Implications of floristic and environmental variation for carbon cycle dynamics in boreal forest ecosystems of central Canada
Article first published online: 24 FEB 2009
2002 IAVS - the International Association of Vegetation Science
Journal of Vegetation Science
Volume 13, Issue 3, pages 327–340, June 2002
How to Cite
Yu, Z., Apps, M. J. and Bhatti, J. S. (2002), Implications of floristic and environmental variation for carbon cycle dynamics in boreal forest ecosystems of central Canada. Journal of Vegetation Science, 13: 327–340. doi: 10.1111/j.1654-1103.2002.tb02057.x
- Issue published online: 24 FEB 2009
- Article first published online: 24 FEB 2009
- Received 16 February 2001; Revision received 1 March 2002; Accepted 4 April 2002.
- Carbon dynamics;
- Correspondence analysis;
- Forest succession;
Abstract. Species composition, detritus, and soil data from 97 boreal forest stands along a transect in central Canada were analysed using Correspondence Analysis to determine the dominant environmental/site variables that differentiate these forest stands. Picea mariana stands were densely clustered together on the understorey DCA plot, suggesting a consistent understorey species composition (feather mosses and Ericaceae), whereas Populus tremuloides stands had the most diverse understorey species composition (ca. 30 species, mostly shrubs and herbs). Pinus banksiana stands had several characteristic species of reindeer lichens (Cladina spp.), but saplings and Pinus seedlings were rare. Although climatic variables showed large variation along the transect, the CCA results indicated that site conditions are more important in determining species composition and differentiating the stand types. Forest floor characteristics (litter and humus layer, woody debris, and drainage) appear to be among the most important site variables. Stands of Picea had significantly higher average carbon (C) densities in the combined litter and humus layer (43530 kg-C.ha-1) than either Populus (25 500 kg-C.ha-1) or Pinus (19 400 kg-C.ha-1). The thick surface organic layer in lowland Picea stands plays an important role in regulating soil temperature and moisture, and organic-matter decomposition, which in turn affect the ecosystem C-dynamics. During forest succession after a stand-replacing disturbance (e.g. fires), tree biomass and surface organic layer thickness increase in all stand types as forests recover; however, woody biomass detritus first decreases and then increases after ca. 80 yr. Soil C densities show slight decrease with ages in Populus stands, but increase in other stand types. These results indicate the complex C-transfer processes among different components (tree biomass, detritus, forest floor, and soil) of boreal ecosystems at various stages of succession.