If you’ve followed this blog for long, the term habitat heterogeneity won’t be unfamiliar. Neither will the phrase ‘shifting mosaic of habitat‘. I’ve spent a lot of words trying to describe the importance of both, as well as various tactics that can create them. Today’s post is dedicated to illustrating what habitat heterogeneity can look like by sharing some photos taken from within the last week across several hundred acres of grassland at our Platte River Prairies. Cody Miller, our preserve manager, is constantly looking for new management ideas to experiment with, and we still have a lot to learn, but we feel pretty good about the way the habitat looks right now.
All the photos below were taken mostly from within one management unit of about 425 acres. I’ve tried to represent the wide variety of habitat patch types currently available across that management unit. That habitat ranges from short/sparse to tall/dense vegetation, with lots of interesting variation in-between. For the most part, each of those habitat patches looks significantly different than it did a year ago, which is where the ‘shifting’ part of a ‘shifting mosaic’ comes into play.
Most of the heterogeneity seen across those 425 acres has been created with recent prescribed fire and grazing treatments. Some, though, has developed more slowly over time, through various restoration projects. Those projects include the conversion of cropland to prairie with diverse seed mixes of 180 or more species. They also include restoration of unplowed, but degraded prairie via overseeding of some missing plant species.
The creation and enhancement of plant diversity adds complexity to the habitat structure by through the architectural variety among plant species. A diverse plant community also helps ensure abundant food and other resources for pollinators, herbivores, predators, and other role players in the prairie. Even more importantly, it fosters ecological resilience, which will help keep all the ecological communities viable through droughts, floods, disease outbreaks, and other stresses. In return, a shifting mosaic of heterogeneous habitat supports diverse plant communities by making sure each plant gets a chance to thrive now and then, regardless of what kind of competitive environment it needs.
I’ve recently become enamored of tile spades as a way to help quantify habitat structure in a way that’s easy to see. In the three photos below, you can see the same spade stuck in the ground in different locations within a management unit. One herd of cattle has access to all three of the locations, but is grazing each of them very unevenly, resulting in heterogeneous habitat. Note how much of the spade’s blade is visible in each photo.
Again, we’re far from having everything figured out, and Cody and I are frequently talking about the numerous questions we want to answer next. Some of those questions require us to collect data to get answers, but for others we just need to try some new ideas and get a feel for how they work. These days, my job is to share ideas and experiences I’ve had, help measure the results of Cody’s management and restoration practices, and then work with Cody to incorporate what we learn into what he tries next. Not all our ideas work, of course, but I’m really happy with the way these prairies have changed over time and the direction in which they’re trending.