气候和土地利用与空间结构在影响大熊猫同域分布大中型哺乳动物物种丰富度中的相对作用

气候因子和土地利用因子是影响生物多样性分布格局的两个主要驱动因素。然而,当前关于气候因子和土地利用因子对生物多样性影响的研究主要集中在物种层面上,在群落水平上对生物多样性的影响依然知之甚少。本研究以大熊猫同域分布大中型哺乳动物为研究对象,结合物种丰富度数据、气候数据、土地利用数据以及经纬度数据,构建基于不同变量组合的多元线性模型,并通过模型拟合优度比较和方差分解等方法,探讨气候因子、土地利用因子和空间结构在影响大熊猫同域分布大中型哺乳动物物种丰富度中的相对作用。结果表明:(1)四川省大熊猫分布的五大山系内的大中型哺乳动物在属数和物种数方面差异较大。其中岷山山系的属数和物种数最高,分别为25属和28种,凉山山系的属数和物种数最低,分别为19属和20种,五大山系内排名前五的优势种分别为大熊猫、羚牛、野猪、中华斑羚、中华鬣羚;(2)大熊猫同域分布大中型哺乳动物物种丰富度在空间分布上差异较大。所有10 km×10 km栅格内的物种数在1-14之间,平均值为6.199±3.475;(3)完全模型(包含所有气候变量、土地利用变量和空间结构变量的模型,CLS)的拟合优度要好于其它6类模型,且包含土地利用变量模型的拟合优度要好于没有包含的模型;(4)气候变量、土地利用变量和空间结构变量共同解释了大熊猫同域分布大中型哺乳动物物种丰富度43.0%的空间变异,其中,土地利用变量对物种丰富度的解释率最高,单独解释率为23.2%,气候变量和空间结构变量的解释率则相对较低,单独解释率分别为6.3%和9.3%。这些研究结果说明土地利用因素是影响大熊猫同域分布大中型哺乳动物物种丰富度最为关键的驱动因素。因此,提高森林覆盖率,减少人为干扰和使用,是实现对大熊猫同域分布哺乳动物综合保护的关键。

黔中平寨水库保护区非点源污染风险评价与敏感区域识别

以黔中平寨水库保护区和准保护区为研究对象,采集了干流断面水样59个,支流断面水样41个,和88个土壤样品,分析评价流域的非点源污染现状,并用GIS进行空间解析。结果表明,枯水期时,流域水质以Ⅰ类居多,占观测点个数的59.62%,Ⅱ~Ⅲ类占15.38%,Ⅳ类占5.77%,Ⅴ类占9.62%;丰水期时,水质以Ⅳ类居多,占72.92%,Ⅰ~Ⅲ类只占22.91%,Ⅴ类占4.17%,主要超标指标为TN、NH3-N、TP,流域呈现出非点源污染的典型特征。通过评价土地利用因子(L)、径流因子(Q)、距离因子(D),利用改进的理想解法(TOPSIS)确定各因子所占的权重,得到流域非点源污染风险评价指数,并将流域划分为4类敏感控制区域。其中,中度敏感区分布较为均匀,主要是靠近水系的坡耕地区域,应对坡耕地进行种植区划调整,并加强对肥料等农用化学品的管理;而高度敏感区域主要分布在准保护区,其污染源主要是城镇生活污水和煤矿开采废水,应加快该区域城镇生活污水集中处置和煤矿废水治理工程的建设力度。

Analysis on the land use and cover change in Tianjin Binhai New Area based on the remote sensing

This paper carries out quantitative analysis on the land use/cover （LU/C） change of 13anjin Binhai New Area in recent 10 years through using land use transition matrix from the three-stage LU/C classification maps of 2000, 2005 and 2010 drafted by means of the National Land Classification System of China based on Landsat TM satellite remote sensing image and the Tianjin Binhai New Area 1：50 000 relief maps. On this basis, the impact of such driving factors as the economy and population on LU/C is further analyzed. The results show that the area of the building land in Binhai New Area has increased significantly over the ten years, and the greenland, wetland, and shoals of high ecological value have been dramatically transformed into the building land and unused land for the development and construction, and the change is more significant in the later five years.

2015—2017年吉林省榆树市水土流失动态变化分析

榆树市是吉林省最大的县级市之一,吉林省人口最多的县级市,也是全国重点商品粮基地县市,获建首批全国现代农业示范区,享有“天下第一粮仓”“祖国的粮豆之乡”等美誉。2015年和2017年榆树市作为松辽流域国家级重点治理区被监测。该文经过资料整理、在Arcgis软件的支持下采取人机交互的方式获取土地利用、野外调查和GIS空间分析,采用USLE模型从而计算出各类侵蚀面积的研究方法,并对比榆树市从2015—2017年3年内,水土流失的变化及未来的发展趋势,对未来榆树市水土土流失监测提供借鉴意义。

Land Use Changes of Valleys Based on Topographic Factors in Beijing Mountainous Regions of China

Land use changes in mountainous regions were greatly enhanced as the rapid development of economy due to the expanded population in developing countries. Acting geographically as the basic unit of mountainous regions, valleys are the primary sites of economic activities. Therefore optimization of land use policy in valleys is of critical important to the sustainable development in mountainous regions. On the basis of land use data in 1995 and 2012, this study explored the changes of land use according to the assessment of varied topographic factors （i.e., altitude and slope） in typical valleys of the Beijing mountainous regions, China. Our results showed that the valley is an efficiently geographical unit to evaluate land use changes in mountainous regions. We also found that major land use changes in mountainous regions of Beijing from 1995 to 2012 were the dramatic losses of grassland to the cultivated and construction lands, while most of these changes took place at the altitude of 0-400m and the slope of 6-15~. Considering the ever increasing economic development in Beijing mountainous regions, the increases of the construction and cultivated lands are inevitable, however, the great changes at a steeper slope imply the need to tailor land use structure coming into line with topographic factors, and suggesting ecological barriers and water conservation must be exercised in the developments of these areas.

A Review on the Driving Mechanisms of Ecosystem Services Change

Ecosystem services have rapidly changed at the global and regional scales in recent years. Exploring the driving mechanisms of ecosystem services change and projecting future change are of increasing importance to inform policy and decision-making options for ecosystem conservation and sustainable use. Although some research has analyzed the influences of land use or climate changes on ecosystem services, a systematic review on the mechanisms of ecosystem services change has not been carried out so far. This work elaborated on the mechanisms of ecosystem services change based on a literature review, and reached four main conclusions.(1)Climate change and land use jointly determine the ecosystem services change through complex and interacting pathways.(2) Whereas the present research progresses mainly focus on the identification of a single influencing factor, they fail in the determination of multiple influencing factors.(3) Although multi-scenario simulations based on remote sensing and climate models are the main means used to predict future changes in ecosystem services,clarifying the interactive mechanisms of multiple factors is the precondition for future projection of ecosystem services change;(4) Therefore, future research should strengthen the analysis and simulation of the effects of human activities on ecosystem services, especially the development of technology to detect the dynamic responses of ecosystem services to major ecological projects, which is crucial to the selection of restoration measures and the regional arrangement of ecosystem conservation projects.