There are many wonderful aspects to the Savanna Project, but the best is the fact that it requires almost no work. We do not burn or spray, and for the most part invasive exotics are ignored until they are interfering with the growth of trees greater than two feet tall. We don't purchase any plants for the savanna, nor do we propagate beyond gathering seeds and tossing them here and there. In this area of adequate rainfall, sufficient seed banks, and seed rain plus animal-assisted dispersal, the do-nothing approach has been extremely successful in establishing the savanna.
Wikipedia defines a savanna as a "mixed woodland-grassland ecosystem characterized by the trees being sufficiently widely spaced so that the canopy does not close." Using this definition I will be able to call my neglected corn field a savanna for many years, as it will take time for the trees to grow sizeable enough to create a canopy. While the long term goal is a forest, the interim condition of mixed herbaceous annuals and perennials, shrubs, and young trees creates a desirable and productive landscape that is conducive to hiking, hunting, and bird watching, and is a living lesson in succession and other ecological principles. Ecologists might object to the use of the term, and call this gently sloping field an early stage of forest succession, but "savanna" has panache and I'll use it as long as I can.
Prior to white settlers arriving from the east, the present day savanna was a closed-canopy forest. In my imagination it consisted of oak, chestnut, beech, walnut, black cherry, hickory, American elm, tulip poplar, and ash, with some persimmon and wild plum scattered throughout, and very little undergrowth in the cool dim beneath the towering giants. While I can't know for sure exactly what grew on this roughly 10 acre plot in the past, there's a good chance many of the aforementioned trees lived here or nearby. With the exception of chestnut, elm, and ash, which have largely succumbed to disease or pest, these trees can be found all over the region, wherever regeneration has been allowed to occur. Brainy eco-nerds refer to these plant communities as Appalachian mixed mesophytic forest of the eastern broadleaf forest bio-region.
When I moved to the land 20 years ago, the site was a played-out corn field, leased to local farmers with little incentive to maintain fertility by manuring or rotating crops. Their goal was to collect government subsidies for growing corn. When they finally retired, the site was a barren expanse of clay devoid of even the toughest invasives. In those days I was perfecting my craft of do-nothing forest regeneration by rarely visiting the site. I was content to interfere with spots closer to my house such as the vegetable garden and orchard. The nearly total lack of soil organic matter and microbial activity in the field meant that years passed with very little change in the site. Eventually low growing pioneers began the process of soil regeneration; now golden rod and blackberry brambles dominate. Sycamores, silver maples, and box elders have begun to creep up from the riparian zone at the base of the slope. Tulip poplars and crabapples have popped up in the depressions where moisture and decaying plant matter collect. White pines and black cherry trees are spreading across the drier top of the slope, and pawpaws have sprung up by the dozens, concentrated in family groups across the entire expanse.
Now that the process of forest regeneration has started, the changes in the savanna seem rapid. Soil is no longer exposed but protected by plants, allowing organic matter to accumulate and rain to be intercepted, slowed, and retained. As trees increase their size, leaf fall has a greater impact, further protecting the ground surface and delivering nutrients mined by roots to the soil. This allows slightly more needy plants to take root. I was pleased to discover butterfly weed (Asclepias tuberosa) and steeplebush (Spiraea tomentosa) growing in the savanna this summer. These natives both sport showy blooms worthy of a cultivated garden, and this is the first time I've observed the latter anywhere ever, so you can imagine my delight at discovering it a short walk from my house.
Animal habitat has greatly improved as the savanna has matured. Rabbits have innumerable hiding places to bolt into when we disturb their nibbling of clover on the paths. Yellow shafted flickers are common, searching for ants on the ground, and flashing white rumps as they fly off. We watch hawks and pileated woodpeckers pass overhead, and disturb white tailed deer on a regular basis. Insects are everywhere, from the easily observable skippers and dragonflies, to the loud and invisible crickets and annual cicadas.
As regeneration gears up, trim tabs present themselves. Not the nautical hardware, but the small acts that create big changes in the future, as described by Buckminster Fuller. One of the easiest and most effective actions I can take is removal of Japanese honeysuckle from young trees. These flexible vines can reach heights of many feet, but only with the help of trees. Left to their own devices they are forced to crawl along the ground, searching for victims. Cutting the vines from saplings and removing the lower branches so the honeysuckle has fewer handholds releases the trees, allowing them to escape the clutches of the honeysuckle. As trunk diameter increases, it become more difficult for the vine to victimize a tree, and a bigger tree means less sun for the invader. Spending a few minutes snipping the vines means a big payoff down the road.
Attempting to eradicate the honeysuckle completely would be fighting a losing battle. The same could be said of the Miscanthus and autumn olive that dot the savanna. While I wish these invasives weren't here, I acknowledge that they provide ecosystem services in the absence of native grasses and shrubs. The maidengrass is creating a great deal of biomass; intercepting rain and preventing erosion; and providing valuable cover for wildlife. The olives do the same, while fixing nitrogen. Could native plants do better? Yes, and someday they will, but for now it's not efficacious to put effort into removal. My emergent forest plays the long game and so do I.
Other quick and easy jump starts on the savanna include manure and wood chip dumps, and brush piles. These spots of concentrated fertility will allow a wider variety of vegetation to take hold. That's the theory anyway, and I look forward to inspecting my piles next summer to see what's happening. For the most part, however, we interfere as little as possible. We've mowed meandering paths across the savanna, mainly for the convenience of humans, so we can easily access and observe the area. It's always so interesting and relaxing to stroll the paths that there is little incentive to do work. Was this the feeling of well-being what our ancestors experienced, walking tall across the savanna, pleased to be able to see such great distances in their relatively new upright stance? Whether the enjoyment comes from ancestral memory or the simple pleasure of watching growth and change doesn't matter: The savanna is a wonderful place and we will enjoy it while it lasts.
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