, M. L. (1996). Fundamentals of Conservation Biology. Blackwell Science Inc., Cambridge, Massachusetts., ISBN 0-86542-371-7.
70. ^ B. W. Bowen, (1999). Preserving genes, species, or ecosystems? Healing the fractured foundations of conservation policy. Molecular Ecology, 8:S5-S10.
71. ^ a b D. B. Wake and V. T. Vredenburg. (2008). Are we in the midst of the sixth mass extinction? A view from the world of amphibians. Proceedings of the National Academy of Sciences of the United States of America, 105: 11466–11473.[7]
72. ^ L. P. Koh, R. R. Dunn, N. S. Sodhi, R. K. Colwell, H. C. Proctor, and V. S. Smith. (2004). Species coextinctions and the Biodiversity Crisis. 305, 1632-1634[8]
73. ^ M. L. McCallum. (2007). Amphibian Decline or Extinction? Current Declines Dwarf Background Extinction Rate. Journal of Herpetology, 41(3): 483–491.[9]
74. ^ J. B. C. Jackson. (2008). Ecological extinction and evolution in the brave new ocean. PNAS 2008 105:11458-11465.[10]
75. ^ R. R. Dunn. (2005). Modern Insect Extinctions, the Neglected Majority. Conservation Biology, 19(4): 1030 - 1036[11]
76. ^ M. E. Soule. (Ed.). (1986). Conservation Biology: The science of scarcity and diversity. Sinauer Associates Inc.
77. ^ C. R. Margules & R. L. Pressey. (2000). Systematic Conservation Planning. Nature, 405: 243-253. [12]
78. ^ Example: Gascon, C., Collins, J. P., Moore, R. D., Church, D. R., McKay, J. E. and Mendelson, J. R. III (eds). (2007). Amphibian Conservation Action Plan. IUCN/SSC Amphibian Specialist Group. Gland, Switzerland and Cambridge, UK. 64pp. [13], see also [14][15]
79. ^ G. W. Luck, G. C. Daily and P. R. Ehrlich. (2003). Population diversity and ecosystem services. 18, (7): 331-336 [16]
80. ^ See also
81. ^ "Gene Patenting". Ornl.gov. http://www.ornl.gov/sci/techresources/Human_Genome/elsi/patents.shtml. Retrieved on 2009-06-21.
82. ^ Edward O. Wilson. 2000. On the Future of Conservation Biology. Conservation Biology, 14(1): 1-3
83. ^ Nee S. (2004), "More than meets the eye",Nature, 429, 804–805.
84. ^ N. E. Stork 2007. Biodiversity: world of insects. Nature 448, 657–658 (9 August 2007)
85. ^ J. A. Thomas, M. G. Telfer, D. B. Roy, C. D. Preston, J. J. D. Greenwood, J. Asher, R. Fox, R. T. Clarke, J. H. Lawton. (2004) Comparative Losses of British Butterflies, Birds, and Plants and the Global Extinction Crisis. Science, 303(5665): 1879 - 1881[17]
86. ^ R. R. Dunn. (2005). Modern Insect Extinctions, the Neglected Majority. Conservation Biology, 19(4): 1030 - 1036. [R. R. Dunn. (2005). Modern Insect Extinctions, the Neglected Majority. Conservation Biology, 19(4): 1030 - 1036]
87. ^ L. P. Koh, R. R. Dunn, N. S. Sodhi, R. K. Colwell, H. C. Proctor, V. S. Smith. (2004). Species Coextinctions and the Biodiversity Crisis. Science, 305(5690):1632-4.[18]

[edit] Further reading

* Leveque, C. & J. Mounolou (2003) Biodiversity. New York: John Wiley. ISBN 0470849576
* Margulis, L., Dolan, Delisle, K., Lyons, C. Diversity of Life: The Illustrated Guide to the Five Kingdoms. Sudbury: Jones & Bartlett Publishers. ISBN 0763708623
* Alexander V. Markov, and Andrey V. Korotayev (2007) "Phanerozoic marine biodiversity follows a hyperbolic trend" Palaeoworld 16(4): pp. 311–318.
* Moustakas, A. & I. Karakassis (in press). A geographic analysis of the published aquatic biodiversity research in relation to the ecological footprint of the country where the work was done. Stochastic Environmental Research and Risk Assessment, Doi: 10.1007/s00477-008-0254-2.
* Novacek, M. J. (ed.) (2001) The Biodiversity Crisis: Losing What Counts. New York: American Museum of Natural History Books. ISBN 1565845706

