Humankind benefits from a multitude of resources and processes that are supplied by natural ecosystems. Collectively, these benefits are known as ecosystem services and include products like clean drinking water and processes like the decomposition of wastes. Ecosystem services are distinct from other ecosystem products and functions because there is human demand for these natural assets. Services can be subdivided into five categories: provisioning such as the production of food and water; regulating, such as the control of climate and disease; supporting, such as nutrient cycles and crop pollination; cultural, such as spiritual and recreational benefits; and preserving, which includes guarding against uncertainty through the maintenance of diversity.

As human populations grow, so do the resource demand imposed on ecosystems and the impacts of our global footprint. Many people have been plagued with the misconception that these ecosystem services are free, invulnerable and infinitely available. However, the impacts of anthropogenic use and abuse are becoming evermore apparent – air and water quality are increasingly compromised, oceans are being over-fished, pests and diseases are extending beyond their historical boundaries, deforestation is eliminating flood control around human settlements. It has been reported that approximately 40-50% of Earth’s ice-free land surface has been heavily transformed or degraded by anthropogenic activities, 66% of marine fisheries are either overexploited or at their limit, atmospheric CO₂ has increased more than 30% since the advent of industrialization, and nearly 25% of Earth’s bird species have gone extinct in the last two thousand years ^[1]. Consequently, society is coming to realize that ecosystem services are not only threatened and limited, but that the pressure to evaluate trade-offs between immediate and long-term human needs is urgent. To help inform decision-makers, economic value is increasingly associated with many ecosystem services and often based on the cost of replacement with anthropogenically-driven alternatives. The on-going challenge of prescribing economic value to nature is prompting transdisciplinary shifts in how we recognize and manage the environment, social responsibility, business opportunities, and our future as a species.

In ecology, an ecosystem is a community of organisms (plant, animal and other living organisms - also referred as biocenose) together with their environment (or biotope), functioning as a unit. ... “Spoilage” redirects here. ... Look up anthropogenic in Wiktionary, the free dictionary. ... Deforestation is the conversion of forested areas to non-forest land use such as arable land, pasture, urban use, logged area or wasteland. ... A fishery (plural: fisheries) is an organized effort by humans to catch fish or other aquatic species, an activity known as fishing. ...

A brief history

The simple notion of human dependence on Earth’s ecosystems probably reaches to the start of our species’ existence, when as hunter-gatherers we benefited from the products of nature to nourish our bodies and the habitats that provided shelter from harsh climates. Recognition of how ecosystems could provide even more complex services to humankind date back to at least Plato (c. 400 BC) who understood that deforestation could lead to soil erosion and the drying of springs ^[2]. However, modern conceptualization of ecosystem services likely began with Marsh in 1864 ^[3] when he challenged the idea that Earth’s natural resources are not infinite by pointing out changes in soil fertility along the Mediterranean. Unfortunately, his observations and cautioning passed largely unnoticed at the time and it wasn’t until the late 1940’s that society’s attention was again brought to the matter. During this era, three key authors – Osborn ^[4], Vogt ^[5], and Leopold ^[6] – awakened and promoted the recognition of human dependence on the environment with the idea of ‘natural capital’. In 1956, Sears ^[7] brought attention to the critical role of the ecosystem in processing wastes and recycling nutrients. An environmental science textbook ^[8] called attention to “the most subtle and dangerous threat to man’s existence… is the potential destruction, by man’s own activities, of those ecological systems upon which the very existence of the human species depends”. The term ‘environmental services’ was finally introduced in a report of the Study of Critical Environmental Problems ^[9], which listed services including insect pollination, fisheries, climate regulation and flood control. In following years, variations of the term were applied but eventually ‘ecosystem services’ became the standard among scientific literature ^[10].

Modern expansions of the ecosystem services concept have come to encompass socio-economic and conservation objectives, which are discussed below. For a more complete history of the concepts and terminology surrounding ecosystem services, see Daily (1997)^[2].

