作　　者： ; ; ; ; ;

机构地区： 中国林业科学研究院

出　　处： 《中国沙漠》 2012年第3期709-716,共8页

摘　　要： 为研究全球变化情景下降雨格局变化对干旱区植被的影响,以甘肃民勤的典型荒漠植被白刺灌丛为研究对象,在生长季内人工模拟不同增雨梯度(+0%、+25%、+50%、+75%和+100%多年平均降水量),分析白刺枝条形态特征的变化规律。结果表明,白刺枝条各形态指标间存在很好的相关性。7—9月,75%和100%增雨的枝条长度显著大于0%增雨,枝条新生叶片数只在8月表现为100%增雨显著大于0%增雨。8—9月,100%增雨的营养枝基部直径显著大于0%增雨,成熟叶片数和干物质重量在增雨梯度下各月均不显著。花枝的基部直径在7—9月均表现为100%增雨显著大于0%增雨,7月100%增雨的花枝成熟叶片数显著大于0%增雨,而花枝干物质重量在6—8月表现为100%增雨显著大于0%增雨。针对降雨格局变化,白刺不同枝条形态特征的调节适应机制之间存在着一定的内在协调性。 Under the background of global change, the variation of precipitation pattern might affect vegeta- tion dynamics in arid zone. Nitraria tangutorum shrub, which is one of typical desert vegetation in Minqin County, Gansu Province, was chose to study the effect of precipitation variation on vegetation dynamics. The change pattern of morphological characteristics of N. tanggtorgm branches was examined under differ- ent simulated rainfall increase treatments （0 %, 25 %, 50 %, 75 % and 100 % increasing of mean annual pre- cipitation, respectively）. Result showed that there was significant correlation among branch morphological indexes. The length of N. tangutorgm branches in the 75% and 100% rainfall increase treatments was significantly greater than that in no rainfall increase treatment from June to September. The number of new leaves of N. tangutorum branches in the 100% rainfall increase treatment was significantly larger than that in no rainfall increase treatment only in August. In August and September, the basal diameter of the vegetative branches in the 100 % rainfall increase treatment was significantly larger than that in no rainfall increase treatment. However, the number of mature leaves and the dry weight of vegetative branches were not significantly different for different rainfall increase treatments. The basal diameter of flower branches in the 100 % rainfall increase treatment was significantly larger than that in no rainfall increase treatment from July to September. The number of mature leaves of flower branches in the 100 % rainfall increase treatment was significantly larger than that in no rainfall increase treatment in July. Dry weight of flower branches in the 100 % rainfall increase treatment was significantly larger than that in no rainfall increase treatment from June to August. Therefore, there is a certain inherent coordination among adaptive mechanisms of different morphological characteristics of N. tangutorura branches under different rainfall increase treatments.

关 键 词： 形态特征 人工增雨 白刺枝条

领　　域： [生物学]