Surface vegetation patterning controls carbon accumulation in peatlands

Abstract

AbstractLocalized ecohydrological feedbacks have been proposed as important internal drivers of patterns and processes in terrestrial ecosystems. However, there is a significant gap between the prominence of theoretical models and the paucity of observations describing linkages between ecosystem structure and functioning. Here we report empirical evidence for strong interactions between surface vegetation patterning and long‐term carbon sequestration rates in four peat bogs in Patagonia on the basis of high‐resolution stratigraphic analyses. Peatland development across the study region was characterized by repeated switches between wet‐ and dry‐adapted plant communities, depicting changes between hollows (wet assemblages) and lawns (dry assemblages) that could represent past surface patterning. We found a site‐specific relationship between the frequency of the wet‐to‐dry cycles and carbon accumulation rates that followed a power function, with rapid vegetation shifts causing high peat accumulation rates. Our results show strong evidence for internal regulation of vegetation dynamics and peatland growth, implying that understanding peatland processes is a prerequisite for peat‐based paleoclimate reconstructions.