Impact factors on distribution and characteristics of natural plant community in reclamation zones of Changjiang River estuary

To identify impact factors on the distribution and characters of natural plants community in reclamation area, with survey data from 67 plant quadrats in July 2009, soil properties data from 216 sampling points in April 2009, and TM (30 m) data in 2006, the composition and characteristics of natural plants community in different time of the Fengxian area in the Changjiang (Yangtze) River estuary were analyzed with two-way indicator species analysis (TWINSPAN), multivariate analysis of variance (MANOVA), detrended canonical correspondence analysis (DCCA) and canonical correspondence analysis (CCA). The results show that: 1) The plant communities in the reclaimed area are mainly mesophytes and helophytic-mesophytic transitional communities, showing a gradient distribution trend with the change in reclamation years. Species richness (MA), species diversity (H) and above-ground biomass also increase with the increase of reclamation years. Nevertheless, they appear to decline slightly in the middle and late reclamation period (> 30 years). 2) With the rise in land use levels, the changes in species richness and species diversity tend to increase at first and then decrease; species dominance (D), however, tends to decline; and above-ground biomass increases slightly. 3) The distribution of the plant community is mainly influenced by the following factors: land use levels (R = 0.55, p < 0.05), soil moisture (R = 0.53, p < 0.05), soil salinity (R = 0.43, p < 0.05) and reclamation time (R = 0.40, p < 0.05).     

基于地理探测器的南京市住宅租金空间分异格局及驱动因素研究

以南京市“一主三副”住宅小区为研究单元,运用GIS中的渔网（Fishnet）分析和探索性空间数据分析（ESDA）对“一主三副”住宅租金的空间分布进行模拟和估计,并利用地理探测器模型从住宅小区的区位特征、建筑特征和邻里特征3个方面探究住宅租金空间分异的影响机制。结果表明：① 南京市住宅租金总体呈上升趋势,空间上表现出主城向副城递减的中心外围模式,住宅租金空间结构逐渐由单核向双核发展,且住宅租金存在显著的空间异质性;② 住宅租金呈现出明显的空间正相关性和区域集聚性,热点区自内城核心区至副城趋于弱化,冷热点空间格局呈圈层结构;③ 交通位势和中心位势是对一主三副住宅租金解释力最大的因素,商务配套、金融设施和住宅房龄的解释力次之,特征因素对主城副城租金的影响强度各异。     

Effect of reclamation time and land use on soil properties in Changjiang River Estuary,China

The objective of this study is to analyze soil physical and chemical properties,soil comprehensive functions and impact factors after different years of reclamation.Based on the survey data taken from 216 soil sampling points in the Fengxian Reclamation Area of the Changjiang (Yangtze) River Estuary,China in April 2009 and remotely sensed TM data in 2006,while by virtue of multivariate analysis of variance (MANOVA),geo-statistical analysis (GA),prin-cipal component analysis (PCA) and canonical correspondence analysis (CCA),it was concluded that:1) With the in-crease in reclamation time,soil moisture,soil salinity,soil electric conductivity and soil particle size tended to decline,yet soil organic matter tended to increase.Soil available phosphorous tended to increase in the early reclamation period,yet it tended to decline after about 49 years of reclamation.Soil nitrate nitrogen,soil ammonia nitrogen and pH changed slightly in different reclamation years.Soil physical and chemical properties reached a steady state after about 30 years of reclamation.2) According to the results of PCA analysis,the weighted value (0.97 in total) that represents soil nutrient factors (soil nitrate nitrogen,soil organic matter,soil available phosphorous,soil ammonia nitrogen,pH and soil particle size) were higher than the weighted value (0.48 in total) of soil limiting factors (soil salinity,soil elec-tric conductivity and soil moisture).The higher the F value is,the better the soil quality is.3) Different land use types play different roles in the soil function maturity process,with farmlands providing the best contribution.4) Soil physi-cal and chemical properties in the reclamation area were mainly influenced by reclamation time,and then by land use types.The correlation (0.1905) of the composite index of soil function (F) with reclamation time was greater than that with land use types (-0.1161).     

基于基尼系数空间分解的江苏省经济发展差异分析

不平等性是区域研究的重点,空间集中作为衡量不平等性的重要手段,是非空间与空间属性的二维统一体。传统的研究仅仅关注了全局非空间上的不均衡性,而忽略了地理空间上的集聚特点,往往不利于识别地理属性的集中特点。引进基尼系数的空间分解这一概念,通过对其空间随机分布性的零假设采用蒙特卡罗方法进行检验,从而判定其分解形式是否内生衡量区域不平等与空间自相关的特性。以1978—2015年江苏省区域经济发展差异的演变进行案例分析,通过蒙特卡罗99次随机模拟检验后,将分解的非邻居项与Moran’s I值进行显著性检验,结果进一步证实了这一分解的有效性与简洁性,表明空间基尼系数可内生测度空间的集聚性与非空间的差异性。     

Major advances in studies of the physical geography and living environment of China during the past 70 years and future prospects

The natural environment provides material essentials for human survival and development. The characteristics,processes, regional differentiation and forcing mechanisms of the elements of the natural environment(e.g. geomorphology,climate, hydrology, soil, etc.) are the main objects of research in physical geography. China has a complex natural environment and huge regional differentiation and therefore it provides outstanding reserach opportunities in physical geography. This review summarizes the most important developments and the main contributions of research in the physical geography and human living environment in China during the past 70 years. The major topics addressed are the uplift of the Tibetan Plateau and the evolution of its cryosphere, the development of fluvial systems, the acidification of the vast arid region of the Asian interior, variations in the monsoon and westerly climate systems on multiple timescales, the development of lakes and wetlands, the watershed system model, soil erosion, past human-environment interactions, biogeography, and physical geographic zonality. After briefly introducing international research developments, we review the history of research in physical geography in China, focusing on the major achievements and major academic debates, and finally we summarize the status of current research and the future prospects. We propose that in the context of the national demand for the construction of an ecological civilization, we should make full use of the research findings of physical geography, and determine the patterns and mechanisms of natural environmental processes in order to continue to promote the continued contribution of physical geography to national development strategies, and to further contribute to the theory of physical geography from a global perspective.     

