Abstract
Within the mountain altitudinal vegetation belts, the shift of forest tree lines and subalpine steppe belts to high altitudes constitutes an obvious response to global climate change. However, whether or not similar changes occur in steppe belts (low altitude) and nival belts in different areas within mountain systems remain undetermined. It is also unknown if these, responses to climate change are consistent. Here, using Landsat remote sensing images from 1989 to 2015, we obtained the spatial distribution of altitudinal vegetation belts in different periods of the Tianshan Mountains in Northwestern China. We suggest that the responses from different altitudinal vegetation belts to global climate change are different. The changes in the vegetation belts at low altitudes are spatially different. In high-altitude regions (higher than the forest belts), however, the trend of different altitudinal belts is consistent. Specifically, we focused on analyses of the impact of changes in temperature and precipitation on the nival belts, desert steppe belts, and montane steppe belts. The results demonstrated that the temperature in the study area exhibited an increasing trend, and is the main factor of altitudinal vegetation belts change in the Tianshan Mountains. In the context of a significant increase in temperature, the upper limit of the montane steppe in the eastern and central parts will shift to lower altitudes, which may limit the development of local animal husbandry. The montane steppe in the west, however, exhibits the opposite trend, which may augment the carrying capacity of pastures and promote the development of local animal husbandry. The lower limit of the nival belt will further increase in all studied areas, which may lead to an increase in surface runoff in the central and western regions.
Highlights
Within the mountain altitudinal vegetation belts, the shift of forest tree lines and subalpine steppe belts to high altitudes constitutes an obvious response to global climate change
The changes in precipitation in the southern and eastern parts of the Tianshan Mountains differ from our results, which may be attributable to the different time frames of our respective investigations
Precipitation in the three study areas did not exhibit a significant increasing or decreasing trend (Fig. 2c). These findings demonstrated that precipitation is not the main factor of altitudinal vegetation belts change
Summary
Within the mountain altitudinal vegetation belts, the shift of forest tree lines and subalpine steppe belts to high altitudes constitutes an obvious response to global climate change. Global warming, a tendency exists for low-altitude species to migrate to high altitudes in altitudinal belts of mountains[10,11,12] These species primarily come from subalpine steppe or forest belts, resulting in an increase in the upper limit of the distribution of steppe belts and tree lines[13,14]. This trend of species migration has led to the emergence of low-altitude species adapted to the warm environment in alpine vegetation belts and the increase of species richness in high altitude areas[15]. Based on the research results, we mainly discussed the impact of the dynamics of the altitudinal vegetation belts on agriculture and animal husbandry
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
