Top 6 Major Threats To Biodiversity

Climate change refers to the long term and irreversible change that occurs in the Earth’s climate. This increase in the temperature of the atmosphere has major effects on the environment such as the seasons, rising of the sea levels, and glacial retreats.

• The biodiversity of organisms are affected regarding their population, distribution, level of the ecosystem, and even the individuals’ morphology and function.
• Because of the increase in temperature, organisms have already adapted by expanding their ranges in latitudes. Because of this behavior, many species population have declined. Aside from this, many animals have exhibited changes in the timings of their physiological functions. These include the birds and insects migrating and mating earlier than usual, which then result in some failure in breeding and production of young.
• Regarding ecosystems, studies revealed that climate change has brought the expansion of many desert ecosystems and thus have effects on the function and services that the ecosystem can provide.

For humans, the rapidly increasing rate in climate change imposes great threats for human security as the natural resources are becoming more and more limited. At present, global warming and climate change already have irreversible impacts on biodiversity. And these effects, if not mitigated, can lead to more significant threats in the future.

Habitat loss refers to changes in the environment that result to the rendering of a specific habitat to be functionally valuable. The habitat can no longer accommodate and support the life of the organisms present, thereby declining their population.

• Habitat loss may either be caused by natural events like natural calamities and geological events or anthropogenic activities like deforestation and man-induced climate change.
• In the process of habitat degradation, the organisms that were once living in a particular area or region are displaced and are forced to relocate; thus resulting in biodiversity reduction.

Indeed, man-made efforts are the prime reasons for habitat loss. At present, the practice of clearing out ecosystems for agriculture conversion and industrial expansion continues to displace organisms of their natural habitat. Other activities include logging and mining.

Be it water, air, or land pollution, all forms of pollution appear to be a threat to all life forms on Earth. However, it plays a major threat to biodiversity when it comes to the nutrient loading of the elements nitrogen and phosphorus.

• In Europe, atmospheric nitrogen is the only pollutant that has not decreased in concentration since the implementation of legislation. Its mere presence poses huge challenges to the conservation measures intended to natural habitats and species living there.
• Furthermore, the presence of nitrogen compounds in water systems can cause eutrophication (excessive plant and algal growth).
• The presence and accumulation of phosphorus in water systems can alter the way food webs function. Excessive phosphorus, like nitrogen can result to the uncontrolled growth of planktonic algae; thus increasing organic matter deposition in the seabed.
• Another form of pollution that can damage and kill living organisms is acid rain. Acid rain, as its name suggests, is rain that is composed of harmful acids (i.e., nitric and sulfuric acid). This rain is usually a result of pollution coming from the excessive burning of fossil fuels.

Some types of pollution, like the depletion of the ozone layer, can be reversible. However, this shall only happen when humans stop or limit the use of various chemicals that contribute to its destruction.

An exotic or unnatural species can be any kind of organism that has been introduced to a foreign habitat. This introduction can cause major threats to the native species as they often become subjected to great competition for resources, disease, and predation. When these species have successfully colonized the area, they are already called “invasive” ones.

• Next to habitat loss, invasive species are ranked as the second biggest threat to biodiversity.
• The greatest threat that invasive species can bring is their capability to change an entire habitat. These species are highly adaptable and can easily dominate a certain area. Because many natural species survive only in a particular environment, they tend to be displaced, or worse, perish.
• Some places have very low possibilities for the invasion of species. Usually, these places include those with harsh environmental conditions like extreme temperatures and high salinity.

Invasive Species Examples

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  When the brown tree snake was introduced to Guam (an island in Pacific ocean), it wiped out 3/4th of the bird population by eating their eggs and young birds from the nests. This is one of the examples of invasive species by predation. Read more about this here.

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  As Hawaiian ducks and North American ducks share similar genetic composition, they mate each other to create a new breed of ducks. This causes of gradual reduction of Hawaiian ducks species. This is an example of invasive species by hybridization. Refer to this good article from University of California for more coverage on this.

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  In the early 1940s, North American beavers were introduced to grow the fur industry in Argentina. The result was very astounding. Beavers chewed down the native South American tree roots and trunks which wiped out about 40 million acres of pure forest area into plain lands. Refer here for further readings on this news.

Most exotic species are brought to a certain place to replace or add something to the vegetation. It is important to note that not all introduced species become invasive. Most of these attempts have become successful.

Overexploitation refers to the act of overharvesting species and natural resources at rates faster than they can actually sustain themselves in the wild. Because of this, species population is put into great risk of reduction.

• Overharvesting, overfishing, and overhunting are some examples of overexploitation.
• Additionally, some species of living organisms find it hard to reproduce when their number is too small.
• So as a population or ecosystem continues to suffer from low species diversity, the probability of getting wiped out completely when a natural disaster or other forces increases.

If the act of overexploitation continues, it can ultimately bring extinction to many species, even if they still exist in the wild.

Aside from the five aforementioned threats, there are still a lot of drivers that may either directly or indirectly contribute to the loss of biodiversity. One good example of this are the epidemics and infectious diseases of wildlife such as Ebola virus disease, infectious bursal disease, and flu. This phenomenon does not only affect wildlife but also human health as well.

• Aside from this, human-induced activities which include economic, technological and scientific, cultural, and demographic factors also have an impact on biodiversity. The desiccation of wetlands and soils owing to the excessive pumping of water tables oftentimes contributes to the death of organisms living in these environments.
• The overuse of natural parks and watershed as tourist destinations and recreational spots also threatens biodiversity due to the fact that humans cause too much noise and perturbations that disrupt the animals’ normal activities.