93-474: The Arthur Rylah Institute for Environmental Research ( ARI ) is the biodiversity research organisation for the government of Victoria , Australia . It provides advice on ecologically sustainable land and water management issues and with regard to threatened native flora and fauna. It is named after Sir Arthur Rylah , a long-serving Victorian politician and deputy state premier between 1955 and 1971. Arthur Rylah Institute for Environmental Research (ARI)
186-410: A Landsat analysis of 100,000 undisturbed sites found that the areas with low tree cover became greener in response to warming, but areas with a lot of trees got more "brown" as some of them died due to the same. In Alaska, the growth of white spruce trees is stunted by unusually warm summers, while trees on some of the coldest fringes of the forest are experiencing faster growth than previously. At
279-552: A dozen biome types, and a single-digit number of biogeographic regions. The 2007 IPCC Fourth Assessment Report concluded that over the last three decades human-induced warming had likely had an influence on many biological systems. The Sixth Assessment Report found that half of all species with long-term data had shifted their ranges poleward (or upward for mountain species). Two-thirds have had their spring events occur earlier. Several European bird species' breeding seasons have been shifted to earlier periods, as indicated by
372-412: A century or more. However, the certainty level is still limited; there's an outside possibility that 1.5 °C (2.7 °F) would be enough to lock in either of the two shifts; on the other hand, reversion to grassland may require 5 °C (9.0 °F), and the replacement of tundra 7.2 °C (13.0 °F). Forest expansion is likely to take longer than decline, as juveniles of boreal species are
465-434: A certain stage, such shifts could become effectively irreversible, making them tipping points in the climate system , and a major assessment designated both processes - reversion of southern boreal forests to grasslands and the conversion of tundra areas to boreal forest - as separate examples of such, which would likely become unstoppable around 4 °C (7.2 °F), though they would still take at least 50 years, if not
558-512: A change which also affects the area's albedo (evergreen trees absorb more heat than the snow-covered ground) and acts as a small, yet detectable climate change feedback . At the same time, eastern Canadian forests have been much less affected; yet some research suggests it would also reach a tipping point around 2080, under the RCP 8.5 scenario which represents the largest potential increase in anthropogenic emissions. It has been hypothesized that
651-399: A cold water habitat that they have adapted to. Some species of freshwater fish need cold water to survive and to reproduce, and this is especially true with salmon and cutthroat trout . Reduced glacier runoff can lead to insufficient stream flow to allow these species to thrive. Ocean krill , a cornerstone species, prefer cold water and are the primary food source for aquatic mammals such as
744-501: A country, endangered species are initially supported on a national level then internationally. Ecotourism may be utilized to support the economy and encourages tourists to continue to visit and support species and ecosystems they visit, while they enjoy the available amenities provided. International biodiversity impacts global livelihood, food systems, and health. Problematic pollution, over consumption, and climate change can devastate international biodiversity. Nature-based solutions are
837-517: A critical tool for a global resolution. Many species are in danger of becoming extinct and need world leaders to be proactive with the Kunming-Montreal Global Biodiversity Framework . Terrestrial biodiversity is thought to be up to 25 times greater than ocean biodiversity. Forests harbour most of Earth's terrestrial biodiversity. The conservation of the world's biodiversity is thus utterly dependent on
930-455: A first-order positive feedback (more ancestors, more descendants) and/or a negative feedback arising from resource limitation. Hyperbolic model implies a second-order positive feedback. Differences in the strength of the second-order feedback due to different intensities of interspecific competition might explain the faster rediversification of ammonoids in comparison to bivalves after the end-Permian extinction . The hyperbolic pattern of
1023-472: A greater volume of wood is being produced today, it now contains less material than just a few decades ago." Historically, a few days of extreme cold would kill most mountain pine beetles and keep their outbreaks contained. Since 1998, the lack of severe winters in British Columbia had enabled a devastating pine beetle infestation, which had killed 33 million acres or 135,000 km by 2008;
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#17327728277161116-405: A home to more than one-tenth of global human population. Changes in global climate pose a number of potential risks to mountain habitats. Climate change can adversely affect both alpine tundra and montane grasslands and shrublands . It increases the number of extreme events such as the frequency and intensity of forest fires , and accelerates snowmelt, which makes more water available earlier in
1209-426: A level an order of magnitude larger than any previously recorded outbreak. Such losses can match an average year of forest fires in all of Canada or five years worth of emissions from its transportation. Climate change and the associated changing weather patterns occurring worldwide have a direct effect on biology, population ecology, and the population of eruptive insects, such as the mountain pine beetle . This
