Biodiversity loss (depletion)

The most unique feature of Earth is the existence of life, and the most extraordinary feature of life is its diversity. Approximately 9 million types of plants, animals, protists, and fungi inhabit the Earth. Two decades ago, at the first Earth Summit, the vast majority of the world’s nations declared that human actions were dismantling the Earth Summit, the vast majority of the world’s nations declared that human actions were dismantling the Earth’s ecosystems, eliminating genes, species, and biological traits at an alarming rate. This observation led to the question of how such loss of biological diversity will alter the functioning of ecosystems and their ability to provide society with the goods and services needed to prosper (Cardinale, Duffy, Gonzalez , & Hooper, 2012).

Biodiversity is the variety in life, including variation among genes, species, and functional traits. It is often measured as: richness is a measure of the number of unique life forms; evenness is a measure of the equitability among life forms; and heterogeneity is the dissimilarity among life forms (Cardinale, Duffy, Gonzalez , & Hooper, 2012).

The main cause of the loss of biodiversity can be attributed to the influence of human beings on the world’s ecosystem, in fact human beings have deeply altered the environment, and have modified the territory, exploiting the species directly, for example by fishing and hunting, changing the biogeochemical cycles and transferring species from one area to another. The threats to biodiversity can be summarized in the following main points:

Altering and loss of the habitats: the transformation of the natural areas determines not only the loss of the vegetable species, but also a decrease in the animal species associated to them.

Introduction of exotic species and genetically modified organisms: species originating from a particular area, introduced into new natural environments can lead to different forms of imbalance in the ecological equilibrium

Pollution: human activity influences the natural environment producing negative, direct, or indirect, effects that alter the flow of energy, the chemical and physical constitution of the environment and abundance of the species

Climate change: heating of the Earth’s surface affects biodiversity because it endangers all the species that adapted to the cold due to the latitude (the Polar species) or the altitude (mountain species).

Overexploitation of resources: when the activities connected with capturing and harvesting (hunting, fishing, farming) a renewable natural resource in a particular area is excessively intense, the resource itself may become exhausted, for example, the case of sardines, herrings, cod, tuna, and many other species that man captures without leaving enough time for the organisms to reproduce (Energy & environment, 2017).

Fig. 1. Main causes of biodiversity loss, with examples of endangered species (IUCN, 2008)

Although there is no way to bring back the species that have already gone extinct, there are several important ways which are listed below, in which humans can slow biodiversity loss.

Protecting Areas: creating protected areas where human activity is limited is the best way to prevent deforestation and exploitation of organisms and the resources they need to survive.

Preventing Species Introductions: it is often much easier and less expensive to prevent a problem from developing in the first place than facing it, once it occurs. This is the case with invasive species, which can wreak havoc when introduced to ecosystems that aren’t prepared to deal with them

Informing/ Educating: education is a powerful tool, and the more people knowing about biodiversity loss, the more they will be prepared to help slow it down. Spreading the word about detrimental human effects on plants and animals can encourage people to change their ways and effect changes to preserve biodiversity.

Slowing Climate Change: climate change is the documented cause of several extinctions that we know about, and has likely caused hundreds of species to become extinct about which we may know. Any efforts as individuals, organizations, or governments, to slow current human- caused global warming is a step towards slowing biodiversity loss (Paleontological Reseach Institution, 2017).

Fig. 2. Map showing the remaining populations of indigenous species as a percentage of their original populations. Blue areas are within proposed safe limits, and red areas are beyond (Natural History Museum, 2016).

References

Cardinale, B., Duffy, J., Gonzalez , A., & Hooper, D. (2012). Biodiversity loss and its impact on humanity (Vol. 486). nature.

Energy & environment, e. s. (2017, 8 20). Causes of the loss of biodiversity, Retrieved 20/8/2017 from: http://www.eniscuola.net/en/argomento/biodiversity1/loss-of-biodiversity/causes-of-the-loss-of-biodiversity/

McKeever, C. (2016). Biodiversity loss breaching safe limits worldwide. Retrieved 20/8/2017 from: http://www.nhm.ac.uk/our-science/science-news/2016/july/biodiversity-breaching-safe-limits-worldwide.html

Paleontological Research Institution, Global Change Project. Retrieved 20/8/2017 from: http://www.priweb.org/globalchange/bioloss/bl_06.html

Figure. 1. Retrieved 20/8/2017 from: http://www.is.mendelu.cz/eknihovna/opory/zobraz_cast.pl?cast=57532

Figure. 2. Retrieved 20/8/2017 from: http://www.nhm.ac.uk/our-science/science-news/2016/july/biodiversity-breaching-safe-limits-worldwide.html