in the same way as humans, biodiversity is just as important to the species of our planet as it is to us. When you add in the benefits that we reap from a diverse environment, it soon becomes apparent that maintaining a stable balance of healthy species and ecosystems is good for everyone.
How is biodiversity related to the health of our ecosystems?
From the perspective of the species themselves, having a wide range of associated species is important as they each rely on one another in order to survive. Every organism within a system has its own role and serves a vital function on a variety of levels, such as bees which act as pollinators for plants, certain species of mussels that use fish as their larval host, or simple predator/prey relationships like between pike and red swamp crayfish [1,2,3].
Remove any one of these species from the equation and the effects on ecosystems can be disastrous, in what is known as a trophic cascade .
Take for example, the classic case of the sea otter . As a predator, sea otters feed on sea urchins, keeping populations in check but when otter populations drop, the urchins proliferate. Urchins then consume huge amounts of kelp, wiping out vast swathes and removing habitat and food for a myriad other species, leaving little more than an underwater desert and the threat of extinction for kelp inhabitants.
Examples of ecosystem services dependent on biodiversity
Biodiversity is also key for the continued provision of ecosystems services it provides, which serve both humans and the systems themselves, although the term is largely used in relation to the benefits reaped by us .
The list of services ecosystems perform for us is extensive and includes:
- soil formation
- nutrient storage
- pollution breakdown
- recovery from unpredictable events
- the provision of biological resources such as medicine and food
- social benefits such as employment, research and recreation.
Why is biodiversity important to the existence of species?
Diversity is important for species in order to maintain resilience against unexpected events, such as sudden climate changes or natural disasters, like forest fires or floods . If a fire tears through a forest where only one species exists and is wiped out by the fire, the forest ecosystem is less likely to deal with this loss than if only one out of 20 species disappeared.
Although some ecosystems may be insensitive to species loss, due to variations in ecosystem types, or the presence of multiple species that perform a similar role, or due to their relative unimportance, or because of other abiotic factors, it is clear that higher numbers of species are needed to ensure stable provision of ecosystem services .
Genetic diversity of species increases resilience
Linked to the idea of resilience is that of genetic diversity, the variations within a species population that allow them to adapt on an individual basis over time, as beneficial genes are passed through generations.
A wider range of genetic diversity allows species to build resistances to diseases, as shown in studies on leaf-cutting ant colonies and fruit flies, and strengthens the possibility that at least some individuals will survive, and by making them less susceptible to inherited disorders [9.10,11].
In essence, any reduction of the diversity of life, whether by human hands or by natural causes, weakens the links that exist among species and habitats. Given the interconnected nature of ecosystems, where a change in one area can have far reaching effects elsewhere, it is therefore vital to maintain as great a variety of species as possible in order to ensure the continued healthy existence of the planet.