PLATO was one of the first generalized Computer assisted instruction systems, originally built by the University of Illinois (U of I) and later taken over by Control Data Corporation (CDC), who provided the machines it ran on. ... Deforestation is the conversion of forested areas to non-forest land use such as arable land, pasture, urban use, logged area or wasteland. ... Severe soil erosion in a wheat field near Washington State University, USA. For erosion as an operation of Mathematical morphology, see Erosion (morphology) Erosion is displacement of solids (soil, mud, rock and other particles) by the agents of ocean currents, wind, water, or ice by downward or down-slope movement... Fertile soil is soil that can support abundant plant life, in particular the term is used to describe agricultural and garden soil. ... A flower-fly pollinating a Common Daisy (Bellis perennis) Pollination is an important step in the reproduction of seed plants: the transfer of pollen grains (male gametes) to the plant carpel, the structure that contains the ovule (female gamete). ... A fishery (plural: fisheries) is an organized effort by humans to catch fish or other aquatic species, an activity known as fishing. ... Flooding in Amphoe Sena, Ayutthaya Province, Thailand. ... Socioeconomics is the study of the social and economic impacts of any product or service offering, market intervention or other activity on an economy as a whole and on the companies, organization and individuals who are its main economic actors. ... Conservation may refer to the following: Politics and policy Ethical Conservation, Moral or legislative progress toward freedom through advanced conduct - socially, fiscally or otherwise; based on governments and ideas Conservation movement, movement seeking to protect plant and animal species as well as the habitats they live in Conservation ethic in...

Examples

Experts currently recognize five categories of ecosystem services ^[11][12]. The following lists represent samples of each:

Provisioning services

• foods (including seafood and game) and spices

• precursors to pharmaceutical and industrial products

• energy (hydropower, biomass fuels)

Regulating services

• carbon sequestration and climate regulation

• waste decomposition and detoxification

• nutrient dispersal and cycling

Supporting services

• purification of water and air

• crop pollination and seed dispersal

• pest and disease control

Cultural services

• cultural, intellectual and spiritual inspiration

• recreational experiences (including ecotourism)

• scientific discovery

Preserving services

• genetic and species diversity for future use

• accounting for uncertainty

• protection of options

To understand the relationships between humans and natural ecosystems through the services derived from them, consider the following cases:
Undershot water wheels on the Orontes River in Hama, Syria Saint Anthony Falls Hydropower is the capture of the energy of moving water for some useful purpose. ... For articles on specific fuels used in vehicles, see Biogas, Bioethanol, Biobutanol, Biodiesel, and Straight vegetable oil. ... Carbon sequestration from a fossil-fuel power station A carbon dioxide sink or CO2 sink is a carbon reservoir that is increasing in size, and is the opposite of a carbon source. The main sinks are the oceans and growing vegetation. ... “Spoilage” redirects here. ... A flower-fly pollinating a Common Daisy (Bellis perennis) Pollination is an important step in the reproduction of seed plants: the transfer of pollen grains (male gametes) to the plant carpel, the structure that contains the ovule (female gamete). ... Wind dispersal of dandelion seeds. ... Carpet beetle larvae damaging a specimen of Sceliphron destillatorius in an entomological collection A pest is an organism which has characteristics that are regarded as injurious or unwanted. ... Ecotourism means ecological tourism, where ecological has both environmental and social connotations. ... Species diversity refers to the number and distribution of species in one location. ...

• In New York City, where the quality of drinking water had fallen below standards required by the U.S. Environmental Protection Agency (EPA), authorities opted to restore the polluted Catskill Watershed that had previously provided the city with the ecosystem service of water purification. Once the input of sewage and pesticides to the watershed area was reduced, natural abiotic processes such as soil adsorption and filtration of chemicals, together with biotic recycling via root systems and soil microorganisms, water quality improved to levels that met government standards. The cost of this investment in natural capital was estimated between $1-1.5 billion, which contrasted dramatically with the estimated $6-8 billion cost of constructing a water filtration plant plus the $300 million annual running costs ^[13].

