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以中国科学院新疆阜康荒漠生态站为试验平台,涡度相关技术为主要技术手段,对盐生荒漠生态系统进行长期水汽、CO_2通量观测,探讨年总降水量变化对盐生荒漠生态系统CO_2通量的影响。选取2个极端降水年份2006年(129 mm)和2007年(231 mm)比较CO_2通量的年内变化特征。2006年的碳吸收强度明显低于2007年,其最大碳吸收值分别为-0.4和-1.6 g C·m~(-2)·d~(-1),2006年的生长季长度为120 d,2007年为160 d。2006年表现为弱的碳吸收,其吸收值为-5 g C·m-2·a-1,群落总生产力与总呼吸分别为114.9和110.1 g C·m-2·a-1,2007年表现为较强的碳吸收,吸收值为-40 g C·m~(-2)·a~(-1),群落总生产力与总呼吸分别为257.7和218.2 g C·m~(-2)·a~(-1)。在干旱年份(2006年),群落总生产力与生态系统蒸散量的线性关系明显弱于湿润年份(2007年),二者的决定系数分别为0.40和0.71。对群落结构进行调查结果表明,在湿润年份,一年生草本植物的比例增加,可以充分利用降水,提高生态系统生产力。
Taking the Fukang Desert Ecological Station of Chinese Academy of Sciences as the experimental platform and the eddy covariance technique as the main technical measures, the long-term water vapor and CO_2 fluxes were observed in saline desert ecosystems to investigate the effect of annual total precipitation on the salt desertification ecosystem CO_2 The impact of flux. The year-by-year variations of CO 2 fluxes were compared between two extreme precipitation years (129 mm) and 2007 (231 mm). The carbon uptake intensity in 2006 was significantly lower than that in 2007, with the maximum carbon uptake values of -0.4 and -1.6 g C · m -2 · d -1, respectively. The growth season in 2006 was 120 days In 2007 to 160 days. In 2006, it exhibited a weak carbon uptake of -5 g C · m -2 · a -1, with a total community productivity and total respiration of 114.9 and 110.1 g C · m -2 · a -1, respectively Showed a strong carbon uptake of -40 g C · m -2 · a -1. The total community productivity and total respiration were 257.7 and 218.2 g C m -2, respectively. · A ~ (-1). In drought years (2006), the linear relationship between total community productivity and ecosystem evapotranspiration was significantly weaker than that of wet year (2007), and the coefficient of determination was 0.40 and 0.71 respectively. The results of surveys of community structure indicate that in wet years, the proportion of annual herbaceous plants increases, making full use of precipitation and improving ecosystem productivity.