KMS XINJIANG INSTITUTE OF ECOLOGY AND GEOGRAPHY，CAS
| 亚洲中部干旱区净初级生产力对气候变化响应的模拟研究 | |
| 朱士华 | |
| Subtype | 硕士 |
| Thesis Advisor | 张弛 |
| 2016 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 北京 |
| Degree Discipline | 地图学与地理信息系统 |
| Keyword | 中亚 Aem 模型 Npp 干旱区 气候变化 |
| Abstract | 中亚干旱区总面积500多万平方公里，分布着世界80%以上的温带荒漠，受气候变化的显著影响。本研究首先收集实验观测数据验证了干旱区生态系统模型AEM，然后运用AEM开展数值模拟实验量化研究了1980~2014年中亚净初级生产力（NPP）的时空格局，评估了不同环境因子（降水、温度、CO2）的相对贡献率及其交互效应。结果表明：过去35年中亚干旱区年均NPP总量为1125±129Tg C（1T=1012）或218±25g C/m2（Mean±SE）。哈萨克斯坦北部地区年NPP值较高（349±39g C/m2），而南疆地区NPP值较低（123±45g C/m2）。温带针叶林NPP值最高（556±82g C/m2），非深根灌木NPP值最低（158±25 g C/m2）。1980~2014年间，中亚NPP总体呈减少趋势（-0.71 g C/（m2•a)），南疆极端干旱区的NPP降低最为显著(-2.05g C/(m2•a))。相较于1980~1984年NPP均值，在1985~2014年间中亚区域NPP总体降低了118Tg或-10%。其中CO2施肥效应促进NPP增加了99.7Tg或+8%，气温升高的正效应促进NPP增加了35.4Tg或+2%，，而降水减少导致NPP降低了221Tg或-18%。研究区内9%的地区的NPP主要控制因子为温度，主要分布在天山和哈萨克斯坦北部等高纬高寒地区。降水主控区面积占整个研究区的69%，主要分布在荒漠平原特别是南疆等植被受水分限制的区域。CO2主控区占研究区面积的20%，主要分布在天山中山带森林区和低海拔地区等水热条件好的区域。本研究表明新疆南部地区是中亚的关键生态脆弱区，其生态安全面临着气候变化的挑战，但21世纪的升温不大可能因刺激自养呼吸而对中亚区域NPP造成显著影响。; More than 80% of world’s temperate desert locates in Central Asia, a 517×106 km2 dryland that experienced strong warming and significant changes in precipitation pattern in the recent decades. The objectives of this study were to quantify spatiotemporal patterns of net primary productivity (NPP) in Central Asia over the past 35 years (1980~2014), and investigate the relative contribution and interactive effect of climate controls including temperature, precipitation, and CO2, using the Arid Ecosystem Model (AEM), which performed well in predicting the dryland ecosystems’ responses to climate changes according to our evaluation. Our results showed the 35-year averaged annual NPP of Central Asia amounted to 1,125Tg C yr-1(1T=1012), or 218±24 g C m-2 yr-1, with an overall declining trend of 0.71 g C m-2 yr-1. The northern Kazakhstan had relatively high NPP of 34939 g C m-2 yr-1, while the southern Xinjiang of China had relatively low NPP of 12245 g C m-2 yr-1. The Temperate Needleleaf Forest had the highest NPP of 55881g C m-2 yr-1. The Non-Phreatophytic Shrub had the lowest NPP of 15825 g C m-2 yr-1. During the last 35-years, the NPP of the southern Xinjiang of China subregion declined significantly with a trend of -2.05 g C m-2 yr-1. Comparing the NPP of the 1985~2014 against the NPP of the 1980~1984, we found the regional NPP decreased 118Tg or -10%, with positive contribution of 35.4Tg or +2% from temperature change, positive contribution of 99.7Tg or +8% from CO2 change, negative contribution of 221Tg or -18% from precipitation change. The temperature was the dominant factor on NPP in 9% of the study area, mainly in the Tianshan mountain and northern Kazakhstan, where the temperature increased by 0.03C yr-1 from 1980~2014. Precipitation was the dominant factor on NPP in 69% of the study area, mainly in the desert subregion and the dryland of southern Xinjiang of China，where the vegetation were limited by water stress. CO2 was the dominant factor on NPP in 20% of the study area, mainly in the lower altitude regions of Tianshan mountain，where the hydrothermal condition was suitable for vegetation growth. This study shows that the Southern Xinjiang of China is the fragile ecologic-environmental subregion of Central Asia, whose ecosystem security is facing the challenges of climate change. However, increasing temperature is unlikely to stimulate autotrophic respiration and cause a significant impact on regional NPP in Central Asia. |
| Subject Area | 地图学与地理信息系统 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xjlas.org/handle/365004/14760 |
| Collection | 研究系统_荒漠环境研究室 |
| Affiliation | 中科院新疆生态与地理研究所 |
| Recommended Citation GB/T 7714 | 朱士华. 亚洲中部干旱区净初级生产力对气候变化响应的模拟研究[D]. 北京. 中国科学院大学,2016. |
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