青藏高原植被生长季变化及对气候的响应研究
于海英
学位类型博士
导师许建初
2010-01
学位授予单位中国科学院研究生院
学位专业植物学
摘要青藏高原是对全球气候变化响应最敏感的区域之一。其特有的高寒生态系统对气候的响应一直是科学家关注的热点。植物物候则是反应气候变化最好的指示器。从植物物候的角度去研究高寒生态系统对气候变化的响应是很值得探讨的,但目前在青藏高原这方面的研究却比较缺乏,且实测数据也有限。因此通过遥感手段研究高原植被生长季变化及对气候的响应具有重要的科学和实践意义。本文首先研究了NDVI与温度和降水的年际变化及相互关系。然后采用在已有基础上进行了改进的斜率法和比率阈值法,利用NDVI数据分别模拟了高原区1982-2006的生长季。经过与实测数据的对比分析,最终选择了比率阈值法和合适的阈值。利用选择的方法和阈值模拟了1982-2006年的生长季,并分析了多年平均生长季的空间分布,然后采用线性趋势分析了研究时段内生长季的年际变化。最后利用多元回归分析方法探讨了植被生长季与温度和降水的关系。研究得出的结果包括以下主要结论:1)比率阈值法在模拟植被生长季时优于斜率法;应用比率阈值法模拟青藏高原草地生长季开始日期和结束日期的最适阈值分别为0.2和0.6。2)草甸和草原5-6月的NDVI值和生长季开始日期都在研究时段内呈现了相似的非线性特点。3)如果以2000年为分界点分析生长季变化,草甸和草原生长季开始日期在2000年前显著提前(分别为0.48 d yr-1和0.62d yr-1),后推迟;草甸的结束日期在整个时段线性不显著, 而草原显著提前(0.52 d yr-1);草甸和草原生长季长度在2000年前显著延长(分别为0.49 d yr-1 和0.55 d yr-1),在2000年后推迟。生长季开始日期与温度和降水的关系比结束日期要显著。冬季温度的显著上升,使植物低温需求量被满足的时间延长,从而使开始日期推迟。春季温度和降水上升,促进生长季开始日期提前。7、8月份温度升高促使草甸结束日期提前,而9月温度的升高和5-9月份降水的增多也会延长草甸生长季结束日期。 最后,本文还指出了研究中在数据、方法中存在的问题,并指出了一些可能解决的途径,希望在以后的研究中能有所改进。
资助项目Tibetan Plateau is one of the most sensitive areas to global climate change. The response of alpine ecosystem to climate change becomes a hot topic of scientific research. Plant phenology is best indicator of climate change. It will be meaningful to look at the response of alpine ecosystem to climate change from the plant phenology point of view. However, phenology research is still very weak on the Tibetan Plateau, and the ground observations are also very limited. Therefore, study on the growing season change and relation with temperature and precipitation will be scientifically and practically meaningful.In this study, we studied the interannual change of NDVI, temperature and precipitation and their correlation. Then the growing season on the Tibetan Plateau was simulated using both the slope method and NDVI ratio method. By comparing the results with ground observation, the NDVI ratio method with certain threshold was selected. Growing season from 1982-2006 was simulated with the selected method and then the spatial and temporal distribution of growing season was analyzed. Finally, we used multi-regression to derive the relation between growing season, temperature and precipitation. Some main conclusions were drawn from this study. NDVI ratio method performs better in simulating the growing season than slope method. The final thresholds selected for simulating the start and end dates of growing season are 0.2 and 0.6, respectively. Both the mean NDVI in May and June and beginning dates of growing season of meadow and steppe shows non-linear trend from 1982 to 2006. However, the beginning dates of growing season of meadow and steppe before 2000 display significant advance trend(0.48 d yr-1 and 0.62d yr-1,respectively), but delay after 2000;the end dats of meadow shows no significant trend during 1982 and 2000,but trend of the end dats of steppe is significant(0.52 d yr-1);the lengths of growing season of meadow and steppe become longer before 2000(0.49d yr-1 and 0.55 d yr-1,respectively), then become shorter afterwards. Relation between temperature and precipitation with beginning dates of growing season is more significant than with end dates. The significantly rising temperature in winter delay the beginning dates of growing season because of the reduction of chilling requirement. Increase of spring temperature and precipitation promotes early beginning dates of growing season. The end dates of growing season are early due to the increase of temperature in July and August, but are late when temperature in September and precipitation from May to September increases.Finally, we figure out the shortcoming of the study and recommend possible way to solve the problem and more detailed future work is required.
语种中文
文献类型学位论文
条目标识符http://ir.kib.ac.cn/handle/151853/16036
专题昆明植物所硕博研究生毕业学位论文
推荐引用方式
GB/T 7714
于海英. 青藏高原植被生长季变化及对气候的响应研究[D]. 中国科学院研究生院,2010.
条目包含的文件
文件名称/大小 文献类型 版本类型 开放类型 使用许可
于海英.pdf(2040KB) 限制开放--请求全文
个性服务
推荐该条目
保存到收藏夹
查看访问统计
导出为Endnote文件
谷歌学术
谷歌学术中相似的文章
[于海英]的文章
百度学术
百度学术中相似的文章
[于海英]的文章
必应学术
必应学术中相似的文章
[于海英]的文章
相关权益政策
暂无数据
收藏/分享
所有评论 (0)
暂无评论
 

除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。