Svoboda | Graniru | BBC Russia | Golosameriki | Facebook

To install click the Add extension button. That's it.

The source code for the WIKI 2 extension is being checked by specialists of the Mozilla Foundation, Google, and Apple. You could also do it yourself at any point in time.

How to transfigure the Wikipedia

Would you like Wikipedia to always look as professional and up-to-date? We have created a browser extension. It will enhance any encyclopedic page you visit with the magic of the WIKI 2 technology.

Try it — you can delete it anytime.

Install in 5 seconds
4,5
Kelly Slayton
Congratulations on this excellent venture… what a great idea!
Alexander Grigorievskiy
I use WIKI 2 every day and almost forgot how the original Wikipedia looks like.
Live Statistics
English Articles
Improved in 24 Hours
Added in 24 Hours
What we do. Every page goes through several hundred of perfecting techniques; in live mode. Quite the same Wikipedia. Just better.
Great Wikipedia has got greater.
.
Leo
Newton
Brights
Milds

Ecosystem ecology

From Wikipedia, the free encyclopedia

Figure 1. A riparian forest in the White Mountains, New Hampshire (USA).

Ecosystem ecology is the integrated study of living (biotic) and non-living (abiotic) components of ecosystems and their interactions within an ecosystem framework. This science examines how ecosystems work and relates this to their components such as chemicals, bedrock, soil, plants, and animals.

Ecosystem ecology examines physical and biological structures and examines how these ecosystem characteristics interact with each other. Ultimately, this helps us understand how to maintain high quality water and economically viable commodity production. A major focus of ecosystem ecology is on functional processes, ecological mechanisms that maintain the structure and services produced by ecosystems. These include primary productivity (production of biomass), decomposition, and trophic interactions.

Studies of ecosystem function have greatly improved human understanding of sustainable production of forage, fiber, fuel, and provision of water. Functional processes are mediated by regional-to-local level climate, disturbance, and management. Thus ecosystem ecology provides a powerful framework for identifying ecological mechanisms that interact with global environmental problems, especially global warming and degradation of surface water.

This example demonstrates several important aspects of ecosystems:

  1. Ecosystem boundaries are often nebulous and may fluctuate in time
  2. Organisms within ecosystems are dependent on ecosystem level biological and physical processes
  3. Adjacent ecosystems closely interact and often are interdependent for maintenance of community structure and functional processes that maintain productivity and biodiversity

These characteristics also introduce practical problems into natural resource management. Who will manage which ecosystem? Will timber cutting in the forest degrade recreational fishing in the stream? These questions are difficult for land managers to address while the boundary between ecosystems remains unclear; even though decisions in one ecosystem will affect the other. We need better understanding of the interactions and interdependencies of these ecosystems and the processes that maintain them before we can begin to address these questions.

Ecosystem ecology is an inherently interdisciplinary field of study. An individual ecosystem is composed of populations of organisms, interacting within communities, and contributing to the cycling of nutrients and the flow of energy. The ecosystem is the principal unit of study in ecosystem ecology.

Population, community, and physiological ecology provide many of the underlying biological mechanisms influencing ecosystems and the processes they maintain. Flowing of energy and cycling of matter at the ecosystem level are often examined in ecosystem ecology, but, as a whole, this science is defined more by subject matter than by scale. Ecosystem ecology approaches organisms and abiotic pools of energy and nutrients as an integrated system which distinguishes it from associated sciences such as biogeochemistry.[1]

Biogeochemistry and hydrology focus on several fundamental ecosystem processes such as biologically mediated chemical cycling of nutrients and physical-biological cycling of water. Ecosystem ecology forms the mechanistic basis for regional or global processes encompassed by landscape-to-regional hydrology, global biogeochemistry, and earth system science.[1]

YouTube Encyclopedic

  • 1/5
    Views:
    628 756
    63 541
    237 010
    207 957
    746 493
  • Ecosystem Ecology: Links in the Chain - Crash Course Ecology #7
  • Flow of energy and matter through ecosystem | Ecology | Khan Academy
  • Energy Flow in Ecosystems
  • Biogeochemical Cycles
  • Ecology - Rules for Living on Earth: Crash Course Biology #40

