A unified explanation for the morphology of raised peatlands

Abstract

Raised peatlands, or bogs, are gently mounded landforms that are composed entirely of organic matter^1-4 and store the most carbon per area of any terrestrial ecosystem⁵. The shapes of bogs are critically important because their domed morphology^4,6,7 accounts for much of the carbon that bogs store and determines how they will respond to interventions^8,9 to stop greenhouse gas emissions and fires after anthropogenic drainage^10-13. However, a general theory to infer the morphology of bogs is still lacking^4,6,7. Here we show that an equation based on the processes universal to bogs explains their morphology across biomes, from Alaska, through the tropics, to New Zealand. In contrast to earlier models of bog morphology that attempted to describe only long-term equilibrium shapes^4,6,7 and were, therefore, inapplicable to most bogs^14-16, our approach makes no such assumption and makes it possible to infer full shapes of bogs from a sample of elevations, such as a single elevation transect. Our findings provide a foundation for quantitative inference about the morphology, hydrology and carbon storage of bogs through Earth's history, as well as a basis for planning natural climate solutions by rewetting damaged bogs around the world.