Net primary productivity and peat accumulation in Southeastern Manitoba
Reader, Richard Joel
Two functional attributes of an ecosystem, net primary production and subsequent dry matter accumulation, were examined in four peatland types (lagg, bog, muskeg, and bog forest) located in southeastern Manitoba. The simple equation "accumulation = income - loss" was expanded in a block diagram to define all potential sources of both income and loss. Annual "income" of litter in the four vegetation zones ranged from 489 to 1750 gm./m.2, which represented 69-90% of the calculated net primary production. "Loss" of dry matter through decomposition in the following year amounted to approximately one quarter of the litter value. Using radiocarbon-dated peat cores, an average annual accumulation rate of 26-51 gm./m.2/yr. was calculated, suggesting that less that ten percent of the annual net primary production will remain as peat. The four vegetation types examined were considered to represent seral stages in the process of secondary succession occurring in the study area. The direction of this succession was hypothesized to be Lagg -> Bog -> Muskeg -> Bog Forest.