Zhang Yong, Liu Lu-Yu, Liu Yi, Zhang Man, An Cheng-Bang
Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, China.
Sci Rep. 2021 Mar 1;11(1):4870. doi: 10.1038/s41598-021-84399-z.
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.
在山地垂直植被带内，森林树木线和亚高山草甸带向高海拔的移动是对全球气候变化的明显响应。然而，山地系统内不同区域的草原带（低海拔）和终年积雪带是否发生类似变化仍未确定。这些对气候变化的响应是否一致也尚不清楚。在此，我们利用1989年至2015年的陆地卫星遥感影像，获取了中国西北天山不同时期的垂直植被带空间分布。我们认为不同垂直植被带对全球气候变化的响应是不同的。低海拔植被带的变化在空间上存在差异。然而，在高海拔地区（高于森林带），不同垂直带的变化趋势是一致的。具体而言，我们重点分析了温度和降水变化对终年积雪带、荒漠草原带和山地草原带的影响。结果表明，研究区域内气温呈上升趋势，是天山垂直植被带变化的主要因素。在气温显著上升的背景下，东部和中部山地草原的上限将向低海拔移动，这可能会限制当地畜牧业的发展。然而，西部的山地草原则呈现相反的趋势，这可能会增加牧场的载畜量，促进当地畜牧业的发展。所有研究区域内终年积雪带的下限都将进一步上升，这可能导致中西部地区地表径流增加。