Transcription

There's a lot of ideas that we just assume we know a lot about because we hear about them all the time. For instance, I know what Pop music is, but if you were to corner me at a party and say, "HANK, What is Pop Music?", I'd be like, "It's uh... it's like, uh... the music that plays on the pop station?" Just because we're familiar with a concept does not mean that we actually understand it. Ecology's kind of the same way: even though it's a common, everyday concept, and ecosystem is a word that we hear a lot, I think most of us would be little stumped if somebody actually asked us what an ecosystem is or how one works, or why they're important, etc. I find it helps to think of an ecosystem, a collection of living and nonliving things interacting in a specific place, as one of those Magic Eye posters, for those of you who were sentient back in 1994. An ecosystem is just a jumble of organisms, weather patterns, geology and other stuff that don't make a lot of sense together until you stare at them long enough, from far enough away, and then suddenly a picture emerges. And just like with Magic Eye posters, it helps if you're listening to Jamiroquai while you're doing it. So, the discipline of ecosystem ecology, just like other types of ecology we've been exploring lately, looks at a particular level of biological interaction on Earth. But unlike population ecology, which looks at interactions between individuals of one species, or community ecology, which looks at how bunches of living things interact with each other, ecosystem ecology looks at how energy and materials come into an ecosystem, move around in it, and then get spat back out. In the end, ecosystem ecology is mostly about eating, who's eating whom, and how energy, nutrients and other materials are getting shuffled around within the system. So today, we're setting the record straight! No more not understanding how an ecosystem works! Starting NOW! So, ecosystems may be a lot like Magic Eye posters, but the way that they're not like a Magic Eye poster is in the way that posters have edges. Ecosystems... I'll just come out and say it: No edge. Only fuzzy, ill-defined gradients that bleed into the ecosystems next door. So actually defining an ecosystem can be kind of hard. Mostly it depends on what you want to study. Say you're looking at a stream in the mountains. This stream gets very little sunlight because it's so small that the trees on its banks totally cover it with shade. As a result, very few plants or algae live in it, and if there's one thing that we know about planet Earth it's that plants are king. Without plants, there are no animals. But somehow there's a whole community of animals living in and around this mountain stream, even though there are few plants in it. So what are the animals doing there, and how are they making their living? From the land, of course! From the ecosystems around it. Because no stream is an island. It isn't there all by itself. All kinds of food, nutrients and other materials drop into the stream from the trees or are washed into it when it rains, leaves and bugs, you name it, flow down from neighboring terrestrial ecosystems. And that stuff gets eaten by bigger bugs, which get eaten by fish, which in turn are eaten by raccoons and birds and bears. So, even though the stream's got its own thing going on, without the rest of the watershed, the animals there wouldn't survive. And without the stream, plants would be thirsty and terrestrial animals wouldn't have as many fish to eat. So where does the ecosystem of the stream start and where does it end? This is a perennial problem for ecologists. Because the way it works, energy and nutrients are imported in from someplace, they're absorbed by the residents of an ecosystem, and then passed around within it for a little while, and then finally passed out, sometimes into another ecosystem. This is most obvious in aquatic systems, where little streams eventually join bigger and bigger waterways until they finally reach the ocean, this flow is a fundamental property of ecosystems. So, at the end of the day, how you define an ecosystem just depends on what you want to know. If you want to know how energy and materials come in, move through, and are pooped out of a knot in a tree that has a very specific community of insects and protists living in it, you can call that an ecosystem. If you want to know how energy and materials are introduced to, used and expelled by the North Pacific Gyre, you can call that an ecosystem. If you want to know how energy and materials move around a cardboard box that has a rabbit and a piece of lettuce in it, you can call that an ecosystem. I might tell you that your ecosystem is stupid, but go ahead! Do whatever you want! The picture you see in an ecosystem's Magic Eye is actually dictated by the organisms that live there and how they use what comes into it. An ecosystem can be measured through figuring out things like its biomass, that is, the total weight of living things in the ecosystem, and its productivity, how much stuff is produced, and how quickly stuff grows back, how good the ecosystem is at retaining stuff. And of course, all these parameters matter to neighboring ecosystems as well because if one ecosystem's really productive, the ones next door are going to benefit. So first things first, where do the energy and materials come from? And to be clear, when I talk about "materials," I'm talking about water or nutrients like phosphorous or nitrogen, or even toxins like mercury or DDT. Let's start out by talking about energy, because nothing lives without energy, and where organisms get their energy tells the story of an ecosystem. You remember physics, right? The laws of conservation state that energy and matter can neither be destroyed or created. They can only get transferred from place to place to place. The same is true of an ecosystem. Organisms in an ecosystem organize themselves into a trophic structure, with each organism situating itself in a certain place in the food chain. All of the energy in an ecosystem moves around within this structure, because when I say energy, of course I mean food. For most