• Pollination of crops by bees is required for 15-30% of U.S. food production; most large-scale farmers import non-native honey bees to provide this service. One study ^[14] reports that in California’s agricultural region, it was found that wild bees alone could provide partial or complete pollination services or enhance the services provided by honey bees through behavioral interactions. However, intensified agricultural practices can quickly erode pollination services through the loss of species and those remaining are unable to compensate for the difference. The results of this study also indicate that the proportion of chaparral and oak-woodland habitat available for wild bees within 1-2 km of a farm can strongly stabilize and enhance the provision of pollination services, thereby providing a potential insurance policy for farmers of this region.

• In watersheds of the Yangtze River (China), spatial models for water flow through different forest habitats were created to determine potential contributions for hydroelectric power in the region. By quantifying the relative value of ecological parameters (vegetation-soil-slope complexes), researchers were able to estimate the annual economic benefit of maintaining forests in the watershed for power services to be 2.2 times that if it were harvested once for timber ^[15].

This article includes a list of works cited or a list of external links, but its sources remain unclear because it lacks in-text citations. ... A flower-fly pollinating a Common Daisy (Bellis perennis) Pollination is an important step in the reproduction of seed plants: the transfer of pollen grains (male gametes) to the plant carpel, the structure that contains the ovule (female gamete). ... Chaparral is a shrubland plant community found primarily in California, USA, that is shaped by a Mediterranean climate (mild, wet winters and hot dry summers) and wildfire. ... Hydroelectric dam diagram The waters of Llyn Stwlan, the upper reservoir of the Ffestiniog Pumped-Storage Scheme in north Wales, can just be glimpsed on the right. ... Timber in storage for later processing at a sawmill Timber is a term used to describe wood, either standing or that has been processed for use—from the time trees are felled, to its end product as a material suitable for industrial use—as structural material for construction or wood...

Ecology

Understanding of ecosystem services requires a strong foundation in ecology, which describes the underlying principles and interactions of organisms and the environment. Since the scales at which these entities interact can vary from microbes to landscapes, milliseconds to millions of years, one of the greatest remaining challenges is the descriptive characterization of energy and material flow between them. For example, the area of a forest floor, the detritus upon it, the microorganisms in the soil and characteristics of the soil itself will all contribute to the abilities of that forest for providing ecosystem services like carbon sequestration, water purification, and erosion prevention to other areas within the watershed. Note that it is often possible for multiple services to be bundled together and when benefits of targeted objectives are secured, there may also be ancillary benefits – the same forest may provide habitat for other organisms as well as human recreation, which are also ecosystem services.

This article or section does not cite any references or sources. ... A microorganism or microbe is an organism that is so small that it is microscopic (invisible to the naked eye). ... The Harvesters, by Pieter Brueghel the Elder, 1565: Peace and agriculture in a pre-Romantic ideal landscape, without sublime terrors The term Landscape as most westerners use it, is completely entrenched in western notions of land, nature and art. ... Detritus may refer to: In geology, detritus is the name for loose fragments of rock that have been worn away by erosion. ... Severe soil erosion in a wheat field near Washington State University, USA. For erosion as an operation of Mathematical morphology, see Erosion (morphology) Erosion is displacement of solids (soil, mud, rock and other particles) by the agents of ocean currents, wind, water, or ice by downward or down-slope movement... This article includes a list of works cited or a list of external links, but its sources remain unclear because it lacks in-text citations. ... Look up habitat in Wiktionary, the free dictionary. ...

The complexity of Earth’s ecosystems poses a challenge for scientists as they try to understand how relationships are interwoven among organisms, processes and their surroundings. As it relates to human ecology, a suggested research agenda ^[14] for the study of ecosystem services includes the following steps:

1. identification of ecosystem service providers (ESPs) – species or populations that provide specific ecosystem services – and characterization their functional roles and relationships;

2. determination of community structure aspects that influence how ESPs function in their natural landscape, such as compensatory responses that stabilize function and non-random extinction sequences which can erode it;

3. assessment of key environmental (abiotic) factors influencing the provision of services;

4. measurement of the spatial and temporal scales ESPs and their services operate on.

