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Biodiversity plays a major role in the productivity and functioning of ecosystems, affects their ability to provide ecosystem services. [2] For example, biodiversity is a source of food, medication, and materials used in industry. Recreation and tourism are also examples of human economic activities that rely on these benefits.
Other researchers believe that the relationship between species diversity and productivity is unimodal within an ecosystem. [27] A 1999 study on grassland ecosystems in Europe, for example, found that increasing species diversity initially increased productivity but gradually leveled off at intermediate levels of diversity. [28]
The diversity of species and genes in ecological communities affects the functioning of these communities. These ecological effects of biodiversity in turn are affected by both climate change through enhanced greenhouse gases, aerosols and loss of land cover [citation needed], and biological diversity, causing a rapid loss of biodiversity and extinctions of species and local populations.
Species distributions and their dynamics over time result from properties of the species, environmental variation..., and interactions between the two—in particular the abilities of some species, especially our own, to modify their environments and alter the range dynamics of many other species." [5] Alteration of an ecological niche by its ...
Environmental economics is related to ecological economics but there are differences. Most environmental economists have been trained as economists. They apply the tools of economics to address environmental problems, many of which are related to so-called market failures—circumstances wherein the "invisible hand" of economics is unreliable ...
Out of a total of 28,400 terawatt-hours (96.8 × 10 ^ 15 BTU) of energy used in the US in 1999, 10.5% was used in food production, [3] with the percentage accounting for food from both producer and primary consumer trophic levels. In comparing the cultivation of animals versus plants, there is a clear difference in magnitude of energy efficiency.
An exception occurs in deep-sea hydrothermal ecosystems, where there is no sunlight. Here primary producers manufacture food through a process called chemosynthesis. [5] Consumers (heterotrophs) are species that cannot manufacture their own food and need to consume other organisms. Animals that eat primary producers (like plants) are called ...
Gross primary production (GPP) is the amount of chemical energy, typically expressed as carbon biomass, that primary producers create in a given length of time.Some fraction of this fixed energy is used by primary producers for cellular respiration and maintenance of existing tissues (i.e., "growth respiration" and "maintenance respiration").