ecosystems, the primary source of energy is the sun, and the organisms that do most of the conversion of solar energy into chemical energy...you know this one. Who rules the world? The plants rule the world. Autotrophs like plants are able to gather up the sun's energy, and through photosynthesis, make something awesome out of it: little stored packets of chemical energy. So whether it's plants, bacteria or protists that use photosynthesis, autotrophs are always the lynchpin of every ecosystem, the foundation upon which all other organisms in the system get their energy and nutrients. For this reason, ecologists refer to plants as primary producers. Now, obviously, the way that energy gets transferred from plants to animals is by an animal eating the plant. For this reason, herbivores are known as primary consumers, the first heterotrophs to get their grubby paws on that sweet, sweet energy. After this stage in the trophic structure, the only way to wrestle the solar energy that was in the plants that the herbivore ate is to, you guessed it, eat the herbivore, which carnivores, known as secondary consumers, are very happy to do. And assuming that the ecosystem is big enough and productive enough, there might even be a higher level of carnivore that eats other carnivores, like an owl that eats hawks, and these guys are called tertiary consumers. And then there are the -vores that decompose all the dead animal and plant matter, as well as the animal poop: detritivores. These include earthworms, sea stars, fiddler crabs, dung beetles, fungi, and anything else that eats the stuff that none of the rest of us would touch with a 3-meter pole. So, that's a nice, hierarchical look at who's getting energy from what or whom within an ecosystem. But of course, organisms within an ecosystem don't usually abide by these rules very closely, which is why these days, we usually talk about food webs, rather than food chains. A food web takes into consideration that sometimes a fungus is going to be eating nutrients from a dead squirrel, and other times squirrels are going to be eating the fungi. Sometimes a bear likes to munch on primary producers, blueberry bushes, and other times it's going to be snacking on a secondary consumer, a salmon. And even the tippy tippy top, predators get eaten by stuff like bacteria in the end, which might or might not be the same bacteria that ate the top predator's poopies. Circle of Life! It's also worth noting that the size and scope of the food web in an ecosystem has a lot to do with things like water and temperature, because water and temperature are what plants like, right? And without plants, there isn't going to be a whole lot of trophic action going on. Take, for example, the Sonoran desert, which we've talked about before. There aren't very many plants there, compared to, say, the Amazon rainforest. So the primary producers are limited by the lack of water, which means that primary consumers are limited by lack of primary producers, and that leaves precious few secondary consumers, a few snakes, some coyotes and hawks. All this adds up to the Sonoran not being a terribly productive place, compared to the Amazon at least, so you might only get to the level of tertiary consumer occasionally. Now, all this conversation about productivity leads me to another point about ecosystem efficiency. When I talk about energy getting passed along from one place to another within an ecosystem, I mean that in a general sense, organisms are sustaining each other, but not in a particularly efficient way. In fact, when energy transfers from one place to another, from a plant or a bunny or from a bunny to a snake, the vast majority of that energy is lost along the way. So, let's take a cricket. That cricket has about 1 calorie of energy in it. And in order to get that 1 calorie of energy it had to eat about 10 calories of lettuce. Where did the other 9 calories go? It is not turned into cricket flesh. Most of it is used just to live, like to power its muscles, or run the sodium potassium pumps in its neurons, it's just used up. So only the 1 calorie of the original 10 calories of food is left over as actual cricket stuff. And then, right after his last meal, the cricket jumps into a spider web and is eaten by a spider, who converts only 10% of the cricket's energy into actual spider stuff. And don't get me started on the bird that eats the spider. This is not an efficient world that we live in. But you want to know what's scary-efficient? The accumulation of toxins in an ecosystem. Elements like mercury, which are puffed out the smokestacks of coal-fired power plants, end up getting absorbed in the ocean by green algae and marine plants. While the tiny animal that eats the algae only stores 10% of the energy it got, it keeps 100% of the mercury. So as we move up the chain, each trophic level consumes ten times more mercury than the last, and that's what we call bioaccumulation. Concentrations get much higher at each trophic level, until a human gets a hold of a giant tuna that's at the top of the marine food chain, and none of that mercury has been lost. It's all right there in that delicious tuna flesh. Because organisms only hold on to 10% of the energy they ingest, each trophic level has to eat about 10 times its biomass to sustain itself. And because 100% of the mercury moves up the food chain, that means that it becomes 10 times more concentrated with each trophic level it enters. That's why we need to take the seafood advisories seriously: as somebody who could eat anything you wanted, it's probably safest to eat lower on the food chain, primary producers or primary consumers. The older, bigger, higher in the food chain, the more toxic it's going to be. And that's not just my opinion, that's ecosystem ecology! Thank you for watching this episode of Crash Course Ecology. And thank you for everyone who helped us put this episode together. If you want to reviews any of the topics we went over today, there's a table of contents over there that you can click on. And if you have any questions or comments for us we're on Facebook or Twitter, or of course, down in the comments below. We'll see you next time.

