Yesterday, Saturday September 7, was California Biodiversity Day. That either means a lot to you or hardly anything at all. Biodiversity, or its long-form version “biological diversity,” is one of those indispensable terms for which there really is no useful synonym. It does not, however, have a spot in the roster of the most poetical expressions in the English language.
Here’s a definition: biological diversity is the amount of variety within a group of organisms on levels ranging from the very small-scale (genes) to larger (species) to even larger (ecosystems). The more differences there are among the living things in a forest, or a conference room, or a Petri dish, the more biologically diverse that place is.
I know. Still not an inspiring term. Looking to other languages isn’t much help: it’s “biodiversité” or ““biodiversidad” or биоразнообразия, pronounced “bioraznubraziya,” a straight literal translation with the Russian words for “bio” and “diversity” stapled together. German does, in addition to “Biodiversität,” offer the synonym “Artenvielfalt,” which means something close to “manifold species,” But that’s less precise and only a little more interesting.
It’s a bit ironic, because the pedestrian term “biological diversity” describes one of the most inspiring phenomena the universe has to offer. Somewhere between 3.6 and 4 billion years ago living things appeared on Earth. From that first group of living things all of us have descended. Redwood trees, sea stars, bubonic plague bacilli, hybrid tea roses, eels and members of the Republican National Committee, Beethoven and tube worms and ocelots and Komodo dragons: all literally related to each other by ties of common descent. (I was going to say “consanguinity” but some of our relatives are bloodless.) Life exuberantly reproduces generations with slight variation and those variations are sorted and remixed and sifted out, and after a mere few billion years our family has changed the planet’s atmosphere and built gigantic mountains out of limestone and split into millions of different subgroups, all different and diverging and entwining lines of descent from our single-celled common ancestor: Big Mama.
The biodiversity of a place is that place’s richness in the number of those lines of descent represented there.
Anyway. When I first heard the word it was in the middle-1980s, and I was drudging through a job watering office plants in Washington DC, and one of my clients was the DC office of the World Resources Institute, and one of the policy guys there had a poster on his door which was substantially similar to this:
… though it was advertising a conference rather than adorning the cover of a book. I admired the poster, the policy guy told me to take it, and it hung on my various walls for close to a decade afterward. Design-wise, the poster pretty much expressed the 1980s-90s vision of what biodiversity meant. Two examples of humid forest (the background and the vignette with the toucan and bromeliad), one even more humid biome (the seafloor-reef thing), and a seasonally brown grassland with a bison in the background. Classic rich ecosystems.
That younger, less desiccated version of me might have been a little surprised to learn that the term “biological diversity” was first used not to describe a coral reef or tropical hardwood forest, but a desert: the Arizona Upland portion of the Sonoran Desert near Tucson. One hundred and three years ago, University of Minnesota botanist J. Arthur Harris published an article in The Scientific Monthly in which he described the Sonoran Desert’s startlingly rich flora, saying close to the end of the piece:
The bare statement that the region contains a flora rich in genera and species and of diverse geographic origin or affinity is entirely inadequate as a description of its real biological diversity.
The concept of biodiversity may not have first occurred to biologists in the context of deserts, but the terminology apparently did.
Nonetheless, 1.03 centuries later, the notion that deserts have biological diversity worth noting is often regarded as counterintuitive, if not dismissed altogether. That’s likely due to a persistent gut assumption that biodiversity and biomass are the same thing. “The place is barren; how can there be more than four species there? Biodiversity is howler monkeys and orchids and vines and freshwater snails in Alabama. The desert is just a 100,000 square miles of kitty litter.”
California’s deserts make up 28 percent of the land area of the state. California’s deserts make up 38 percent of the known plant diversity of the state. A portion of California is known far and wide as a biodiversity hotspot. That portion is called the California Floristic Province, and it laps over into Oregon and Baja, with just a sliver of the Nevada side of Tahoe, as shown in the red overlay here:
You will perhaps have noticed that the California Floristic Province, declared one of 33 global “biodiversity hotspots” by Conservation International in 1996, excludes the state’s deserts. And yet those deserts host a disproportionate number of the state’s plant species, with expert desert botanists predicting that number will grow as about a hundred new species are discovered each century. There is an area in the Mojave National Preserve that has been called the center of shrub diversity in California, and California is nothing if not shrub-diverse. An acre of the Mojave Desert can have more species diversity than an acre of old-growth redwood forest.
Think of living things as books. The Redwood Forest Library has many times more books than the Mojave Desert library. But the Mojave Library has more single copies of rare books. There are not a few rare books in the Redwood Library as well, but most of the shelf space is taken up by thousands of copies of the same dozen books.
Desert mariposa lily, Calochortus kennedyi
I’ve been thinking about this this past week because pressure is once again building for industrial development in the deserts, which constitute the largest intact North American ecosystem south of the boreal tundra. I spent some of last week writing comments on a ludicrously large solar facility in southern Nevada that would obliterate excellent desert tortoise habitat with as many as 900 juvenile torts on it right now. There is once again a move to build a giant commercial airport in the Ivanpah Valley to serve Las Vegas. Gold mines are starting up again, and every month there’s a new suburb proposed for old-growth desert habitat somewhere.
And the Green New Deal, as good and overdue an idea as it is, is a huge potential threat to the desert and its biological diversity, not only because of utility-scale solar projects like the one I wrote comments on, but also due to new transmission lines and wind turbines in sensitive mountain habitats and the ongoing demand for rare earth metals for electronics and lithium for batteries.
We saw something like this a decade ago, and though we did not lose we lost far too much. The desert has an order of magnitude more defenders now than it did then. Random people are far more likely to grant that the desert has value beyond being a potential mine or landfill. We’ve done good work in the last decade.
We’re gonna have to keep at it, I guess is what I’m saying. The desert and its manifold species need more help than ever.
Mojave poppy bee, a candidate for Endangered Species Act protection. Zach Portman photo.