辽宁省自然保护地空间分布格局与重叠现状分析

  目的  通过对辽宁省自然保护地重叠现状进行定性与定量的分析,描述辽宁省6类235处自然保护地空间分布情况与重叠现状及特征,由此对辽宁省自然保护地空间分布格局现状进行评价,为辽宁省自然保护地的整合优化提供科学参考与理论依据。  方法  利用最邻近指数分析与核密度分析,评价辽宁省自然保护地空间分布现状,同时提出了自然保护地镶嵌体的概念,通过分析镶嵌体内部的重叠板块占比情况,对辽宁省自然保护地重叠现状进行定性与定量的分析,相较于传统重叠率分析方法,为分析一个区域内多层重叠的情况我们提出了自然保护地多元重叠率计算方法。  结果  （1）辽宁省自然保护地的最邻近比率为0.904,表明辽宁省自然保护地分布属聚集型分布;（2）结合自然保护综合地理区划,辽宁省自然保护地主要形成4个聚集区域;（3）辽宁省自然保护地存在重叠情况的自然保护地数量占自然保护地总数的50.43%,重叠面积占辽宁省自然保护地的8.63%。重叠情况主要发生在自然保护区与自然公园之间,数量共107处,面积达134 421.1 hm2;（4）辽宁省存在重叠的斑块中两层重叠82处、三层重叠13处、四层重叠1处;（5）辽宁省可划分为36个自然保护地镶嵌体,其中内部重叠率高于50%的保护地镶嵌体有8处,最高为81.34%;低于10%的保护地镶嵌体有6个,最低为1.82%。  结论  将重叠保护地进行整合优化时,镶嵌体重叠率过高代表保护服务功能与划定保护范围过剩,整合时对于这种情况所涉及的保护地建议以合并为主。下一步对于计划新建自然保护地应将现有保护服务力度较低或中等区域进行补充完善,将如辽东半岛阔叶落叶林与湿地区南部的沿海陆域利用起来。在解决重叠与地质遗迹等情况后确保保护等级不下降,保证保护力度与保护效率。      

Interacted Effect of Arbuscular Mycorrhizal Fungi and Polyamines on Root System Architecture of Citrus Seedlings

Either arbuscular mycorrhizal fungi (AMF) or polyamines (PAs) may change root system architecture (RSA) of plants, whereas the interaction of AMF and PAs on RSA remains unclear. In the present study, we studied the interaction between AMF (Paraglomus occultum) and exogenous PAs, including putrescine (Put), spermidine (Spd) and spermine (Spm) on mycorrhizal development of different parts of root system, plant growth, RSA and carbohydrate concentrations of 6-m-old citrus (Citrus tangerine Hort. ex Tanaka) seedlings. After 14 wk of PAs application, PA-treated mycorrhizal seedlings exhibited better mycorrhizal colonization and numbers of vesicles, arbuscules, and entry points, and the best mycorrhizal status of taproot, first-, second-, and third-order lateral roots was respectively found in mycorrhizal seedlings supplied with Put, Spd and Spm, suggesting that PAs might act as a regulated factor of mycorrhizal development through transformation of root sucrose more into glucose for sustaining mycorrhizal development. AMF usually notably increases RSA traits (taproot length, total length, average diameter, projected area, surface area, volume, and number of first-, second-, and third-order lateral roots) of only PA-treated seedlings. Among the three PA species, greater positive effects on RSA change and plant biomass increment of the seedlings generally rank as Spd>Spm>Put, irrespective of whether or not AMF colonization. PAs significantly changed the RSA traits in mycorrhizal but not in non-mycorrhizal seedlings. It suggests that the application of PAs (especially Spd) to AMF plants would optimize RSA of citrus seedlings, thus increasing plant growth (shoot and root dry weight).     

Use of Human Excreta as Manure in Rural China

Empirical research has shown that the use of manure significantly improves crop yield, soil fertility and water and moisture conservation. Despite these documented benefits, however, there is a concern on the downward trend of manure use in agriculture in China. This paper examines factors contributing to this downward trend, with a particular focus on human excreta used in agriculture. Empirical analysis based on data from stratified random sampling of rural households in five provinces of China shows that about 85% of human excreta was still used as manure in agriculture in 2007 which was less than a decade ago when nearly all human excreta was used as manure. Econometric results suggest that income growth, rising population density and improvement in rural transportation significantly contribute to declining use of human excreta as manure in agriculture. These results imply that the current downward trend will continue given China＇s rising economic growth, urbanization and rural infrastructural improvement.     

