沙坡头自然保护区不同固沙技术生态效益监测评价

Ecological Benefit Monitoring and Evaluation of Different Sand-Fixing Techniques in Shapotou National Nature Reserve

【目的】为了深入了解设置沙障后不同固沙条件下植被物种组成、多样性的变化规律。【方法】以扎设草方格、尼龙网格、草绳方格固沙的沙地植被恢复技术示范区为研究对象,分析不同固沙模式对土壤风蚀、水分和电导率以及草本植物群落组成的影响,总结不同固沙模式对沙地植被恢复区的土壤风蚀、水分和电导率及植物多样性指数的影响规律。【结果】结果表明,①从总风蚀速率来看,流动沙丘风沙活动最强,为0.15 cm·d^(-1),且以沉积为主;草方格沙丘风沙活动最弱,为0.04 cm·d^(-1);土壤风蚀的总风蚀速率较流动沙丘减小0.11 cm·d^(-1)。沙丘风蚀与沉积的净变化速率在草方格沙丘最小,为-0.04 cm·d^(-1);流动沙丘最为剧烈,为0.15 cm·d^(-1);土壤风蚀的净变化速率较流动沙丘减小0.19 cm·d^(-1)。②流动沙丘和尼龙网格沙丘在不同土层深度的土壤水分和电导率无明显变化(P>0.05);草绳方格沙丘土壤水分含量由大到小依次为表层、深60 cm、深40 cm(P<0.05),不同土层深度电导率差异不显著(P>0.05);草方格沙丘土壤电导率由大到小依次为表层、深60 cm、深40 cm(P<0.05),土层深度对水分含量的影响较小(P>0.05)。③不同固沙模式对多度和物种数无显著影响(P>0.05)。不同固沙模式中,草本植被多样性指数无显著差异(P>0.05),表现较为一致的趋势;草方格沙丘的香浓-威纳指数、均匀度指数、物种数均最高,分别为0.93、0.57和1.80。【结论】综合分析表明,草方格固沙模式下植被恢复效果较好,对土壤水分和电导率影响较小;草绳方格固沙对土壤水分和电导率的影响较大。建议在后续沙地生态修复时,以草方格固沙为主,草绳方格为辅。

[Objective]Insights into the variation patterns of plant species composition and diversity under different sand-fixing conditions after the establishment of sand barriers.[Method]Taking the demonstration area of sand vegetation restoration technology created by tying grass squares,nylon grids,and grass rope squares as the research object,the effects of different sand fixation modes on soil wind erosion,water and conductivity,as well as the composition of herbaceous plant communities were investigated.The impact of different sand fixation modes on soil wind erosion,water and conductivity,and plant diversity index in the sand vegetation restoration area was elucidated.[Result]①From the perspective of total wind erosion rate,the wind sand activity in mobile sand dunes is the strongest at 0.15 cm·d^(-1),and sedimentation is the main form.The wind sand activity in grass square sand dunes is the weakest at 0.04 cm·d^(-1),and the total wind erosion rate of soil wind erosion has decreased by 0.11 cm·d^(-1);The net change rate of wind erosion and sedimentation in sand dunes is the smallest at-0.04 cm·d^(-1) in grassy grid dunes,and the most severe at 0.15 cm·d^(-1) in mobile sand dunes.The net change rate of soil wind erosion has decreased by 0.19 cm·d^(-1).②There were no significant changes in soil moisture and electrical conductivity in mobile sand dunes and nylon mesh sand dunes at different soil depths(P>0.05);The soil moisture content of the straw rope grid was as follows:surface,60 cm deep,40 cm deep(P<0.05),but the difference in electrical conductivity was not significant(P>0.05);The soil conductivity of grass square sand dunes showed as follows:surface,depth 60 cm,depth 40 cm(P<0.05),but the influence of soil depth on water content was relatively small(P>0.05).③Different sand fixation modes had no significant impact on abundance and species number(P>0.05).There was no significant difference in the diversity index of herbaceous vegetation among different sand fixation models(P>0.05),but it showed a relatively consistent trend.The Shannon Wiener index and evenness index of grass checkered sand dunes are both the highest,with values of 0.93,0.57 and 1.80,respectively.[Conclusion]Comprehensive analysis shows that the vegetation restoration effect under the grass grid sand fixation model is good,but its impact on soil moisture and electrical conductivity is weak;Grass rope grid sand fixation has a high impact on soil moisture and conductivity,so in the subsequent ecological restoration of sandy land,grass rope grid sand fixation is the main method,supplemented by grass rope grid sand fixation.