科尔沁沙地沙丘植被对丘间低地水体的影响北大核心CSCD

在流动沙丘以建立固沙植被的方式向固定沙丘转化的过程中,植被将改变沙丘水分再分配过程,影响沙丘的水文调节功能,甚至可能引起沙丘生态系统水资源失衡。为探明植被对沙丘水文调解功能的影响,以科尔沁沙地不同植被盖度的沙丘-丘间地水体组合体为研究对象,于2021年生长季开展了沙丘植被盖度、丘间低地水体变化特征、气象因素的动态观测,以期明确沙丘植被变化对丘间低地水体的影响。结果表明:(1)沙丘植被盖度影响沙丘水分对外补给能力,随着沙丘表面固沙植被盖度增加,单位面积沙丘对外水分补给能力降低,表现为流动沙丘(58.25 mm)>半固定沙丘(24.75 mm)>固定沙丘(14.87 mm),占同期降水量的比例分别为21.39%、9.09%、5.46%。(2)生长季流域降水补给量、植被盖度、气温显著影响沙丘对丘间低地水体的水分补给量,丘间低地水体获补量与流域降水补给量显著正相关,与植被盖度、气温极显著负相关。(3)依据水量平衡原理推导出沙丘水分对外补给量(Y)与影响因素(降水补给量X_(1),植被盖度X_(2),平均气温X_(3))的关系模型,Y=1052.737+0.1X_(1)-11.459X_(2)-37.585X_(3),R2=0.641。可根据模型预测沙丘水分对外补给量,为流动沙丘生物治理模式的合理选择提供支持。

Effects of dune vegetation on water dynamics in interdune lowland in the Horqin Sandy Land

In the process of shifting dune to fixed dune by constructing sand-fixing vegetation， vegetation changed the water redistribution process of dune， affected the hydrological regulation function of dune， and may even cause the imbalance of water resources in dune ecosystem. In order to explore the influence of vegetation on the hydrological mediation function of dunes， this experiment took dunes with different vegetation coverage and dune interdune water bodies in Horqin Sandy Land as the research objects. In the growing season of 2021， dynamic observations of dune vegetation coverage， characteristics of interdune lowland water and meteorological factors were carried out to clarify the impact of dune vegetation on the interdune lowland water. The results showed that： （1） Dune vegetation coverage affected the external water recharge capacity of dunes. With the increased of sand vegetation coverage， the external water recharge capacity of dunes per unit area decreased， in the order of mobile dune （58.25 mm） > semi-fixed dune （24.75 mm） > fixed dune （14.87 mm）， and the proportions of precipitation in the same period were 21.39%， 9.09% and 5.46%， respectively. （2） In the growing season， precipitation recharge， vegetation coverage and air temperature significantly affected the water replenishment amount of dune to the interdune lowland water body， which was significantly positively correlated with precipitation recharge， and significantly negatively correlated with dune coverage and air temperature. （3） Based on the principle of water balance， the relationship model between external water replenishment amount of dune and influencing factors is deduced， and the expression is as follows： Y=1052.737+0.1X₁-11.459X₂-37.585X₃， R²=0.641， where Y is the external water replenishment amount of dune， X₁ is the precipitation replenishment amount of the catchment， X₂ is vegetation coverage， X₃ is the average temperature. The model can be used to predict the external water supply of dune， which can provide a basis for the choice of mode for control mobile dune.