报告人：孙桂全教授（山西大学复杂系统研究所）

时间：2018年7月16日（周一）16:00-17:00

地点：东区教学科研综合楼A座701

报告人简介：孙桂全，山西大学复杂系统研究所教授，博士生导师。主要从事种群和传染病斑图形成机理研究，以及一些具体的传染病(如狂犬病和H7N9禽流感等)控制措施。近五年，在国内外重要学术期刊发表SCI论文40余篇，1篇论文入选“中国百篇最具影响国际学术论文”，10篇论文入选“ESI高被引论文”(7篇第一作者，2篇通讯作者)，5篇论文入选“ESI热点论文”，在科学出版社出版网络动力学合著1部，以第一完成人于2017年获得山西省科学技术奖(自然科学类)一等奖，以第三完成人获得教育部高等学校科学研究优秀成果奖(自然科学类)二等奖。主持国家自然科学基金项目3项(其中面上项目1项)，山西省优秀青年基金1项，参与国家自然科学基金重点项目1项，获得“山西省青年拔尖人才”、“山西省高校优秀青年学术带头人”、“山西省高等学校131领军人才”和“博士后国际交流计划”。

报告摘要：It is well known that vegetation patterns characterize the distribution of the vegetation and provide some signs for vegetation protection. The positive feedbacks regulation between the water and plant biomass play an important role in the vegetation patterns in semi-arid environments, yet its influence on vegetation patterns is far from being well understood. In order to reveal a mechanism of positive feedbacks on pattern formation, a water-biomass model in semi-arid environments with soil-water diffusion feedback is presented. Our results reveal that, as the soil-water diffusion intensity decreases, the pattern transitions: gap patterns→stripe (labyrinth) patterns→spot patterns emerge. More importantly, when the soil-water diffusion feedback intensity is smaller, the feedback will promote the growth of the vegetation; when the feedback intensity is much larger, the vegetation biomass will decrease and the feedback may induce the emergence of desertification. Additionally, the rainfall can also induce the pattern transition. As the rainfall capacity increases, the vegetation disappears and becomes the uniform vegetation state. Our findings highlight the relationship among feedback intensity, rainfall and pattern dynamics of the vegetation.