基于生态最优性原理的黄土高原适宜植被分布研究

Vegetation suitability research provides guidance for rational distribution of vegetation restoration, which has important significance for the sustainability of vegetation restoration in the Loess Plateau. In arid and semi-arid regions, soil water is the integrative state variable that plays key roles in many eco-hydrological processes. Vegetation suitability in the Loess Plateau is determined by the interactions between vegetation and soil water. It is thus of great theoretical and practical significances to explore their interactions, quantify vegetation suitability and map vegetation distribution. This projects intends to model soil moisture dynamics and water balance of typical re-vegetated species and plant water stress and water use could calculated by the model results. Based on ecological optimality theory, plant suitability vector was developed on the tradeoff between maximization of water use and simultaneous minimization of water stress. Through the suitability vector, suitable re-vegetated species could be identified and their distribution could be mapped, then the hydrological effects of the suitable vegetation distribution pattern were detected, which could provide decision support for the sustainable development of the Loess Plateau.

植被适宜性研究是指导植被恢复布局的科学依据，对于黄土高原生态恢复的可持续性具有重要意义。干旱半干旱地区，土壤水分是重要的生态变量，显著影响生态水文过程，黄土高原植被适宜性主要由植被与土壤水分之间相互作用关系决定。探究黄土高原区域植被与土壤水分相互关系，量化植被的适宜性并进行适宜恢复植被空间分布制图具有重要的理论和现实意义。本研究采用随机土壤水分平衡模型模拟黄土高原典型恢复物种的土壤水分动态和水量平衡，根据模拟结果表征植被水分压力和水分利用效率，基于生态最优性原理，根据植被水分压力与水分利用效率之间的权衡发展黄土高原植被适宜性向量，量化植被适宜性，进行区域适宜恢复植被的空间分布制图，并探究适宜恢复植被格局的水文效应，为黄土高原生态修复的适宜性和可持续发展提供重要决策支持。

黄土高原植被恢复取得显著成果，但不合理的植被建设也带来显著负面效应，区域尺度上进行植被恢复合理布局是黄土高原生态修复与治理可持续发展的现实需求，研究植被与土壤水分之间的关系、定量评估干旱半干地区植被适宜性、揭示植被变化的水文水资源效应可以为黄土高原植被建设提供科学指导。项目围绕恢复植被对于土壤水分的适应规律，开展了典型恢复样地野外调查，在延安羊圈沟、南泥湾子流域建立了典型恢复物种的生态水文过程观测样地，收集整理了黄土高原土地覆盖、气候、土壤和DEM等数据，计算了随机土壤水分平衡模参数，模拟了典型恢复物种的土壤水分动态及水量平衡，解析了其在降雨梯度上的变异特征；探究黄土高原典型样带刺槐人工林和撂荒草地植被特征，分析了典型乡土物种的潜在适生区及驱动因子；结合生态最优性原理与随机土壤水分平衡模型，发展了考虑水分利用和水分压力的植物适宜性定量方法，识别了典型恢复物种的适宜分布格局，并预测了未来气候情境下恢复物种的适宜分布范围，评估了适宜植被分布格局的生态水文效应。项目发表论文3篇。