艾比湖湿地植物多样性特征及其影响因素研究

植物α和β多样性的变化与土壤、地貌及人为干扰等生态因子有密切的关系。主要选择沿湖从博尔塔拉河(简称博河)B,鸟岛N,鸭子湾Y,奎屯河K和在距湖岸H0km(近湖岸带)、H5km(湖滨带)、H10km(湿地-绿洲过渡带)、H15km(近精河绿洲带)范围的8个研究区,于2012年10月分别对样地乔木、灌木和草本进行调查。结果表明:(1)艾比湖湿地共出现植物16科46属32种,藜科和禾本科种类最多,样地上分布的草本植物比较丰富。(2)植物α多样性变化特征:沿湖周4个样地平均物种Margalef丰富度指数表现一致为:鸟岛N>鸭子湾Y>博河B>奎屯河K;Simposon多样性指数、Shannon-Wiener多样性指数和Mc Intosh均匀度指数表现为奎屯河最大。在距湖岸不同生境样地中平均物种Margalef丰富度指数、Simposon多样性指数和Shannon-Wiener多样性指数、Mc Intosh均匀度指数表现为距湖H10km值最大。植物α多样性指标的变化主要与土壤养分指标中的全磷、p H、全氮显著相关,其次是全盐指标显著相关。(3)不同生境下植物β多样性特征为H0km到H5km。H5km到H10km生境间Cody指数变大,其中H5km到H10km生境间Cody指数变化最大。H5km与H10km、H10km与H15km其资源异质性明显,物种替代速率达到了最大

中国全方位外交下的对日战略探析

中国的全方位外交是新时期应对国内外复杂局势的重要战略选择。日本的多重身份定位决定了它是考验中国外交智慧的一项重大课题。冷战结束至今,中日关系在纠葛中寻求协调,而近年来美国重返亚太以及日本对华战略疑虑强化,使得两国纠葛情形更多出现于人们视野,并增加了协调的难度。为更理性把控中日关系,助力全方位外交,中国需找准双方在历史与现实冲突、文化与意识反差、一山二虎对峙、大战略同类别与异目标等方面的纠葛结点所在,从核心利益底线思维、外交路径拓展、地区多边机制深化、坚持不懈自强等路径来探寻具有针对性的对日战略

2000—2013年河南省耕地的时空变化分析

耕地的时空变化是耕地保护关注的核心问题。根据2000和2013年的2期土地利用空间数据,运用GIS技术和土地利用转换矩阵等方法,分析了2000—2013年河南省耕地的时空变化。耕地的时空变化包括数量变化和空间变化2个方面,全省耕地的数量变化表现为面积减少3.53%,空间变化表现为10.69%的耕地与其他土地利用类型发生了空间位置的变换。从土地利用综合区来看,中原城市群区和豫西南区耕地的数量变化与空间变化相对较大,而黄淮四市区和豫北区相对较小。从省辖市来看,鹤壁、济源和洛阳耕地的数量变化表现为面积增加,其余15个市皆表现为面积减少;另外,郑州等市耕地面积的减少幅度较大,三门峡等市耕地的空间变化幅度较大。全省各土地利用综合区以及各省辖市耕地的空间变化幅度皆大于数量变化幅度,而且二者的变化并不一致,例如,18个市中三门峡耕地的空间变化幅度最大,但数量变化幅度最小。因此,耕地的空间变化与数量变化皆应受到足够的重视。本研究结果为深入分析河南省耕地总量动态平衡状况,进而研究因地制宜的保护对策提供了科学信息

Individual and social optima of rural land allocation by stakeholders: a case study on eco-fragile areas of northern China

Divergences in preferences over the allocation of rural land among stakeholders are getting stronger with the decrease of rural land area. This paper analyses the degree of divergences among different stakeholders over the allocation of four types of land: cultivated land, grassland, forest and other land, and explores the optimal allocation from the social perspective of balancing economic and ecological benefits. Considering the heterogeneity of stakeholders that are concerned with land-use decisions, we distinguish four types of stakeholders, namely, ecological authorities, economic authorities, herders and farmers. The diverging preferences of these four stakeholder types over the different types of land use were quantified using the Analytic Hierarchy Process. Weights for each stakeholder type were derived for three scenarios: equal weights, weights based on income distribution and weights based on labour force distribution. Welfare analysis was employed then to determine the individual optimal allocation by maximising the utility function of each stakeholder type. Social optimal allocation was derived by maximising the social welfare function, which is the weighted sum of individual utilities. Tai Pusi County, located in an eco-fragile area of northern China, was taken as a case to present the empirical analysis. Individual optima revealed the degree of divergences among stakeholders and the social optima revealed the optimal allocation based on social welfare. Our results provide policy insights on how to achieve an efficient allocation of rural land, balancing the ecological and economic benefits of different stakeholders from different types of land

能源开发区产业结构演变的环境效应分析——以榆林市为例

以榆林市为例,利用典型相关分析、IIISNE及空间分析相结合,定量分析了1996—2014年能源开发区产业结构演变对环境影响。研究表明:榆林市以1998年为拐点,三次产业结构由41.5∶30.3∶28.2转变为4.8∶68.3∶26.9;产业结构的环境影响指数均值高达2.86,属中上水平,并呈现出不断提升态势。其中,第二产业对环境总体影响程度最大,第三产业影响程度最小。IIISNE在空间上南北差异显著,北部煤炭资源富集区较高,且较严重区域呈现加速集中态势

Evaluation of methods of nutrient and water management on tea performance and nutrient loss in the Danjiangkou Reservoir area, China