History

Ecosystem ecology is philosophically and historically rooted in terrestrial ecology. The ecosystem concept has evolved rapidly during the last 100 years with important ideas developed by Frederic Clements, a botanist who argued for specific definitions of ecosystems and that physiological processes were responsible for their development and persistence.[2] Although most of Clements ecosystem definitions have been greatly revised, initially by Henry Gleason and Arthur Tansley, and later by contemporary ecologists, the idea that physiological processes are fundamental to ecosystem structure and function remains central to ecology.

Figure 3. Energy and matter flows through an ecosystem, adapted from the Silver Springs model.[3] H are herbivores, C are carnivores, TC are top carnivores, and D are decomposers. Squares represent biotic pools and ovals are fluxes or energy or nutrients from the system.

Later work by Eugene Odum and Howard T. Odum quantified flows of energy and matter at the ecosystem level, thus documenting the general ideas proposed by Clements and his contemporary Charles Elton.

In this model, energy flows through the whole system were dependent on biotic and abiotic interactions of each individual component (species, inorganic pools of nutrients, etc.). Later work demonstrated that these interactions and flows applied to nutrient cycles, changed over the course of succession, and held powerful controls over ecosystem productivity.[4][5] Transfers of energy and nutrients are innate to ecological systems regardless of whether they are aquatic or terrestrial. Thus, ecosystem ecology has emerged from important biological studies of plants, animals, terrestrial, aquatic, and marine ecosystems.

Ecosystem services

Main article: Ecosystem services

Ecosystem services are ecologically mediated functional processes essential to sustaining healthy human societies.[6] Water provision and filtration, production of biomass in forestry, agriculture, and fisheries, and removal of greenhouse gases such as carbon dioxide (CO2) from the atmosphere are examples of ecosystem services essential to public health and economic opportunity. Nutrient cycling is a process fundamental to agricultural and forest production.

However, like most ecosystem processes, nutrient cycling is not an ecosystem characteristic which can be “dialed” to the most desirable level. Maximizing production in degraded systems is an overly simplistic solution to the complex problems of hunger and economic security. For instance, intensive fertilizer use in the midwestern United States has resulted in degraded fisheries in the Gulf of Mexico.[7] Regrettably, a “Green Revolution” of intensive chemical fertilization has been recommended for agriculture in developed and developing countries.[8][9] These strategies risk alteration of ecosystem processes that may be difficult to restore, especially when applied at broad scales without adequate assessment of impacts. Ecosystem processes may take many years to recover from significant disturbance.[5]

For instance, large-scale forest clearance in the northeastern United States during the 18th and 19th centuries has altered soil texture, dominant vegetation, and nutrient cycling in ways that impact forest productivity in the present day.[10][11] An appreciation of the importance of ecosystem function in maintenance of productivity, whether in agriculture or forestry, is needed in conjunction with plans for restoration of essential processes. Improved knowledge of ecosystem function will help to achieve long-term sustainability and stability in the poorest parts of the world.

Operation

Biomass productivity is one of the most apparent and economically important ecosystem functions. Biomass accumulation begins at the cellular level via photosynthesis. Photosynthesis requires water and consequently global patterns of annual biomass production are correlated with annual precipitation.[12] Amounts of productivity are also dependent on the overall capacity of plants to capture sunlight which is directly correlated with plant leaf area and N content.