1302-460: A limit would also cap the number of species. While records of life in the sea show a logistic pattern of growth, life on land (insects, plants and tetrapods) shows an exponential rise in diversity. As one author states, "Tetrapods have not yet invaded 64 percent of potentially habitable modes and it could be that without human influence the ecological and taxonomic diversity of tetrapods would continue to increase exponentially until most or all of
1395-566: A rapid growth in biodiversity via the Cambrian explosion . In this period, the majority of multicellular phyla first appeared. The next 400 million years included repeated, massive biodiversity losses. Those events have been classified as mass extinction events. In the Carboniferous , rainforest collapse may have led to a great loss of plant and animal life. The Permian–Triassic extinction event , 251 million years ago,
1488-436: A reduction in population of up to 50% in the majority of U.S. freshwater streams, according to most climate change models. The increase in metabolic demands due to higher water temperatures, in combination with decreasing amounts of food will be the main contributors to their decline. Additionally, many fish species (such as salmon) use seasonal water levels of streams as a means of reproducing, typically breeding when water flow
1581-465: A sixfold increase in the area of forest burned, compared to the period from 1970 to 1986. While fire suppression policies have played a substantial role as well, both healthy and unhealthy forests now face an increased risk of forest fires because of the warming climate. A 2018 study found that trees grow faster due to increased carbon dioxide levels; however, the trees are also 8–12 percent lighter and denser since 1900. The authors note, "Even though
1674-590: A third of the Earth's land mass) and are home to approximately 80% of the world's biodiversity. About 1 billion hectares are covered by primary forests. Over 700 million hectares of the world's woods are officially protected. The biodiversity of forests varies considerably according to factors such as forest type, geography, climate and soils – in addition to human use. Most forest habitats in temperate regions support relatively few animal and plant species and species that tend to have large geographical distributions, while
1767-970: Is 'planned' diversity or 'associated' diversity. This is a functional classification that we impose and not an intrinsic feature of life or diversity. Planned diversity includes the crops which a farmer has encouraged, planted or raised (e.g. crops, covers, symbionts, and livestock, among others), which can be contrasted with the associated diversity that arrives among the crops, uninvited (e.g. herbivores, weed species and pathogens, among others). Associated biodiversity can be damaging or beneficial. The beneficial associated biodiversity include for instance wild pollinators such as wild bees and syrphid flies that pollinate crops and natural enemies and antagonists to pests and pathogens. Beneficial associated biodiversity occurs abundantly in crop fields and provide multiple ecosystem services such as pest control, nutrient cycling and pollination that support crop production. Effects of climate change on biomes Climate change
1860-413: Is already now altering biomes , adversely affecting terrestrial and marine ecosystems . Climate change represents long-term changes in temperature and average weather patterns. This leads to a substantial increase in both the frequency and the intensity of extreme weather events . As a region's climate changes, a change in its flora and fauna follows. For instance, out of 4000 species analyzed by
1953-405: Is an increase in biodiversity from the poles to the tropics . Thus localities at lower latitudes have more species than localities at higher latitudes . This is often referred to as the latitudinal gradient in species diversity. Several ecological factors may contribute to the gradient, but the ultimate factor behind many of them is the greater mean temperature at the equator compared to that at
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#17327728277162046-401: Is because temperature is a factor which determines insect development and population success. Prior to climatic and temperature changes, the mountain pine beetle predominately lived and attacked lodgepole and ponderosa pine trees at lower elevations, as the higher elevation Rocky Mountains and Cascades were too cold for their survival. Under normal seasonal freezing weather conditions in
2139-475: Is decreasing today. Climate change also plays a role. This can be seen for example in the effects of climate change on biomes . This anthropogenic extinction may have started toward the end of the Pleistocene , as some studies suggest that the megafaunal extinction event that took place around the end of the last ice age partly resulted from overhunting. Biologists most often define biodiversity as
2232-491: Is estimated at 5.0 x 10 and weighs 50 billion tonnes . In comparison, the total mass of the biosphere has been estimated to be as much as four trillion tons of carbon . In July 2016, scientists reported identifying a set of 355 genes from the last universal common ancestor (LUCA) of all organisms living on Earth. The age of Earth is about 4.54 billion years. The earliest undisputed evidence of life dates at least from 3.7 billion years ago, during