Recently, a technique has been developed to improve and standardize the evaluation of ESP functionality by quantifying the relative importance of different species in terms of their efficiency and abundance ^[16]. Such parameters provide indications of how species respond to changes in the environment (i.e. predators, resource availability, climate) and are useful for identifying species that are disproportionately important at providing ecosystem services. However, a critical drawback is that the technique does not account for the effects of interactions, which are often both complex and fundamental in maintaining an ecosystem and can involve species that are not readily detected as a priority. Even so, estimating the functional structure of an ecosystem and combining it with information about individual species traits can help us understand the resilience of an ecosystem amidst environmental change.

The hierarchy of scientific classification. ... This article does not cite its references or sources. ... This article or section does not adequately cite its references or sources. ... For the band see Resilience (band) Resilience generally means the ability to recover from (or to resist being affected by) some shock, insult, or disturbance. ...

Ecosystem Function and Biodiversity

Many ecologists also believe that the provision of ecosystem services can be stabilized with biodiversity. Also with increased biodiversity there would be a greater variety of different types of ecosystem services available to society.The link between biodiversity, species richness, and ecosystem stability is important to understand to be able to know how to conserve resources, as well as to create designs to utilize these resources.

The Redundancy and Rivet Hypotheses

The redundancy (sometimes referred to as the Functional Compensation) and rivet hypotheses seek to explain how an ecosystem functions, based on the ecological role of organisms within it. The redundancy and rivet hypotheses are the most commonly used explanations for the link between ecosystem function and its biodiversity, but others included the “idiosyncratic” and the “null” hypothesis.^[17] The redundancy hypothesis states that there are more than one species that share the same function in an ecosystem, thus each species' performance in the ecosystem is “redundant”^[18]. The redundancy hypothesis is accredited to Brian H. Walker and his article “Biodiversity and Ecological Redundancy” published in the academic journal Conservation Biology in 1992. With each species lost in an ecosystem another species with a similar function will be able to satisfy an ecosystem's need for a certain process or action preformed by the lost species. However, as more species are lost the ecosystem slowly loses its efficiency as it reaches critical points where the remaining species can not compensate for their lost companions. For the conservation of ecosystems this implies, “special attention to be paid to functional groups that are represented by only one or two species.”^[19]. The redundancy hypothesis believes that "species redundancy enhances ecosystem resilience"^[20].
In the rivet hypothesis,(sometimes called "rivet popping") proposed by Paul Ehrich, “all species make a contribution to ecosystem performance.”^[21] It uses the analogy of the rivets in an airplane wing to compare the exponential effect each species loss will have on the function of an ecosystem. If one species is lost there is only a small loss in efficiency, however if multiple are lost the the ecosystem will experience a large drop in its functions and essentially fall apart, just as an airplane wing would if it lost too many rivets that held it together. This idea assumes that species are more specialized in their roles and that compensation is not as high as in the redundancy theory, and therefore, each species is highly valuable to the ecosystem. The main difference between these theories is the rate at which the loss of species affects the function of the ecosystems. The rates of these theories can be illustrated with statistical models. In the redundancy model the function of the ecosystem decreases slowly with every species lost, while in the rivet model ecosystem function decreases rapidly. Rainforests are among the most biodiverse ecosystems on earth Biodiversity is the variation of taxonomic life forms within a given ecosystem, biome or for the entire Earth. ...

There are many experiments testing these differing hypotheses both in the field and the lab. In ECOTRON, a laboratory in the UK in which many of the biotic and abiotic factors of nature can be simulated, there are studies on the effects of earthworms and symbiotic bacteria on plant roots.^[22] The laboratoy experiments seem to favor the rivet hypothesis. However, a study on grasslands at Cedar Creek Reserve in Minnesota seems to favor the redundancy hypothesis, as have other field studies.^[23] Look up biotic in Wiktionary, the free dictionary. ... This article or section does not adequately cite its references or sources. ...

