Woody plant cover trends and potential drivers in the Horqin temperate steppe, northeast China: Remote sensing-based computation and modeling
Woody plant cover trends and potential drivers in the Horqin temperate steppe, northeast China: Remote sensing-based computation and modeling
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DOI：
10.1016/j.ecolind.2022.109789
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发表时间：
2023-02
影响因子：
6.9
通讯作者：
Qian Chen;Xiaoyu Yang;Se-Myoung Kwon;Yiran Li;Jiankang Liu;Kebin Zhang
中科院分区：
文献类型：
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作者：
Qian Chen;Xiaoyu Yang;Se-Myoung Kwon;Yiran Li;Jiankang Liu;Kebin Zhang
科尔沁温带草原是我国北方最大的草原。在多种潜在驱动因子的共同干扰下，该地区原生草本植被出现不同程度的退化，木本植物已成为该地区的优势植被。一方面，木本植物在防沙治沙、提供食物/木材产品等方面发挥着重要作用，另一方面，这种转化过程对草原生态系统的结构和功能产生了重要影响。有必要阐明木本植物覆盖变化的模式和决定因素。针对目前缺乏高时空分辨率的木本植被遥感数据的问题。基于高分辨率卫星影像和随机森林模型，研究表明，科尔沁温带草原近35年来木本植物覆盖度年均值为17.55%，显著增加面积约占总面积的43.7%.对增强回归树模型的分析显示，潜在的驱动因素主要归因于气候变化（即，年平均气温、年平均风速和年降水量）和放牧强度的影响，累积贡献率接近70%。此外，大规模和高密度的植树造林也可能是木本植物覆盖增加的原因。在气候极端事件频发的背景下，保持和提高草原生产力，避免盲目造林造成的区域气候恶化，制定合理的放牧管理政策，是保证半干旱温带草原相对生态稳定，实现区域农牧经济相对可持续发展的迫切需要。
The Horqin temperate steppe is the largest grassland in northern China. With the combined disturbance of multiple potential drivers, the native herbaceous vegetation has degraded with different intensity, and woody plants have transformed into the dominant vegetation in this area. On the one hand, woody plants play an important role in sand control, food/timber product provision, etc. On the other hand, this transformation process significantly affects the steppe ecosystem structure and function. It is necessary to clarify the patterns and determinants of woody plant cover changes. In view of the lack of high spatio-temporal resolution remote sensing data for woody cover. Here, based on high-resolution satellite images and the random forest model, the study reports the annual mean woody plant cover of the Horqin temperate steppe is 17.55 % over the past 35 years, and the significant increase area is approximately 43.7 % of the total area. Analysis of the boosted regression tree model showed potential drivers were mainly attributed to climate change (i.e., mean annual temperature, mean annual wind speed, and annual precipitation) and grazing intensity, with the cumulative contribution approaching 70 %. Furthermore, large-scale and high-density afforestation could also be responsible for the increase in woody plant cover. Against the background of frequent climate extremes, maintaining and improving steppe productivity, avoiding regional climate deterioration caused by blind afforestation, and developing a reasonable grazing management policy is the urgently needed to ensure the relative ecological stability of semi-arid temperate steppes and to achieve relatively sustainable development of the regional agro-pastoral economy.