Oak Forest Restoration Versus Savanna Restoration:
Here’s an example of using an erroneous official vegetation label “Oak Forest” or “Oak Woodland” and even “Floodplain Forest”, instead of the more ecologically accurate concept “Savanna” for restoration target goals. What do we mean by the term forest, or the more nebulous term “woodlands”?
These two sites are within a few miles of one another, and occupy the same landform, a terminal moraine over well drained soils.
Picture 1 represent the starting point for both sites, that following the removal of keystone herbivores, experienced Terrestrial Eutrophication and Afforestation (TEA), a positive feedback loop that facilitates high nitrogen flows and increases in shade, that are eventually dominated by low quality shade tolerant nitrophilic species, which in turn causes a complete collapse in food webs, and the capacity to provision ecosystem services (soil building, carbon sequestration, water purification, biodiversity, recreational opportunities, etc.).
Pictures 2 and 4 show the Savanna target, 2 years after low quality woody removal, 80% canopy reduction, employing Species Integrity Indexes (SII, based on a species capacity to contribute to ecological integrity) to help inform woody harvest. The savanna target, with good graminoid growth, allows us, within 2 years, to burn, hay or graze, which allows us to regulate chemical (nutrient flows) to the benefit of native species and detriment of undesirable species.
Pictures 3 and 5, show the “Oak Forest” or “Oak Woodland” target goal, where we removed the so called invasive species (invasive species are better understood as symptomatic of TEA and the catastrophic loss of keystone processes, grazing and human induced fire to maximize grazing, and not as “invasive”). The result of the Oak Woodland target, is a temporary pause from non-native vegetation, but the intense shade and low quality native vegetation fueling high nitrogen flows, plus the lack of fuel loads for frequent-easy fire, and the lack of edible vegetation that upscales nutrients into complex-recalcitrant food webs, ensures the “oak forest” target being held in epidemic (Holling, 1959, 1973, 1986, et al. 1996a, 1996b, et al. 1996c, 2001, et al. 2002).
How much more time and money will we spend on erroneous vegetation targets, such as “Oak Forest“, “Oak Woodlands” and “Floodplain Forest“?
Let us move the science of ecological restoration forward by employing systems science.
Holling, C.S. 1959. The components of predation as revealed by a study of small mammal predation in the European pine sawfly. Canadian Entomologist 91:293-320.
Holling, C.S. 1973. Resilience and Stability of Ecological Systems. Annual Review of Ecology and Systematics, Vol. 4, 1-23.
Holling, C.S. 1986. The Resilience of Terrestrial Ecosystems: Local Surprise and Global Change. In: Sustainable Development of the Biosphere. Editors W.C. Clark, and R.E. Mann, 292-320. Cambridge University Press.
Holling, C.S., Meffe, G.K. 1996a. Command and Control and the Pathology of Natural Resource Management. Conservation Biology, Volume 10, Issue 2
Holling, C. S. (1996)b. Engineering resilience versus ecological resilience. Engineering within ecological constraints, . Ed. Schulze, P.C. National Academy of Engineering.31(1996), 32.
Holling, C. S., Peterson, G., Marples, P., Sendzimir, J., Redford, K., Gunderson, L., & Lambert, D. (1996)c. Self-organization in ecosystems: lumpy geometries, periodicities and morphologies. Global change and terrestrial ecosystems, 2, 346.
Holling, C.S. 2001. Understanding the complexity of economic, ecological, and social systems. Ecosystems (4) 390-405.
Holling, C.S., and L.H. Gunderson. 2002. Panarchy: Understanding Transformations in Human and Natural Systems. Island Press.