Biodiversity is a household word these days, as reports of climate change become more frequent and endangered species lists grow. What exactly makes biodiversity so important? Why can’t we get by without it? What does nature provide that we can’t emulate?
Worth to humans
Animals and plants serve a role in human societies by promoting rest and relaxation, providing spaces for recreation, serving as a framework for discussions and education about the environment, and providing the food, clothing, and shelter that we need to survive. Further, a large proportion of the pharmaceuticals that we depend on are derived from compounds naturally synthesized by organisms for one purpose or another. Aspirin, morphine, and quinine are three of the major drugs that nature has given to us, and, given that we know of and have catalogued almost 2 million organisms but expect that there are at the very least just as many we don’t know about, there surely are many more potential cures waiting to be discovered.
Though ecosystems might appear straightforward to us, they rarely are. A case in point is the roots of plants… while it might appear that they are simply taps to pull water and nutrients out of the ground, they rely on microorganisms to break down those nutrients to the point that they can ingest and utilize them for their own needs and worms to help counteract the natural tendency of soil to compactify over time. Every species occupies its own ecological niche, some of which we’re aware of, and some of which we’re not, and some, like these organisms, are the only niche in their ecosystem. (Also keep in mind that, in a closed system, mass has to be recycled in order for life to exist.) Some common roles are scavenger, producer, and detritovore, and these roles recur in (most) every ecosystem we’ve observed, though the particulars of how these functions are accomplished may change.
Of course, the picture is a little more complicated than that, as each organism in an ecosystem has others that it affects- by preying on it, by being preyed upon, by helping, by suppressing- and the relative balance you may see when observing a site is underlain by the amount of time and number/degree of interactions that it took to reach an “equilibrium state”. This interreliance is such that it is often difficult to say what the effects of a species leaving (through extinction or migration) an ecosystem or entering it (via migration or introduction) will be, and the degradation of the abiotic (non-living) environment as well as the conditions of and links between species add to the stress a given organism is undergoing.