Temporal and spatial variations of NDVI in Lake Baikal

Terrestrial vegetation is an important component of ecosystem. Quickly and accurately monitoring the status of vegetation growth and evolution has certain reference meaning in the socio-economic constructions and ecological studies. Remote sensing is an effective measure to monitor vegetation at regional and global scales. Taking the sensitive area to the global climate and environmental change, Lake Baikal and Siberia, the present study aims to explore the response of vegetation to the climate changes. The data of monthly NDVI / MODIS data, with a spatial resolution of 0.05 deg from 2003 to 2008 were used in this study. The results showed that the yearly variations of NDVI were well corresponding to the growth and decline of vegetation and seasonal changes, which showed obvious phenological phenomena. Correlation analysis presented that with increasing in temperature and precipitation, NDVI increased gradually and vegetations grew well. Moreover, the influence of the precipitation on vegetation was slightly lower than that of the temperature. From 2003 to 2008, the change of NDVI showed a gradual upward trend except the low value in 2006. In the growing seasons, NDVI from 2003 to 2008, roughly showed an upward trend; in non-growing seasons, NDVI showed a roughly linear downward trend. The spatial distribution of NDVI in the west Lake Baikal was relatively lower, and the highest value appeared in the north, followed by the south and east. Different vegetation types emerged in the different NDVI values. NDVI of the tundra was the lowest, followed by scrub and agricultural land, the NDVI values of the wetlands and grassland were relatively high, and the NDVI value of forest lands was the maximum.