Tree Species Effects on Potential Production and Consumption of Carbon Dioxide, Methane, and Nitrous Oxide: The Siberian Afforestation Experiment
- 857 Downloads
Changes in tree species composition could affect how forests produce and consume greenhouse gases, because the soil microorganisms that carry out these biogeochemical transformations are often sensitive to plant characteristics. We examined the effects of thirty years of stand development under six tree species in Siberian forests (Scots pine, spruce, arolla pine, larch, aspen and birch) on potential rates of soil CO2 production, N2O-reduction and N2O production during denitrification, and CH4 oxidation. Because many of these activities relate to soil N turnover, we also measured net nitrification and N mineralization. Overall, the effects of tree species were more pronounced on N2O and CH4 fluxes than on CO2 production. Tree species altered substrate-induced respiration (SIR) and basal respiration, but the differences were not as large as those observed for N transformations. Tree species caused similar effects on denitrification potential, net N mineralization, and net nitrification, but effects on N2O reduction were idiosyncratic, resulting in a decoupling of N2O production and reduction. CH4 oxidation was affected by tree species, but these effects depended on soil moisture: increasing soil moisture enhanced CH4 oxidation under some tree species but decreased it under others. If global warming causes deciduous species to replace coniferous species, our results suggest that Siberian forests would support soil microbial communities with enhanced potential to consume CH4 but also to produce more N2O. Future predictions of CH4 uptake and N2O efflux in boreal and temperate forests need to consider changes in tree species composition together with changes in soil moisture regimes.
KeywordsTree Species Basal Respiration Tree Species Composition Denitrification Potential Soil Microbial Diversity
Unable to display preview. Download preview PDF.
- Adamsen A P S, King GM 1993 Methane consumption in temperate and subarctic forest soils: rates, vertical zonation, and responses to water and nitrogen. Appl. Environ. Microbiol. 56, 485–490.Google Scholar
- Binkley D 1994 The influence of tree species on forest soils: processes and patterns. In Proceedings of the Trees and Soil Workshop, Lincoln University, 28 February–2 March 1994. Eds. D.J. Mead and I.S. Cornforth. pp 1–33. Arg. Soc. New Zealand Spec. Pub. No.10. Lincoln University Press, Canterbury.Google Scholar
- Conrad R 1995 Soil microbial processes involved in production and consumption of atmospheric trace gases. In Advances in microbial ecology. Ed. J Gwynfryn Jones. pp.207–250. Plenum Press, New York, N.Y.Google Scholar
- FAO 1990 Soil map of the world, revised legend. FAO, Rome, Italy.Google Scholar
- Mikola M 1985 The effect of tree species on the biological properties of forest soil. Nat. Swed. Env. Protect. Board 3017, 1–29.Google Scholar
- Priha O, Grayston S J, Pennanen T and Smolander A 1999a Microbial activities related to C and N cycling and microbial community structure in the rhizospheres of Pinus sylvestris, Picea abies and Betula pendula seedlings in an organic and mineral soil. FEMS Microbiol. Ecology 30, 187–199.Google Scholar
- Wedin D A and Tilman D 1990 Species effects on nitrogen cycling: a test with perennial grasses. Oecologia 84, 433–441.Google Scholar