2.1 Study site
The watershed in this study, designated as Hill Forest Two (HF2), is
characterized as a 38-year-old mixed pine-hardwood stand located within
the Piedmont region of North Carolina (NC) (Figure 1). The catchment
drains the first-order streams in the large Flat River watershed at
North Carolina State University’s Hill Demonstration Forest in northern
Durham County, NC. HF2 is 12 hectares in size, and dominated by loblolly
pine (Pinus taeda), white oak (Quercus alba ), tulip poplar
(Liriodendron tulipifera) , sweetgum (Liquidambar
styraciflua), chestnut oak (Quercus prinus ), Virginia pine
(Pinus virginiana ), northern red oak (Quercus
rubra ), red maple (Acer rubrum) , American beech (Fagus
grandifolia ), pignut hickory (Carya glabra) , and mockernut
hickory (Carya tomentosa ). Upland soils are defined as
well-drained with a depth to the water table higher than two meters (m).
They tend to function in a similar drainage capacity in the growing
season (i.e., May-October) and non-growing season (i.e.,
November-April). The NC Geological Survey (1988) reported that the soil
substrate (Carolina Slate Belt, CSB) is comprised mostly of rocks formed
through volcanic activity and deposits. The total land surface in CSB
covers 9 % of NC and extends into the surrounding states of Virginia
and South Carolina (Cleland et al., 2007). The soil series is mainly
comprised of Tatum and Appling types. Additional soil and watershed
descriptive details can be found in Boggs et al. (2013, 2016).