Wildlife Conservation Society Canada & School of Environment and Sustainability, University of Saskatchewan Saskatoon,, Canada
An emerging hypothesis is that hydroclimatic shifts and anthropogenic-driven nitrogen deposition would lead to a shift in the dominant plant group in Sphagnum peatlands, triggering a transition from a carbon sink to a source. But Sphagnum-vascular plants interaction is complex and includes facilitative interactions that are crucial to the productivity of Sphagnum and carbon sequestration. Our conceptual review suggests that vegetation structure in Sphagnum peatlands is driven primarily by hydrology, rather than competition among plant functional groups. We propose a conceptual model that presents probable combinations of global change factors and their implications for carbon sequestration.