2325-441: Is high and migrating to the ocean after spawning. Because snowfall is expected to be reduced due to climate change, water runoff is expected to decrease which leads to lower flowing streams, affecting the spawning of millions of salmon. To add to this, rising seas will begin to flood coastal river systems, converting them from fresh water habitats to saline environments where indigenous species will likely perish. In southeast Alaska,
2418-427: Is local biodiversity, which directly impacts daily life, affecting the availability of fresh water, food choices, and fuel sources for humans. Regional biodiversity includes habitats and ecosystems that synergizes and either overlaps or differs on a regional scale. National biodiversity within a country determines the ability for a country to thrive according to its habitats and ecosystems on a national scale. Also, within
2511-523: Is more quickly returned to the atmosphere. Slow growing trees incorporate atmospheric carbon for decades. Warmer-than-ideal conditions result in higher metabolism and consequent reductions in body size despite increased foraging, which in turn elevates the risk of predation . Indeed, even a slight increase in temperature during development impairs growth efficiency and survival rate in rainbow trout . Many species of freshwater and saltwater plants and animals are dependent on glacier -fed waters to ensure
2604-593: Is not distributed evenly on Earth . It is greater in the tropics as a result of the warm climate and high primary productivity in the region near the equator . Tropical forest ecosystems cover less than one-fifth of Earth's terrestrial area and contain about 50% of the world's species. There are latitudinal gradients in species diversity for both marine and terrestrial taxa. Since life began on Earth , six major mass extinctions and several minor events have led to large and sudden drops in biodiversity. The Phanerozoic aeon (the last 540 million years) marked
2697-401: Is possible to build fractal hyper volumes, whose fractal dimension rises to three moving towards the equator . A biodiversity hotspot is a region with a high level of endemic species that have experienced great habitat loss . The term hotspot was introduced in 1988 by Norman Myers . While hotspots are spread all over the world, the majority are forest areas and most are located in
2790-561: Is so full, that that district produces the most variety which is the most examined." Biodiversity is the result of 3.5 billion years of evolution . The origin of life has not been established by science, however, some evidence suggests that life may already have been well-established only a few hundred million years after the formation of the Earth . Until approximately 2.5 billion years ago, all life consisted of microorganisms – archaea , bacteria , and single-celled protozoans and protists . Biodiversity grew fast during
2883-405: Is uncertainty as to how strongly the fossil record is biased by the greater availability and preservation of recent geologic sections. Some scientists believe that corrected for sampling artifacts, modern biodiversity may not be much different from biodiversity 300 million years ago, whereas others consider the fossil record reasonably reflective of the diversification of life. Estimates of
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2976-792: The Eoarchean era after a geological crust started to solidify following the earlier molten Hadean eon. There are microbial mat fossils found in 3.48 billion-year-old sandstone discovered in Western Australia . Other early physical evidence of a biogenic substance is graphite in 3.7 billion-year-old meta-sedimentary rocks discovered in Western Greenland .. More recently, in 2015, "remains of biotic life " were found in 4.1 billion-year-old rocks in Western Australia . According to one of
3069-597: The IPCC Sixth Assessment Report , half were found to have shifted their distribution to higher latitudes or elevations in response to climate change. Furthermore, climate change may cause ecological disruption among interacting species, via changes in behaviour and phenology , or via climate niche mismatch. For example, climate change can cause species to move in different directions, potentially disrupting their interactions with each other. Examples of effects on some biome types are provided in
3162-713: The Phanerozoic (the last 540 million years), especially during the so-called Cambrian explosion —a period during which nearly every phylum of multicellular organisms first appeared. However, recent studies suggest that this diversification had started earlier, at least in the Ediacaran , and that it continued in the Ordovician . Over the next 400 million years or so, invertebrate diversity showed little overall trend and vertebrate diversity shows an overall exponential trend. This dramatic rise in diversity
3255-461: The Stone Age , species loss has accelerated above the average basal rate, driven by human activity. Estimates of species losses are at a rate 100–10,000 times as fast as is typical in the fossil record. Loss of biodiversity results in the loss of natural capital that supplies ecosystem goods and services . Species today are being wiped out at a rate 100 to 1,000 times higher than baseline, and
3348-409: The blue whale . In general, freshwater bodies such as streams can be strongly affected by heatwaves. However, the impact could vary strongly depending on the presence or absence of predators in the stream community. In their absence, the impacts are much more severe and the local extinction of most species could occur, homogenizing the community. Species of fish living in cold or cool water can see
