Understanding the impacts of ‘Grain for Green’ land management practice on land greening dynamics over the Loess Plateau of China

Land greening in China is regarded as contributing a great deal to greening of the Earth. The phenomenon is mainly attributed to climate change, arising atmospheric CO₂ and ‘Grain for Green’ (GFG) land management policies. However, limited knowledge is known how much land greening is from contributions of the GFG practice. Therefore, the study took the typical region of the GFG practice, the Loess Plateau, as the study area, and used 1982–2015 satellite-observed GIMMS3g normalized difference vegetation index (NDVI) data, ERA-Interim climatic variables (precipitation, temperature and solar radiation) and atmospheric CO₂ concentration data with the help of a developed TPRC-based NDVI model to derive GFG-induced NDVI after 1999. Furthermore, this study tracked the spatial-temporal dynamics of GFG-induced NDVI and assessed contributions of the GFG practice to regional vegetation changes. Results showed that satellite-observed NDVI and TPRC-based NDVI both exhibited an increasing spatial pattern from the northwestern to southeastern Loess Plateau, but their greening trends were separately 0.0022 and 0.0009 per year in 1982–2015 (p < 0.05). Note that the satellite-observed greening trend was much steeper with a slope of 0.0056 per year after 2006 (p < 0.05). The subsequent analyses documented that GFG-induced land greening were largely responsible for the steep trend. In space, evident greening patterns began to be observed in the central Loess Plateau from 2006 to 2008, afterwards expanded towards eastern and southwestern Loess Plateau. In 2011–2015, the increase magnitude of GFG-induced land greening in the Loess Plateau averagely accounted for 8.5 % in comparison to estimated TPRC-based NDVI, but in six natural zones were various, ranging from 3.2%–15.7%. In some regions of central Loess Plateau, GFG-induced NDVI contributed even more than 20 % to vegetation increase. This study highlights that land use management contributes more to land greening dynamics over the Loess Plateau compared to climate change and arising atmospheric CO₂ concentration. These findings likely provide some valuable information for curbing or enhancing specific-location vegetation changes in future regional land management and planning.     

Market-based grazing land transfers and customary institutions in the management of rangelands: Two case studies on the Qinghai-Tibetan Plateau

Beginning in the early 1990’s, grazing lands once held in common were contracted to individual households in the rangeland regions of China. The resulting fragmentation of rangelands has led to ecological and social problems. As China seeks to address intractable poverty and rangeland degradation, attention has turned to rental, or transfer, of contracted grazing land as a market-based approach to re-aggregating grazing land into larger units that support economies of scale. However, given that many pastoral regions still maintain community customary institutions, what the relationship between market mechanisms and local customary institutions should be in rangeland management needs further analysis. This paper applies comparative case studies of two types of relationships between market mechanisms and customary institutions: (1) market mechanisms that replace customary institutions in the case of Axi village, and (2) market mechanisms that are embedded within customary institutions in Xiareer village. This allows contrast of the impacts of differing approaches on livelihoods, livestock production, and wealth differentiation among pastoral households. We found that there is a higher level of livestock mortality, lower livestock productivity, and higher livestock production cost in Axi Village compared to Xiareer Village. In addition, household asset levels are higher and there is less income differentiation in Xiareer Village. It is concluded that embedding market mechanisms within customary institutions has had notable benefits for the herders of Xiareer Village, because it is a better fit to the coupled pastoral social-ecological system. Based on these findings, we argue that in pastoral communities where the rangeland transfer system for contracted grazing land has not yet been implemented, it is critical to reconsider China’s current policy approach to pay greater attention to the innovative management systems being developed in local regions. Instead of considering market-based approaches as oppositional to traditional institutions, options that derive from the interaction of market-based and customary institutions should be considered.     

