Chewing Up Enviro-myths

I've laughed with frustration when, on the one hand, environmentalists say grazing is extremely damaging to the environment and must be banned on federal lands, and on the other, they call some century-old cattle ranch pegged for development a pristine ecosystem that must be saved.

Now the publication Conservation Biology has a study that's probably quite close to the truth: cattle are good for the environment.

Before the greenies amoung you actually turn green, take a moment to consider biological history. Before ranchers came to the west, there were large grazing animals all over the place -- buffalo, elk, and so forth. They interfaced with the land just as cows do.

They are no longer with us, and with their departure, an important aspect of natural ecosystem balancing disappeared. Cows replace this function quite efficiently:

Cattle grazing could help endangered species

There may be a surprise in store for environmentalists - removing cattle grazing could actually be damaging to the environment

There may be a surprise in store for environmentalits - removing cattle grazing could actually be damaging to the environment.

An article published in the latest issue of Conservation Biology finds that cattle grazing plays an important role in maintaining wetland habitat necessary for some endangered species. Removing cattle from grazing lands in the Central Valley of California could, inadvertently, degrade the vernal pool habitat of fairy shrimp and tiger salamanders.

Cattle grazing influences the rates of evaporation which work together with climate to determine the depth and duration of wetland flooding. Cattle have been grazing in the land for roughly 150 years and have become a naturalized part of the ecosystem.

"In practical terms, this means that grazing may help sustain the kinds of aquatic environments endangered fairy shrimps need to survive," author Christopher R. Pyke states.

The authors looked at 36 vernal pools on two different geologic formations on a 5000-ha ranch in eastern Sacramento County, California. Their experiments found that removal of grazing reduced the duration of wetland flooding by an average of 50 days per year.

Their simulations show that climate change could compound these impacts, potentially, leaving endangered fairy shrimp and tiger salamanders without enough time to mature before their temporary aquatic environments disappear.

"Consequently, land managers can play an important role in climate change impacts, i.e. they can exacerbate or ameliorate, the local impacts of global change," Pyke adds. Conservationists may find that grazing is not always a negative factor, and it presents real opportunities to adapt to climate variability and climate change.

The study is published in the October issue of Conservation Biology.