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Overexploiting sea otters resulted in cascade effects which destroyed kelp forest ecosystems. Overexploitation of species can result in knock-on or cascade effects. This can particularly apply if, through overexploitation, a habitat loses its apex predator. Because of the loss of the top predator, a dramatic increase in their prey species can ...
Mass extinctions are characterized by the loss of at least 75% of species within a geologically short period of time (i.e., less than 2 million years). [18] [51] The Holocene extinction is also known as the "sixth extinction", as it is possibly the sixth mass extinction event, after the Ordovician–Silurian extinction events, the Late Devonian extinction, the Permian–Triassic extinction ...
Demographic drivers include the expanding human population; rate of population increase over time; spatial distribution of people in a given area (urban versus rural), ecosystem type, and country; and the combined effects of poverty, age, family planning, gender, and education status of people in certain areas. [16]
Planting trees in tropical climates with wet seasons has another advantage. In such a setting, trees grow more quickly (fixing more carbon) because they can grow year-round. Trees in tropical climates have, on average, larger, brighter, and more abundant leaves than non-tropical climates.
Regarding the effects of afforestation on long-term carbon stocks and carbon sequestration these decrease when trees are less than 5 years old and increase quickly thereafter. [86] This means trees from monoculture planting that do not survive never reach full potential for carbon sequestration to offset China's carbon output.
Biodiversity loss has bad effects on the functioning of ecosystems. This in turn affects humans, [ 45 ] because affected ecosystems can no longer provide the same quality of ecosystem services , such as crop pollination , cleaning air and water, decomposing waste, and providing forest products as well as areas for recreation and tourism .
[5] [6] 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. [7]
Paul Martin at Rampart Cave, home of the Shasta ground sloth in Grand Canyon, ca. 1975. Paul Schultz Martin (born in Allentown, Pennsylvania in 1928, died in Tucson, Arizona September 13, 2010) [1] [2] was an American geoscientist at the University of Arizona who developed the theory that the Pleistocene extinction of large mammals worldwide was caused by overhunting by humans. [3]