降水变化对红松阔叶林土壤微生物生物量生长季动态的影响  

Effects of precipitation variation on growing seasonal dynamics of soil microbial biomass in broadleaved Korean pine mixed forest

作　　者：王宁[1] 王美菊[1] 李世兰[1] 王楠楠[1] 冯富娟[1] 韩士杰[2] 

机构地区：[1]东北林业大学,哈尔滨150040 [2]中国科学院沈阳应用生态研究所,沈阳110016

出　　处：《应用生态学报》2015年第5期1297-1305,共9页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(41105104);国家基础科学人才培养基金项目(201226A3)资助

摘　　要：红松阔叶林是中国东北山区地带性顶极植被,具有重要的生态学意义,长白山是研究温带森林对大气降水变化正负反馈的理想地带.本文以长白山原始红松阔叶林为对象,研究了土壤微生物生物量碳和氮对降水变化的响应.结果表明：在5—9月的生长季中,土壤微生物生物量碳和氮平均值分别为879.09和100.03 mg·kg-1,二者均随土壤深度增加呈下降趋势.随着降水量的增加,土壤微生物生物量碳、氮均增加,且0~5 cm表层土比5~10 cm表层土变化剧烈;土壤微生物生物量碳氮比随降水增加呈下降趋势.降水变化对土壤微生物生物量碳和氮的平均值影响显著,降水增加的影响更为突出.微生物生物量碳和氮在生长季内呈现出相似的变化规律,5月最低,之后先升高后降低再升高,出现1~2个波峰,但峰值大小和出现时间随降水量和土壤层次而变,0~5 cm土层的微生物生物量碳和氮的季节变化较大.微生物生物量碳、氮分别与土壤有机质和总氮含量呈显著正相关.不同降水条件下土壤理化性质的差异与土壤微生物生物量碳、氮的时空异质性紧密相关.降水变化可使土壤微生物群落结构与组成发生改变.Broadleaved Korean pine mixed forest is the zonal climax vegetation in Northeast China and it plays a significant role in maintaining the ecological security. Changbai Mountains is a suitable region to study the positive and negative feedback mechanisms of temperate forest for precipitation variation. This study analyzed responses of soil microbial biomass carbon（ SMBC） and microbial biomass nitrogen（ SMBN） to precipitation variation（ ± 30%） in original broadleaved Korean pine mixed forest of Changbai Mountains. The results showed that,during the growing seasons（ from May to September）,the averages of SMBC and SMBN were 879. 09 and 100. 03 mg·kg-1,respectively. Moreover,both of these two parameters gradually decreased with the soil depth. The contents of SMBC and SMBN all increased with the increasing precipitation,and the changes of SMBC and SMBN in the 0-5 cm soil layer were stronger than in the 5-10 cm soil layer. The value of SMBC / SMBN declined with the increase of precipitation. The precipitation variation significantly influenced the means of SMBC and SMBN. Compared with precipitation reduction,precipitation enhancement affected the indices much significantly. Both SMBC and SMBN showed similar seasonal patterns,which were the lowest in May,and after that,they increased and then decreased and increased again,showing 1-2 peaks in the growing season. However,the value and occurring time of the peaks varied with the precipitation and soil layer,and the seasonal variations of SMBC and SMBN in the 0-5 cm soil layer were higher than in the 5-10 cm soil layer. SMBC and SMBN had significant positive correlation with organic matter and total nitrogen content. The variances of soil physical and chemical properties caused by precipitation variation were closely related with the difference in spatial-temporal patterns of the soil microbial biomass in the forest. In conclusion,the precipitation variations could cause the change of the soil microbial community structure and composition.

关 键 词：土壤微生物生物量 季节动态 空间格局 降水变化 红松阔叶林 

分 类 号：S714.3[农业科学—林学]