3441-504: The tropics . Brazil 's Atlantic Forest is considered one such hotspot, containing roughly 20,000 plant species, 1,350 vertebrates and millions of insects, about half of which occur nowhere else. The island of Madagascar and India are also particularly notable. Colombia is characterized by high biodiversity, with the highest rate of species by area unit worldwide and it has the largest number of endemics (species that are not found naturally anywhere else) of any country. About 10% of
3534-417: The world population growth arises from a second-order positive feedback between the population size and the rate of technological growth. The hyperbolic character of biodiversity growth can be similarly accounted for by a feedback between diversity and community structure complexity. The similarity between the curves of biodiversity and human population probably comes from the fact that both are derived from
3627-752: The "totality of genes , species and ecosystems of a region". An advantage of this definition is that it presents a unified view of the traditional types of biological variety previously identified: Biodiversity is most commonly used to replace the more clearly-defined and long-established terms, species diversity and species richness . However, there is no concrete definition for biodiversity, as its definition continues to be defined. Other definitions include (in chronological order): According to estimates by Mora et al. (2011), there are approximately 8.7 million terrestrial species and 2.2 million oceanic species. The authors note that these estimates are strongest for eukaryotic organisms and likely represent
3720-467: The 1960s, western Canadian boreal forests, and particularly the western coniferous forests , had already suffered substantial tree losses due to drought, and some conifers were getting replaced with aspen . Similarly, the already dry forest areas in central Alaska and far eastern Russia are also experiencing greater drought, placing birch trees under particular stress, while Siberia 's needle-shedding larches are replaced with evergreen conifers -
3813-554: The ARI releasing information about scientific research on plants and animals. The ARI annual report summarises key activities and research completed that have importance in changing the way Australian fauna and flora thrive in 21st century environments. Biodiversity Biodiversity is the variability of life on Earth . It can be measured on various levels. There is for example genetic variability , species diversity , ecosystem diversity and phylogenetic diversity. Diversity
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3906-457: The Amazon rainforest has been the greatest threat to it, and the main reason why, as of 2022, about 20% of it had been deforested and another 6% "highly degraded". Yet, climate change is also a threat as it exacerbates wildfire and interferes with precipitation. It is considered likely that hitting 3.5 °C (6.3 °F) of global warming would trigger the collapse of rainforest to savannah over
3999-458: The Earth's surface and provide a home to more than one-tenth of the global human population. Changes in global climate pose a number of potential risks to mountain habitats. Boreal forests , also known as taiga , are warming at a faster rate than the global average, leading to drier conditions in the Taiga , which leads to a whole host of subsequent impacts. Climate change has a direct impact on
4092-606: The IUCN's critically endangered . Numerous scientists and the IPBES Global Assessment Report on Biodiversity and Ecosystem Services assert that human population growth and overconsumption are the primary factors in this decline. However, other scientists have criticized this finding and say that loss of habitat caused by "the growth of commodities for export" is the main driver. Some studies have however pointed out that habitat destruction for
4185-461: The available eco-space is filled." It also appears that the diversity continues to increase over time, especially after mass extinctions. On the other hand, changes through the Phanerozoic correlate much better with the hyperbolic model (widely used in population biology , demography and macrosociology , as well as fossil biodiversity) than with exponential and logistic models. The latter models imply that changes in diversity are guided by
4278-516: The boreal environments have only a few states which are stable in the long term - a treeless tundra/steppe, a forest with >75% tree cover and an open woodland with ~20% and ~45% tree cover. Thus, continued climate change would be able to force at least some of the presently existing taiga forests into one of the two woodland states or even into a treeless steppe - but it could also shift tundra areas into woodland or forest states as they warm and become more suitable for tree growth. Consistent with that,
4371-550: The course of around a century (50-200) years, although it occur at between 2 °C (3.6 °F) to 6 °C (11 °F) of warming. Forest fires in Indonesia have dramatically increased since 1997 as well. These fires are often actively started to clear forest for agriculture. They can set fire to the large peat bogs in the region and the CO 2 released by these peat bog fires has been estimated, in an average year, to be 15% of
4464-540: The current sixth mass extinction match or exceed rates of loss in the five previous mass extinction events in the fossil record . Biodiversity loss is in fact "one of the most critical manifestations of the Anthropocene " (since around the 1950s); the continued decline of biodiversity constitutes "an unprecedented threat" to the continued existence of human civilization. The reduction is caused primarily by human impacts , particularly habitat destruction . Since
