1974-2017年洪湖湿地自然保护区景观格局演变及驱动力分析

摘要

This study took Honghu National Nature Reserve as an example to investigate the driving forces on Landscape pattern changes based on the land use and land change data of 1974, 1979, 1984, 1990, 1996, 2001, 2006, 2009, 2014 and 2017, which were obtained from interpretation of Landsat images. Correlation analysis was adopted for finding characteristics of the interaction by combining with meteorological hydrological data such as temperature, precipitation and water stage. The results showed that: Land use intensity index risen from 207 at the begining of the study to 249.36 at the end of the study during the period of1974-2017, these changes were more due to enlargement in the interference of human activities for land-use change. About 30％ of the natural wetlands translated into ponds, farmland and bottomland and construction land by 2017. The landscape pattern indices of different types have changed greatly, the lakeside zone has formed a low enclosed ponds dominated by aquaculture after entering twenty-first Century. On the whole, landscape tended to be diversified, fragmented, reduced in connectivity and weakened in stability. The correlation coefficient between land use intensity index and the composite index of landscape pattern is 0.84, it shows that LUCC is very closely related to the landscape pattern. With the increase of land use intensity, the landscape is more fragmented, the degree of connectivity between patches is weakly, the landscape aggregation degree of the area is decreasing, and the landscape heterogeneity is increasing. In general, the Honghu Wetland Nature Reserve is affected obviously by human interference. The goal of maintaining the balance of Honghu wetland ecosystem is achieved through rational exploitation and utilization, returning farmland to grass and lake, restoring the vegetation of the lakeside zone, increasing the diversity of its aquatic plants, realizing the effective restoration of the wetland, improving its structure and function. A combination of the natural restoration of vegetation and the establishment of demonstration area of vegetation restorations is carried out, and the hygrophilous vegetation, emergent aquatic vegetation, floating vegetation, floating-leaved vegetation, and submerged vegetation, should be constructed from the lakeside to the heart of the lake.%利用Landsat系列遥感影像数据 (1974、1979、1984、1990、1996、2001、2006、2009、2014和2017年) 解译得到的土地利用/土地覆盖变化 (LUCC) 结合研究区44年的气温、降水量、水位等气象水文数据, 构建LUCC经验统计模型和计算景观格局指数, 探讨1974-2017年洪湖国家级自然保护区景观格局变化的主要驱动因素.研究结果表明:土地利用强度指数由1974年的207增加到2017年的249.36, 人类开发利用湖滨带的程度增强, 到2017年约有30％的自然湿地转化为坑塘、农田和滩地及建设用地.不同地表覆盖类型的景观格局指数均发生了较大变化, 2000年以后湖滨带逐渐形成了以养殖为主的低矮围景观.总体上景观趋于破碎化、连通性降低、稳定性变弱.洪湖湿地自然保护区土地利用强度指数与景观格局综合指数呈较显著的正相关, 两者的相关系数为0.84, 土地利用强度增加则景观更加破碎、斑块之间的连接程度减弱、区域的景观聚集度下降和景观异质性增加.总体而言, 洪湖湿地自然保护区受人为干扰影响明显, 开展封湖育草自然恢复与建立植被恢复示范区相结合, 构建自湖滨至湖心的梯度变化完整的湿生植被-挺水植被-漂浮植被-浮叶植被-沉水植被的水生植物群落, 退耕还草、退垸还湖、修复湖滨带植被, 大幅度提高洪湖的自净能力, 增加其水生植物多样性, 实现湿地的有效修复, 改善其结构和功能, 维系洪湖湿地生态系统的平衡.