Some ecological factors in secondary succession: upland hardwood. I. Evaporation studies in the Sycamore creek region
The central hardwood region has been divided by foresters into the "upland type" and the "bottom-land type." Tillotson (7). Under the upland type there is a subtype, "mixed hardwoods and conifers." The upland type includes the areas with higher, well-drained soils; the bottom-land type is characteristic of the moister, slower drained soils. From an ecological point of view, there are a number of natural vegetational groups which represent successional stages leading up to the widespread Beech-maple climax. The later stages in both the xerophytic and hydrophytic succession are dominated by certain tree species. The exact species of these groups and the relative duration of the successive stages are influenced, of course, by many factors, floristic, topographic, edaphic and climatic, variable over the region.