泛长三角城市资源环境压力演化特征及门槛效应

基于资源消耗和环境污染视角构建城市资源环境压力评价指标体系,探讨2000-2017年泛长三角城市资源环境压力时空演化特征及城镇化的门槛效应与作用机理。研究发现:①泛长三角地区资源环境压力呈逐年递增趋势,以"快速-中速-慢速"的节奏持续走高;②各城市资源环境压力均不同程度由低压力向高压力类型演替,并呈现"东高西低、南高北低"格局;③经济增长、工业化水平及人口密度存在显著门槛效应,消费水平、固定资产投资、进出口贸易对资源环境压力具有显著正向作用,能源强度降低和技术创新水平提高有利于减轻资源环境压力,而环境规制和能源消费的影响作用不显著。     

地方品质驱动新时期中国城市创新力时空演化

针对2001—2016年中国地级市地方品质驱动创新力时空演化格局的研究表明:①2001年来地市创新力差异趋于持续扩大,且呈明显的阶段性变化,创新力差异自2008年来趋于缓慢下降,而创新力空间集聚性不断增强。②东部沿海地市存在稳定提升创新活力的多邻域创新极,中西部高创新力地市多位于经济实力较强的区域中心。③地市创新力演化存在固着的"核心-边缘"空间结构,且呈现出时变的累积与惯性效应,创新高增长协同发展态势整体较弱。④地方服务品质、消费品质、信息化水平、基础设施及医疗服务品质对创新力具有重要影响,地方环境品质、交通便利和吸纳外资品质的影响程度较弱。     

南海南部最近几十年珊瑚钙化趋势与大气CO2浓度升高和全球变暖的联系

本研究11个现代滨珊瑚年龄在16~49年之间,包括两个种属Porites lutea和P.lobata,于2008年7~9月采自南海南部南沙群岛海域水深3~4m处。用数字图像技术和实测方法沿珊瑚骨骼主生长轴测量生长率、密度和钙化率。结果表明,自1993~2008年,11个珊瑚平均生长率为 0.96±0.05cm/a,16年增加了10.77%,变化率0.67% /a; 密度为 1.17±0.03g/cm3,16年减小了6.92%,变化率为-0.43% /a; 钙化率为 1.13±0.05g/cm2 ·a,16年增加了2.69%,变化率为0.17% /a。标准差分析显示,密度是3个生长参数中最不易变化的参数,因此,钙化率变化主要取决于生长率。珊瑚3个生长参数的趋势变化为: 多数珊瑚生长率和钙化率都增加而其密度减小,少数珊瑚3个生长参数都增加或都减小。线性相关分析显示,多数珊瑚生长率和钙化率与大气CO2浓度和温度正相关而其密度与之负相关,然而,少数珊瑚与之反相关或相关关系不明显。这些相关关系进一步揭示,过去50年,人类活动产生的温室气体增加引起南海表层温度升高使珊瑚呼吸作用增强,从而导致其生长率和钙化率增加而密度减小。而且,少数珊瑚对大气CO2浓度升高和全球增温显示的差异响应可能与珊瑚样品个体生长的差异和局地环境的影响有关。     

中国城市流动人口房租收入比时空格局及驱动因素

针对2012～2016年中国城市不同职业流动人口房租收入比时空变动特征及驱动力的研究表明:①流动人口房租收入比整体上呈"东高西低,南高北低"分异态势,较高及以上等级房租收入比地市集中于东部沿海发达地区及中西部省会城市。②各职业房租收入比逐渐形成金字塔形结构,但职业间房租收入比差距较大。③东部地区流动人口房租收入比多呈向下和平稳混杂分布,中部地区呈向下、平稳和向上镶嵌分布,西部地区以平稳为主,向上转移为辅。④经济、人口、社会及预期因素对房租收入比的解释力依次降低,消费水平、租赁户比例、地产投资密度、人口吸引力及收入水平是影响房租收入比的关键因素。     

1978-2011年间中国区域消费水平的时空演变

区域消费水平是经济发展的重要动力。本文以1978-2011年间我国各省区的人均消费品零售额表征区域消费水平,在我国区域消费水平差异测度的基础上,对区域消费水平差异的时间序列值进行突变点检测,进而将我国区域消费水平变化划分为1978-1986年和1986-2011年2个阶段。通过利用传统马尔科夫链及空间马尔科夫链方法,分别构建人均消费水平的非空间和空间马尔科夫转移概率矩阵,对1978-1986年与1986-2011年2个阶段的区域消费水平的时空格局演变特征进行分析。研究结果表明：（1）区域消费水平在2个研究时段内的变化均存在着“俱乐部趋同”现象,无论是低消费水平与高消费水平区域均沿着最初类型稳步演进。（2）区域消费水平变化受到来自邻域消费水平背景的影响,使得其趋同的过程在空间上不独立。（3）区域间消费水平相互作用呈现出显著的东西分异特征,东部地区多为区域自身消费水平与邻域消费水平同时向上转移的状态,西部地区多为向下转移的状态,而中部地区多为平稳分布,邻域消费水平的状态变化较大。