Which best describes biodiversity

Multiple impacts especially the addition of climate change to the mix of forcing functions can cause thresholds, or rapid and dramatic changes in ecosystem function even though the increase in environmental stress has been small and constant over time. Understanding such thresholds requires having long-term records, but such records are usually lacking or monitoring has been too infrequent, of the wrong periodicity, or too localized to provide the necessary data to analyze and predict threshold behavior C28 , S3.

Shifts to different regimes may cause rapid substantial changes in biodiversity , ecosystem services , and human well-being.

Regime shifts have been commonly documented in pelagic systems due to thresholds related to temperature regimes and overexploitation C Some regime shifts are essentially irreversible, such as coral reef ecosystems that undergo sudden shifts from coral-dominated to algal-dominated reefs C The trigger for such phase shifts usually includes increased nutrient inputs leading to eutrophic conditions and removal of herbivorous fishes that maintain the balance between corals and algae.

Once the thresholds both an upper and a lower threshold for the two ecological processes of nutrient loading and herbivory are passed, the phase shift occurs quickly within months , and the resulting ecosystem—though stable—is less productive and less diverse.

Consequently, human well-being is affected not only by reductions in food supply and decreased income from reef-related industries diving and snorkeling, aquarium fish collecting, and so on , but also by increased costs due to diminished ability of reefs to protect shorelines.

Algal reefs are more prone to being broken up in storm events, leading to shoreline erosion and seawater breaches of land C Introduced invasive species can act as a trigger for dramatic changes in ecosystem structure, function, and delivery of services.

Biodiversity plays an important role in ecosystem functions that provide supporting, provisioning, regulating, and cultural services. These services are essential for human well-being. However, at present there are few studies that link changes in biodiversity with changes in ecosystem functioning to changes in human well-being.

Protecting the Catskill watersheds that provide drinking water for New York City is one case where safeguarding ecosystem services paid a dividend of several billion dollars. Further work that demonstrates the links between biodiversity, regulating and supporting services , and human well-being is needed to show this vital but often unappreciated value of biodiversity C4, C7, C Species composition matters as much or more than species richness when it comes to ecosystem services.

Ecosystem functioning, and hence ecosystem services, at any given moment in time is strongly influenced by the ecological characteristics of the most abundant species, not by the number of species. The relative importance of a species to ecosystem functioning is determined by its traits and its relative abundance. Thus conserving or restoring the composition of biological communities , rather than simply maximizing species numbers, is critical to maintaining ecosystem services C Local or functional extinction, or the reduction of populations to the point that they no longer contribute to ecosystem functioning, can have dramatic impacts on ecosystem services.

Local extinctions the loss of a species from a local area and functional extinctions the reduction of a species such that it no longer plays a significant role in ecosystem function have received little attention compared with global extinctions loss of all individuals of a species from its entire range. Loss of ecosystem functions, and the services derived from them, however, occurs long before global extinction.

Often, when the functioning of a local ecosystem has been pushed beyond a certain limit by direct or indirect biodiversity alterations, the ecosystem-service losses may persist for a very long time C Changes in biotic interactions among species—predation, parasitism, competition, and facilitation—can lead to disproportionately large, irreversible, and often negative alterations of ecosystem processes.

In addition to direct interactions, such as predation, parasitism, or facilitation, the maintenance of ecosystem processes depends on indirect interactions as well, such as a predator preying on a dominant competitor such that the dominant is suppressed, which permits subordinate species to coexist. Interactions with important consequences for ecosystem services include pollination; links between plants and soil communities , including mycorrhizal fungi and nitrogen-fixing microorganisms; links between plants and herbivores and seed dispersers; interactions involving organisms that modify habitat conditions beavers that build ponds, for instance, or tussock grasses that increase fire frequency ; and indirect interactions involving more than two species such as top predators, parasites, or pathogens that control herbivores and thus avoid overgrazing of plants or algal communities C Many changes in ecosystem services are brought about by the removal or introduction of organisms in ecosystems that disrupt biotic interactions or ecosystem processes.

Because the network of interactions among species and the network of linkages among ecosystem processes are complex, the impacts of either the removal of existing species or the introduction of new species are difficult to anticipate C See Table 1. Table 1. As in terrestrial and aquatic communities , the loss of individual species involved in key interactions in marine ecosystems can also influence ecosystem processes and the provisioning of ecological services. For example, coral reefs and the ecosystem services they provide are directly dependent on the maintenance of some key interactions between animals and algae.

As one of the most species-rich communities on Earth, coral reefs are responsible for maintaining a vast storehouse of genetic and biological diversity. Substantial ecosystem services are provided by coral reefs—such as habitat construction, nurseries, and spawning grounds for fish; nutrient cycling and carbon and nitrogen fixing in nutrient - poor environments; and wave buffering and sediment stabilization.

The total economic value of reefs and associated services is estimated as hundreds of millions of dollars. Yet all coral reefs are dependent on a single key biotic interaction: symbiosis with algae. Biodiversity affects key ecosystem processes in terrestrial ecosystems such as biomass production , nutrient and water cycling, and soil formation and retention—all of which govern and ensure supporting services high certainty.

The relationship between biodiversity and supporting ecosystem services depends on composition, relative abundance, functional diversity , and, to a lesser extent, taxonomic diversity. What describes the transition from one phase to another in the business cycle? What term describes the. What best describes an adaptation? What are the three dimensions of biodiversity? Which characteristics describes most nonmetals in solid phase? What process describes the phase change from liquid to solid?

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Give me food and I will live give me water and I will die what am I? What is bigger than an asteroid but smaller than Mercury and farther from the sun than Neptune? Has a human ever been mailed via the United States Postal Service? Still have questions? Most people recognize biodiversity by species—a group of individual living organisms that can interbreed.

If biodiversity of an area is not preserved it can lead to environmental disasters such as forest fires and floods. It can lead to soil erosion and habitat loss of plants and animals which ultimately will cause the extinction of vulnerable species. It can cause climatic changes and ecosystem instability. The benefits of conserving biodiversity Biodiversity supports food security and sustained livelihoods through overall genetic diversity. It promotes at least one of the three objectives of the Convention: the conservation of bio-diversity, sustainable use of its components ecosystems, species or genetic resources , or fair and equitable sharing of the benefits of the utilisation of genetic resources.

Skip to content. Home » Biology Biology. October 10, thanh. Answers Which of the following best describes a biodiversity "hotspot"? Biodiversity hotspot is a region where large numbers of animals are brought together into an enclosure Explanation: When we are talking about biodiversity hotspot, it entails a concentrated region where living organisms are brought together.