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70-398: The region boasts high biodiversity , as the river forms a clear border zone between the northern and southern flora and fauna of Northern Europe . Agriculture and forestry have evolved as a result of changes in the steel and iron industries. More than 100 ‘Leader+ projects’ designed for sustainable development testify to the high dynamism of the region. The biosphere reserve benefits from

140-489: 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 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

210-475: A chapter to the river. She describes the formation of the Dalälven as a race between the rivers Storån and Fuluälven from their sources to the sea. During the race, these rivers receive help from many tributaries, but also encounter many obstacles (lakes to fill, hills to pierce, etc.), so that halfway through, upon recognizing each other's merits, they unite their efforts. Biodiversity Biodiversity

280-501: 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

350-517: 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

420-538: A deep valley and enters into a flat country, uniquely marked by some eskers . During the remaining 120 kilometres (75 mi) that it travels to the sea, the river, now called the Lower Dalälven ( Nedre Dalälven ), alternates between large bays ( fjärdar ) and rapids . This section is also characterized by regular flooding, sometimes over vast areas. The first rapids are those at Avesta, called Storfors and Lillfors ( big chute and little chute ), after which

490-455: 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

560-508: A highly participatory governance system as well as numerous partnerships with universities and research centres for environmental monitoring . The Dalälven is the southernmost of the big rivers of northern Sweden. It extends 541 kilometres (336 mi) between the mountains of Dalarna and the Baltic Sea , which makes it the second longest river in the country after the Göta älv . However,

630-460: 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

700-405: 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

770-590: 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

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840-979: 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. Uppsala County Uppsala County ( Swedish : Uppsala län )

910-547: Is a county or län on the eastern coast of Sweden , whose capital is the city of Uppsala . It borders the counties of Dalarna , Stockholm , Södermanland , Västmanland , Gävleborg , and the Baltic Sea . The northern parts of the province of Uppland encompasses Uppsala County. The main aim of the County Administrative Board is to fulfill the goals set in national politics by the Riksdag and

980-405: 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

1050-491: 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

1120-402: 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 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

1190-427: 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

1260-686: Is met by the Vanån , its principal tributary. Its course then becomes more sinuous, tracing broad loops. It then enters Gagnef Municipality where it joins Österdalälven. After the junction of the Österdalälven and Västerdalälven, the river heads east, passing Borlänge , Dalarna's largest city, then receiving the waters of the Lillälven, itself fed by the Faluån , a river which goes through Falun , Dalarna's second largest city. The river then continues to Avesta where it strongly changes character. It leaves

1330-458: 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 the lower bound of prokaryote diversity. Other estimates include: Since

1400-401: 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

1470-561: 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

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1540-479: 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 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

1610-405: 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

1680-513: 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, 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

1750-792: 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

1820-466: The Government , to coordinate the interests of the county, promote its development, establish regional goals and safeguard the due process of law in the handling of each case. The County Administrative Board is a Government Agency headed by a Governor. See List of Uppsala Governors . The County Council of Uppsala or Region Uppsala (previously Landstinget i Uppsala län ), which is appointed by

1890-713: 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

1960-461: 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

2030-504: 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

2100-417: 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

2170-748: The Görälven and Fuluälven. These rivers have their sources not far from each other in Älvdalen Municipality in the Scandinavian Mountains . Fuluälven heads south along the east face of the mountain Fulufjället , while the Görälven flanks Fulufjället to the west, crossing the frontier with Norway where it takes the name Ljøra . After the confluence this river continues south, passing Sälen and then Malung and forking east to arrive in Vansbro Municipality . At Vansbro , it

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2240-606: 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

2310-582: 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 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

2380-461: 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

2450-553: 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 the insects then everything is going to collapse." In 2020 the World Wildlife Foundation published

2520-540: 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

2590-529: The electorate of the county, is primarily responsible for health care and public transportation . The most recent county elections include: The table details all Riksdag election (general election) results of Uppsala County since the unicameral era began in 1970 . The blocs denote which party would support the Prime Minister or the lead opposition party towards the end of the elected parliament. The County of Uppsala inherited its coat of arms from

2660-512: 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

2730-481: The end of the last ice age partly resulted from overhunting. Biologists most often define biodiversity as 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

2800-451: 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

2870-428: 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

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2940-491: 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

