生态水文平衡状态下宁夏地区植被承载力模拟

Simulation of Vegetation Carrying Capacity in Ningxia Under Eco-hydrological Balance

基于Eagleson的生态水文最优性理论,从区域尺度上,综合多种环境变量,模拟宁夏地区生态水文平衡状态下植被最优盖度,进而确定植被承载力,并研究在不过分消耗土壤水分的前提下不同植被类型的最优盖度。结果表明:(1)在研究期内(2000—2019年),基于Eagleson生态最优性理论得到的平衡植被覆盖度与实际植被覆盖度相关关系为0.86,模型模拟良好,除去农田,宁夏地区的多年平均植被盖度为0.048~0.984,模拟的平衡植被覆盖度为0.153~0.840,植被盖度在空间上具有较好的一致性,南部地区较高,呈现由南向北逐渐降低的趋势。(2)从植被承载力空间分布来看,绝大部分区域实际植被覆盖度与模拟的平衡植被覆盖度的差值小于0.05,未处于超载状态,植被超载区主要位于泾源县。(3)乔灌草3种土地利用类型的模拟植被最优盖度均表现为从南到北逐渐减少,从多年平均来看,草地的模拟植被最优盖度为0.223~0.841,灌木林地的模拟植被最优盖度为0.186~0.659,而乔木林地的模拟植被最优盖度为0.153~0.635。研究结果有助于科学指导当地生态环境建设,为同类地区生态恢复建设提供理论支撑。

Based on the eco-hydrological optimality theory of Eagleson,from the regional scale,a variety of environmental variables were integrated to simulate the optimal vegetation coverage under the eco-hydrological balance in Ningxia,and then determine the vegetation carrying capacity and study the optimal coverage of different vegetation types under the premise of not consumption of soil moisture.The results showed that:(1)During the study period(2000—2019),the correlation between the balanced vegetation coverage and the actual vegetation coverage based on Eagleson’s ecological optimality theory was 0.86,indicating that the model was well simulated.Excluding farmland,the average annual vegetation coverage in Ningxia was 0.048~0.984,and the simulated balanced vegetation coverage was 0.153~0.840.The vegetation coverage had a good spatial consistency,and the southern region was higher,showing a trend of decreasing gradually from south to north.(2)From the perspective of spatial distribution of vegetation carrying capacity,the difference between actual vegetation coverage and simulated equilibrium vegetation coverage in most regions was less than 0.05,indicating that they were not in overload state,and the vegetation overload area was mainly located in Jingyuan County.(3)The optimal coverage of simulated vegetation for the three land use types of grassland,shrubland and woodland decreased gradually from south to north.From the perennial average,the optimal coverage of simulated vegetation was 0.223~0.841 for grassland,0.186~0.659 for shrub land,and 0.153~0.635 for woodland.The research results are helpful to scientifically guide the local ecological environment construction and provide theoretical support for the ecological restoration construction in similar areas.