Thank you. Make a one time donation Make a monthly donation. Why is biodiversity important? By Julie Shaw. This post was updated on May 17, Wildlife support healthy ecosystems that we rely on. Keeping biodiverse ecosystems intact helps humans stay healthy.
Read more: Poaching, deforestation reportedly on the rise since COVID lockdowns Deforestation is also accelerating climate breakdown , which in turn may boost the spread of disease by allowing disease carriers like mosquitoes to extend their geographic ranges and infect new populations of humans. Biodiversity is an essential part of the solution to climate change. Biodiversity is good for the economy. Biodiversity is an integral part of culture and identity. Further Reading: Without traditional knowledge, there is no climate change solution Protections for African wildlife face growing threat: a lack of money We can limit global warming to 1.
As reported by CNN May 5, , One third of all our food—fruits and vegetables—would not exist without pollinators visiting flowers. But honeybees, the primary species that fertilizes food-producing plants, have suffered dramatic declines in recent years, mostly from afflictions introduced by humans. Bees are vital to bio diversity. There are , plants for example for which bees are essential to pollination, from melons to pumpkins, raspberries and all kind of fruit trees — as well as animal fodder — like clover.
Researchers are finding reasons for the massive decline hard to pinpoint, but suspect a combination of various diseases, environmental pollution, environmental degradation leading to less diversity for bees to feed from, for example and farming practices such as pesticides, large monoculture cropping, etc. The link and dependency between plants, bees, and human agriculture is so crucial, the two scientists writing up years of research into the problem summarized with this warning:.
Humankind needs to act quickly to ensure that the ancient pact between flowers and pollinators stays intact, to safeguard our food supply and to protect our environment for generations to come. These efforts will ensure that bees continue to provide pollination and that our diets remain rich in the fruits and vegetables we now take for granted.
An example from the seas originally mentioned here years ago but removed because the link to the story no longer worked , was described by National Geographic Wild in a program called, A Life Among Whales broadcast June 14, It noted how a few decades ago, some fishermen campaigned for killing whales because they were threatening the fish supply and thus jobs. A study in the journal Science , notes that these large animals — such as lions, leopards, wolves and bears — are in decline, due to declining habitats and persecution by humans..
This also has a negative impact on the environment, perhaps partly formed by outdated-views that predators are harmful for other wildlife. As a simple example, the loss of a large carnivore may mean in the short term the herbivores they prey on may increase in numbers but this can also result in a deterioration of the environment as the herbivores can graze more, largely unchecked. Human intervention to perform the same services would be more costly.
Nature can often be surprisingly resilient, often without the need for human interventions. For example, a documentary aired on the BBC I unfortunately forget the name and date, but in the s described two national parks in Africa where elephant populations had grown quite large within those artificial boundaries.
The usual way to deal with this was to cull the population to try and keep the ecosystem in balance. Without this, elephants were stripping vegetation bare, affecting other animals, too. A scientist pleaded with park management not to cull and let nature take its course. Being against prevailing thought, they would not agree. In the end they agreed to let one park have its elephants culled, while the other would be left alone. A few years later, they found the park with the culled population had remained in poor condition.
The park where things were left alone has naturally regenerated; the large elephant populations eventually reduced in number as they undermined their own resource base. The natural pace at which this happened allowed vegetation to grow back. 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.
Concentrations of carbonate ions are now lower than at any time during the last , years. The impacts on ocean biological diversity and ecosystem functioning will likely be severe, though the precise timing and distribution of these impacts are uncertain. Pollution from nutrients nitrogen and phosphorous and other sources is a continuing and growing threat to biodiversity in terrestrial, inland water and coastal ecosystems.
Modern industrial processes such as the burning of fossil fuels and agricultural practices, in particular the use of fertilizers, have more than doubled the quantity of reactive nitrogen - nitrogen in the form that is available to stimulate plant growth - in the environment compared with pre-industrial times. Put another way, humans now add more reactive nitrogen to the environment than all natural processes, such as nitrogen-fixing plants, fires and lightning. In terrestrial ecosystems, the largest impact is in nutrient-poor environments, where some plants that benefit from the added nutrients out-compete many other species and cause significant changes in plant composition.
Typically, plants such as grasses and sedges will benefit at the expense of species such as dwarf shrubs, mosses and lichens. Nitrogen deposition is already observed to be the major driver of species change in a range of temperate ecosystems, especially grasslands across Europe and North America, and high levels of nitrogen have also been recorded in southern China and parts of South and Southeast Asia.
Biodiversity loss from this source may be more serious than first thought in other ecosystems including high-latitude boreal forests, Mediterranean systems, some tropical savannas and montane forests. Nitrogen has also been observed to be building up at significant levels in biodiversity hotspots, with potentially serious future impacts on a wide variety of plant species. Large parts of Latin America and Africa, as well as Asia, are projected to experience elevated levels of nitrogen deposition in the next two decades.
Although the impacts have mainly been studied in plants, nitrogen deposition may also affect animal biodiversity by changing the composition of available food. In inland water and coastal ecosystems, the buildup of phosphorous and nitrogen, mainly through run-off from cropland and sewage pollution, stimulates the growth of algae and some forms of bacteria, threatening valuable ecosystem services in systems such as lakes and coral reefs, and affecting water quality.
It also creates "dead zones" in oceans, generally where major rivers reach the sea. In these zones, decomposing algae use up oxygen in the water and leave large areas virtually devoid of marine life. The number of reported dead zones has been roughly doubling every ten years since the s, and by had reached around [See Figure 15]. While the increase in nutrient load is among the most significant changes humans are making to ecosystems, policies in some regions are showing that this pressure can be controlled and, in time, reversed.
Among the most comprehensive measures to combat nutrient pollution is the European Union's Nitrates Directive [See Box 16 and Figure 16]. Overexploitation and destructive harvesting practices are at the heart of the threats being imposed on the world's biodiversity and ecosystems, and there has not been significant reduction in this pressure.
Changes to fisheries management in some areas are leading to more sustainable practices, but most stocks still require reduced pressure in order to rebuild.
Bushmeat hunting, which provides a significant proportion of protein for many rural households, appears to be taking place at unsustainable levels. Overexploitation is the major pressure being exerted on marine ecosystems, with marine capture fisheries having quadrupled in size from the early s to the mid s. Total catches have fallen since then despite increased fishing effort, an indication that many stocks have been pushed beyond their capacity to replenish.
Innovative approaches to the management of fisheries, such as those that give fishermen a stake in maintaining healthy stocks, are proving to be effective where they are applied [See Box 17]. Invasive alien species continue to be a major threat to all types of ecosystems and species. There are no signs of a significant reduction of this pressure on biodiversity, and some indications that it is increasing. Intervention to control alien invasive species has been successful in particular cases, but it is outweighed by the threat to biodiversity from new invasions.
In a sample of 57 countries, more than alien species, including vascular plants, marine and freshwater fish, mammals, birds and amphibians, with a demonstrated impact on biodiversity have been found, with an average of over 50 such species per country and a range from nine to over This is most certainly an underestimate, as it excludes many alien species whose impact has not yet been examined, and includes countries known to lack data on alien species.
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