**1. Introduction**

During the past decades, the vegetation-climate interaction has been a research focus of meteorology, climatology, geography, and ecology. The contents mainly include the impact of climate change on ecosystem and the feedback of vegetation cover change to atmosphere. Investigation on the correlation between vegetation variation and climate change and its influencing mechanisms are the basis for the studies on climate change adaptation and mitigation.

The response of terrestrial ecosystem to climate change, a complex issue in the field of global change, has been focused on in the last 30 years [1]. Vegetation cover has been proven to be governed by climatic factors, such as precipitation, temperature, solar radiation, and CO2 concentration. Therefore, variation in vegetation and its relationship with climatic factors reflected the sensitivity and vulnerability of the ecosystem to climate change (i.e., the responding processes) [2]. In many studies, the normalized difference vegetation index (NDVI) was selected to detect the impact of climate change on vegetation activity in Eurasia, [3–5]. Although the temperature increase was detected to dominate the vegetation cover and its dynamic in the northwestern China, western China, and the Tibetan Plateau, the impact of precipitation in the arid and semiarid regions may be more significant. The complicated and spatial heterogeneous effects of climate change on NDVI indicate the need to conduct further investigation at regional scales. Recently, in order to make clear the role of vegetation cover in the regional climate change, several studies on the feedback of land cover to atmosphere were conducted, especially after 1990s [6]. Land cover change (LCC) was documented as important as atmospheric circulation and solar orbit perturbations in climate change [7]. On the other hand, the feedback is regional-dependent due to the complicated climate and LCC in different regions.

The Karst region in the southwest China presents the transformation from vegetation covered landscape to exposed basement rocks, which was defined as the Karst rock desertification (KRD). In this region, the natural ecosystem is vulnerable while the human disturbance is severe. Earlier studies mainly emphasized the impact of land use change on vegetation cover [8–10], lacking consideration of climate change impacts at large scales. Furthermore, it is unknown the climatic effects of land cover change in the Karst region, especially land degradation. Therefore, in this chapter, the southwestern Karst region of China was selected to conduct land-atmosphere interactions research.
