Biodiversity Loss

Intro——————–Climate Change——————–Biodiversity Loss

Biodiversity loss may not get as much attention as climate change, but it’s just as problematic. Biodiversity can be defined in a number of ways. Here, we’ll define it as the grouping of the genetic, species, and ecosystem diversities all into one. As we’ll see in this section, these 3 types of diversities are all interconnected and interdependent.

Genetic Diversity

Genetic diversity describes the total number of genetic variations that a species has in its gene pool. For an example of a genetic variation, think of the human gene that determines eye color, where variations can range from black to blue. Strong genetic diversity is driven by numerous different genetic variations that are ‘mixed’ together during reproduction. With greater gene pools, the odds that 2 mating individuals will have different genetic codes is higher. Strong genetic diversity within a species is closely related to their strength and ability to survive.  As a counterexample, think of 2 siblings that reproduce [whose genetic code is very similar], their children have a higher risk of being born with disabilities.

With more diverse individuals, the species will adapt better to their ever-evolving environment, making the species stronger as a whole.

Species Diversity

Species diversity is self-explanatory. A higher number of different animals and plants leads to greater species diversity. One easy way to show the importance of species diversity is with the food chain. We all know at least one example of the ‘ladder’ that features the ultimate predators [like a lion] at the top and the defenseless prey [like grass] at the bottom. Each species feeds on the ladder step below itself – but would not survive without it.

Strong species diversity implies that a predator will not have to depend on a single prey. Instead, the predator will have multiple options that can satisfy its diet. This way, when the population of one of the prey species lowers, the predator will predate more on the other sources of food due to the prey’s rareness [not a conscious choice, just statistical]. Contrarily, if a prey species’ population size increases, predators are more likely to feed on it. This provides balance within the ecosystem as it regulates and limits each species’ demography – ensuring that resources aren’t over-exploited by a single species. A balanced and diverse ecosystem is a strong ecosystem.

Where a weak ecosystem’s food chain is dependent on each ladder step, a strong ecosystem can be visualized as multiple ladders side-by-side. If a ladder step is weakened, you can always rely on the other steps next to it.

Ecosystem Diversity

Ecosystem diversity is extremely important as well and its effects are easier to visualize than for the previous two.

An ecosystem is a natural environment in which plants, animals, and their surroundings coexist in balance. Many different ecosystems exist around the world, and they all help regulate the Earth. Jungles, deserts, glaciers, savannahs, reefs, prairies, oceans, and many more all have unique characteristics that literally make the world a better place. Jungles and forests play essential roles in the water and carbon cycles. Deserts and glaciers may seem like uninhabitable wastes of space, but they help regulate the Earth’s energy balance with their reflectiveness. Oceans don’t reflect much, but they do help mitigate global warming by absorbing a quarter of our CO2 emissions every year.

Maintaining our diverse ecosystems around the globe is essential if we are to preserve our remaining natural environments and the life they contain, improve yields, limit global warming, mitigate the effects of climate change, and more. If it had to be summed up in a single sentence: biodiversity helps improve/preserve anything that involves the natural world – which we depend on heavily.

Threats

Biodiversity is beautiful and balanced – but fragile. 5 major causes of biodiversity loss are a direct result of human activity, following the acronym H.I.C.O.P.:

Habitat loss describes the physical deterioration or ‘shrinking’ of a species’ environment. Affected species are seeing huge declines in their population size, and many are forced to migrate quickly into other ecosystems all at once, significantly unbalancing it. This can cause invasive species.

Invasive species are characterized as such when a single species starts dominating an ecosystem. This considerably weakens ecosystems since it doesn’t allow species diversity or balance. They’re especially problematic when foreign species integrate a new environment and start outcompeting native species, as the native species are often crucial for ensuring ecosystem balance. Invasive species can occur naturally, but are often a consequence of human activity because of a rapid change in their environment.

Climate change describes the change in the climate. Since you’ve made it this far, we’re going to assume you know what we’re talking about. Climate change can seriously affect biodiversity, as it threatens species that depend on a stable climate pattern. The list of such species isn’t limited to polar bears and penguins – species all around the world have adapted to a very specific climate. An abrupt change in climatic conditions [like the one we’re seeing now] severely endangers most species, as they don’t have time to adapt to different living conditions in such a short amount of time. To maintain their climatic conditions, roughly half of species assessed globally have already shifted poleward and/or to higher elevations. Unfortunately, such migrations can introduce invasive species.

Overharvesting describes the excessive and destructive tendency we have to hunt species faster than they can procreate, or grow crops faster than soil can heal. It takes no expert to see that this leads to extinction of animal species and degradation of farmlands. This human characteristic isn’t new or unheard of. With examples ranging from the wooly mammoth to the dodo bird, humans haven’t always shown their long-term thinking capabilities. As species go extinct and soil fertility drops, biodiversity levels decrease and entire ecosystems weaken.

Pollution describes the contamination of any environment that results in nature degradation. Air, water, soil, and noise: these don’t describe The Last Airbender‘s 4 nations, these are all serious types of pollution. Toxicity present in the first 3 elements directly endangers species – especially those that live near sources of pollution. Often overlooked, noise pollution also impacts nearby species, since some of them rely on their hearing for survival and mating calls. It’s not just near cities either. Pollution can occur in remote parts of the world where biodiversity is strong, as shown by oil spills every so often. Pollution significantly weakens ecosystems, as species and their environment are damaged simultaneously.