库布齐东缘沙漠化逆转过程中土壤呼吸及其温度敏感性变化  

Variations of soil respiration and its temperature sensitivity in the reversion process of desertification in the eastern Hobq Desert,China

作　　者：王博[1] 段玉玺[1] 王伟峰[1] 刘宗奇 李晓晶[1] 刘源 WANG Bo;DIJAN Yu-xi;WANG Wei-feng;LIU Zong-qi;LI Xiao-jing;LIU Yuan(Inner Mongolia Forestry Research Institute,Hohhot 010010,China)

机构地区：[1]内蒙古自治区林业科学研究院

出　　处：《应用生态学报》2020年第1期104-112,共9页Chinese Journal of Applied Ecology

基　　金：林业科技创新平台项目(2019132021);内蒙古自然科学基金项目(2017MS0368)资助~~

摘　　要：为研究沙漠化逆转过程对土壤呼吸速率(Rs)及其温度敏感性(Q10)的影响,在库布齐沙漠东缘选取流动沙地、半固定沙地、藻结皮固定沙地、地衣结皮固定沙地和苔藓结皮固定沙地5个不同逆转阶段,采用静态暗箱-气相色谱法测定不同阶段样地Rs并计算Q10,并同步分析环境因子对Rs的影响。结果表明:随沙地固定和植被演替,Rs逐渐增大,表现为苔藓结皮固定沙地(0.78μmol·m^-2·s^-1)>地衣结皮固定沙地(0.67μmol·m^-2·s^-1)>藻结皮固定沙地(0.46μmol·m^-2·s^-1)>半固定沙地(0.42μmol·m^-2·s^-1)>流动沙地(0.29μmol·m^-2·s^-1),且Rs均为生长季大于非生长季。Q10值规律相反,为流动沙地(3.28)>半固定沙地(2.93)>藻结皮固定沙地(2.54)>地衣结皮固定沙地(1.91)>苔藓结皮固定沙地(1.84),且均为非生长季大于生长季。5个阶段样地Rs与土壤温度均呈显著正相关,但仅流动沙地和半固定沙地Rs与土壤含水量呈正相关,其余3种固定沙地Rs与土壤含水量无相关性。Rs与土壤全氮、有机碳、容重、孔隙度、细菌数量、放线菌数量及真菌数量均显著相关。在沙漠化逆转过程中,土壤碳氮含量及微生物群落数量的增加、土壤质地的改善、植物生物量的积累可显著增强土壤呼吸并降低其温度敏感性,是改变荒漠土壤碳循环格局的主要驱动力,同时也可明显改变水分因子对土壤呼吸的影响程度。To clarify the effects of desertification reversal on soil respiration rate(Rs)and its temperature sensitivity(Q10),five different reversal stages were selected:mobile dune,semi-fixed sandland,algae crust fixed sandland,lichen crust fixed sandland,and moss crust fixed sandland in the eastern Hobq Desert.Rsat different stages were measured by static chamber-gas chromatography and the Q10 was calculated.We analyzed the effects of environmental factors on Rs.The results showed that Rs gradually increased with sand fixation and vegetation succession:moss crust fixed sandland(0.78μmol·m^-2·s^-1))>lichen crust fixed sandland(0.67μmol·m^-2·s^-1))>algae crust fixed sandland(0.46μmol·m^-2·s^-1))>semi-fixed sandland(0.42μmol·m^-2·s^-1))>mobile dune(0.29μmol·m^-2·s^-1)).The Rsof growing season was higher than that of non-growing season.Q10 of Rsat different reversal stages followed the order:mobile dune(3.28)>semi-fixed sandland(2.93)>algae crust fixed sandland(2.54)>lichen crust fixed sandland(1.91)>moss crust fixed sandland(1.84).The Q10 of non-growing season was higher than that of growing season.There was positive correlation between Rsand soil temperature.Rsof mobile and semi-fixed sand was positively correlated with soil water content,but not in other three fixed sandlands.Rswas correlated with soil total nitrogen,organic carbon,bulk density,porosity,quantity of bacteria,quantity of actinomycetes and quantity of fungi.Our results indicated that in the process of desertification reversal,the increases of soil organic carbon and nitrogen content and the abundance of microbes,the improvement of soil texture and the accumulation of plant biomass could dramatically enhance soil respiration and reduce its temperature sensitivity,which were the main driving forces to change carbon cycle of desert soil,and mediate the effects of soil water on soil respiration.

关 键 词：土壤呼吸 温度敏感性 沙漠化逆转 水热因子 土壤性状 

分 类 号：S154.1[农业科学—土壤学]