Here in the Plains I'm always thinking about grassland diversity, and how areas of my garden that are thicker and more varied seem to perform better on average (this from a casual observer with no scientific training). Of course, I often think about diversity because there's a corn field over there, one over there, and another right there. Monculture mecca.
A recent University of Minnesota study proves that a diverse plot of grassland species has 2.5 times the biomass of a single-species plot. This means more wildlife and a stronger environment--storing carbon, filtering water, providing food for wildlife, creating natural fertilizer, etc.
Most striking was that after a long period of time, if you take out one species, the plot's biomass decreases. After a while, the plants have become so dependent on one another--each having its own niche--that the greater whole suffers. Reminds me a little of humanity. So if we farmed smarter (non monoculture) we could actually produce more food on less land, thus reducing the need to clear cut forests and the last of the grasslands.
And here's an Ohio study that shows non native plants have an advantage over natives as climate change occurs. This year, flowers bloomed weeks earlier--for natives, that means before their insect pollinator partners emerged (synced up evolutionarily over thousands of years), which translates to no propagation of the next generation.
As a wildlife gardener working with native plants, I see a moral imperative growing season by season. This summer 2.5" of rain in nearly four months has vastly decreased insect life. The planet is changing. More droughts, longer droughts, more violent temp swings, colder winter spells--the more I touch the soil, the more I understand. If we value diversity in humans, why not in the environment? But then again, anyone different from us often gets chastised, shunned, murdered. It's no surprise then what our planet is turning into. If we love our children, we must instill within them the love of what sustains them.
"A change is required of us, a healing of the betrayed trust between humans and earth. Caretaking is the utmost spiritual and physical responsibility of our time, and perhaps that stewardship is finally our place in the web of life, our work, the solution to the mystery of what we are. There are already so many holes in the universe that will never again be filled, and each of them forces us to question why we are permitted such loss, such tearing away at the fabric of life, and how we will live with our planet in the future." -- Linda Hogan, Dwellings.