[edit] External links

* How many species on Earth?
* ECNC-European Centre for Nature Conservation
* The WILD Foundation and CEMEX Collaborate on International Wilderness and Biodiversity Conservation in Mexico
* COHAB Initiative: The importance of biodiversity to human health and well-being
* NatureServe: This site serves as a portal for accessing several types of publicly available biodiversity data

[edit] Documents

* Biodiversity Synthesis Report (PDF) by the Millennium Ecosystem Assessment (MA, 2005)
* Convention on Biological Diversity Text of the Convention

[edit] Tools

* GLOBIO, an ongoing programme to map the past, current and future impacts of human activities on biodiversity
* World Map of Biodiversity an interactive map from the United Nations Environment Programme World Conservation Monitoring Centre

[edit] Resources

* Biodiversity Heritage Library - Open access digital library of taxonomic literature.
* Biodiversity of Altai-Sayan Ecoregion.
* DMOZ - Open Directory Project.
* Encyclopedia of Life - Documenting all species of life on earth.
* National Biodiversity Network - NBN Gateway.
* Microdocs, Diversity.
* Economics of Species protection & Management NOAA Economics

Retrieved from "http://en.wikipedia.org/wiki/Biodiversity"
Categories: Biodiversity | Environmental science
Hidden categories: All articles with dead external links | Articles with dead external links from June 2009 | Articles to be split from August 2008 | All articles to be split | All articles with unsourced statements | Articles with unsourced statements from December 2008 | Articles with unsourced statements from October 2008
Views

* Article
* Discussion
* Edit this page
* History

Personal tools

* Log in / create account

Navigation

* Main page
* Contents
* Featured content
* Current events
* Random article

Search

Interaction

* About Wikipedia
* Community portal
* Recent changes
* Contact Wikipedia
* Donate to Wikipedia
* Help

Toolbox

* What links here
* Related changes
* Upload file
* Special pages
* Printable version
* Permanent link
* Cite this page

Languages

* Afrikaans
* العربية
* Azərbaycan
* Bosanski
* Български
* Català
* Česky
* Cymraeg
* Dansk
* Deutsch
* Eesti
* Ελληνικά
* Español
* Esperanto
* Euskara
* فارسی
* Français
* Galego
* 한국어
* हिन्दी
* Bahasa Indonesia
* Italiano
* עברית
* Latviešu
* Lietuvių
* Magyar
* മലയാളം
* Malti
* मराठी
* Nederlands
* 日本語
* ‪Norsk (bokmål)‬
* ‪Norsk (nynorsk)‬
* Novial
* Occitan
* Polski
* Português
* Română
* Русский
* Shqip
* Simple English
* Slovenščina
* Српски / Srpski
* Suomi
* Svenska
* தமிழ்
* Українська
* اردو
* Tiếng Việt
* 中文

Powered by MediaWiki
Wikimedia Foundation

* This page was last modified on 16 July 2009 at 23:01.
* Text is available under the Creative Commons Attribution/Share-Alike License; additional terms may apply. See Terms of Use for details.
Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization.
* Privacy policy
* About Wikipedia

Bunga Rampai Biologi

Halaman

Selasa, 21 Juli 2009

Ecology

Budidaya Jamur Merang

Budidaya Jamur Merang

Budidaya Jamur Merang

Biodiversity

E-Learning

Entri Populer

Pengikut

PageRank

Rss

Cari Blog Ini

Arsip Blog

Bio

Halaman

Selasa, 21 Juli 2009

Ecology

Budidaya Jamur Merang

Budidaya Jamur Merang

Budidaya Jamur Merang

Biodiversity

Bio

Langganan