Forest soil CO2 efflux models improved by incorporating topographic controls on carbon content and sorption capacity of soils

摘要: Improved models are needed to predict the fate of carbon in forest soils under changing environmental conditions. Within a temperate sugar maple forest, soil CO2 efflux averaged 3.58 µmol m−2 s−1 but ranged from 0.02 25.35 s−1. Soil based on temperature and moisture explained approximately same amount variance gentle steep hillslopes (r2 = 0.506, p < 0.05 r2 0.470, respectively). When content sorption capacity were added models, explanation increased slightly hillslope 0.567, 0.05) substantially 0.803, 0.05). organic-rich surface mineral soil, was positively related negatively rates. There general patterns smaller pools lower upland positions than lowland wetland positions, likely result hydrological transport particulate dissolved substances downslope, leading higher positions. However, magnitude mitigated by layer soils, which correlated efflux. More accurate estimates must take into account topographic influences pool, factors that affect rates transformation, as well physicochemical determine fraction pool can be transformed.