拉萨河源头麦地卡湿地景观格局及功能动态分析

Analysis of landscape pattern and ecological service function of the Mcdika wetland reserve

在全球变化的大背景下,如何保护好高原湿地显得非常迫切。为了有效保护拉萨河源头,采用遥感影像解译和模型评估方法,分析拉萨河源头麦地卡湿地的土地利用格局现状特征和服务功能变化,结果表明:麦地卡湿地保护区湿地面积减少5825hm2,湿地面积减少以沼泽湿地为主,草地面积增加5727 hm2,未利用地面积仅增加98.5 hm2;近30年来因气温和地表温度升高明显,暖干化的气候变化趋势导致湿地面积萎缩,天然牧草地面积显著增加;调节服务是麦地卡湿地保护区主要的生态服务功能,占总服务价值的70%,湿地面积尤其是沼泽湿地面积的萎缩是麦地卡湿地保护区生态服务功能减弱的主要原因。

Against the background of global climate change, how to effectively protect the Mcdika plateau wetland is an urgent question that needs to be addressed. To effectively protect the source of Lhasa River, this study used the remote sensing image interpretation method and model evaluation method to analyze the characteristics of change in the landscape pattern of the Mcdika wetland and evaluated changes in its ecosystem services function. The results show that the area of the Mcdika wetland has decreased by 5825 hm^2, most of which is marsh wetland. Grassland and unused land area have increased by 5727 hm^2 and 98.5 hm^2, respectively. Furthermore, the trend of climate warming and drying, indicated by clear increases in temperature and ground temperature over the past 30 years, has led to the shrinking of the wetland area and a significant increase in the area of alpine meadow. The results of ecosystem services function show that the main ecological service function of the Mcdika wetland reserve is regulation, which accounts for 70% of the total. The shrinking of the wetland area is the primary reason for the weakening of the ecological service function of the Mcdika wetland reserve.