Aboveground net primary production along a bog-fen-marsh gradient in southern boreal Alberta, Canada

Abstract

:Total aboveground plant production in a bog, three rich fens and two marshes were determined via the multiple harvest and cranked wire techniques. These peatlands follow a gradient of increasing pH, water flow, and surface water nutrient concentrations from the bog to the rich fens to the eutrophic marshes. The net primary production (NPP) values were as follows: (i) bog, 390 g m-2 year-1, (ii) three rich fens (riverine sedge fen, lacustrine sedge fen, and floating sedge fen), 409 g m-2 year-1, 277 g m-2 year-1 and 356 g m-2 year-1, respectively, and (iii) one riverine and one lacustrine marsh, 323 g m-2 year-1 and 757 g m-2 year-1, respectively. Overall, the bog and the three fens had a similar NPP but they were significantly less productive than the marshes. Along this bog-fen-marsh gradient, moss and shrub production decreased and herb production increased. Herb and moss production exhibited a greater variation between years than among sites within each year. Shrub production remained similar during both years of this study. A significant tree stratum was only present in the bog. Generally, NPP was greater in 1994 than in 1993. Comparisons with other NPP data from bogs, fens, and marshes throughout North America showed that the results of this study complement a latitudinal gradient of NPP for bogs. The latitudinal gradient for NPP in fens and marshes is less pronounced.