4557-704: The ecological resources of low-income countries, which was explained as a result of a process whereby wealthy nations are outsourcing resource depletion to poorer nations, which are suffering the greatest ecosystem losses. A 2017 study published in PLOS One found that the biomass of insect life in Germany had declined by three-quarters in the last 25 years. Dave Goulson of Sussex University stated that their study suggested that humans "appear to be making vast tracts of land inhospitable to most forms of life, and are currently on course for ecological Armageddon. If we lose
4650-512: The end of the Maastrichtian , just before that extinction event. However, many other taxa were affected by this crisis, which affected even marine taxa, such as ammonites , which also became extinct around that time. The biodiversity of the past is called Paleobiodiversity. The fossil record suggests that the last few million years featured the greatest biodiversity in history . However, not all scientists support this view, since there
4743-451: The estimated global value of ecosystem services (not captured in traditional markets) at an average of $ 33 trillion annually. With regards to provisioning services, greater species diversity has the following benefits: With regards to regulating services, greater species diversity has the following benefits: Greater species diversity Agricultural diversity can be divided into two categories: intraspecific diversity , which includes
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#17327728277164836-428: The expansion of agriculture and the overexploitation of wildlife are the more significant drivers of contemporary biodiversity loss, not climate change . Biodiversity is not evenly distributed, rather it varies greatly across the globe as well as within regions and seasons. Among other factors, the diversity of all living things ( biota ) depends on temperature , precipitation , altitude , soils , geography and
4929-463: The expansion will be seen over regions such as "southwest North America, the northern fringe of Africa, southern Africa, and Australia". Many of the species at risk are Arctic and Antarctic fauna such as polar bears Climate change is also leading to a mismatch between the snow camouflage of arctic animals such as snowshoe hares with the increasingly snow-free landscape. Mountains cover approximately 25 percent of earth's surface and provide
5022-712: The extinction of species' interactions. As a consequence of the spatial decoupling of species-species associations, ecosystem services derived from biotic interactions are also at risk from climate niche mismatch. Whole ecosystem disruptions will occur earlier under more intense climate change: under the high-emissions RCP8.5 scenario, ecosystems in the tropical oceans would be the first to experience abrupt disruption before 2030, with tropical forests and polar environments following by 2050. In total, 15% of ecological assemblages would have over 20% of their species abruptly disrupted if as warming eventually reaches 4 °C (7.2 °F); in contrast, this would happen to fewer than 2% if
5115-523: The figure dropping to 0% at 2 °C (3.6 °F) warming and beyond. On Earth, biomes are the main constituent parts of the biosphere , defined by a distinctive biological community and a shared regional climate . A single biome would include multiple ecosystems and ecoregions . According to the World Wildlife Fund classification, terrestrial, marine and freshwater environments each consist of hundreds of ecoregions, around
5208-440: The following. Research into desertification is complex, and there is no single metric which can define all aspects. However, more intense climate change is still expected to increase the current extent of drylands on the Earth's continents. Most of the expansion will be seen over regions such as "southwest North America, the northern fringe of Africa, southern Africa, and Australia". Mountains cover approximately 25 percent of
5301-551: The forest ecosystems, such as the whitebark pine forests of the Rocky Mountains. Increased temperatures also allow the pine beetle to increase their life cycle by 100% : it only takes a single year instead of two for the pine beetle to develop. As the Rockies have not adapted to deal with pine beetle infestations , they lack the defenses to fight the beetles. The Amazon rainforest is the largest tropical rainforest in
5394-491: The genetic variation within a single species, like the potato ( Solanum tuberosum ) that is composed of many different forms and types (e.g. in the U.S. they might compare russet potatoes with new potatoes or purple potatoes, all different, but all part of the same species, S. tuberosum ). The other category of agricultural diversity is called interspecific diversity and refers to the number and types of different species. Agricultural diversity can also be divided by whether it
5487-587: The insects then everything is going to collapse." In 2020 the World Wildlife Foundation published a report saying that "biodiversity is being destroyed at a rate unprecedented in human history". The report claims that 68% of the population of the examined species were destroyed in the years 1970 – 2016. Of 70,000 monitored species, around 48% are experiencing population declines from human activity (in 2023), whereas only 3% have increasing populations. Rates of decline in biodiversity in
