Which affects biodiversity loss the most

Share this page:. What is biodiversity? Find out facts and figures about endangered species in Europe Why is biodiversity important? Main reasons for biodiversity loss. Changes in land use e. Direct exploitation such as hunting and over-fishing. Climate change. Invasive alien species. What measures does the Parliament propose? Find out more. Invasive species cause competition for native species.

Four hundred of the endangered species under the Endangered Species Act are at risk due to this competition. Global decline in amphibian species : This Limosa Harlequin Frog Atelopus limosus , an endangered species from Panama, died from a fungal disease called chytridiomycosis. The red lesions are symptomatic of the disease. Lakes and islands are particularly vulnerable to extinction threats from introduced species.

In Lake Victoria, as mentioned earlier, the intentional introduction of the Nile perch was largely responsible for the extinction of about species of cichlids. The accidental introduction of the brown tree snake via aircraft from the Solomon Islands to Guam in has led to the extinction of three species of birds and three to five species of reptiles endemic to the island.

Several other species are still threatened. The brown tree snake is adept at exploiting human transportation as a means to migrate; one was even found on an aircraft arriving in Corpus Christi, Texas.

Constant vigilance on the part of airport, military, and commercial aircraft personnel is required to prevent the snake from moving from Guam to other islands in the Pacific, especially Hawaii. Islands do not make up a large area of land on the globe, but they do contain a disproportionate number of endemic species because of their isolation from mainland ancestors.

It now appears that the global decline in amphibian species recognized in the s is, in some part, caused by the fungus Batrachochytrium dendrobatidis , which causes the disease chytridiomycosis. There is evidence that the fungus, native to Africa, may have been spread throughout the world by transport of a commonly-used laboratory and pet species: the African clawed toad Xenopus laevis.

It may well be that biologists themselves are responsible for spreading this disease worldwide. The North American bullfrog, Rana catesbeiana , which has also been widely introduced as a food animal, but which easily escapes captivity, survives most infections of Batrachochytriumdendrobatidis and can act as a reservoir for the disease.

The global warming trend is recognized as a major biodiversity threat, especially when combined with other threats such as habitat loss. Climate change, specifically, the anthropogenic caused by humans warming trend presently underway, is recognized as a major extinction threat, particularly when combined with other threats such as habitat loss.

Scientists disagree about the probable magnitude of the effects, with extinction rate estimates ranging from 15 percent to 40 percent of species by Scientists do agree, however, that climate change will alter regional climates, including rainfall and snowfall patterns, making habitats less hospitable to the species living in them. Grizzly-polar bear hybrid : Since , grizzly bears Ursus arctos horribilis have been spotted farther north than their historic range, a possible consequence of climate change.

As a result, grizzly bear habitat now overlaps polar bear Ursus maritimus habitat. The two kinds of bears, which are capable of mating and producing viable offspring, are considered separate species as historically they lived in different habitats and never met. However, in a hunter shot a wild grizzly-polar bear hybrid known as a grolar bear, the first wild hybrid ever found. The warming trend will shift colder climates toward the north and south poles, forcing species to move with their adapted climate norms while facing habitat gaps along the way.

The shifting ranges will impose new competitive regimes on species as they find themselves in contact with other species not present in their historic range.

One such unexpected species contact is between polar bears and grizzly bears. Previously, these two species had separate ranges. Now, with their ranges are overlapping, there are documented cases of these two species mating and producing viable offspring. Many contemporary mismatches to shifts in resource availability and timing have recently been documented.

Range shifts are already being observed. The same study suggests that the optimal shift based on warming trends was double that distance, suggesting that the populations are not moving quickly enough. Range shifts have also been observed in plants, butterflies, other insects, freshwater fishes, reptiles, and mammals.

Climate gradients will also move up mountains, eventually crowding species higher in altitude and eliminating the habitat for those species adapted to the highest elevations.

Some climates will completely disappear. The rate of warming appears to be accelerated in the arctic, which is recognized as a serious threat to polar bear populations that require sea ice to hunt seals during the winter months; seals are the only source of protein available to polar bears.

A trend to decreasing sea ice coverage has occurred since observations began in the mid-twentieth century. The rate of decline observed in recent years is far greater than previously predicted by climate models.

Finally, global warming will raise ocean levels due to glacial melt and the greater volume of warmer water. Sara Contu. Human activities are causing major changes in biological communities worldwide. These changes can harm biodiversity and ecosystem function. Ecosystem function is important for supporting plant and animal communities, and ensuring the long-term survival of human populations. However, species do not all respond equally to these threats. Declines in species often reflect the relationships between species and ecological patterns.

There is an urgent need to model the response of biodiversity on the intensity of human activity and the species' ecological attributes. By fully understanding how species respond to human activities we can make projections that inform policy.

PREDICTS is a collaborative project that uses approaches similar to a meta-analyses to investigate how local biodiversity typically responds to human pressures, such as land-use change, pollution, invasive species and infrastructure. For example, a population cannot recover more quickly than the time needed to give birth to a new generation, and recovery will often take several generations.

Moreover, human institutions are often slow to reach decision and to implement them. In addition, none of the drivers appears to be slowing or well controlled and we have not yet seen all of the consequences of changes that occurred in the past.

The extinction of species due to habitat loss has a significant lag time. For some species this process can be rapid, but for other sit may take to 10 years.

Time lags between habitat reduction and extinction provide an opportunity for humans to restore habitats and rescue species from extinction. Notwithstanding this, habitat restoration measures will not be likely to save the most sensitive species, which will become extinct soon after habitat loss. This summary is free and ad-free, as is all of our content.

You can help us remain free and independant as well as to develop new ways to communicate science by becoming a Patron! Previous Question. Next Question. What factors lead to biodiversity loss? Overexploitation and interactions between drivers. Five major indirect drivers that influence biodiversity are: Change in Economic activity: Global economic activity is now nearly seven times what it was 50 years ago and it is expected to grow further.

The many processes of globalization have been removing regional barriers, weakening national connections, and increasing the interdependence among people and between nations.

Population change: World population has doubled in the past forty years, reaching 6 billion in The fact that more and more people live in cities increases the demand for food and energy and thereby pressures on ecosystems.

Socio-Political factors: The trend toward democratic institutions over the past 50 years has enabled new forms of management of environmental resources.