MNA’s mission includes studying Michigan’s natural history. While every visit to a sanctuary brings a chance of expanding your knowledge and appreciation of nature, MNA also seeks to support dedicated scientists who try to understand our world and its fascinating flora and fauna. When done in a way that is compatible with conservation, MNA encourages scientific research on sanctuaries.
This post is the second in a series of posts on research done in MNA sanctuaries. Emily Grman is a postdoctoral researcher in Dr. Lars Brudvig’s lab in the Department of Plant Biology at Michigan State University. She is interested in how species assemble into plant communities. To study Michigan prairie restorations, Lars and Emily teamed up with Tyler Bassett, a Ph.D. student also in the Plant Biology Department at MSU and at the Kellogg Biological Station. More information is available on Dr. Grman’s website.
Of the vast areas of tallgrass prairie that once flourished in the central United States, less than 1% remains. In Michigan, scattered patches of native prairie once intermingled with savanna and woodland communities, but nearly all have been converted to cropland or development. This massive habitat loss has threatened the persistence of prairie plant and animal species. Over the past few decades, conservationists have increasingly used prairie restoration as a tool to reverse habitat loss. Prairie restoration in Michigan frequently involves adding seed of native prairie species and returning fire to former agricultural land. These restoration efforts often produce communities with an abundance of native plant species that can provide habitat for prairie insects and animals, but these restored prairies don’t replicate remnant, untilled prairies. This is partly because we still don’t completely understand the complex ecological interactions that allow ecosystems to accumulate species as they recover from a disturbance or change through time. Clearly, though, this information is essential. We must understand how to reconstruct communities in order to successfully rebuild lost prairie ecosystems.
In my current research, I aim to understand how species assemble into a community. I am a postdoctoral researcher in Dr. Lars Brudvig’s lab in the Department of Plant Biology at Michigan State University. To study the assembly of plant communities in Michigan prairie restorations, Lars and I teamed up with Tyler Bassett, a Ph.D. student also in the Plant Biology Department at MSU and at the Kellogg Biological Station. In summer 2011, our research team collected data on the plant communities in five remnant prairies in southwest Michigan, including three MNA properties: the Betty and Ralph Campbell Memorial Plant Preserve at Helmer Brook, Prairie Ronde Savanna, and Sauk Indian Trail. We compared those data to 27 restored prairies throughout southwest Michigan, many on private lands.
We learned that restored prairies and remnant prairies in Michigan differ in important ways. Dominant C4 prairie bunchgrasses, such as big bluestem and indiangrass, were more abundant in restorations than in remnant prairies. We also found some prairie plant species in remnants that we never encountered in restorations, such as Pennsylvania sedge (Carex pensylvanica), veiny pea (Lathyrus venosus), and early goldenrod (Solidago juncea). Some of these differences may be due to the seed mixes used during restorations: none of those remnant prairie species were included in restoration seed mixes, and seed mixes often had high densities of C4 grasses. Even so, including rare prairie species in seed mixes did not guarantee that they would become part of the prairie community. Of the 65 different prairie species commonly included in seed mixes, more than 25% never established in our transects, and another 40% established less than half the time. Despite this, restored prairies had nearly as many species as the remnant prairies: we found 36 species in restorations (on average, per 10 m2 sampling area) and 41 species in remnants.
From this study, we learned that while prairie restoration can create diverse grasslands to provide habitat for many native species, restoration has not recreated the communities we see in rare prairie remnants that have never been tilled. Therefore we believe it is essential to continue to preserve the rare gems of remnant prairie habitat scattered throughout southwest Michigan.