As a city dweller driving across the vast expanse of Montana last year, I was struck by the sight of innumerable large rolls of hay lying scattered across the tilled prairies. The prairies of Montana are part of the Great Plains of North America, which cover a large part of central and eastern parts of the state. Being extremely productive ecosystems harboring some of the richest soil on the planet, these grasslands have largely been converted to human agricultural use. This conversion is a useful example of an important ecological principle.
The Great Plains of North America were once home to an estimated 20 to 30 million bison. Slaughtered by the millions, these ecosystem engineers were nearly driven to extinction. The grazing action, migratory routes, and other behavioral characteristics of bison were critical to the maintenance of mixed-grass prairies of Montana and other parts of the Great Plains.
While intact, these prairies could support a wide diversity of species, all ultimately sustained by the grasses growing abundantly there. The energy stored in the grass by photosynthesis flowed through complex networks of animal species, supporting diverse food webs. Once humans tilled the land and converted it to their own personal use, the energy in the plants was no longer available to those species that had once lived there. The result was an enormous decrease in biodiversity, which is the variety of living things found living and interacting in any given ecosystem.
While we might wonder how the biodiversity of a prairie in Montana makes any difference to us, it is through the interactions of all the various organism found in any ecosystem that these systems are able to provide the services on which our own lives depend, but which we generally take for granted.
Every moment of our lives we rely on clean air and water, among very many other resources and services that are provided for free by the actions of ecosystems around the world. When ecosystems are disrupted by the processes that destroy biodiversity, their ability to supply resources and services is diminished, which ultimately impacts all life on Earth.
So, as in the example of the disappearance of the complex ecosystem found on intact Montana prairie, conversion of intact ecosystems to simplified systems dedicated to human use results in the loss of important resources and services to all life on Earth, even human beings.
Biodiversity is the glue that holds ecosystems together. We must protect it.
This photo was taken with a Canon EF100-400 mm f/4.5 – 5.6L lens zoomed to 100 mm on a Canon EOS 5D Mk. III. The exposure was set to 1/125 sec at f/8.0 and ISO 400.