Temperature dependence of nitrogen mineralization and microbial status in O_H horizon of a temperate forest ecosystem

作     者：Ali Bagherzadeh Rainer Brumme Friedrich Beese 

作者机构：Department of AgricultureAzad University of MashhadEmamyeh Boulevard Institute of Soil Science and Forest NutritionGeorg-August-University of GoettingenBuesgenweg 237077 GoettingenGermany 

出 版 物：《Journal of Forestry Research》 (林业研究（英文版）)

年 卷 期：2008年第19卷第1期

页      面：37-43页

核心收录：

学科分类：09[农学] 0903[农学-农业资源与环境] 

基　　金：Institutfür Bodenkunde und Waldernhrung  Georg-August-Universitt  Gttingen Germany 

主　　题：beech spruce nitrogen mineralization forest floor temperature temperature sensitivity index (Q10) 

摘      要：It was hypothesized that increasing air and/or soil temperature would increase rates of microbial processes including litter decomposition and net N mineralization, resulting in greater sequestration of carbon and nitrogen in humus, and consequently development in OH horizon （humus horizon）. To quantify the effect of temperature on biochemical processes controlling the rate of OH layer development three adjacent forest floors under beech, Norway spruce and mixed species stands were investigated at Soiling forest, Germany by an incubation experiment of OH layer for three months. Comparing the fitted curves for temperature sensitivity of OH layers in relation to net N mineralization revealed positive correlation across all sites. For the whole data set of all stands, a Q10 （temperature sensitivity index） value of 2.35-2.44 dependent on the measured units was found to be adequate for describing the temperature dependency of net N mineralization at experimental site. Species-specific differences of substrate quality did not result in changes in biochemical properties of OH horizon of the forest floors. Temperature elevation increased net N mineralization without significant changes in microbial status in the range of I to 15℃. A low Cmic /Corg （microbial carbon/organic carbon） ratio at 20℃ indicated that the resource availability for decomposers has been restricted as reflected in significant decrease of microbial biomass.