Description |
Spatial patterns in 13C/12C ratios of soil and sedimentary organic carbon are related to the woody cover distribution in a landscape and can aid in reconstructing environments. Woody cover is, in turn, controlled by climate, hydrology, and disturbance regime within an ecosystem. Geomorphology, disturbance, hydrology, and climate are the major factors that drive material fluxes and biogeochemical transformation in landscapes and should be accounted for when reconstructing past environments from soils and sediments. Disturbance, mainly from fire and other anthropogenic activities such as tree harvesting, offset climatic driven moisture availability by creating open woodlands and grasslands within a landscape. On the other hand, geomorphology and hydrology exert strong effects on floodplains with meandering river systems supporting higher woody cover than straight channels. In lakes, the water inflow and outflow dynamics, bathymetry, and watershed geomorphology influence the water balance, material fluxes, and consequently, the biogeochemical characteristics in the water column and sediments. We evaluate how we may reconstruct historic and prehistoric environments through geochemical proxies including stable isotopes and mineralogy, and biological proxies such as diatoms, charcoal, and palynology. |