Attribution analysis and multi-scenario prediction of NDVI drivers in the Xilin Gol grassland,China

Grassland degradation is influenced by climate change and human activities, and has become a major obstacle for the development of arid and semi-arid areas, posing a series of environmental and socio-economic problems. An in-depth understanding of the inner relations among grassland vegetation dynamics, climate change, and human activities is therefore greatly significant for understanding the variation in regional environmental conditions and predicting future developmental trends. Based on MOD...     

民勤县生态承载力动态趋势与驱动力分析

在全球变暖的大气候背景下,自然与人文因素的双重驱动下,民勤县的生态环境急剧恶化,民勤县生态承载力动态趋势的定量评价和驱动力分析对于促进该地区生态环境保护和可持续发展具有重要意义。文中利用基于生态足迹方法的生态承载力时间动态趋势评价方法,建立了民勤县1990-2007年18年间生态承载力供给与需求的时间动态趋势模型,对其趋势的变化速率与剪刀差进行了定量评价,预测了各项指标2008-2017年10年间的发展趋势,并分析了导致该趋势变化的自然与人文因素驱动力。研究结果表明:民勤县过去18年间人均生态承载力供给和需求呈差异不断增大的反向发展趋势,其中人均生态承载力需求加速增长,而人均生态承载力供给加速降低,供求趋势的剪刀差呈持续增大趋势,年均增长率达7.12%;其间,全县可载人口数持续降低,至2007年,民勤县可载人口数降至16.5万人,超载人口数增至14.7万人;未来10年内民勤县的生态承载力供求矛盾将呈不断加剧的态势,不可持续发展的状况将日趋严重。导致民勤县生态承载力供求矛盾不断加剧的主要驱动力包括水资源日益匮乏、土地生产力不断降低、人口压力持续增大,人口消费量急剧增长,消费结构和土地利用方式的不合理等等。     

基于P-E-R区域匹配模式的新疆可持续发展问题探讨

采用相对资源承载力的研究思路与计算方法,计算了新疆14个地、州、市的人口-经济-资源的相对经济承载力指数和向资源承载力指数及其匹配模式,分析了它们P-E-R区域匹配模式的特点。提出了可持续发展的对策与建议。     

基于P-E-R区域匹配模式的宁夏可持续发展问题研究

运用相对资源承载力的研究方法,计算了宁夏5个地级市2004年至2008年的人口经济比较压力指数和人口资源比较压力指数.对2008年宁夏5个地级市的相对经济承载力和相对资源承载力进行了分析,阐利述了2008年宁夏P-E-R区域匹配模式的结构特征及5年间各市人口经济比较压力指数和人口资源比较压力指数的动态变化.并且提出了宁...     

植物医学:我国农业现代化进程中的病害治理挑战､机遇和创新

在我国的农业现代化进程中,病害问题已经演变成为制约我国种植业可持续发展的重要因素之一,而建立在“病原学说”基础之上的病理学理论以及在其指导下形成的各类以“杀(抑)菌”为首要目标的防治措施难以应对当前病害严重发生的复杂局面。本文剖析了当前我国农业生产上病害严重发生的原因,认为主要是由于生产者在经济利益的驱动下,主观上对土、肥、水等自然资源进行掠夺性经营,实践中采取连年单一种植和化学品持续大量投入等不良栽培措施,导致农田理、化、生物学性状严重劣化和生态失衡,从而引发作物严重衰弱、“易感”和环境的极端“利病”所致。基于此,笔者倡导以重视寄主生理状态和不良环境因素的影响为重要内容的病害发生的“全面病因学说”以及以此为核心内容和基础的“植物保健医学”的发展,并对相关概念、历史和成功案例作了简介。在具体防病实践上笔者倡导以健康栽培为核心的作物病害综合治理策略及其应用,即一方面设法减少传统“病原物”的数量累积和阻断侵染,另一方面更加注重农田生态系统中理、化和生物学性状的改善,以重塑、促进和维护农田生态平衡,进而实现增强寄主抗性、促进寄主植物生长和防病治病的目标。上述观点是对传统病理学病害防治理论的补...     

Effects of temperature and light on seed germination of ephemeral plants in the Gurbantunggut Desert,China: implications for vegetation restoration

Seed germination is a key transitional stage in plant life cycle and is strongly regulated by temperature and light. Therefore, research on the effects of temperature and light on seed germination is extremely meaningful for vegetation restoration, especially in desert ecosystems. Seeds of 28 ephemeral plants collected from the Gurbantunggut Desert of China were incubated at different temperatures (5°C/1°C, 15°C/5°C, 20°C/5°C, 25°C/10°C and 30°C/15°C) in 12-h light/12-h darkness or continuous darkness regimes, and the responses of seed germination to temperature and light and the germination speed were studied in 2016. Results showed that seed germination percentage of the 28 ephemeral plants significantly differed to temperature and light. We classified the studied plants as the following groups based on their responses to temperature: 1 low temperature responsed plants, 12 moderate temperature responsed plants, 7 high temperature responsed plants, 4 non-responsed plants and 5 plants of no germination. It should be noted that Corispermum lehmannianum Bunge is sensitive to both moderate and high temperatures. There were 4 groups of plant in response to light, i.e., 7 light responsed plants, 10 dark responsed plants, 6 light non-responsed plants and 5 plants of no germination. Based on seed germination speed of the 28 ephemeral plants, we divided them into 4 patterns of germination, i.e., very rapid, moderately rapid, moderate and slow. Combining variations of temperature, precipitation and sand dune types in the study area, we suggested that very rapid and moderately rapid germinated plants could be used to moving sand dunes in early spring during vegetation restoration, moderate germinated plants could be used to semi-fixed sand dunes in late autumn, and slow germinated plants could be used to sand plain in summer. Thus, seedling establishment and vegetation restoration would be improved by considering seed germination characteristics of these ephemeral plants in the Gurbantunggut Desert, China.