3010-431: The ice sheet, 10,000 years ago. At that time, the Lower Dalälven was below sea level and was in the zone corresponding to today's Dalarna, which was the first area settled. The first settlers in the region settled the banks of the river and its tributaries, as well as the shore. They were hunter-gatherers. In the Lower Dalälven, which extended bit by bit, the eskers were the best sites for the first permanent settlements. It

3080-596: 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

3150-737: 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

3220-419: The largest lake in the entire catchment area, and the seventh largest in all of Sweden, with a surface area of 292 kilometres (181 mi). This lake is formed by the largest impact crater in western Europe, of a diameter of 75 kilometres (47 mi). The river leaves the lake at Leksand and continues south to its confluence with Västerdalälven. Västerdalälven is itself born of the confluence of two rivers,

3290-508: The logging stayed small-scale. Four major sawmill companies dominated the logging in River Dalälven: Korsnäs AB at Lake Runn ( Falun ), established in 1858; Kopparbergs och Hofors Sågverks Bolag at Lake Hosjön ( Falun ), which started in 1861 and bought its competitor Carlfors Sågverksbolag in 1874; Stora Kopparbergs Bergslags AB , which modernized its mill at the rapids of Domnarvet ( Borlänge ) in 1863; and

3360-625: The mill in Älvkarleby , which was replaced by Skutskär sawmill in 1870. Log driving in River Dalälven reached its peak in 1952, when about 30 million logs per year were driven. It ended in most of the river in 1970. However, in the river's lower reaches, the driving continued until 1971, with some final emptying of the stocks in 1972. In 1973 the whole river was closed for log driving, and in 1977 all logging installations along River Dalälven were decommissioned. In The Wonderful Adventures of Nils , Swedish author Selma Lagerlöf dedicates

3430-877: 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

3500-468: 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

3570-546: 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")

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3640-412: 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

3710-468: The rapids at Gysinge and then another great fjärd, Hedesundafjärden-Bramsöfjärden. The river passes through the rapids at Söderfors towards Untrafjärden, then by the rapids of Untra towards Marmafjärden, and then the rapids of Lanforsen. Finally, goes through its last rapids at Älvkarleby before rejoining the Baltic Sea. The first settlers in the region of the Dalälven arrived after the retreat of

3780-729: 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 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

3850-584: 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

3920-913: 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

3990-645: The river changes names several times, and only becomes the Dalälven at the confluence of the Västerdalälven ( West Dalälven ) and the Österdalälven ( East Dalälven ), which happens at Djurås . The principal of these two rivers, Österdalälven, begins where the Storån and Sörälven meet, near Idre . Both the Storån and Sörälven begin in Norway, but soon reach the northwest of Dalarna . After their confluence,

4060-577: The river enters into a series of narrow lakes (Idresjön, Alvrosfjorden, Kringelfjorden, Hedfjorden, Särnasjön, etc.). It then pools into the lake Trängsletsjön, 70 kilometres (43 mi) in length, formed by the Trängslet Dam . The river then arrives at Mora where it receives the waters of the Oreälven , one of its major tributaries and empties itself immediately after into the Lake Siljan ,

4130-472: The river forms the lake Bäsingen, then the rapids Näs bruk , then the lake Bysjön. It forms the frontier between Västmanland County to the south and Dalarna County to the north. It then forms the rapids at Tyttbo, and right after, one of its largest fjärds, that of Färnebofjärden National Park , forming the frontier between Uppsala County to the south and Gävleborg County to the north. More than 200 islands are strewn over this fjärd. The river continues to

4200-693: 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

4270-419: 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

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4340-773: 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

4410-630: 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

4480-652: 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 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

4550-436: Was easy to nourish oneself, thanks to the river, and these places were also the easiest to defend. Besides this, the river was easiest to cross at this point. When agriculture developed, the lands south of the basin proved most fertile, and so the rest of the basin was used principally for pasture. There were some fields surrounding the villages, but were not very fertile. The forests were used for pasturing animals and fodder

4620-507: 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 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

4690-562: Was harvested in the wetlands. Transhumance was adopted. In certain cites, the wetlands and lakes were partially drained to try to recover good-quality agricultural lands. Log driving in River Dalälven is documented from the 1600s onward. An important factor behind it was the 1607 prohibition from Charles IX of cutting wood closer than one Swedish mile from Falun Mine . However, until the Storskiftet land amalgamation reform and England's abolition of customs on wood products in 1849,

4760-483: 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

4830-401: 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

4900-567: 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

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