Knowledge Resource Center for Ecological Environment in Arid Area
| 中国植被活动对气候变化响应的复杂特征研究 | |
| 其他题名 | Study on the Complex Characteristics of Vegetation Activity Response to Climate Change in China |
| 焦珂伟 | |
| 出版年 | 2018 |
| 学位类型 | 博士 |
| 导师 | 吴绍洪 ; 高江波 |
| 学位授予单位 | 中国科学院大学 |
| 中文摘要 | 气候变化对植被活动的影响反映出多要素、多过程耦合的交互作用，并呈现出随不同区域水热组合及下垫面类型与属性变化的差异性。基于此，本研究以地理学“过程—格局”耦合为理论基础，针对中国植被活动对气候变化响应的非线性以及时空多维性，借助模型模拟、加权回归以及时空统计等技术手段，系统研究其异质性、动态性和脆弱性等复杂特征。主要结论如下：（1）过去30余年中国植被活动对气候变化的响应格局基于地理加权回归（GWR）等方法，探究了1982—2013年中国植被活动（NDVI）及其动态特征对气候变化响应的时空格局。中国植被活动与温度指标在空间上的负相关关系主要集中在东北、西北及东南部分地区；针对不同气候指标的标准化系数对比可知，植被活动受水分控制作用较为显著的区域主要集中在北方地区以及青藏高原，温度的主导作用区域则分布在华东、华中及西南地区，其中年均最高气温对植被活动的主导区域范围最广；植被动态与气候变率的回归结果表明，中国东北、东部沿海等区域增温速率的升高会通过加剧干旱等机制对植被活动产生抑制作用，而黄土高原等地区水分变率对植被活动的强弱起到了重要的正向调节作用。（2）中国植被活动时空变异的气候因子敏感性与贡献度应用时间敏感性分析、累积斜率变化率比较以及地理探测器等方法，基于陆面模式（CoLM）对光合速率的模拟以及植被覆盖（NDVI）状况来表征植被活动时空变化，研究时空尺度上影响植被活动的气候变化的敏感性和贡献率。对植被动态而言，光合速率的减小对升温的敏感性较高的区域主要集中在中国东北部和中部地区，体现出气候对植被活动影响的非线性特征，但升温的贡献率随时间变化有所下降；北方和青藏高原大部分地区的植被活动过程对降水变化的敏感性较高，包括降水对植被活动过程中的直接作用和通过调节其它气候要素带来的间接影响，体现出植被活动对气候交互作用的响应特征，并且多数区域的降水贡献率随时间变化逐渐提高。对植被活动分布而言，降水变化是影响大多数地区植被活动格局的主导气候要素，北方部分地区和青藏高原的植被活动分布对水热要素的敏感程度都较高，尤其是对于降水量相差100mm以上区域，植被活动格局的差异性最为显著。而水热要素对亚热带/热带地区植被动态与空间分布的贡献程度相对较低，敏感性程度也相对较弱。（3）融合敏感性与适应性的植被活动响应气候变化脆弱性通过对脆弱性内涵的进一步解析，剥离出敏感性和适应性两部分重要内容，并将两者量化后进行综合集成，构建一个基于响应过程的生态系统对气候变化脆弱性的定量评估体系。该方法强调了生态系统适应性在脆弱性评估研究中的重要作用，应用于中国生态系统（NPP）对气候变化脆弱性的评估结果表明：从过去到未来的70年时段内（1981-2050年），中国将有近三成的陆地生态系统对气候变化产生脆弱性，其中以草地和荒漠生态系统最为严重，主要分布在天山和内蒙古高原地区；对气温和降水的敏感性和适应性的作用效果和贡献大小的不同导致了中国生态系统脆弱带的区域性差异，例如黄土高原西北部等地区升温的不利影响较大，对气温的高敏感性是生态系统脆弱性的主因，而东南部的脆弱性主要是受生态系统对降水变化的适应性影响。（4）未来30年中国植被活动对气候变化的响应特征未来30年（2021—2050年，RCP4.5情景）气候变化对中国植被活动（NPP）影响的空间分布与动态特征的结果表明，北方地区生态系统对气候变化的脆弱性区域较过去30多年相比有所增加，且对降水的脆弱性水平要高于气温；随着水热特征的变化，西北等一些地区影响植被活动分布的主导气候因子产生变化，东北地区甚至出现与过去相反的气候-植被关系，而植被活动对降水的响应格局将表现出向南移动的趋势；青藏高原植被活动的增强以及中东部地区植被活动减弱的现象表明，虽然增温速率过高将会对植被活动产生抑制作用，但降水变率可能会改变植被所需的水热条件从而起到调节作用；中国北方大部分地区的植被活动可能对干旱条件逐渐适应，但南方多数地区仍将继续受到水分减少的抑制作用。 总之，从时空维度的动态性和异质性，以及集成非线性与多要素协同效应的脆弱性，系统开展植被活动对气候变化响应的复杂特征研究，不仅继承与丰富了地理学和生态学的学术传统，而且对于全面深入地掌握中国自然生态系统响应不同气候要素的变化，并明确国家尺度生态效应具有显著贡献，以期可为区域可持续发展与科学应对气候变化提供科技支撑。 |
| 英文摘要 | The impact of climate change on vegetation activity reflects the interaction of multi-factors and multi-processes coupling, and it also presents the spatial heterogeneity with the variation of hydrothermal condition and land coverage in different regions. According to the geographic logic of "process and pattern coupling", a systematic study of the complex characteristics of vegetation activity response to climate change in China from heterogeneity, dynamics and vulnerability, in connection with its nonlinearity and temporal-spatial multidimensionality through methods such as model simulation, weighted regression, and spatiotemporal statistics. The main conclusions are summarized as follows:(1) The response pattern of vegetation activity to climate change over the past 30 years in China.The spatial distribution and dynamic characteristics of the response of vegetation activity (NDVI) to climate change from 1982 to 2013 in China were investigated by the geographically weighted regression (GWR) model and some other statistical methods. The results noted that the spatial non-stationary relationship between vegetation activity and surface temperature was appeared in China. The significant negative temperature-vegetation relationship was distributed in northeast, northwest and southeast parts. At then, by comparing the normalized regression coefficients for different climate