The long-term control of fertilizer pollution in the Danjiangkou Reservoir is an important task, and promoting good fertilizer pollution control methods is necessary to conserve water quality. A 3-year experiment was conducted to evaluate the fertilizer losses, economic benefits, and feasibility of different nutrient and water management methods in the area. The experiment included the following treatments: (1) local recommended fertilizer dose (450, 144, and 189 kg ha(-1) y(-1) of N, P2O5, and K2O) under rain-fed conditions (CK); (2) chicken manure at 7500 kg ha(-1) without drip irrigation (OF); (3) same dosage of treatment OF but with drip irrigation (OFD); and (4) drip fertigation with 30% of the fertilization dose of CK (DF). The results showed that organic fertilizer and drip fertigation treatments reduced total N (TN) and total P (TP) losses compared to CK due to considerably less amounts of N and P nutrient inputs. Total N runoff losses, and TN and TP concentrations in leaching water did not differ significantly among treatments OF, OFD, and DF. Net income among the CK, OF, and OFD treatments did not differ significantly. Treatment DF resulted in 19.5% and 13.8% more net income than CK and OFD, respectively. Such results provided guidance for promotion to maximize benefits and minimize environmental impacts

中国河流地貌研究进展——纪念沈玉昌先生100年诞辰

2016年是中国现代河流地貌研究的开拓者和奠基人沈玉昌先生100年诞辰,本文对中国河流地貌研究进展进行综述,以资纪念。研究涉及4个方面:1水系发育与河谷地貌演变,包括大江大河水系历史发育和山区河流地貌;2侵蚀与产沙过程,包括有物理成因基础的侵蚀产沙模型、侵蚀产沙过程的尺度效应、植被对侵蚀的影响及临界现象、坡面细沟发育过程模拟等;3河床过程与河型,包括河道冲淤过程、河床演变、河型成因与演变等;4河流地貌系统研究,包括流域系统不同子系统的耦合关系、河流地貌系统中的高含沙水流和多营力地貌过程、河流地貌系统对于自然因素变化和人类活动的响应、河流地貌系统中的泥沙灾害和河流地貌系统的实验研究等。50年前沈玉昌先生与钱宁先生提出在地貌学与河流动力学相结合的基础上发展中国河流学科。文中对此方面的进展进行了综述,并提出了需要深化和解决的问题

中国水泥碳排放测算的影响因素分析与不确定度计算

作为水泥生产大国和CO_2排放大户,中国水泥行业的CO_2排放在国际上受到越来越广泛的重视,然而不同的研究结果之间存在不同程度的差异.为了定量研究中国水泥碳排放测算的影响因素,对碳排放因子的测算、运营边界的界定及水泥熟料或水泥成品的产量这3个影响因素做了详细分析,并对碳排放因子的不确定度做了定量计算.结果发现,影响中国水泥碳排放测算的最主要因素是碳排放因子,而该因素又与生产工艺、燃料和熟料水泥比等密切相关.本研究结果比IPCC、EDGAR、CDIAC和WBCSD/CSI等研究结果均低,并且差异逐年显著,以水泥碳排放来自碳酸盐分解的部分为例,2000年相差约65 Mt,而2012年差值接近450 Mt.计算表明,中国水泥碳排放不确定度为12%~22%.因此,水泥碳排放测算的影响因素较多,在计算中国水泥碳排放量时不可照搬国外研究的参数

西藏农牧区家庭生活用水特征及其影响因素

农村家庭用水结构调查与影响因素分析是分析农村用水情况,保障用水安全的基础。采用问卷调查和实测的方式获取西藏自治区9个县(市、区)的84个家庭的用水数据,对比分析不同家庭的用水量及用水结构,总结了西藏农村家庭用水的影响因素。研究表明:农村家庭人均生活用水量在33~38 L/d之间,家庭差异显著,主要集中在洗衣、洗菜、洗碗用水三项,家庭生活用水的主要用水项是卫生用水和厨房用水;生产方式与文化风俗习惯影响家庭用水水平,人口组成影响用水结构,常住人口数和家庭收入水平与家庭人均用水量呈现显著负相关

Different effects of plant-derived dissolved organic matter (DOM) and urea on the priming of soil organic carbon

Soil organic carbon (SOC) mineralization is important for the regulation of the global climate and soil fertility. Decomposition of SOC may be significantly affected by the supply of plant-derived labile carbon (C). To investigate the impact of plant-derived dissolved organic matter (DOM) and urea (N) additions on the decomposition of native SOC as well as to elucidate the underlying mechanisms of priming effects (PEs), a batch of incubation experiments was conducted for 250 days by application of C-13-labeled plant-derived DOM and urea to soils. The direction of PE induced by the addition of DOM was different from the addition of N, i.e. it switched from negative to positive in DOM-amended soils, whereas in the N-treated soil it switched from positive to negative. Adding DOM alone was favorable for soil C sequestration (59 +/- 5 mg C per kg soil), whereas adding N alone or together with DOM accelerated the decomposition of native SOC, causing net C losses (-62 +/- 4 and -34 +/- 31 mg C per kg soil, respectively). These findings indicate that N addition and its interaction with DOM are not favorable for soil C sequestration. Adding DOM alone increased the level of dissolved organic carbon (DOC), but it did not increase the level of soil mineral N. Changes in the ratio of microbial biomass carbon (MBC) to microbial biomass nitrogen (MBN) and microbial metabolic quotient (qCO(2)) after the addition of DOM and N suggest that a possible shift in the microbial community composition may occur in the present study. Adding DOM with or without N increased the activities of beta-glucosidase and urease. Changes in the direction and magnitude of PE were closely related to changes in soil C and N availability. Soil C and N availability might influence the PE through affecting the microbial biomass and extracellular enzyme activity as well as causing a possible shift in the microbial community composition