【摘要】 在毛乌素沙地开发整治研究中心北试实验地选取了七块样地,并依据建群植被外貌特征划分为臭柏群落、臭柏灌丛、油蒿群落三类。用根钻对各样地一个生长季内的根系进行了五次取样,同时测量土壤水分、枝条生长长度、温湿度等一些气象因子。对活细根分级并称干重,发现臭柏、油蒿不同径级细根的季节动态不同,不同土层内相同径级的细根生产动态也不相同:①臭柏与油蒿D≤2 mm的细根生物量在4~5月份都有一个快速增长的阶段,随后增长格局各不相同。②臭柏灌丛中,1 mm<D≤2 mm的细根在5月和8月有两个峰值,油蒿群落在6月和10月出现两个峰值,臭柏群落变化比较平缓。③相关分析结果显示:臭柏群落细根生物量动态与0~15 cm土壤含水率和空气相对湿度相关性显著,臭柏灌丛细根生物量与空气相对湿度相关显著,油蒿群落与气象因子和土壤水分以及地面枝条生长量相关性不显著。活细根的季节动态可以反映整个生长季中,地下部分的代谢状态,也为我们评价群落健康状况、演替阶段、研究细根周转提供参考。更多还原

【Abstract】 7sampling sites on the north of Developing and Managing Research Center in Mu Us Sandland were chosen.The sites were classified into three types which named as Sabina vulgariscommunity,Sabina vulgariscluster and the Artemisia ordosicacommunity according to the physiognomy of constructive species’.Soil coring method was used to obtain the roots randomly,sampling five times in a growth seasonl,and the soil water content,branch growing length and some climate factors were measured at the same time.The living fine roots were classified into two parts according to the diameter and the dry weight.The results showed the fine roots which have different diameter scales have different seasonal dynamics,so do the fine roots which have the same diameter scale in different depth.①The fine root of D≤2 mm(D is diameter of root) for both S.vulgarisand A.ordosica have a rapid increase stage in Apr.to May,the following month show difference pattern.②The fine root of 1 mm<D≤2 mm have an other pattern: there are two peak value at May and Aug.For S.vulgariscluster at Jun.and Oct.,the A.ordosicacommunity has peak value too,and S.vulgariscommunity has a stable seasonal dynamic.③Correlation analyze showed: the biomass of fine roots have significant correlation to 0~15 cm soil water contents and relative humidity for S.vulgariscommunity.Homoplastically,the biomass is significantly related to humidity for S.vulgariscluster.A.ordosica has no significant relation these factors.The living fine root seasonal dynamic can reflects the metabolize of underground,but also.it is helpful to evaluate the healthy condition,succession stage and study fine root turnover further.更多还原