The Portfolio Effect

One explanation, known as the portfolio effect, compares biodiversity to stock holdings, where diversification minimizes the volatility of the investment, or in this case, the risk in stability of ecosystem services ^[24]. This is related to the idea of response diversity where a suite of species will exhibit differential responses to a given environmental perturbation and therefore when considered together, they create a stabilizing function that preserves the integrity of a service ^[25].

Functional Compensation

Functional compensation, a third possibility, is characterized by a particular species increasing its efficiency at providing a service when conditions are stressed in order to maintain aggregate stability in the ecosystem ^[26]. However, such increased dependence on a compensating species places additional stress on the ecosystem and often enhances its susceptibility to subsequent disturbance. The theory "congeneric homotaxis" by Hill and Wiegert proposes that a from of species redundancy, "contributes to regulatory control of ecosystems and is sensitive to ecosystem stress"^[27]. A coral reef near the Hawaiian islands is an example of a complex marine ecosystem. ... In ecology, a disturbance is a temporary change in average environmental conditions that causes a pronounced change in ecosystem structure that lasts longer than the change in the environment. ...

Economics

Further information: Environmental economics

There is an extensive disparity between the actual and perceived values of ecosystem services. The reasons for such incongruence are probably related to society’s generally tardy and limited acknowledgment of our interrelatedness with the natural environment. Although environmental awareness is rapidly improving in our contemporary world, ecosystem capital and its flow are still poorly understood, threats continue to impose, and we suffer from the so-called ‘tragedy of the commons’ ^[28]. Many efforts to inform decision-makers of current versus future costs and benefits now involve organizing and translating scientific knowledge to economics, which articulate the consequences of our choices in comparable units of impact on human well-being ^[29]. An especially challenging aspect of this process is that interpreting ecological information collected from one spatial-temporal scale does not necessarily mean it can be applied at another; understanding the dynamics of ecological processes relative to ecosystem services is essential in aiding economic decisions ^[30]. Weighting factors such as a service’s irreplaceability or bundled services can also allocate economic value such that goal attainment becomes more efficient.

Environmental economics is a subfield of economics concerned with environmental issues (other usages of the term are not uncommon). ... It has been suggested that Tyranny of the Commons be merged into this article or section. ... This article needs additional references or sources for verification. ...

The economic valuation of ecosystem services also involves social communication and information, areas that remain particularly challenging and are the focus of many researchers. In general, the idea is that although individuals make decisions for any variety of reasons, trends reveal the aggregative preferences of a society, from which the economic value of services can be inferred and assigned. The six major classifications of economic value for ecosystem services include ^[31]:

1. Avoided Cost – services allow society to avoid costs that would have been incurred in the absence of those services (e.g. waste treatment by wetland habitats avoids health costs)
2. Replacement Cost – services could be replaced with man-made systems (e.g. restoration of the Catskill Watershed cost less than the construction of a water purification plant)
3. Factor Income – services provide for the enhancement of incomes (e.g. improved water quality increases the commercial take of a fishery and improves the income of fishers)
4. Travel Cost – service demand may require travel, whose costs can reflect the implied value of the service (e.g. value of ecotourism experience is sufficient that a visitor is willing to pay to get there)
5. Hedonic Pricing – service demand may be reflected in the prices people will pay for associated goods (e.g. coastal housing prices exceed that of inland homes)
6. Contingent Valuation – service demand may be elicited by posing hypothetical scenarios that involve some valuation of alternatives (e.g. visitors willing to pay for increased access to national parks)

Management and policy A subtropical wetland in Florida, USA, with an endangered American Crocodile. ... Restoration ecology is the study of returning degraded ecosystems and landscapes to a reference state where ecological communities and processes are re-established. ... Control room and schematics of the water purification plant to Bret lake. ... Water quality is the physical, chemical and biological characteristics of water, characterized through the methods of hydrometry. ... A lobster boat unloading its catch in Ilfracombe harbour, North Devon, England. ... Ecotourism means ecological tourism, where ecological has both environmental and social connotations. ...

