国家生态保护重要区域植被长势遥感监测评估

国家生态保护重要区域植被长势对于维持区域生态系统结构和功能的稳定性至关重要.以国家重点生态功能区、国家重要生态功能区、国家生物多样性保护优先区和国家级自然保护区等四类生态保护重要区域为研究区,选取年累积NDVI作为指示因子,监测评估了1998-2007年间国家生态保护重要区域的植被长势特征.结果表明:(1)国家生态保护重要区域总面积为536.59万km2,占全国陆地国土面积的55.89％.国家生物多样性保护优先区与国家重点生态功能区、国家重要生态功能区的重叠面积较大,分别占到相应生态功能区总面积的53.36％和50.20％.国家级自然保护区与其他三种类型区域的空间叠加关系较好,尤其与国家重点生态功能区,重叠面积占国家级自然保护区总面积的75.10％.国家重点生态功能区和国家重要生态功能区的重叠面积分别占各自面积的63.73％和39.15％.(2)对于植被长势总体状况,国家生态保护重要区域中东部的植被状况好于西部.植被状况较差的区域面积为10.59％,植被状况一般的区域面积为29.59％,植被状况好的区域面积为23.44％,植被状况较好的区域面积为36.39％.国家级自然保护区和生物多样性保护优优先区的植被状况好于国家重要生态功能区和国家重点生态功能区.国家级自然保护区的空间分布差异最大.(3)对于植被长势变化趋势,国家生态保护重要区域的植被状况整体呈现出变好趋势.62.39％区域面积的植被状况较为稳定,22.69％区域面积的植被状况呈现出变好趋势,14.93％区域面积的植被状况呈现出变差趋势.国家重要生态功能区的植被变好趋势最为明显,其次为国家生物多样性保护优先区.国家生物多样性保护优先区的植被变化趋势空间差异最大,国家级自然保护区的植被变化趋势空间差异最小.

Satellite-based monitoring and appraising vegetation growth in national key regions of ecological protection

With the development of China, government is coming to realize the important of the nature and ecology conservation. In recent ten years, the government has set up many national key regions of ecological protection, and taken lots of effective measures to protect nature and ecology, then supporting the sustainable development. These regions mainly include National Key Ecological Function Region (KEFR), National Important Ecological Function Region (IEFR), National Biodiversity Protection Priority Region (BPRR) and National Natural Reserve Region (NNPR). It is well known to us that vegetation is one of the most important and active ecological element, and vegetation growth in national important ecological protection region is very important for maintaining stabile structure and function of regional ecosystem. In this paper, these national key regions are taken as the study region, cumulative NDVI is taken as the instruction factor, and vegetation growth is monitored and evaluated. Based on the SPOT VEGATATION NDVI from 1998 to 2007, mean value, standard deviation and linear change trend coefficient this period are calculated, and spatio-temporal statistical feature of vegetation growth is analyzed. The results show that: (1) Total area of the important ecological protection regions is 536.59 km², accounting for 55.89% of the national land area. BPRR and KEFR and IEFR overlapped area is up to 53.36% and 50.20% of the total corresponding ecological function area respectively. NNPR and the other three types of area overlapped area are good, especially with KEFR, its area accounts for 75.10% of NNPR. For KEFR and IEFR, overlapped area is respectively 63.73% and 39.15% of the corresponding types regions. (2) About general vegetation growth from 1998 to 2007 in these regions, middle and eastern area is better than that of the western regions. About the vegetation growth, there is about 10.59% in poor level, about 29.59% in common level, about 23.44% in well level, and about 36.39% in better level. NNPR and BPRR are better than KEFR and IEFR. The difference of spatial distribution is the most remarkable. (3) About change trend of vegetation from 1998 to 2007 in these regions, general trend in these regions is a slightly increasing. 62.39% of these regions is a relatively stable trend, 22.69% of these regions is in a better trend, 14.93% of these regions is in a bad trend. IEFR is the most obvious vegetation trend, the second is BPRR. BPRR in the different of change trend is maximum, NNPR is minimum. For different types of national ecological protection areas, these results are different beneficial to different national important ecological protection region. For NNPR, these can reflects the effectiveness of the protection after their establishment in a certain extent. For others, these can be used as the background of the ecological state, and carried out the analysis of the effectiveness of national ecologically important protected areas in the future.