1993-2003年间温州沿海互花米草变迁

Variation of the Spartina alterniflora Loisel along Coastal Wenzhou as Aided by TM Images

互花米草由于其适应性和生长速度对当地环境产生很大影响,从而成为人们关注的外来入侵植物.为了弄清温州沿海自20世纪80年代末引种以来互花米草的变化以及影响,在比较1993年、2000年和2003年的TM遥感影像的基础上,对温州滩涂互花米草进行实地调查和访问.结果显示,温州滩涂互花米草1993年总面积为3.921km2,2000年总面积为4.552km2,2003年总面积为6.361km2.龙湾等地方互花米草面积减少,是因为互花米草淤高后被开发成为海水养殖池塘.互花米草入侵、超越原生滩涂植被,并且在海堤外形成单优种群,表明互花米草很强的竞争力和扩张能力.互花米草在温州没有形成成熟的种子,依靠根茎无性繁殖.

Three Landsat images of 1993a 2000a and 2003a TM multi-spectral images were used for the mapping of Spartina alterniflora Loisel in the intertidal zone of the Wenzhou. The images were processed with ERDAS Imagine 8.5 image processing software. After being geometrically corrected, Karhunen-Loeve （K-L） transformation and atmospheric correction the area of interest was subset. Repeated GPS field investigations and interface interpretation produced 3 vector thematic layers that were used to build a GIS database. The results showed that the total area of Spartina alterniflora Loisel in the three years in the Wenzhou region was 3.921km^2 （in 1993a）, 4.552km^2 （in 2000a）, 6.361km^2 （in 2003a）, respectively, Indicating great ability of the plant to expand. In Longwan and a few other places the areas of the plant decrease as the intertidal flat formed by the intruded grass was transformed to fishery farms.