5580-574: The institute. The institute was subsequently incorporated into various Victorian Government Departments since then including the Ministry for Conservation, the Department of Conservation Forests and Lands, the Department of Sustainability and Environment; and is currently (2017) in the Department of Environment Land Water and Planning. There have been many published reports, journal articles, book sections, books, theses and conference proceedings from
5673-596: The interactions between other species. The study of the spatial distribution of organisms , species and ecosystems , is the science of biogeography . Diversity consistently measures higher in the tropics and in other localized regions such as the Cape Floristic Region and lower in polar regions generally. Rain forests that have had wet climates for a long time, such as Yasuní National Park in Ecuador , have particularly high biodiversity. There
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#17327728277165766-737: The interference of the hyperbolic trend with cyclical and stochastic dynamics. Most biologists agree however that the period since human emergence is part of a new mass extinction, named the Holocene extinction event , caused primarily by the impact humans are having on the environment. It has been argued that the present rate of extinction is sufficient to eliminate most species on the planet Earth within 100 years. New species are regularly discovered (on average between 5–10,000 new species each year, most of them insects ) and many, though discovered, are not yet classified (estimates are that nearly 90% of all arthropods are not yet classified). Most of
5859-430: The lower bound of prokaryote diversity. Other estimates include: Since the rate of extinction has increased, many extant species may become extinct before they are described. Not surprisingly, in the animalia the most studied groups are birds and mammals , whereas fishes and arthropods are the least studied animals groups. During the last century, decreases in biodiversity have been increasingly observed. It
5952-452: The lower elevations, the forest ecosystems that pine beetles inhabit are kept in balance by factors such as tree defense mechanisms, beetle defense mechanisms, and freezing temperatures. It is a simple relationship between a host (the forest), an agent (the beetle) and the environment (the weather and temperature). However, as climate change causes mountain areas to become warmer and drier, pine beetles have more power to infest and destroy
6045-877: The montane forests of Africa, South America and Southeast Asia and lowland forests of Australia, coastal Brazil, the Caribbean islands, Central America and insular Southeast Asia have many species with small geographical distributions. Areas with dense human populations and intense agricultural land use, such as Europe , parts of Bangladesh, China, India and North America, are less intact in terms of their biodiversity. Northern Africa, southern Australia, coastal Brazil, Madagascar and South Africa, are also identified as areas with striking losses in biodiversity intactness. European forests in EU and non-EU nations comprise more than 30% of Europe's land mass (around 227 million hectares), representing an almost 10% growth since 1990. Generally, there
6138-411: The most important driver. Boreal forests, also known as taiga , are warming at a faster rate than the global average. leading to drier conditions in the Taiga , which leads to a whole host of subsequent issues. Climate change has a direct impact on the productivity of the boreal forest, as well as health and regeneration. As a result of the rapidly changing climate, trees show declines in growth at
6231-468: The mountains in order to adapt to long-term changes in regional climate. Such uphill shifts of both ranges and abundances have been recorded for various groups of species across the world. In some mountain areas, such as the Himalayas , climate change appears to promote the appearance of various invasive species of shrubs , eventually converting them to shrublands. Changes in precipitation appear to be
6324-468: The planet's species went extinct prior to the evolution of humans. Estimates on the number of Earth's current species range from 10 million to 14 million, of which about 1.2 million have been documented and over 86% have not yet been described. However, a May 2016 scientific report estimates that 1 trillion species are currently on Earth, with only one-thousandth of one percent described. The total amount of related DNA base pairs on Earth
6417-546: The poles. Even though terrestrial biodiversity declines from the equator to the poles, some studies claim that this characteristic is unverified in aquatic ecosystems , especially in marine ecosystems . The latitudinal distribution of parasites does not appear to follow this rule. Also, in terrestrial ecosystems the soil bacterial diversity has been shown to be highest in temperate climatic zones, and has been attributed to carbon inputs and habitat connectivity. In 2016, an alternative hypothesis ("the fractal biodiversity")
6510-412: The present global macroscopic species diversity vary from 2 million to 100 million, with a best estimate of somewhere near 9 million, the vast majority arthropods . Diversity appears to increase continually in the absence of natural selection. The existence of a global carrying capacity , limiting the amount of life that can live at once, is debated, as is the question of whether such
6603-428: The productivity of the boreal forest, as well as its health and regeneration. Almost no other ecosystem is as vulnerable to climate change as coral reefs . Updated 2022 estimates show that even at a global average increase of 1.5 °C (2.7 °F) over pre-industrial temperatures, only 0.2% of the world's coral reefs would still be able to withstand marine heatwaves , as opposed to 84% being able to do so now, with
