衡水湖湿地植被对人为干扰的响应及其保护成效

It has always been a hot spot of the protection efficacy of wetland and its response to human disturbance in wetland science. However, existing researches were mostly about the construction of evaluation index systems of protection efficacy of protected areas. Study on the influence of human activities on wetland protection efficacy and response of wetland vegetation to human disturbance were little. On the basis of previous researches, this project takes research about the spatio-temporal dynamic pattern of vegetation and human activity at Hengshui Lake, using remote sensing and GIS. Then we develop the study about the response of wetland vegetation to human disturbance at Hengshui Lake with the human disturbance index and landscape index, etc. Moreover, the composition and structure of plant community will be analyzed, developing the study about the response of wetland plant community to different types and intensity of human interference with the sample investigation. By constructing the evaluation model of protection efficacy to vegetation, the protection efficacy to wetland at Hengshui lake nature reserve will be evaluated. The response process of wetland vegetation to human disturbance and key influencing factors of protection efficacy will be revealed, providing technological support for wetland conservation and restoration.

湿地保护成效及其人为干扰影响是湿地科学的研究热点之一。但已有研究多停留在自然保护地保护成效评估体系构建上，对人类活动如何影响湿地保护成效，湿地植被对人为干扰的响应仍鲜有报道。在前期研究的基础上，运用遥感和GIS技术，分析衡水湖湿地植被和人类活动时空动态格局；使用人为干扰度指数和景观指数等，分析人为干扰对衡水湖湿地植被的影响；通过样地调查，植物群落组成和结构分析，开展不同干扰类型和干扰强度下湿地植物群落的响应研究；构建植被保护成效评估模型，开展衡水湖湿地保护成效研究；揭示衡水湖湿地植被对人为干扰的响应规律和影响保护成效的关键因素，为湿地修复和保护工作提供科技支撑。

本项目开展了衡水湖湿地植被和人类活动时空动态格局、人为干扰对湿地景观格局动态变化影响、湿地植被对人为干扰的响应、湿地保护成效等研究。发现近些年衡水湖自然保护区景观动态变化局限在林地、草地和道路用地等局部。景观动态变化导致了保护性景观和人为干扰景观等破碎化程度不断增强和聚集程度降低，景观异质性明显增加，景观多样性和均匀度指数保持增长，优势景观斑块连通性降低。自然保护区边缘人工景观的增加明显高于衡水湖自然保护区内部，表现为明显的溢出效应。而且人类活动显著改变了衡水湖湿地的植物种类组成和植物群落格局。植物多样性随人为干扰增强呈先增加后减少的趋势。景观多样性指数和植物丰富度指数均在中度干扰下最高，符合中度干扰假说。原生植物、入侵植物、景观植物和农田杂草等不同植物类群对人类干扰的响应强度不同，导致物种更替和植物群落结构改变。提出了植被综合质量变化指数和景观压力指数等模型，以评估湿地保护区的保护成效。衡水湖自然保护区景观保护成效较好，景观发展强度和景观压力指数均在下降。但局部景观发展强度和景观压力有所上升，特别是湖区自然湿地周边。衡水湖湖区湿地植被综合质量变化指数为-0.55，湿地植被综合质量变差。自然湿地周边公园绿地和鱼塘等增加导致了景观发展强度和压力指数增长，成为影响其保护成效的主要因素。同时，我国湿地保护体系对野生动植物的保护比例越来越大，湿地保护成效不断提升。该结果对揭示湿地植被对高强度人为干扰的响应机制具有重要意义，为湿地保护成效及其主要影响因素研究奠定了基础。