Net primary productivity (NPP) is the primary measure of biomass accumulation within an ecosystem. Net primary productivity can be calculated by a simple formula where the total amount of productivity is adjusted for total productivity losses through maintenance of biological processes:

NPP = GPP – Rproducer
Figure 4. Seasonal and annual changes in ambient carbon dioxide (CO2) concentration at Mauna Loa Hawaii (Atmosphere) and above the canopy of a deciduous forest in Massachusetts (Forest). Data show clear seasonal trends associated with periods of high and low NPP and an overall annual increase of atmospheric CO2. Data approximates of those reported by Keeling and Whorf[13] and Barford.[14]

Where GPP is gross primary productivity and Rproducer is photosynthate (Carbon) lost via cellular respiration.

NPP is difficult to measure but a new technique known as eddy co-variance has shed light on how natural ecosystems influence the atmosphere. Figure 4 shows seasonal and annual changes in CO2 concentration measured at Mauna Loa, Hawaii from 1987 to 1990. CO2 concentration steadily increased, but within-year variation has been greater than the annual increase since measurements began in 1957.

These variations were thought to be due to seasonal uptake of CO2 during summer months. A newly developed technique for assessing ecosystem NPP has confirmed seasonal variation are driven by seasonal changes in CO2 uptake by vegetation.[15][14] This has led many scientists and policy makers to speculate that ecosystems can be managed to ameliorate problems with global warming. This type of management may include reforesting or altering forest harvest schedules for many parts of the world.

Decomposition and nutrient cycling

Decomposition and nutrient cycling are fundamental to ecosystem biomass production. Most natural ecosystems are nitrogen (N) limited and biomass production is closely correlated with N turnover.[16][17] Typically external input of nutrients is very low and efficient recycling of nutrients maintains productivity.[5] Decomposition of plant litter accounts for the majority of nutrients recycled through ecosystems (Figure 3). Rates of plant litter decomposition are highly dependent on litter quality; high concentration of phenolic compounds, especially lignin, in plant litter has a retarding effect on litter decomposition.[18][19] More complex C compounds are decomposed more slowly and may take many years to completely breakdown. Decomposition is typically described with exponential decay and has been related to the mineral concentrations, especially manganese, in the leaf litter.[20][21]

Figure 5. Dynamics of decomposing plant litter (A) described with an exponential model (B) and a combined exponential-linear model (C).

Globally, rates of decomposition are mediated by litter quality and climate.[22] Ecosystems dominated by plants with low-lignin concentration often have rapid rates of decomposition and nutrient cycling (Chapin et al. 1982). Simple carbon (C) containing compounds are preferentially metabolized by decomposer microorganisms which results in rapid initial rates of decomposition, see Figure 5A,[23] models that depend on constant rates of decay; so called “k” values, see Figure 5B.[24] In addition to litter quality and climate, the activity of soil fauna is very important [25]

However, these models do not reflect simultaneous linear and non-linear decay processes which likely occur during decomposition. For instance, proteins, sugars and lipids decompose exponentially, but lignin decays at a more linear rate[18] Thus, litter decay is inaccurately predicted by simplistic models.[26]

A simple alternative model presented in Figure 5C shows significantly more rapid decomposition that the standard model of figure 4B. Better understanding of decomposition models is an important research area of ecosystem ecology because this process is closely tied to nutrient supply and the overall capacity of ecosystems to sequester CO2 from the atmosphere.

Trophic dynamics

Trophic dynamics refers to process of energy and nutrient transfer between organisms. Trophic dynamics is an important part of the structure and function of ecosystems. Figure 3 shows energy transferred for an ecosystem at Silver Springs, Florida. Energy gained by primary producers (plants, P) is consumed by herbivores (H), which are consumed by carnivores (C), which are themselves consumed by “top- carnivores”(TC).

One of the most obvious patterns in Figure 3 is that as one moves up to higher trophic levels (i.e. from plants to top-carnivores) the total amount of energy decreases. Plants exert a “bottom-up” control on the energy structure of ecosystems by determining the total amount of energy that enters the system.[27]

However, predators can also influence the structure of lower trophic levels from the top-down. These influences can dramatically shift dominant species in terrestrial and marine systems[28][29] The interplay and relative strength of top-down vs. bottom-up controls on ecosystem structure and function is an important area of research in the greater field of ecology.