6696-418: The quantity of CO 2 produced by fossil fuel combustion. Research suggests that slow-growing trees are only stimulated in growth for a short period under higher CO 2 levels, while faster growing plants like liana benefit in the long term. In general, but especially in rainforests , this means that liana become the prevalent species; and because they decompose much faster than trees their carbon content
6789-584: The rate of extinctions is increasing. This process destroys the resilience and adaptability of life on Earth. In 2006, many species were formally classified as rare or endangered or threatened ; moreover, scientists have estimated that millions more species are at risk which have not been formally recognized. About 40 percent of the 40,177 species assessed using the IUCN Red List criteria are now listed as threatened with extinction —a total of 16,119. As of late 2022 9251 species were considered part of
6882-913: The researchers, "If life arose relatively quickly on Earth...then it could be common in the universe ." There have been many claims about biodiversity's effect on the ecosystem services , especially provisioning and regulating services . Some of those claims have been validated, some are incorrect and some lack enough evidence to draw definitive conclusions. Ecosystem services have been grouped in three types: Experiments with controlled environments have shown that humans cannot easily build ecosystems to support human needs; for example insect pollination cannot be mimicked, though there have been attempts to create artificial pollinators using unmanned aerial vehicles . The economic activity of pollination alone represented between $ 2.1–14.6 billion in 2003. Other sources have reported somewhat conflicting results and in 1997 Robert Costanza and his colleagues reported
6975-430: The sea rises by 3.96 cm/year, redepositing sediment in various river channels and bringing salt water inland. This rise in sea level not only contaminates streams and rivers with saline water, but also the reservoirs they are connected to, where species such as sockeye salmon live. Although this species of Salmon can survive in both salt and fresh water, the loss of a body of fresh water stops them from reproducing in
7068-566: The shifts in nestling ringing dates. The range of hundreds of North American birds has shifted northward at an average rate of 1.5 km/year over the past 55 years. Furthermore, climate change may disrupt the ecology among interacting species, via changes on behaviour and phenology , or via climate niche mismatch. The disruption of species-species associations is a potential consequence of climate-driven movements of each individual species in opposite directions. Climate change may, thus, lead to another extinction, more silent and mostly overlooked:
7161-871: The southern limit of their range, and are migrating to higher latitudes and altitudes (northward) to remain their climatic habitat, but some species may not be migrating fast enough. The number of days with extremely cold temperatures (e.g., −20 to −40 °C (−4 to −40 °F) has decreased irregularly but systematically in nearly all the boreal region, allowing better survival for tree-damaging insects. The 10-year average of boreal forest burned in North America, after several decades of around 10,000 km (2.5 million acres), has increased steadily since 1970 to more than 28,000 km (7 million acres) annually., and records in Canada show increases in wildfire from 1920 to 1999. Early 2010s research confirmed that since
7254-693: The species of the Earth can be found in Colombia, including over 1,900 species of bird, more than in Europe and North America combined, Colombia has 10% of the world's mammals species, 14% of the amphibian species and 18% of the bird species of the world. Madagascar dry deciduous forests and lowland rainforests possess a high ratio of endemism . Since the island separated from mainland Africa 66 million years ago, many species and ecosystems have evolved independently. Indonesia 's 17,000 islands cover 735,355 square miles (1,904,560 km ) and contain 10% of
7347-419: The terrestrial diversity is found in tropical forests and in general, the land has more species than the ocean; some 8.7 million species may exist on Earth, of which some 2.1 million live in the ocean. It is estimated that 5 to 50 billion species have existed on the planet. Assuming that there may be a maximum of about 50 million species currently alive, it stands to reason that greater than 99% of
7440-479: The upcoming years. As of 2012, some studies suggest that 25% of all mammal species could be extinct in 20 years. In absolute terms, the planet has lost 58% of its biodiversity since 1970 according to a 2016 study by the World Wildlife Fund. The Living Planet Report 2014 claims that "the number of mammals, birds, reptiles, amphibians, and fish across the globe is, on average, about half the size it
7533-459: The warming were to stay below 2 °C (3.6 °F). Research into desertification is complex, and there is no single metric which can define all aspects. However, more intense climate change is still expected to increase the current extent of drylands on the Earth's continents: from 38% in late 20th century to 50% or 56% by the end of the century, under the "moderate" and high-warming Representative Concentration Pathways 4.5 and 8.5. Most of
