Carbon sequestration in intact rare ecosystems and their encroaching forests (Michigan, USA)

Rising atmospheric carbon dioxide levels are impacting global
temperatures, ecological systems, and human societies. Natural carbon
sequestration through the conservation of soil and native ecosystems may
slow or reduce the amount of CO2 in the atmosphere, and thus slow or
mitigate the rate of global warming. Most of the research investigating
carbon sequestration in natural systems occurs in forested ecosystems,
however rare ecosystems such as coastal plain marshes and wet-mesic sand
prairie collectively may serve as significant carbon sinks. Our objectives
were to measure and assess the importance of carbon sequestration in three
rare ecosystems (oak-pine barrens, coastal plain marsh, and wet-mesic sand
prairie) in western Lower Michigan. We measured carbon in standing
vegetation, dead organic matter, and soils within each ecosystem and
adjacent encroaching forested areas. Driven by tree carbon, total carbon
stocks in encroaching areas were greater than in intact rare ecosystems.
Soil organic carbon was greater in all intact ecosystems, though only
significantly so in coastal plain marsh.  Principal components
analysis explained 72% of the variation and revealed differences between
intact ecosystems and their encroaching areas. Linear models using the
ratio of red to green light reflectance successfully predicted SOC in
intact coastal plain marsh and wet-mesic sand prairie. Our results infer
the importance of these rare ecosystems in sequestering carbon in soils
and support the need to establish federal or state management practices
for the conservation of these systems.