沙区人工固沙植物水分适宜度模糊数学模型及应用

以固沙植物油蒿和柠条为研究对象，探讨了样区土壤水分变化的模糊属性特征；运用模糊数学方法，建立了水分适宜度的概念及其模型，并进行实例计算与分析．结果表明：柠条在单播情况下随着营林密度的升高，其适宜度值呈现下降趋势；混播比单播具有较高的适宜度值，其中以5000株/hm^2混播下适宜度最高，植被覆盖率最大，是值得推广的一种营林方式．试验条件下，植被覆盖率高者，其适宜度亦高，二者呈现出一致性．文中分析了油蒿与柠条对水分竞争与共存的机理，有关结论为人工固沙林稳定发展提供了科学依据．

Fuzzy mathematical model of water fitness for artificial sand-binding vegetation in desert and its application

In the construction of artificial sand-binding forest in Western China,water is the primary factor among the necessary environmental conditions.With the sand-binding vegetation Caragana Korshiskii and Artemisia ordisica as the objects of study,the fuzzy properties of soil water is discussed.Using the approach of fuzzy mathematics,the concept and model of water fitness are constructed.The example and results show that the value of fitness will decrease with the increase of forest density.Blending insemination has higher fitness than single insemination,because the former can reach its maximum and cover rate at 5000 per hectare.Under the experimental conditions,the cover rate is in accordance with the fitness.The paper also analyzes the scientific mechanism of water competition and plant coexistence,which can give scientific support to the development of artificial sand-binding forest.