Picture a grassland dominated by little bluestem and other grass species. One that has an abundance of wildflowers, including bird’s foot violet, goat’s rue, partridge pea, and numerous varieties of goldenrod, bushclover, and tickclover – among many others. This prairie is one of only a few remnant prairies remaining in an ecosystem that once covered large swaths of North America. Less than 1% of that ecosystem now remains in good condition, and most of its remnants are on sandy soils or steep slopes where farming and other human practices are difficult. Sound familiar? What if I told you this grassland ecosystem is found in places like North Carolina, Alabama, and Florida? Oh, and that when it’s in really good condition, it’s full of pine trees…
Longleaf pine woodland (grassland?) in North Carolina.
If you live in the Midwest or Great Plains regions of North America, you were likely picturing a nearby tallgrass or mixed-grass prairie as I was describing that grassland. Our prairies here sound, look, and function very much like the grasslands of the longleaf pine ecosystems in the southeastern United States. Both rely heavily on frequent fire to maintain the species and habitat structure their species rely on. The main difference is that longleaf pine grasslands have longleaf pine.
So if longleaf and midwestern prairies are so similar, why is there so little interaction between those of us working in the two ecosystem types? It’s a question that has bothered me for years. I’m not anywhere close to an expert on longleaf, having visited only twice during prescribed fire training courses. On the other hand, I felt very much at home while I was there. I recognized many of the plants – if not the species, at least the genus – and it wasn’t hard to imagine that I was walking through a midwestern oak savanna (with pine cones). Click HERE to see some photos of longleaf pine wildflowers.
Frequent fire is used to keep longleaf ecosystems in good condition. Mature longleaf pine trees are very resistant to fire, and the fire keeps woody species from becoming overly abundant in the understory.
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Deciduous trees and shrubs can quickly start to encroach in longleaf pine communities when fire frequency decreases.
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Young longleaf pines - not just older ones - are resistant to fire. When very young, longleaf pines spend several years in a "grass stage" in which the growing point is at the ground level. In the grass stage, the tree invests in root growth belowground and resembles a bunchgrass aboveground - protecting it from fires. The tree in this photo is in the "bottle brush" stage, a phase in between the grass stage and a more mature tree. During this stage, the tree is at its most vulnerable to fire - until it reaches a size that it can again withstand burning.
It seems crazy to me that we’re not consistently exchanging ideas and strategies between midwestern prairies and longleaf pine grasslands – especially because we’re both struggling with many of the same issues. Both systems become choked with brush and trees in the absence of frequent fire. Invasive species are a major issue. Perhaps most importantly, both midwestern prairie and longleaf pine are nearly gone, making restoration a critical need if the ecosystems are to survive. Restoration efforts involve both the rehabilitation of degraded remnant natural areas and the reconversion of farm land to native vegetation.
I’ve been part of a couple efforts to start information exchanges through The Nature Conservancy and through the Grassland Restoration Network. Both have mostly fizzled, but the little bit of exchange we managed only strengthened my conviction that we need to keep trying. From what I can tell, many midwestern prairie ecologists could learn a lot from the way longleaf ecologists focus on ecosystem function – especially fire – as a way to measure success and manipulate habitat. That heavy emphasis on restoring ecological process is very different from the more species composition-oriented thinking among many midwestern prairie ecologist. At the same time, I think many longleaf ecologists could gain from infusing their process-oriented approach with more emphasis on plant diversity and the insect and animal diversity associated with those plant species. In some ways, the differences between longleaf and tallgrass prairie thinking are similar to those between eastern and western prairie thinking within the Central U.S. (as discussed in an earlier post).
One specific opportunity I see is to provide longleaf ecologists better access to lessons learned from the long history of diverse prairie restoration efforts in the Midwest, in which hundreds of plant species are included in seed mixtures. Most efforts to convert farm fields to longleaf pine communities (with notable exceptions) focus mainly on establishing longleaf pines and grass – largely as a way to facilitate reintroduction of fire. Increasing the diversity of herbaceous plant species could have some big benefits ecologically, and shouldn’t slow down process of reintroducing fire. The extent to which midwestern techniques would transfer south is something we should be exploring together.
How do we build the connections? If I knew the answer, I wouldn’t be writing this post. However, I do think there are some important steps. One would be to ensure that longleaf pine ecologists are encouraged and invited to attend the meetings such as the biennial North American Prairie Conference. Getting us all in the same place to share ideas is absolutely the best way to exchange information. Better yet, maybe someone in Alabama or South Carolina can host an upcoming prairie conference so that Midwestern prairie folks are forced to come down and see for themselves the wonderful longleaf grasslands. Facilitating involvement from Midwestern prairie ecologists in existing longleaf conferences would also be valuable (to everyone).
In addition, I think organizations like The Nature Conservancy and others that span multiple states have a responsibility to lead the way in facilitating communication and collaboration. It’s certainly not easy. It’s hard enough to work between adjacent states, let alone regions. On the other hand, none of us have figured out all the challenges in grassland conservation, so we need all the help we can get. Working and experimenting in separate laboratories without sharing results is just silly.
If anyone sees an opportunity for building bridges between north and south on this issue, please let me know if I can help.
For more information about longleaf pine ecosystems, visit the Longleaf Alliance website.
The Prairie Ecologist 