Responses of Soil Biological Properties of Betula Roots and Rhizosphere to Short-Term Temperature and CO2 Elevation in the Subalpine Zone

Abstract

Abstract: Responses of root biomass,microbe quantities,and enzyme activities in rhizospheric soil of Betula albo-sinensis with high and low densities (13.5 stems·m^-2 and 4.5 stems·m^-2,respectively) to elevated atmospheric CO₂ concentration (15.5±1.0 μmol·L^-1 enrichment) and/or temperature (2.4±0.4　℃ elevation) under the controlled conditions in situ which have been monitored in the subalpine forest zone of the western Sichuan Province.The primary results indicated that root biomass increased when atmospheric temperature and/or CO₂ was elevated under the high and low density.The quantities of bacteria and epiphyte under high and low density,and actinomycetes under low density treatments were promoted by temperature elevation,while quantities of bacteria and epiphytes increased just under high density when CO₂ was elevated.Pohyphenol oxidase activity was reduced significantly under temperature elevation in both density treatments.Catalase activity increased under CO₂elevation,whereas urease and pohyphenol oxidase decreased in both density treatments.Pohyphenol oxidase and catalase activities decreased under temperature and CO₂elevation (ETC) in high and low density treatments,while urease activities varied with plant density under both temperature and CO₂ elevation (ETC).

Key words: Subalpine forest soil, soil enzyme activity, elevated temperature, atmospheric CO₂ elevation, soil microbe

JIANG Shun-Yuan, SUN Hui, QIN Ji-Hong, WU Yang, YANG Wan-Qin, YANG Zhi-Rong. Responses of Soil Biological Properties of Betula Roots and Rhizosphere to Short-Term Temperature and CO2 Elevation in the Subalpine Zone[J]. journal6, 2008, 29(3): 91-96.

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