湿地边界确定研究进展

本文分析了目前湿地边界确定存在的困难及各种湿地边界指标及其标准在湿地边界确 定过程中存在的问题， 将系统论的基本原理与自然地理学相结合， 分析了湿地系统与陆地系统和 水体系统之间本质特征的区别， 认为: 由于湿地边界存在的客观性， 湿地边界确定的困难并不能 说明其边界就不能确定; 用人为"规定"的标准来确定湿地的边界是不科学的， 任何自然综合体的 边界只能认识而不是人为规定的; 由于湿地多样性， 从湿地本身特征无法确定湿地边界的情况 下， 由于湿地是位于水陆交错带的一个自然综合体， 只要抓住了湿地隐域性的本质， 确定了水体 系统与陆地系统的边界也就确定湿地系统的边界。通过对湿地边界各种指标的合理性和可重复 性分析， 提出地带性土壤诊断层尖灭点作为湿地边界指标， 分析了其科学性和可行性， 并提出了 湿地边界确定的方法。

Study on the Theory and Methods of the Identification of Wetlands Boundary

Based on the analysis on the difficulty of wetland boundary identification and its causes,and having reviewed the wetland boundary indicators and their criteria selected at present,the paper suggested that,under the condition that the mechanism of wetland formation process has not been fully understood,all of the wetland boundaries based on hydrology and vegetation criteria are to some extent arbitrary boundaries.Wetland boundaries based on arbitrary criteria are not wetland's natural boundaries,because the natural boundaries of any complex can only be cognized,not be "man-prescribed".Even if there is no controversy on the criteria,it is usually impractical to identify wetland boundaries in the field accurately,because it takes repeated visits over a lengthy period of time(several years),and both seasonal conditions and then recent weather conditions should be considered when these indicators are applied.Wetland boundaries based on instantaneity indicators are unrepeatable and controversial.Aiming to resolve the problems on wetland boundary delineation,the paper analyzed the principles of the System Theory and physical geography related to wetland boundary delineation,and put forward a new method for wetland upper boundary identification.The method suggested that,under the condition that the mechanism of wetland formation processes has not been fully understood,"black box" method of System Theory can be used to identify wetland boundaries scientifically;when it is difficult to identify wetland boundary based on the characteristics of wetlands itself,if the boundaries of aquatic and terrestrial systems can be identified,they can be regarded as the wetland's lower and upper boundaries;the lower limit of rooted plants is chosen as the indicator for delineating wetland lower boundary,and the thinning-out point of the diagnostic horizon of zonal soil is chosen as the indicator for wetland's upper boundary,because the thinning-out point is a kind of critical point,and it can factually reflect the long-term interaction result of all environmental elements.The scientificity and feasibility of the method was also analyzed.The characteristics of the diagnostic horizon,which is less responsive to short-term change than wetland vegetation and hydrology,make sure that the delineating result is repeatable,and that the controversy can be avoided.