| Title: | Grazing Altered the Pattern of Woody Plants and Shrub Encroachment in a Temperate Savanna Ecosystem |
| Author(s): | Zhang Z; Zhang B; Zhang X; Yang X; Shi Z; Liu Y; |
| Address: | "Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China. zzy100083@163.com. Research Institute of Forestry Policy and Information, Chinese Academy of Forestry, Beijing 100091, China. zzy100083@163.com. Beijing Station of the Forestry Science and Technology Extension, Beijing 100029, China. zbbeilin@126.com. Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China. zhangxiao978@caf.ac.cn. Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China. yangxh@caf.ac.cn. Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China. shizj@caf.ac.cn. Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China. liuyanshu@caf.ac.cn" |
| Journal Title: | Int J Environ Res Public Health |
| ISSN/ISBN: | 1660-4601 (Electronic) 1661-7827 (Print) 1660-4601 (Linking) |
| Abstract: | "Ulmus pumila-dominated temperate savanna is an important tree-grass complex ecosystem in the Otindag sand land, northern China. To date, few investigations have been undertaken on the spatial patterns and structure of this ecosystem and its driving factors under different grazing pressures. The objective of our study therefore is to explore whether grazing has affected the population structure/pattern of woody plants and shrub encroachment in a temperate savanna ecosystem. Results indicate that species richness and seedlings decreased with increasing grazing pressure. An increase in grazing pressure did not significantly affect adult-tree density, but it hindered the normal regeneration of U. pumila seedlings, further inducing population decline. U. pumila seedlings had a more significant aggregated distribution than juvenile or adult trees. The adult and juvenile trees had an aggregated distribution at the small scale and a random distribution at the large scale. Shrubs also showed a significant aggregated distribution. No clear effect on the spatial patterns of adult trees was observed; however, there was a noticeable effect for juveniles and seedlings under different grazing pressures. U. pumila seedlings had a positive association with their juveniles and Spiraea aquilegifolia, but a negative association with Caragana microphylla. Shrub encroachment occurred with decreasing grazing pressures. In conclusion, overgrazing led to the decline of U. pumila population, but the decrease in grazing pressure increased shrub encroachment in the temperate savanna ecosystem. Moderate grazing management may be a better way to enhance the stability of U. pumila population and reduce shrub encroachment" |
| Keywords: | Biodiversity China *Grassland *Herbivory *Plants Ulmus pumila-dominated temperate savanna grazing pressure population structures shrub encroachment spatial association spatial patterns; |
| Notes: | "MedlineZhang, Zhiyong Zhang, Bo Zhang, Xiao Yang, Xiaohui Shi, Zhongjie Liu, Yanshu eng Research Support, Non-U.S. Gov't Switzerland 2019/01/27 Int J Environ Res Public Health. 2019 Jan 24; 16(3):330. doi: 10.3390/ijerph16030330" |
