摘要
使用与ＴＭ１、２、３、４波谱通道相一致的手携式光谱仪，测试了典型草原代表植被类型之一的大针茅草原轻度、中度、重度三种利用强度的草地植被反射波谱特征．Ｄｕｎｃａｎ方差分析结果指出：三类草地植被和土壤背景的波谱特征之间存在显著差异，其中重度利用的冷蒿草原与其它二类草地的波谱特征差异最为明显．利用ＴＭ２、ＴＭ３二波段反射率ＰＣＡ结果和四个波段反射率之和，建立了识别三类草地的波谱指标及其阈值．相关分析表明：轻度、中度、重度利用草地的ＮＤＶＩ与ＲＶＩ均与产草量显著相关，最佳相关关系分别为直线、对数曲线和双曲线．
Stipa grandis steppe is one of main community types in the temperate,typical steppe zone of eastern Mongolia plateau.The changes of spectal reflectances of vegetations and their dominant species,soil-background under grazing influence were measured on a representative grazing gradient in July to August,1995,with a portable radiometer,which was spectrally configure to match bands 1,2,3,4 of the Landat4 Thematic Mapper(TM).1) while the grazing intensity increased,the reflectances in TM1 and TM3 bands of high coespitose grasses synusia were increased but the reflectance of low coespitose grasses synusia and Artimisia frigida decreased;2) the result of analysis of variance and Duncan multiple comprision showed:there were significance difference of vegetations and soil-background reflectance among lightly,moderately and heavily grazing communities.The tendence of reflectance variations in 4 bands were:lightly grazing <moderately grazing <heavily grazing and TM4<TM2<TM3<TM1.however there was not sagnificant difference of Vegetation Indexes(RVI,NDVI) and soil-background regression lines among three communisities;3) two equations were established by the sum ( P ) of the reflectances in 4 bands with the first component scores ( X 1 ) and the second component scores ( X 2 ) of PCA,made by the reflectances of TM2 and TM3 bands.respectively:P=0.60X 1+51.50(1) P=20.0X 2+43.70(2) The equation 1) can distinguish the heavily grazing community from the moderately grazing community with 94.74% probility and distinguish the lightly gazing community from mederately grazing community with 80% probility by equation 2);4) the result of regression analysis indicated:there were significant corralations between RVI or NDVI and biomass for three different grazing intensity communities,respectively.The most optimum correlative forms were: y=ax+b; ln y=a+bx and 1/y=a+b/x, respectievly. but there was higher correlation between PVI and biomass in the heavily grazing community,only.
出处
《内蒙古大学学报（自然科学版）》
CAS
CSCD
1997年第1期92-98,共7页
Journal of Inner Mongolia University：Natural Science Edition
基金
国家自然科学基金
关键词
波谱特征
草原
大针茅草原
植被
退化草原
degraded grassland\ reflectance spectral\ discrimination\ correlation