7626-773: The way in which we interact with and use the world's forests. A new method used in 2011, put the total number of species on Earth at 8.7 million, of which 2.1 million were estimated to live in the ocean. However, this estimate seems to under-represent the diversity of microorganisms. Forests provide habitats for 80 percent of amphibian species , 75 percent of bird species and 68 percent of mammal species. About 60 percent of all vascular plants are found in tropical forests. Mangroves provide breeding grounds and nurseries for numerous species of fish and shellfish and help trap sediments that might otherwise adversely affect seagrass beds and coral reefs, which are habitats for many more marine species. Forests span around 4 billion acres (nearly
7719-630: The world's flowering plants , 12% of mammals and 17% of reptiles , amphibians and birds —along with nearly 240 million people. Many regions of high biodiversity and/or endemism arise from specialized habitats which require unusual adaptations, for example, alpine environments in high mountains , or Northern European peat bogs . Accurately measuring differences in biodiversity can be difficult. Selection bias amongst researchers may contribute to biased empirical research for modern estimates of biodiversity. In 1768, Rev. Gilbert White succinctly observed of his Selborne, Hampshire "all nature
7812-500: The world. It is twice as big as India and spans nine countries in South America . This size allows it to produce around half of its own rainfall by recycling moisture through evaporation and transpiration as air moves across the forest; tree losses interfere with that capability, to the point where if enough is lost, much of the rest will likely die off and transform into a dry savanna landscape. For now, deforestation of
7905-418: The worst-affected by the climate shifs, while the temperate species capable of replacing them have slower growth rates. Disappearance of forest also causes detectable carbon emissions, while gain acts as a carbon sink: yet the changes in albedo more than outweigh that in terms of climate impact. In the western U.S., since 1986, longer, warmer summers have resulted in a fourfold increase in major wildfires and
7998-519: The year and reduces availability later in the year, while the reduction in snow cover insulation can paradoxically increase cold damage from springtime frost events. It also causes remarkable changes in phenology . Studies suggest a warmer climate would cause lower-elevation habitats to expand into the higher alpine zone. Such a shift would encroach on rare alpine meadows and other high-altitude habitats. High-elevation plants and animals have limited space available for new habitat as they move higher on
8091-482: Was 40 years ago". Of that number, 39% accounts for the terrestrial wildlife gone, 39% for the marine wildlife gone and 76% for the freshwater wildlife gone. Biodiversity took the biggest hit in Latin America , plummeting 83 percent. High-income countries showed a 10% increase in biodiversity, which was canceled out by a loss in low-income countries. This is despite the fact that high-income countries use five times
8184-553: Was estimated in 2007 that up to 30% of all species will be extinct by 2050. Of these, about one eighth of known plant species are threatened with extinction . Estimates reach as high as 140,000 species per year (based on Species-area theory ). This figure indicates unsustainable ecological practices, because few species emerge each year. The rate of species loss is greater now than at any time in human history, with extinctions occurring at rates hundreds of times higher than background extinction rates. and expected to still grow in
8277-483: Was marked by periodic, massive losses of diversity classified as mass extinction events. A significant loss occurred in anamniotic limbed vertebrates when rainforests collapsed in the Carboniferous , but amniotes seem to have been little affected by this event; their diversification slowed down later, around the Asselian / Sakmarian boundary, in the early Cisuralian (Early Permian ), about 293 Ma ago. The worst
8370-569: Was officially opened by Queen Elizabeth II on 8 April 1970 as part of the Fisheries and Wildlife Division of the Victorian state government. The foundation Director was Alfred Dunbavin Butcher, who also had an association with Melbourne Zoo and Healesville Sanctuary . He had a keen interest in art and this attracted a large collection of wildlife art and the commissioning of a large mural at
8463-401: Was proposed to explain the biodiversity latitudinal gradient. In this study, the species pool size and the fractal nature of ecosystems were combined to clarify some general patterns of this gradient. This hypothesis considers temperature , moisture , and net primary production (NPP) as the main variables of an ecosystem niche and as the axis of the ecological hypervolume . In this way, it
8556-567: Was the Permian-Triassic extinction event , 251 million years ago. Vertebrates took 30 million years to recover from this event. The most recent major mass extinction event, the Cretaceous–Paleogene extinction event , occurred 66 million years ago. This period has attracted more attention than others because it resulted in the extinction of the non-avian dinosaurs , which were represented by many lineages at
8649-425: Was the worst; vertebrate recovery took 30 million years. Human activities have led to an ongoing biodiversity loss and an accompanying loss of genetic diversity . This process is often referred to as Holocene extinction , or sixth mass extinction . For example, it was estimated in 2007 that up to 30% of all species will be extinct by 2050. Destroying habitats for farming is a key reason why biodiversity
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