旱区植被建设与生境旱化的生态学因果关系

Ecological causality between vegetation construction and habitat drought in arid areas

旱区科学绿化的核心是“以水定绿”,其前提依据之一就是植被建设与生境旱化间潜在的因果关系。在生态学上,特别是对复杂生态系统而言,因果关系往往难以准确界定并描述。科学实践“以水定绿”,必须搞清旱区植被建设与水文循环的关系,明确生境旱化发生的依据和条件。为此,本文从“以水定绿”生态学因果关系的理论内涵、应用模式入手,以科学绿化试点示范省建设(宁夏)为例,分别从区域尺度、景观尺度和生态系统尺度,分析植被建设与生境旱化之间的因果关系,指出相关认识和实践中存在的矛盾与问题,提出“以水定绿”科学绿化实践的原则和建议。

The core of scientific greening in arid areas is‘greening based on water'.One of its preconditions is the potential causal relationship between vegetation construction and habitat drought.However,the causal relationship between factors or processes in ecology is generally difficult to accurately define and describe,especially for complex ecosystems.To scientifically carry out‘greening based on water',it is necessary to clarify the relationship between vegetation construction and hydrological cycle in drylands,and clarify the basis and conditions for habitat drought.Taking the construction of scientific greening pilot demonstration province in Ningxia as an example,we started with the theoretical connotation and application model of ecological causality of‘greening based on water',and empirically analyzed the causal relationship between vegetation construction and habitat drought at the regional,landscape,and ecosystem scale,respectively.The contradictions and problems in relevant understanding and practice were pointed out,and the principles and suggestions of scientific practice of‘greening based on water'were put forward.