不同载畜率下荒漠草原生长季地表特征及对风沙通量的影响

Effects of Stocking Rates on Land Surface Characteristics and Wind-blown Sand Fluxes during Growing Season in Desert Steppe

为探寻不同载畜率下荒漠草原地表特征变化及其对风蚀作用的影响,以内蒙古荒漠草原(短花针茅为建群种)为研究对象,通过对2021年5~10月植物群落盖度、枯落物盖度、土壤结皮盖度及裸地率的连续测定和风蚀土的收集,开展不同载畜率下不同高度的风沙通量与地表特征关系研究。结果表明:在荒漠草原植物生长季,载畜率显著影响地表特征(P<0.05),载畜率增加使植物群落盖度、草层高度、枯落物盖度、土壤结皮盖度降低,裸地率增大;10 cm、30 cm、100 cm三个集沙高度的风沙通量随载畜率增加均呈增加趋势且30 cm高度以下尤其显著(P<0.05)。0~100 cm高度总风沙通量在重度放牧区最高,较对照区增加了69.4%,较轻度、中度放牧区的风沙通量分别增加44.3%、7.6%;不同载畜率下,地表特征对风沙通量有显著影响(典型相关系数0.8960),风沙通量与植物群落盖度、枯落物盖度和土壤结皮盖度均呈负相关,与裸地率呈正相关,其中土壤结皮盖度对风沙通量影响最大(载荷系数为-1.3865)。载畜率梯度干扰下的地表特征对土壤风蚀有直接影响,且干旱环境下的土壤结皮盖度对抑制风蚀有较明显作用。

In order to explore the effects of different stocking rates on land surface characteristics and wind erosion in desert steppe,we conducted a study in Inner Mongolia desert grassland,dominated by Stipa breviflora.Continuous measurements of vegetation cover,litter cover,soil crust cover,and bare land cover,as well as wind-blown soil collection,were carried out from May to October 2021 to investigate the relationship between wind-sand flux and surface characteristics at different heights under different stocking rates.The results showed that during the growing season of desert grassland plants,stocking rate had a significant effect on surface characteristics(P<0.05),with an increase in stocking rate leading to a decrease in vegetation cover,grass height,litter cover,and soil crust cover,and increase in bare land rate.Wind-sand flux at three different sand trap height(10 cm,30 cm,100 cm)increased with stocking rate,particularly below 30 cm(P<0.05).The total wind-sand flux from 0 to 100 cm was highest in the heavily grazed area,increasing by 69.4% compared to the control area,with increases of 44.3% and 7.6% in the lightly and moderately grazed areas,respectively.Surface characteristics had a significant impact on wind-sand flux under different stocking rates(canonical correlation coefficient of 0.8960),with negative correlations between wind-sand flux and vegetation cover,litter cover,and soil crust cover,and a positive correlation with bare land rate.Soil crust cover had the greatest impact on wind-sand flux(loading coefficient of-1.3865).Surface characteristics under different stocking rates had a direct effect on soil wind erosion,and soil crust cover played a significant role in inhibiting wind erosion in arid environments.