This post was written by Eric Chien, one of our Hubbard Fellows. Eric comes from Minnesota and brings great energy to our prairie stewardship work. He’s also very bright, and an engaging writer, as you’ll see in this and other posts.
The sky is my mountain. I recently heard Jeff Walk from Illinois Nature Conservancy articulate this notion of prairie geography. If westerners are defined by their mountains, those of us from the Midwest and Great Plains are defined by our skies. Prairies are open horizons. Even on the most heavily plowed landscapes, the ghosts of prairies loom as long as the land stretches toward an expansive sky.
Flat land compensates the viewer with tremendous skies.
All landscapes affect the prejudices about comfort and beauty of those born to them. I know someone who moved to Minnesota from the West for a job and was gone within the week, overcome by the flatness of the land. That might be a little dramatic, but I can understand the uneasiness. For me claustrophobia and paranoia rises in deeply wooded landscapes that lack the promise of a lake or field offering a glimpse beyond the trees. I think we all have that affinity for particular aesthetics to some degree, and because of that I think we can all empathize with the plight of prairie wildlife.
Unlike humans, most prairie wildlife lacks the flexibility to adapt to the uneasiness brought on by changes in their natal landscapes. Prairie chickens may be the most well known of the prairie wildlife terrorized when the land loses the sky, but they are almost certainly not the only ones. One needs only to watch the predatory efficacy of hawks and owls from their perches high atop the crowns of trees to understand why the development of tall vertical structure results in the extirpation of prairie species. There are more trees than ever closing off the sky, threatening to fundamentally alter the ecology, composition, and aesthetics of our prairies.
Historical records from the mid-late 1800’s in Nebraska’s Lower Platte River Valley (to the east of our Platte River Prairies) suggest trees occurred as widely scattered individuals and small clusters; a far cry from the ubiquitous shelterbelts and heavily wooded groves that cloak what almost certainly was formerly prairie. Trees and the changes they have already wrought and continue to promise are why most of our field season at the Platte River Prairies has played out to the whine of chainsaws.
The small row of trees on the horizon may seem insignificant, but the removal of those trees would visually reconnect three chunks of prairie; potentially having pronounced effects on grassland bird nesting occurrences and brood rearing success. Photo by Eric Chien.
I am haunted by trees. Back on June 8th, Katherine and I picked up chainsaws and walked into a grove of cottonwoods along a creek bottom. On September 23rd, another 10ft tall Siberian elm twirled to the ground. In between, we spent hundreds of more hours felling, bucking, and stacking trees. Always to the backdrop of more deep green tree lines on the near horizon; a reminder of how far trees have come, and how far prairie stewards have to go.
Katharine Hogan (Hubbard Fellow), technician Calla Olson, and I spent several days extracting a row of large twisting mulberry trees from between two stretches of fence. Photo by Eric Chien
Looking down the fence line of this tree removal project illustrates the process. Sawyers fell, limb, and buck trees, while a tractor follows behind and piles material into burn piles within the interior of the prairie. Photo by Eric Chien
The most time intensive portion of tree removal, and thus limiting factor, is the organization and removal of downed tree material. Left on the ground, mature trees rarely burn up well in prescribed fires, and the skeletons impede maneuvering within the area during future management actions. Photo by Eric Chien
Despite the specter of an advancing forest, I love tree cutting. I like to think of tree control on the prairie as the big game hunting version of plant management. Removing mature trees demands thorough planning, and constant attention to one’s surroundings. To date, I am not aware of an incidence of death by reed canary grass. Put that focus factor together with the fact that there are few prairie management activities with as immediately noticeable impact as the removal of dramatic woody encroachment, and it is a task ready made for those of us brain dead from spraying, and still cultivating patience for observing the effects of our work. Walking through a completed tree removal, or thinning, noting the full sunlight, and the unrestrained wind, gives me the same feeling as looking at a maturing prairie restoration. I think in many ways it is an equally profound change in the land; a taking back of the sky, and a return of a prairie.
Two Corrections:
1. I erroneously spelled Katharine’s name (the correct version is “Katharine” not “Katherine”)
2.While I wish I could take credit for the photo of myself moving brush with the tractor, it was in fact Katharine.
Apologies to my fellow Fellow.
Is climate change expected to product more trees or reduce their number? Or is human activity the overwhelming factor?
Not suggesting that human activity is not causing climate change I meant “planting trees” vs climate.
I am by no means up to date on all the research being done around changes in forest productivity and range in response to climate shifts, but I do know there is a large number of recent and ongoing research projects across the world exploring that very topic.
From what I have seen, I get the sense that the answer to whether climate changes taken as a whole will produce a significant net gain or loss in trees will be hard to predict given the differential changes experienced by each ecosystem (i.e. wetter in some places, drier in others). Some of that climatic change might drive loss or gain of trees, but many forests will likely largely experience significant shifts in species composition rather than loss of forest cover.
The increased availability of CO2 is a hypothesized driver for globally observed tree and shrub expansion into mesic grasslands, but the primacy of CO2 concentration in woody plant encroachment into grasslands is not clear (Archer et al. 2005). Without long-term ecological studies at scale controlling for the effects of land use change, altered fire regimes, as well as climatic changes, it will probably be hard to parse that apart enough to know how much tree encroachment is going to be a new reality under climate change, and how much tree cover we can control with management practices. I do get the sense that we are a long way from having the management capacity for reducing the number of trees to the point where we might be approaching that climate vs. land use history threshold.
This is just the little I know concerning the topic, but a great question, and one worth considering as we think about continued management.
A concern I have had about tree removal is the sequestered carbon that gets released. Is there any possibility the wood being removed could be utilized as a substitute for a non-renewable fossil fuel? I am sure the economics would not make sense unless the entire cost of using non-renewable fossil fuel was considered. What could be done to make the use of renewable fuels economically competitive to prevent carbon from getting released into the atmosphere without any of the energy being utilized?
I appreciate your thoughts, James. I, too, am trying to figure out how to handle this carbon stuff!
Fascinating!
How counterintuitive… “greenies” removing trees! I like the intro about big sky instead of mountains. Australia has lots of big sky (and few big mountains). We also have lost a lot of our grasslands, probably for all the same reasons as you have lost prairie.