青藏高原东缘山地古冰川沉积物化学参数指示意义

对于冰川沉积物化学特征的分析,可以有效地反映当地古环境的气候状况,本文通过对青藏高原东缘的古冰川山地的冰碛物进行采样,结合部分其他山地样品数据,进行地球化学元素实验,计算以及对比其化学参数。得到青藏高原东缘等十处古冰川山地冰川沉积物化学组分构成,利用CIA等参数分析其对当地环境的指示意义。     

青藏高原东坡一座充满神奇魅力的城市——雅安市生态旅游景观资源研究

基于较详尽的资料,分析雅安市自然、社会、经济概况,生态旅游可持续发展的原则,生物、地文、水体和人文生态等旅游景观特色资源。结果表明:(1)3N生态旅游已成为当今世界的潮流。(2)雅安市是一个充满独特魅力的生态旅游城市。(3)雅安市具有世界罕见的生物生态旅游景观资源,非常丰富的地文、水体和人文生态旅游景观资源,各种资源分布广泛,相互交叠。(4)雅安市素有天府之肺之称,空气和水资源质量优异。(5)雅安市生态旅游景观资源具有储量丰富、资源类型众多、文化多元和区位优势良好等特色。(6)在雅安市生态旅游资源开发中应注意遵循永续利用、保护性开发、特色性、协调性、社会经济效益和环境效益相统一等原则。     

甘肃黄土高原生态环境建设的问题与政策建议

新中国成立以来，甘肃黄土高原人民为了遏止该区域生态环境不断恶化的趋势，坚持不懈地进行大规模生态建设，创造了令世人赞叹的业绩。但是，若从建设效率的角度审视，所取得的成效与50多年所付出的巨大代价反差明显，区域生态环境至今依然是“局部有所改善，全局持续恶化”的状况。通过实地考察，该文对以往生态环境建设中存在的主要问题进行了实事求是的分析，探究问题的症结所在，提出了出台“黄土高原土地特区”政策等提高生态环境建设效率的5点政策建议.     

黄土高原地区生态足迹研究

基于黄土高原地区资源与环境遥感调查数据，介绍了生态足迹的基本概念，计算方法及目前研究现状，对黄土高原地区1991年的人均生态足迹分析结果表明，黄土高原地区1991年人均生态足迹赤字为0．6761hm^2。     

青藏铁路格拉段货物列车开行方案

根据青藏铁路格拉段特殊的自然、经济条件和铁道第一勘察设计院提供的车流量预测资料,结合实际运营经验,编制出区段重空车流斜表,再根据列车牵引重量和各区间的车流量,确定管内列车的行车量,从而编制格拉段的货物列车开行方案。     

青藏铁路格拉段货运车流组织及货物列车开行方案

根据铁道第一勘察设计院在青藏铁路格拉段设计可行性研究报告中对各站货物到发量预测,分析了格拉段的货流特点,提出了适应高原特点的车流组织原则,设计确定了青藏铁路格拉段的货物列车开行方案。     

青藏线运输能力适应性综合评价分析

在分析影响青藏线运输能力因素的基础上,建立了青藏线运输能力适应性模糊综合评价指标体系和模型,分3个层次对该线运输能力适应性进行综合评价,认为青藏线运输能力适应性水平是高的,整个运输组织方案是可行的,但还需对特大灾害和事故下的应对方案和措施进行研究。     

Multi-time scale analysis of precipitation variation in Guyuan, China： 1957-2005

Morlet wavelet transformation is used in this paper to analyze the multi-time scale characteristics of precipitation data series from 1957 to 2005 in Guyuan region. The results showed that （1） the annual precipitation evolution process had obvious multi-time scale variation characteristics of 15-25 years. 7-12 years and 3-6 years, and different time scales had different oscillation energy densities; （2） the periods at smaller time scales changed more frequently, which often nested in a biggish quasi periodic oscillations, so the concrete time domain should be analyzed if necessary; （3） the precipitation had three main periods （22-year, 9-year and 4-year） and the 22-year period was especially outstanding, and the analysis of this main period reveals that the precipitation would be in a relative high water period until about 2012.