Trophic dynamics can strongly influence rates of decomposition and nutrient cycling in time and in space. For example, herbivory can increase litter decomposition and nutrient cycling via direct changes in litter quality and altered dominant vegetation.[30] Insect herbivory has been shown to increase rates of decomposition and nutrient turnover due to changes in litter quality and increased frass inputs.[1][31]

However, insect outbreak does not always increase nutrient cycling. Stadler[32] showed that C rich honeydew produced during aphid outbreak can result in increased N immobilization by soil microbes thus slowing down nutrient cycling and potentially limiting biomass production. North atlantic marine ecosystems have been greatly altered by overfishing of cod. Cod stocks crashed in the 1990s which resulted in increases in their prey such as shrimp and snow crab[29] Human intervention in ecosystems has resulted in dramatic changes to ecosystem structure and function. These changes are occurring rapidly and have unknown consequences for economic security and human well-being.[33]

Applications and importance

Lessons from two Central American cities

The biosphere has been greatly altered by the demands of human societies. Ecosystem ecology plays an important role in understanding and adapting to the most pressing current environmental problems. Restoration ecology and ecosystem management are closely associated with ecosystem ecology. Restoring highly degraded resources depends on integration of functional mechanisms of ecosystems.[34]

Without these functions intact, economic value of ecosystems is greatly reduced and potentially dangerous conditions may develop in the field. For example, areas within the mountainous western highlands of Guatemala are more susceptible to catastrophic landslides and crippling seasonal water shortages due to loss of forest resources. In contrast, cities such as Totonicapán that have preserved forests through strong social institutions have greater local economic stability and overall greater human well-being.[35]

This situation is striking considering that these areas are close to each other, the majority of inhabitants are of Mayan descent, and the topography and overall resources are similar. This is a case of two groups of people managing resources in fundamentally different ways. Ecosystem ecology provides the basic science needed to avoid degradation and to restore ecosystem processes that provide for basic human needs.

