甘肃省民勤县荒漠绿洲过渡带典型灌丛植物的滞尘量效应

Dust Retention Effects of Typical Shrub Plants in Desert Oasis Transition Zone in Minqin County of Gansu Province

[目的]开展荒漠绿洲过渡带典型灌丛滞尘研究,为区域防风固沙树种滞尘效益评价和绿洲防护体系建设提供依据。[方法]通过野外调查采样,室内水洗过滤等方法,定量分析了荒漠绿洲过渡带梭梭(Holoxylon ammodendron)、柽柳(Tamarix chinensis)、白刺(Nitraria tangutorum)3种植物在3月上旬(冬态)和6月下旬(夏态)滞尘量和滞尘粒度沿荒漠至绿洲4 km范围内的时空变化特征。[结果]滞尘量从荒漠到绿洲逐步递减,3月上旬梭梭、柽柳、白刺平均递减20.74%,16.13%,14.72%,6月下旬平均递减14.37%,9.23%,26.54%。3月上旬梭梭的滞尘量最大,约为172.36 g/株~、6月下旬柽柳的滞尘量最大,约为345.16g/株。3月上旬3种灌木所滞尘土的粒径主要为20~50μm,约占41.00%,梭梭有少量滞尘的粒径为500~1000μm,约占总量的15.00%;6月下旬所滞尘土的粒径大量分布于100~200μm,少量分布于5~10μm。[结论]在3月和6月,3种灌木的滞尘量从荒漠到绿洲均呈现出递减的趋势,灌丛植物的滞尘量、滞尘粒径受时间、空间及植物叶表面特征的共同影响。

[Objective]Dust retention of typical shrublands in a desert-oasis ecotone was quantified,in order to provide a basis for the evaluation of dust retention benefits of regional windbreak and sand-fixing tree species and the construction of oasis protection systems.[Methods]Field investigations and sampling,indoor washing filtration,and other methods were used to determine the temporal and spatial variation characteristics of dust retention amount and particle size of three shrub species(Holoxylon ammodendron,Tamarix chinensis,and Nitraria tangutorum)in the desert-oasis transition zone along the 4-km range from desert to oasis in early March(winter state)and late June(summer state).[Results]The amount of dust retention gradually decreased from desert to oasis.In early March,the average decreases in dust retention of Haloxylon ammodendron,Tamarix chinensis,and Nitraria tangutorum were 20.74%,16.13%and 14.72%,respectively.In late June,the average decreases were 14.37%,9.23%,and 26.54%,respectively.In early March,Haloxylon ammodendron had the largest amount of dust retention,about 172.36 g/plant.In late June,Tamarix chinensis had the largest amount of dust retention,about 345.16 g/plant.In the first ten days of March,the dust particle size for the three shrubs mainly ranged from 20 to 50μm,accounting for about 41.00%of the dust that was trapped.A small amount of dust trapped by Haloxylon ammodendron had particle sizes of 500 to 1000μm,accounting for about 15.00%of the total.In late June,the particle size of the dust ranged from 100 to 200μm,and a small amount ranged from 5 to 10μm.[Conclusion]In March and June,the dust retention of the three shrubs showed a decreasing trend from desert to oasis.The dust retention and dust retention particle size of shrub plants were affected by time,space,and plant leaf surface characteristics.