退化草原碱蓬土壤微生物生物量的季节动态模型

SEASONAL DYNAMICS MODEL OF SUEDA GLAUCA SOIL MICROBIAL BIOMASS IN THE DEGENERATED GRASSLAND IN NORTHEASTERN CHINA

研究了东北退化草原土壤微生物生物量的季节变化 ,生态因子的季节变化以及生态因子对土壤微生物生物量的综合作用规律 .微生物生物量w和呼吸速率wt 的季节动态呈单峰上凸式曲线变化 ,8月份有明显的高峰值出现 ,其值为 :w/mgg-1=4.9,wt/mgg-1d-1=2 8.1.同时利用IRM模型研究了生态因子对土壤微生物生物量变化的综合作用规律 :Mt+△t=M t0[1+(0 .2 1rn-wt)△t],生态因子对土壤微生物生长的综合作用指数rn 在整个生长季节的变化范围为 :0 .0 2 73～ 0 .72 6 4,其中 7～ 8月份rn 较大 ,对微生物生长的限制作用较小 ,微生物生长较快 .5月、6月、9月和 10月rn 较小 ,对微生物生长的限制作用较大 ,微生物生长较慢 .图 2表 4参

The seasonal variation patterns of the microbial biomass and the ecological factors,and the integrated effects of the ecological factors on soil microbes in the degenerated grassland were studied. The seasonal dynamics of microbial biomass and respiration rate were found to vary seasonally by following a curve with peak values in August which were w /mg g -1 =4.9, w t /mg g -1 d -1 =28.1. In addition, the integrated effects of ecological factors on microbes were also studied with the IRM model: M t + △ t = M t 0 [1+(0.21 r n - w t )△ t ]. r n , the integrated action index of ecological factors on microbial biomass, ranged from 0.027 3 to 0.726 4. Higher values of r n occurred in July and August during which there were less inhibitory effects on microbial biomass, while lower values of r n occurred in May,June,September and October during which there were more inhibitory effects on microbial biomass. Fig 2, Tab 4, Ref 12