Wednesday, June 15, 2011

Prairie reconstruction alng the Platte River

Today I deviated from the plan.  Instead of looking at large-scale native prairies, I spent the morning with Chris Helzer looking at restored/reconstructed prairies on The Nature Conservancy property along the Platte River in Central Nebraska.  In my daily professional life back home, reconstructions are the norm.  That’s the bulk of what we do.  I’m here because Chris is doing some things very differently from the way we do them back in Wisconsin. 
The thing Chris is doing that’s most different from what we do is using grazing as a management tool.  Much as fire is intimately linked to grasslands, herbivory has also been an integral part of many grassland ecosystems.  Not many Americans don’t know the story of enormous herds of bison thundering across the Plains.  But I’ve heard conflicting opinions as to what extent bison influenced the prairies in the Midwest.  Regardless of what the historical role bison played, cows are a fact of life in much of the open lands of the west.  And Chris is using that to his advantage. 
The goal of his restorations is not to mimic or emulate historic prairies.  We don’t have enough information about what the prairies looked like or how they changed on seasonal or annual bases.  We do know that prairies were amazingly diverse and supported remarkable assemblages of plant and animal species.  The goal is to create as biologically diverse grasslands as possible in hopes of providing suitable habitat for as many animals as possible.  To successfully accomplish that we need to use all available tools possible.  Grazing is one of those tools.  Cows prefer some plant species to others, so some are favored while others get suppressed.  The number of cows used, when they’re allowed onto a field, the duration they’re in place, all have impacts on the end result, so cows be used to accomplish a number of specific objectives, with the end target of a more diverse prairie.  The results suggest that grazing is doing exactly that.
The second part of the story today was the relationship of, and interaction between, fire and grazing.  Like humans at a salad bar, cows select the freshest vegetation.  If given the choice between a field that is resprouting after a fire and one that is rank with decadent material, cows will choose the fresh leaves.  Chris and others have recognized that preference and are using it to focus cows’ effort.  It’s a fascinating idea that I could have listened to Chris describe for many more hours than we had available.  I was reminded, again, that prairies are complex ecosystems with many species and processes at work. 
Chris has a blog about his work (his obvious passion!) which he supplements with amazing photos he takes:http://prairieecologist.com/author/theprairieecologist/



A series of storms in the distance as the sun sets in Nebraska. 

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