Earth has seen the coming and going of many organisms in the last 4.5 billion years. While species loss is not new, the rate of extinction has increased dramatically over the decades. The loss of biodiversity suggests that Earth may be entering its next mass extinction. This has only exacerbated by a multitude of human activities, such as habitat encroachment and pollution. These disappearances of faunas and floras are not only losses of nature’s wonders, but also threats to humanity itself.
One of the biggest factors that contribute to biodiversity loss is shrinking living space. Habitat encroachment has been a result of both natural and human causes, the latter of which has played a greater role. Deforestation to meet consumer demands is devastating forest habitats that house about two-thirds of the world’s species. In 1996, about 86 percent of Canadian forests were harvested by clearcutting, of which less than half the trees cut were reseeded. Such unsustainable practices make clear results of species loss. As harvests are not followed by replantation, a net loss in counts directly reduces plant diversity and destroys natural habitats, where many species depend on for survival.
Increased farming has been another partaker of habitat loss. As large fields are occupied for crop production, more and more wildlife are displaced from their homes. In Prairie ecozones of southern Canada, only 13 percent of the short-grass and 19 percent of the mixed-grass prairies remain. These statistics illustrate how large-scale agriculture has impacted endemic species. When people exploit vast areas of fertile land, the severity of habit loss increases. Brazil is a good example of destructive forest-to-farmland conversions. In the past 30 years, approximately 17 percent of the Amazon rainforest, an area equivalent to that of France, has been altered for human consumption. The poor attempt of Brazil’s strive for a better economy is done with little concern for the environment. Its actions are at the consequence of a decreased carrying capacity for Brazilian species. According to study, destruction of tropical rainforests affects 74 percent of at-risk birds. As such, issues with habitat destruction are most prevalent in countries with rich lands and forestry dependent economies.
The introduction of non-native species also decreases biodiversity. Innovations in transport facilitated not only the easier migration of people, but also the spread of invasive organisms. In Australia, humans have brought in cane toads to control destructive beetles in Queensland’s sugarcane crops. Despite speculations, cane toads were not only insufficient in reducing beetle population, but also came to be pests that targeted indigenous species. The toad’s poison made it as harmful a prey as it was a predator. According to one study, cane toads also spiked competition as they ruined one-third of nest attempts by ground-nesting rainbow bee-eaters. Australia is known for its abundance in marsupials, but as invasive species spread, many endemic organisms are threatened. A similar situation is occurring within the Amazon rainforest. Introduction of non-native species, especially fish varieties, is a major concern to local populations. Reports from the 1990s verified reductions of native species by 50 percent, with the vanish of seven small fish species by 1992. As native organisms lack exposure to outside competition, many cannot match the efficiency of foreign invaders. In this way, local faunas become disadvantaged and less offsprings are likely to survive under flourishing competitor populations.