Aboveground net primary productivity varies across topographic position (which affects microclimate and plant species distribution) and in a watershed could be inaccurately quantified if data are limited by inadequate sampling of topographic position. My objective was to create a spatially explicit aboveground C budget in a small forested temperate watershed using C stored in trees and leaf litter C flux. The average ANPP at the watershed was 550 gC m-2 yr-1; however, interpolated maps suggest that the ANPP could vary from 223 to 3410 gC m-2 yr-1 across the watershed. The hypothesis was that the spatial variability in aboveground C could be explained by tree genera and topographic characteristics such as aspect, elevation, and slope angle. Trees on the south aspect stored more average gC m-2 yr-1 than trees on the north, and more average gC m-2 was stored in aboveground biomass on planar surfaces than plots located in swales. Leaf litter C flux (gC m-2 yr-1) was not correlated with any topographical feature due to the immense variation of litter contribution across the watershed. In addition, the common method of using elevated litter traps to predict C donated to the soil from leaf litter at the trap location was assessed by comparing collected leaf litter C of the elevated litter traps to C accumulated in litter in surrounding floor plots. The elevated traps collected 40 percent more litter than the forest floor; overestimating C donated to the soil. Future studies should incorporate spatially explicit C budgets and consider using floor plots in addition to elevated litter traps to determine accurate C distribution.
Smith, Lauren A. (2013): Aboverground Carbon Distribution across a temperate watershed. Master of Science, Ecology, The Pennsylvania State University, p. 72.
This Paper/Book acknowledges NSF CZO grant support.
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