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Biodiversity and Why it Matters

By Frank Schiavone

Habitat and species loss is a major challenge in Southern California. In fact, Southern California has been identified as one of eight “hot spots” worldwide where species loss is occurring at unprecedented rates. Many of the plant and animal communities here rank as some of the most threatened in the world. According to a nationwide survey of biologists by the American Museum of Natural History, “seven out of ten biologists believe that we are in the midst of a mass extinction of living things, and that this loss of species will pose a major threat to human existence in the next century.”

Unlike prior extinctions, this crisis is “mainly the result of human activity and not natural phenomena.” These scientists “rate biodiversity loss as a more serious environmental problem than the depletion of the ozone layer, global warming, or pollution and contamination.” Indeed, the vast majority of scientists polled believe that “during the next thirty years as many as one-fifth of all species alive today will become extinct, and one third think that as many as half of all species on the Earth will die out during that time.”

When we talk about extinction, most of us think of the Bengal tiger or panda. But these signature species are only a small part of the story. The overall numbers of species on the edge are daunting. Of the 40,168 species that the 10,000 scientists in the World Conservation Union have assessed, one in four mammals, one in eight birds, and one in three amphibians are at risk of extinction.

What is biodiversity and why should we care? Biodiversity is defined as the sum of an area’s genes (the building blocks of inheritance), species (organisms that can interbreed), and ecosystems (amalgamations of species in their geological and chemical landscapes). The richer an area’s biodiversity, the tougher its immune system, since biodiversity includes not only the number of species but also the number of individuals within that species, and all their inherent genetic variations - life’s only army against the “diseases of oblivion”.

The renowned E.O Wilson has called it “a fragile membrane of organisms wrapped around the Earth”. We owe everything to this membrane of life. Literally everything. The air we breathe. The food we eat. The materials of our homes, our clothes, and our medicines. Goods and services that we can’t even imagine we’ll need someday will come from species we have yet to identify. It is the fabric of life and existence itself.

Here in the West Valley, habitat and species loss is a real problem - a problem we are unfortunately unwilling to confront. The highly specialized plants and animals that are present here are recognized as globally imperiled.

Anyone who has ever planted a garden or a tree here knows that this is a pretty tough place to make a living if you are plant or animal. Harsh substrates, high winds, relentless heat, and prolonged periods of drought make life challenging to say the least. Common perceptions of scrub and chaparral plant communities are that they are barren wastelands devoid of any interest or robust animal life. Nothing can be further from the truth.

Our natural communities contain vast assemblages of highly adapted plants and animals (literally hundreds) arrayed in a complex, interlaced mosaic. These species use highly ingenious “life strategies” to survive the harsh conditions here. (Black-tailed jackrabbits, for example, can tolerate internal temperatures of 111 F.) Many species exist only here, on the fans of our mountains and foothills and in canyon washes or wash floodplains where alluvial soils have coalesced.

It is a mistake to think that critical gene pools exist only in coral reefs or rain forests. Our natural communities exhibit the species diversity of three primary ecoregions (coastal scrublands, forest, and desert). The coalescence of both mountain and canyon topsoils, including the seeds they carry, have created over millions of years a biological richness that simply cannot be duplicated.

Obviously, there are very few “large-bodied” animals as they are constrained by food and water. There are no vast herds or super-predators. But a Serengeti does exist here. It’s just comprised of scaled down inhabitants. The same struggle between prey and predator still occurs. The same biological rhythms still occur. The loss of a species, however small, still irrevocably changes the balance of the living system.

Today, we are witness to the sixth great extinction. It’s time to open not only our eyes but our hearts as well.

Copyright © 2008 Frank Schiavone