兴安落叶松林土壤微生物生物量季节动态及影响因素

应用氯仿熏蒸浸提法测定了大兴安岭塔河地区兴安落叶松林(Larix gmelinii Rupr.)土壤微生物生物量碳(Cm)和微生物量氮(Nm)的季节动态变化,并研究了其与土壤养分因子和土壤环境因子的关系。结果表明:兴安落叶松林的Cm的变化范围为70.02～1 065.38 mg.kg-1,其Nm的变化范围依次为:15.63～75.18 mg.kg-1。Cm和Nm基本于5—6月呈上升趋势、6—8月呈下降趋势,9月又达到一个最大值,之后开始下降,其中出现1～2个峰值的季节变化格局。Pearson相关分析表明,Cm与Nm呈显著相关(P<0.05),Cm与土壤温度(TS)呈显著负相关(P<0.05),Cm与土壤有机碳(CS,O)和土壤全氮(NT)呈极显著正相关(P<0.01)。Nm与土壤有机碳(CS,O)和土壤全氮(NT)呈极显著正相关(P<0.01)。

Soil Microbial Biomass Dynamics and Influence Factors in Larix gmelinii Forest in Daxing' an Mountains

The seasonal dynamics of soil microbial biomass carbon and nitrogen in a Larix gmelinii forest in Tahe Forestry Bureau of Daxing’an Mountains were studied by using the chloroform fumigation extraction method.The relationships between soil microbial biomass dynamics and environmental factors were also analyzed.Results showed that the microbial biomass carbon ranged from 70.02 to 1 065.38 mg·kg-1,and the microbial biomass nitrogen from 15.63 to 75.18 mg·kg-1 in larch forest.The microbial biomass carbon and nitrogen basically showed an upward trend from May to June and a downward trend from June to August,and reached the maximum value in September,then began to decline,which exhibited a seasonal variation pattern with 1-2 peaks.Pearson correlation analysis indicated that the microbial biomass carbon was significantly correlated with microbial biomass nitrogen(P<0.05).The microbial biomass carbon was negatively correlated with soil temperature(P<0.05),and positively correlated with soil organic content and soil total nitrogen(P<0.01).The microbial biomass nitrogen was positively correlated with soil organic content and soil total nitrogen(P<0.01).