关键词: 植被指数NDVI, 温度变化, 太白山

Abstract: Taibai Mountain, the peak of Qinling Mountains, is located in the middle hinterland of Qinling Mountains. Based on NDVI data of Taibai Mountains Nature Reserve in May which were derived from remote sensing and in site survey, we analyzed the spatial-temporal changes of vegetation index for different vegetation zones during 1979 to 2009, as well as their responses to temperature. The results showed that the area where the average NDVI in May was higher than 0.2 accounts for 89.5% of the total Taibai Mountain, which indicates a good vegetation cover in the mountain nowadays. However, the significant vertical deviation was found in NDVI. The value of NDVI is generally over 0.2 for the low altitude regions while ranges from 0.2 to 0.5 for the high altitude regions. The pixles where NDVI increased and decreased significantly during the past three decades account for 4.88% and 3.92%, respectively, and no change was found in about 56% of the total pixles. The annual mean temperature in the study area tends to increase with a slope of 0.35℃/10 a during the last 30 years. The vegetation changes became more sensitive to temperature with the increase of altitude, which indicates that the ecosystem of Taibai Mountain that is characterized by a small human disturbance and a high elevation deviation has become a sensitive place responding to climate change.

Key words: NDVI, temperature change, Taibai Mountain