Climate change and the expansion of resource extraction into northern peatland-dominated areas pose a threat to the terrestrial carbon stock and net carbon sequestration function of peatlands. Projecting and protecting the integrity of the peatland carbon stock requires an understanding of peatland vulnerability and the environmental conditions that can compromise resilience. To this end, peat depth may act as a potent metric to summarize peatland resilience. Shallow peatlands exhibit differences in key structural characteristics from their deeper counterparts, with higher bulk density, lower organic matter content, lower hydraulic conductivity, greater tree density and height, and lower microtopographic complexity. These structural differences influence the strength of ecohydrological feedback mechanisms, generally resulting in weaker regulatory mechanisms (negative feedbacks) and stronger destabilizing mechanisms (positive feedbacks). Ultimately, these differences in form and function result in systems that have a profound contrast in ecohydrological behaviour, exhibiting more frequent water table fluctuations, longer periods when the water table is above and below the optimum depth, and shorter periods where the surface soil water tension is in equilibrium with the water table. We hypothesize that this leads to greater decomposition, lower productivity, and thus a smaller net carbon sequestration. As a consequence, these shallow peatlands are disproportionately more vulnerable to disturbances, such as drought and wildfire. By creating an inventory of peat depth we can identify where vulnerable systems are located and prioritize their conservation.