中文摘要：

对古尔班通古特沙漠南缘降雨模式和不同生活型植物对小雨量降水的生理响应进行了研究。通过分析1998-2007年的降雨数据，发现本区的降水模式为小雨量，高频率，0～5mm的小雨量降雨占总降雨频次的89．8％，平均降雨间隔在6d左右。选择了本区具有代表性的16种植物，利用叶片相对含水量作为指标，研究了不同生活型植物对小雨量降雨（1、2、3、4和5mm）的响应。结果表明，所有草本植物（11种）对2—5mm的降雨都有不同程度的响应，只有1种灌木（驼绒藜Ceratoides latens），对4mm降雨有响应。这12种植物在降雨后的第1天，叶片相对含水量显著增加，水分状况得到显著改善，表明这些植物对小雨量（≤5mm）降雨有显著响应，而半灌木（沙漠绢蒿Seriphidium santolinum）、灌木（梭梭Haloxylon ammodendron、柽柳Tamarix ramosissima）、小乔木（白梭梭Haloxylon persicum）对5mm以下的降雨均无显著响应，小雨量降雨可能主要是被1年生草本植物所利用。通过统计各降雨梯度上响应的植物种数发现，在降雨量达到3mm时开始响应的植物种类最多。综合考虑降雨模式与不同生活型植物对小雨量降雨的响应特点，高频率的小雨量降雨，可能是维持本区较高植被覆盖度的重要原因。

英文摘要：

This paper studied the size characters of rainfall in south edge of Garbantunggut Desert and the responses of different life-form plants there to small rainfall events. Based on the analysis of the precipitation data in 1998-2007, the study area had a high frequency but low amount of precipitation. Rainfall events occurred every 6 days averagely, and most （ 89.8% ） of the events were ≤5 mm. Sixteen representative plant species were selected and their leaf relative water content （RWC） was used as the parameter to investigate the responses of different life-form plants in the area to small rainfall events （1, 2, 3, 4, and 5 mm）. The results showed that all 11 herb species had different degrees of responses to 2-5 mm rainfall, and only one shrub species Ceratoides lateens responded to 4 mm rainfall significantly. The leaf RWC of the 12 species increased significantly after one day of rainfall, suggesting that these species had significant responses to small rainfall events （ ≤5 mm）. Sub-shrub （Seriphidium santolinum）, shrub （Haloxylon ammodendron, Tamarix ramosissima） , and small tree （Haloxylon persicum） did not respond to the rainfall events ≤ 5 mm. Small rainfall events mainly benefited herb species, and the high frequency but low amount of rainfall partially explained the relatively high vegetation cover in this area.