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| In this photo of a slope adjacent to a kettle bog, all the larger trees are oaks, while all the saplings and leaves in the foreground are red maple. |
From CW Dick Lab blog
by Christopher Dick, associate professor, ecology and evolutionary biology; associate curator and associate chair for museum collections, U-M Herbarium; director; E.S. George Reserve
Summary: Oak-dominated forests in the E.S. George Reserve and elsewhere in the eastern U.S. are being replaced by maples and other fire-sensitive trees. Oak forests may be a legacy of Native American fire practices that predate European settlement.
Two years ago a U-M team* established a Forest-GEO tree inventory plot in the E.S. George Reserve (see 2014 blog post; or listen to this NPR interview). Students and faculty mapped and measured all woody stems ≥1 cm diameter in 23 hectares of oak-hickory forest (the plot is the size of 46 football fields!). “Big Woods” plot includes > 45,000 stems from 41 tree and shrub species.
Oak-hickory is perhaps the most extensive deciduous forest type of eastern North America. In the Big Woods Plot the most common large trees are black oak (Quercus velutina) and white oak (Q. alba) with subdominant shagbark hickory (Carya ovata) and pignut hickory (C. glabra). These are drought-tolerant (xerophytic) species that do well on sandy glacial debris. Tree core studies indicate that the large oak cohort established ca. 150 years ago (J. Vandermeer, pers. com.).