湿地定义研究进展

Review on Studies of Wetland Definition

基于对湿地定义的概述,分析了各种湿地定义存在的主要问题及其根源,从湿地的发生学因素与诊断特征、"正常情况"与"非正常情况"、湿地定义的多样性、定义问题与边界问题的关系等方面,对湿地定义研究中的共识进行了剖析。分析结果表明,湿地土壤和湿地植被不是所有湿地个体共同的诊断特征,只有湿地水文特征是区分湿地与非湿地的本质特征;对湿地水文阈值的研究,至今还没有找到科学的理论和方法;湿地的客观外延是"正常情况下"的湿地外延与"非正常情况下"湿地特殊外延之和,目前所有湿地定义的外延与湿地的客观外延都不是全同关系,因而所有的湿地定义都是存在问题的;湿地定义研究中所有问题的根源都在于理论基础薄弱。基于逻辑学关于概念的外延确定与内涵确定的理论和方法,认为只有在构建湿地外延确定与内涵确定的理论、方法和科学性评价标准的基础上,才能科学地定义湿地;在明确湿地客观外延的基础上,将湿地内涵的概括具体化为对"要素—指标—阈值"的逐级概括,从而指出湿地定义研究的主体内容和方向。随着对湿地水文、土壤和植被特征研究的深入,湿地边界阈值会越来越明确,统一的、科学的湿地定义必将出现。

Wetland definition is the cornerstone of the theoretical system of wetland science. Without single agreed-upon scientific wetland definition, the development of wetland science has been severely hampered. On the basis of the review on the study of wetland definition, especially the American wetland definition, the paper analyzed the main problems that various wetland definitions had, thoroughly dissected the common understandings in the research of wetland definition from the aspects such as embryological factors and diagnostic characteristics of wetlands, ＂normal conditions＂ and ＂abnormal conditions＂, diversity of wetland definition, the relationship between wetland definition and boundary issues, coming to a conclusion that wetland soil and wetland vegetation are not the diagnostic characteristics shared by all the wetland units. Only the hydrologic characteristic is the essential characteristic that can distinguish wetlands and non-wetlands. Though wetland hydrology is the genetic factor in wetland formation, the genetic threshold can become the reliable diagnostic characteristic when it＇s clear. Hence ＂one-parameter-definition＂ of hydrology is scientific. However, researches on hydrological threshold have not found a scientific theory and method yet, so all the present hy- drological thresholds lack theoretical basis. Wetland objective denotation is the combination of wetland deno- tation under ＂normal conditions＂ and particular wetland denotation under ＂abnormal conditions＂, but all the current denotation and objective denotation of wetlands are not the same, thus there existing problems in all the current wetland definitions. The weak base of theory is the root of this problem. To define the wetland scientifically, theories, methods and scientific evaluations to determine the denotation and connotation of wetland standard should be built based on the basic principles and methods for determining the denotation and connotation of the concept in logic. Founded on the clear wetland objective denotation, wetland connotation summary can be specific as the summary of ＂parameter-indicator-threshold＂ level by level, pointing out the main content and direction of wetland definition research. As our research on hydrology, soil and vegetation characteristics continues, the wetland boundary threshold would become clearer, and a unified, scientific wetland definition will certainly appear.