机构地区:[1]中国科学院植物研究所,北京100093 [2]中国科学院大学,北京100049 [3]青城山-都江堰旅游景区管理局,四川都江堰611843
出 处:《林业科学研究》2014年第6期809-814,共6页Forest Research
基 金:国家重点基础研究发展计划项目(2009CB825103)
摘 要:在2010年整个生长季内,采用土钻法和内生长法,对新疆干旱区柽柳细根生物量、季节动态、分解与周转进行了研究.结果表明:柽柳群落土壤含水量随着土层深度的增加而增加.10~20 cm土层土壤有机碳储量最大,随后随着土壤深度的增加,有机碳含量逐渐降低.方差分析表明:不同土层有机碳含量差异显著.细根生物量的月平均值为54.51 g·m^-2,群落细根生产量为58.64 g·m^-2.细根生物量呈明显的季节变化趋势,即5-9月逐渐增加,9月达到最大值,9-10月逐渐下降;在土壤剖面垂直变化上,细根生物量随土层深度的增加呈先增加后降低的趋势,0~10、10~20、20~30、30~40、40~50、50~60 cm各土层细根生物量所占比例分别为19.53%、30.05%、26.41%、12.01%、7.33%、4.67%.双因素方差分析表明:不同取样时间、不同土层之间的活细跟生物量、死细根生物量均差异极显著.柽柳群落细根年分解量、年死亡量、净生产力分别为17.41、33.75、83.60 g·m^-2 ·a^-1年周转率为1.98次·a^-1,通过细根死亡进入土壤中的有机碳为(42.68±5.40)g·m^-2·a^-1,占土壤有机碳含量的2.12%.这表明,尽管柽柳群落通过细根周转进入土壤中的有机碳仅占现存土壤有机碳的一小部分,但从较长的时间尺度来看,柽柳群落细根对干旱区生态系统地下有机碳的补充具有重要作用.The fine root production and turnover are important parts of the terrestrial ecosystem carbon cycle,but few researches were conducted on fine root turnover and its contribution to soil carbon cycling of Tamarix ramosissima Lour.community in arid ecosystem.In this research,a typical native T.ramosissima community was selected,and the continuous soil drilling method and fine root bag method were used to investigate the monthly fine root dynamic,production and fine root turnover from May to October,2010 (the whole growing season).The results showed that the soil water content increased with the depth of soil,while the soil organic carbon decreased.The mean fine root biomass in the community was 93.10 g · m^-2 and the live fine root biomass and dead fine root biomass were 73% and 27% of total fine root biomass in the community,respectively.The dynamics of biomass and necromass of fine root in the T.ramosissima community showed the same pattern in the growing season,the biomass slightly increased from May to September,and then decreased.The fine root biomass in the community increased at first,and then reduced gradually with the increase of soil depth.The fine root biomass in 0-40 cm soil layer was the largest parts,with 88.01% of total fine root biomass for the community.The fine root decomposition rate showed a sharp decline to the minimum then declined steadily for the community,and the annual fine root decomposition rate was 51.24% for the community.351 days and 1 359 days were needed to reach half decomposition and 95% decomposition for the community.The net productivity of fine root in the community was 118.81 g · m^-2,the fine root annual turnover rate was 1.98 times · a^-1,and the annual input from fine root mortality to underground soil organic carbon was 42.68 g · m^-2.a^-1 These results showed that the annual input from fine root turnover to underground soil organic carbon counted for only a small portion of the soil organic carbon,however,in a long time,the fine root carbon is a crucial for soil ca
关 键 词:柽柳群落 细根生物量 细根分解与周转 土壤有机碳
分 类 号:S793.5[农业科学—林木遗传育种]
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