factors, it presented moisture dominants for vegetation activity in the North China and the Tibetan Plateau, and the regions with temperature dominants for vegetation activity were distributed in the East, Middle and Southwest China, where the annual mean maximum temperature accounts for the largest areas. Furthermore, the regression coefficients between NDVI dynamics and climate variability indicated that the higher warming rate could result in the weakened vegetation activity in the Northeast China and eastern coastal regions through some mechanisms such as enhanced drought, while the moisture variability could mediate the hydrothermal conditions for the enhancement of vegetation activity in the Loess Plateau and some other regions.(2) Climate sensitivity and contribution of temporal and spatial variation in vegetation activity in China.The spatiotemporal variation of vegetation activity was characterized as photosynthetic rate based on the simulation of the common land model (CoLM), and vegetation cover (NDVI). And then, the sensitivity of the vegetation activity to hydrothermal variations and the contribution of climatic factors on the spatial-temporal scales were studied by the application of time-sensitivity analysis, comparative method of the slope changing ratio of cumulative quantity, and geographical detectors. For the dynamics of vegetation activity, the negative effects of warming on vegetation activity were primarily concentrated in the northeastern and central parts of China. The sensitivity of decreasing photosynthetic rate to warming was higher, which reflected the nonlinear characteristics of the climate impact on vegetation activity. However, the degree of contribution of warming decreased over time. And then, vegetation activity processes sensitivity to precipitation variation in most parts of the North China and the Tibetan Plateau were relatively higher, including the direct effects of precipitation on vegetation activity and the indirect effects through other climate factors, which reflected the response characteristics of vegetation activity on the climate interaction. And the contribution rates of precipitation to vegetation in these regions gradually increased over time. For the distribution of vegetation activity, the precipitation variation was the dominant climatic factor affecting the pattern of vegetation activity in most regions. The distribution of vegetation activity in some parts of North China and the Tibetan Plateau was highly sensitive to the hydrothermal factors. In particular, the difference in the pattern of vegetation activity was most significant for areas where the precipitation varies by more than 100mm. In addition, the contribution of hydrothermal factors to the dynamics and spatial distribution of vegetation activity in the subtropical and tropical regions was relatively low, and the degree of sensitivity was also comparatively weak.(3) The vulnerability of vegetation activity in response to climate change: integrating sensitivity and adaptability.Through analysis of the concept of vulnerability, we propose a response-based quantitative method to assess ecosystem vulnerability, integrating the concepts of sensitivity and adaptability. Compared with previous research, this method emphasizes the critical role of adaptability, which enhances the scientificity and reasonableness of assessing ecosystem vulnerability. This method was applied to assess ecosystem (NPP) vulnerability in China from past to future (1981-2050). The results indicated that vulnerability would develop in nearly 30% of the terrestrial ecosystems of China. Vulnerability would be severe in the grassland and desert ecosystems, distributed mainly in the Tianshan Mountain and the Inner Mongolia Plateau. As the effects and contribution of sensitivity and adaptability to temperature and precipitation differ, obvious regional differences exist between the ecosystem vulnerability zones in China. For example, the effects of climate warming would be severe in the northwest of the Loess Plateau, with vulnerability caused mainly by high sensitivity to warming, whereas ecosystem vulnerability in the southeastern part would be caused mainly by low adaptability to precipitation.(4) The response of vegetation activity to climate change over the next 30 years in China.The spatial distribution and dynamic characteristics of climate change effects on vegetation activity (NPP) in China in the future (from 2021 to 2050, RCP4.5) were investigated using a geographically weighted regression (GWR) model. The results revealed that the areas of ecosystem vulnerability to climate change in North China will be increased compared to the past 30 years, and the eco-vulnerability to precipitation variation will higher than that to warming in the future. The spatial correlation between vegetation activity and climate change may be altered due to the varying climate features and vegetation cover. There will be different dominant climatic factors for vegetation activity distribution in some regions such as Northwest China, and even opposite correlations in Northeast China. Additionally, the response of vegetation activity to precipitation will move southward in the next three decades. In contrast, although the high warming rate will restrain the vegetation activity, precipitation variability could modify hydrothermal conditions for vegetation activity. This observation is exemplified in the projected future enhancement of vegetation activity in the Tibetan Plateau and weakened vegetation activity in East and Middle China. Furthermore, vegetation activity in most parts of North China may adapt to an arid environment, whereas in many southern areas, vegetation will be repressed by water shortage in the future.In summary, from the dynamics and heterogeneity in both spatial and temporal dimensions, as well as the vulnerability of integrated nonlinearity and the superposition effect of multi-factors, this study on the complex characteristics of vegetation activity response to climate change, which is also the core field of research on terrestrial ecosystems response to climate change, will promote the academic tradition of geography and ecology. Moreover, detection on the regional effects of climate change can be helpful for sustainable development and copying with climate change impacts and risks. |
| 中文关键词 | 植被活动 ; 气候变化 ; 空间异质性 ; 动态性 ; 脆弱性 |
| 英文关键词 | vegetation activity climate change spatial heterogeneity dynamics vulnerability |
| 语种 | 中文 |
| 国家 | 中国 |
| 来源学科分类 | 自然地理学 |
| 来源机构 | 中国科学院地理科学与资源研究所 |
| 资源类型 | 学位论文 |
| 条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/288084 |
| 推荐引用方式 GB/T 7714 | 焦珂伟. 中国植被活动对气候变化响应的复杂特征研究[D]. 中国科学院大学,2018. |
| 条目包含的文件 | 条目无相关文件。 | |||||
| 个性服务 |
| 推荐该条目 |
| 保存到收藏夹 |
| 导出为Endnote文件 |
| 谷歌学术 |
| 谷歌学术中相似的文章 |
| [焦珂伟]的文章 |
| 百度学术 |
| 百度学术中相似的文章 |
| [焦珂伟]的文章 |
| 必应学术 |
| 必应学术中相似的文章 |
| [焦珂伟]的文章 |
| 相关权益政策 |
| 暂无数据 |
| 收藏/分享 |
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。