See also


References

  1. ^ a b c Chapman, S.K., Hart, S.C., Cobb, N.S., Whitham, T.G., and Koch, G.W. (2003). "Insect herbivory increases litter quality and decomposition: an extension of the acceleration hypothesis". in: Ecology 84:2867-2876.
  2. ^ Hagen, J.B. (1992). An Entangled Bank: The origins of ecosystem ecology. Rutgers University Press, New Brunswick, N.J.
  3. ^ Odum, H.T. (1971). Environment, Power, and Society. Wiley-Interscience New York, N.Y.
  4. ^ Odum, E.P 1969. "The strategy of ecosystem development". in: Science 164:262-270.
  5. ^ a b c Likens, G. E., F. H. Bormann, N. M. Johnson, D. W. Fisher and R. S. Pierce. (1970). "Effects of forest cutting and herbicide treatment on nutrient budgets in the Hubbard Brook watershed-ecosystem". in: Ecological Monographs 40:23-47.
  6. ^ Chapin, F.S. III, B.H., Walker, R.J., Hobbs, D.U., Hooper, J.H., Lawton, O.E., Sala, and D., Tilman. (1997). "Biotic control over the functioning of ecosystems". in: Science 277:500-504.
  7. ^ Defries, R.S., J.A. Foley, and G.P. Asner. (2004). "Land-use choices: balancing human needs and ecosystem function". in: Frontiers in ecology and environmental science. 2:249-257.
  8. ^ Chrispeels, M.J. and Sadava, D. (1977). Plants, food, and people. W. H. Freeman and Company, San Francisco.
  9. ^ Quinones, M.A., N.E. Borlaug, C.R. Dowswell. (1997). "A fertilizer-based green revolution for Africa". In: Replenishing soil fertility in Africa. Soil Science Society of America special publication number 51. Soil Science Society of America, Madison, WI.
  10. ^ Foster, D. R. (1992). "Land-use history (1730-1990) and vegetation dynamics in central New England, USA". In: Journal of Ecology 80: 753-772.
  11. ^ Motzkin, G., D. R. Foster, A. Allen, J. Harrod, and R. D. Boone. (1996). "Controlling site to evaluate history: vegetation patterns of a New England sand plain". In: Ecological Monographs 66: 345-365.
  12. ^ Huxman TE, ea.(2004). "Convergence across biomes to a common rain-use efficiency". Nature. 429: 651-654
  13. ^ Keeling, C.D. and T.P. Whorf. (2005). "Atmospheric CO2 records from sites in the SIO air sampling network". In: Trends: A Compendium of Data on Global Change. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A.
  14. ^ a b Barford, C. C., ea. (2001). "Factors controlling long and short term sequestration of atmospheric CO2 in a mid-latitude forest". In: Science 294: 1688-1691
  15. ^ Goulden, M. L., J. W. Munger, S.-M. Fan, B. C. Daube, and S. C. Wofsy, (1996). "Effects of interannual climate variability on the carbon dioxide exchange of a temperate deciduous forest". In: Science 271:1576-1578
  16. ^ Vitousek, P.M. and Howarth, R.W. (1991). "Nitrogen limitation on land and in the sea: how can it occur?" In: Biogeochemistry 13:87-115.
  17. ^ Reich, P.B., Grigal, D.F., Aber, J.D., Gower, S.T. (1997). "Nitrogen mineralization and productivity in 50 hardwood and conifer stands on diverse soils". In: Ecology 78:335-347.
  18. ^ a b Melillo, J.M., Aber, J.D., and Muratore, J.F. (1982). "Nitrogen and lignin control of hardwood leaf litter decomposition dynamics". In: Ecology 63:621-626.
  19. ^ Hättenschwiler S. and P.M. Vitousek (2000). "The role of polyphenols in terrestrial ecosystem nutrient cycling". In: Trends in Ecology and Evolution 15: 238-243
  20. ^ Davey MP, B Berg, P Rowland, BA Emmett. 2007. Decomposition of oak leaf litter is related to initial litter Mn concentrations. Canadian Journal of Botany. 85(1). 16-24.
  21. ^ Berg B, Davey MP, Emmett B, Faituri M, Hobbie S, Johansson MB, Liu C, De Marco A, McClaugherty C, Norell L, Rutigliano F, De Santo AV. 2010. Factors influencing limit values for pine needle litter decomposition - a synthesis for boreal and temperate pine forest systems. Biogeochemistry. 100: 57-73
  22. ^ Meentemeyer, V. 1978 "Macroclimate and lignin control of litter decomposition rates". in: Ecology 59:465-472.
  23. ^ Aber, J.D., and J.M., Melillo (1982). "Nitrogen immobilization in decaying hardwood leaf litter as a function of initial nitrogen and lignin content". In: Canadian Journal of Botany 60:2263-2269.
  24. ^ Olson, J.S. (1963). "Energy storage and the balance of producers and decomposers in ecological systems". In: Ecology 44:322-331.
  25. ^ Castro-Huerta, R.; Falco, L.; Sandler, R.; Coviella, C. (2015). "Differential contribution of soil biota groups to plant litter decomposition as mediated by soil use". PeerJ. 3: e826. doi:10.7717/peerj.826. PMC 4359044. PMID 25780777.
  26. ^ Carpenter, S.A. (1981). "Decay of heterogeneous detritus: a general model". In: Journal of theoretical biology 89:539-547.
  27. ^ Chapin F.S. III, Matson, P.A., and Mooney, H.A. (2003). Principles of terrestrial ecosystem ecology. Springer-Verlag, New York, N.Y.
  28. ^ Belovsky, G.E. and J.B. Slade. (2000). "Insect herbivory accelerates nutrient cycling and increases plant production". In: Proceedings of the national academy of sciences (USA). 97:14412-14417.
  29. ^ a b Frank et al. 2005.
  30. ^ Hunter, M.D. (2001). "Insect population dynamics meets ecosystem ecology: effects of herbivory on soil nutrient dynamics". In: Agricultural and Forest Entomology 3:77-84.
  31. ^ Swank, W.T., Waide, J.B., Crossley, D.A., and Todd R.L. (1981). "Insect defoliation enhances nitrate export from forest ecosystems". In: Oecologia 51:297-299.
  32. ^ Stadler, B., Solinger, St., and Michalzik, B. (2001). "Insect herbivores and the nutrient flow from the canopy to the soil in coniferous and deciduous forests". In: Oecologia 126:104-113
  33. ^ The intimate relation between ecosystem services and well-being was highlighted in the Millennium Ecosystem Assessment
  34. ^ Ehrenfeld, J.G. and Toth, L.A. (1997). "Restoration ecology and the ecosystem perspective". in: Restoration Ecology 5:307-317.
  35. ^ Conz, B.W. 2004. Continuity and Contestation: Conservation Landscapes in Totonicapán, Guatemala. University of Massachusetts Masters of Science thesis.
This page was last edited on 6 June 2024, at 12:41
Basis of this page is in Wikipedia. Text is available under the CC BY-SA 3.0 Unported License. Non-text media are available under their specified licenses. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc. WIKI 2 is an independent company and has no affiliation with Wikimedia Foundation.
Contact WIKI 2
Introduction
Terms of Service
Privacy Policy