Although progress continues to be made on ecological and economic fronts with respect to the valuation of ecosystem services, the challenges in policy implementation and management are enormous. The administration of common pool resources is a subject of extensive academic pursuit. From defining the problems to finding solutions that can be applied in practical and sustainable ways, there is much to overcome. Considering options must balance present and future human needs, and decision-makers must frequently work from valid but incomplete information. Existing legal policies are often considered insufficient since they typically pertain to human health-based standards that are mismatched with necessary means to protect ecosystem health and services. To improve the information available, one suggestion has involved the implementation of an Ecosystem Services Framework (ESF), which integrates the biophysical and socio-economic dimensions of protecting the environment and is designed to guide institutions through multidisciplinary information and jargon, helping to direct strategic choices. Novel and expedient methods are needed to deal with managing Earth’s ecosystem services. Local to regional collective management efforts might be considered appropriate for services like crop pollination or resources like water. Another approach that has become increasingly popular over the last decade is the marketing of ecosystem services protection. Payment and trading of services is an emerging world-wide small-scale solution where one can acquire credits for activities such as sponsoring the protection of carbon sequestration sources or the restoration of ecosystem service providers. In some cases, banks for handling such credits have been established and conservation companies have even gone public on stock exchanges, defining an evermore parallel link with economic endeavors and opportunities for tying into social perceptions (Daily et al. 2000). However, concerns for such global transactions include inconsistent compensation for services or resources sacrificed elsewhere and misconceived warrants for irresponsible use. Another approach has been focused on protecting ecosystem service ‘hotspots’. Recognition that the conservation of many ecosystem services aligns with more traditional conservation goals (i.e. biodiversity) has led to the suggested merging of objectives for maximizing their mutual success. This may be particularly strategic when employing networks that permit the flow of services across landscapes, and might also facilitate securing the financial means to protect services through a diversification of investors.

References

1. ^ Vitousek, P.M., J. Lubchenco, H.A. Mooney, J. Melillo. 1997. Human domination of Earth’s ecosystems. Science 277: 494-499.
2. ^ ^{a b} Daily, G.C. 1997. Nature’s Services: Societal Dependence on Natural Ecosystems. Island Press, Washington. 392pp.
3. ^ Marsh, G.P. 1864 (1965). Man and Nature. Charles Scribner, New York. 472pp.
4. ^ Osborn, F. 1948. Our Plundered Planet. Little, Brown and Company: Boston. 217pp.
5. ^ Vogt, W. 1948. Road to Survival. William Sloan: New York. 335pp.
6. ^ Leopold, A. 1949. A Sand County Almanac and Sketches from Here and There. Oxford University Press, New York. 226pp.
7. ^ Sears, P.B. 1956. “The processes of environmental change by man.” In: W.L. Thomas, editor. Man’s Role in Changing the Face of the Earth (Volume 2). University of Chicago Press, Chicago. 1193pp.
8. ^ Ehrlich, P.R. and A. Ehrlich. 1970. Population, Resources, Environment: Issues in Human Ecology. W.H. Freeman, San Francisco. 383pp. - see p.157
9. ^ Study of Critical Environmental Problems (SCEP). 1970. Man’s Impact on the Global Environment. MIT Press, Cambridge. 319pp.
10. ^ Ehrlich, P.R. and A. Ehrlich. 1981. Extinction: The Causes and Consequences of the Disappearance of Species. Random House, New York. 305pp.
11. ^ Daily, G.C. 2000. Management objectives for the protection of ecosystem services. Environmental Science & Policy 3: 333-339.
12. ^ Millennium Ecosystem Assessment (MEA). 2005. Ecosystems and Human Well-Being: Synthesis. Island Press, Washington. 155pp.
13. ^ Chichilnisky, G. and G. Heal. 1998. Economic returns from the biosphere. Nature 391: 629-630.
14. ^ ^{a b} Kremen, C. 2005. Managing ecosystem services: what do we need to know about their ecology? Ecology Letters 8: 468-479.
15. ^ Guo, Z.W., X.M. Xio and D.M. Li. 2000. An assessment of ecosystem services: water flow regulation and hydroelectric power production. Ecological Applications 10: 925-936.
16. ^ Balvanera, P. C. Kremen, and M. Martinez. 2005. Applying community structure analysis to ecosystem function: examples from pollination and carbon storage. Ecological Applications 15: 360-375.
17. ^ Lawton, John H. “What do species Do in Ecosystems?”, Oikos, Dec 1994.vol71,no.3,pp368. Nordic Society Oikos <http:links.jstor.org/sici?sici=0030-1299%28199412%2971%3A3%3 >
18. ^ Walker, Brian H.. "Biodiversity and ecological redundancy." Conservation Biology Vol.6, no.1March 1992 18-23. 29 May 2007 <http://www.jstor.org/view/08888892/di995152/99p0094o/0?citationAction=save&charset=u&frame=noframe&dpi=3&userID=a9e9214e@ucsc.edu/01cc99331a00501be4646&config=jstor&citationPath=08888892-di995152-99p0094o&PAGE=0>
19. ^ Ehrlich, Paul, and Brian Walker/ “Rivets and Redundancy”. BioScience.vol48.no.5 May 1998.pp.387. American Institute of Biological Sciences <http://links.jstor.org/sici?sici=0006-3568%28199805%2948%3A5% >
20. ^ Shahid Naeem (1998) Species Redundancy and Ecosystem ReliabilityConservation Biology 12 (1), 39–45.doi:10.1046/j.1523-1739.1998.96379.x.
21. ^ Lawton, John H. “What do species Do in Ecosystems?”, Oikos, Dec 1994.vol71,no.3,pp368. Nordic Society Oikos <http:links.jstor.org/sici?sici=0030-1299%28199412%2971%3A3%3 >
22. ^ Lawton, John H. “What do species Do in Ecosystems?”, Oikos, Dec 1994.vol71,no.3,pp368. Nordic Society Oikos <http:links.jstor.org/sici?sici=0030-1299%28199412%2971%3A3%3 >
23. ^ Grime, J.P. “Biodiversity and Ecosystem Function: The Debate Deepend.” Science. Vol 277,no.533029 Aug 1997
24. ^ Tilman, D., C.L. Lehman, and C.E. Bristow. 1998. Diversity-stability relationships: statistical inevitability or ecological consequence? The American Naturalist 151: 277-282.
25. ^ Elmqvist, T., C. Folke, M. Nyström, G. Peterson, J. Bengtsson, B. Walker and J. Norberg. 2003. Response diversity, ecosystem change and resilience. Frontiers in Ecology and the Environment 1: 488-494.
26. ^ Frost, T.M., S.R. Carpenter, A.R. Ives, and T.K. Kratz. 1995. “Species compensation and complementarity in ecosystem function.” In: C. Jones and J. Lawton, editors. Linking species and ecosystems. Chapman and Hall, London. 387pp.
27. ^ Shahid Naeem (1998) Species Redundancy and Ecosystem Reliability,Conservation Biology 12 (1), 39–45.doi:10.1046/j.1523-1739.1998.96379.x
28. ^ Hardin, G. 1968. The tragedy of the commons. Science 162: 1243-1248.
29. ^ Daily, G.C., T. Söderqvist, S. Aniyar, K. Arrow, P. Dasgupta, P.R. Ehrlich, C. Folke, A. Jansson, B. Jansson, N. Kautsky, S. Levin, J. Lubchenco, K. Mäler, D. Simpson, D. Starrett, D. Tilman, and B. Walker. 2000. The value of nature and the nature of value. Science 289: 395-396.
30. ^ DeFries, R.S., J.A. Foley, and G.P. Asner. 2004. Land-use choices: balancing human needs and ecosystem function. Frontiers in Ecology and the Environment 2: 249-257.
31. ^ Farber, S.C., R. Costanza and M.A. Wilson. 2002. Economic and ecological concepts for valuing ecosystem services. Ecological Economics 41: 375-392.

See also

• Nature's services
• Ecological goods and services
• Ecological effects of biodiversity
• Biodiversity
• Ecosystem Services
• Ecosystem
• Diversity-function debate