吉林省农村人力资本存量以及投资效率研究

采用教育年限法估计了1993 ～2012年吉林省农村人力资本存量,利用DEA模型计算了其投资效率,并与发达和不发达省份进行了比对.结果表明,吉林省农村人力资本存量逐年递增,但年均增长率为其余各省的一半,增长率较小;吉林省农村人力资本投资效率较为一般,保持农村人力资本投资效率规模报酬递增,并无投入冗余现象,投入结构较为合理;但是综合效率为0.636,属于DEA无效单元,全要素生产率指数呈不断上升趋势,技术效率和规模效率指数都为1.基于此,从调整投资结构、合理配置教育资源、医疗资源,转变政府职能和培育农村市场等方面提出政策建议.     

莱芜市人口的具有外生变量的时间序列预测模型

基于人口总量与经济增长有强相关关系,结合时间序列预测模型的良好适应性,建立了将经济增长作为外生变量的人口时间序列预测模型,以莱芜市1989-2011年人口总量和GDP总量数据为例,建立了莱芜市人口发展趋势的含外生变量的时间序列模型,并对模型的精确度进行检验,模型结果精确度较为理想。然后对2012-2016年莱芜市人口总量及其增长速度进行了预测,结果显示,"十二五"期间莱芜市总人口在未来几年将保持年均增长量为0.4万人,环比平均增长速度为0.3%,人口总规模将近130万。     

Effect of polyamine on seed germination of wheat under drought stress is related to changes in hormones and carbohydrates

Drought is a multifaceted stress condition that inhibits crop growth. Seed germination is one of the critical and sensitive stages of plants, and its process is inhibited or even entirely prevented by drought. Polyamines(PAs) are closely associated with plant resistance to drought stress and seed germination. However, little is known about the effect of PA on the seed germination of wheat under drought stress. This study investigated the involvement of PAs in regulating wheat seed germination under drought stress. Six wheat genotypes differing in drought resistance were used, and endogenous PA levels were measured during seed germination under different water treatments. In addition, external PA was used for seed soaking and the variation of hormones, total soluble sugar and starch were measured during the seed germination under different water treatments. These results indicated that the free spermidine(Spd) accumulation in seeds during the seed germination period favored wheat seed germination under drought stress; however, the free putrescine(Put) accumulation in seeds during the seed germination period may work against wheat seed germination under drought stress. In addition, seed soaking in Spd and spermine(Spm) significantly relieved the inhibition of seed germination by drought stress; however, soaking seeds in Put had no significant effect on seed germination under drought. External Spd and Spm significantly increased the endogenous indole-3-acetic acid(IAA), zeatin(Z)+zeatin riboside(ZR), abscisic acid(ABA), and gibberellins(GA) contents in seeds and accelerated the seed starch degradation and increased the concentration of soluble sugars in seeds during seed germination. This may promote wheat seed germination under drought stress. In conclusion, free Spd and Put are key factors for regulating wheat seed germination under drought stress and the effects of Spd and Put on seed germination under drought notably related to hormones and starch metabolism.     

2006—2015年中国乡村人口与住房面积的时空协同研究

为研究中国乡村建设用地扩张现状及其驱动因素，利用乡村人口统计数据和乡村住宅建筑面积现状数据，对我国乡村地区人口与乡村住房面积变化的整体时序特征、空间分异格局及其耦合和协同状态进行了定量分析。结果表明：2006—2015年，我国乡村常住人口呈现线性减少趋势，年均减少1.32×10⁷人，而乡村户籍人口数量也于2008年后进入极缓慢减少的阶段；乡村户籍人口与乡村常住人口数量的差值逐年攀升，至2015年末，已达到改革开放以来最高的2.0×10⁸人；而我国乡村住房面积仍呈现持续增长态势，年均递增2.48%，年均增长5.8×10⁸m²。全国常住和户籍口径下的乡村人均住房面积变化均呈现增长态势。常住口径下，25个省份的乡村人均住房面积呈现稳定的线性增长；在而户籍口径下，所有省份的乡村人均住房面积均表现为增长。研究时段内，我国整体乡村人口与住房面积变化的时序关联呈现不协同的特征，并且住房面积变化速率高于人口变化速率。27个省份的乡村常住人口与住房面积变化也呈现上述相同的特点；而户籍口径下，全国各评价省份的住房面积变化速率均高于人口变化速率，其中21个省份乡村户籍人口与住房面积基本呈现协同变化。推进城乡发展统一规划管理，逐步破除城乡二元结构，改革户籍制度，疏导城乡人口流动，是解决在乡村常住人口减少过程中乡村住房面积不降反增这一问题的指导思想。     

The Discovery of America: The first Americans may have swept the Western Hemisphere and decimated its fauna within 1000 years

I propose a new scenario for the discovery of America. By analogy with other successful animal invasions, one may assume that the discovery of the New World triggered a human population explosion. The invading hunters attained their highest population density along a front that swept from Canada to the Gulf of Mexico in 350 years, and on to the tip of South America in roughly 1000 years. A sharp drop in human population soon followed as major prey animals declined to extinction. Possible values for the model include an average frontal depth of 160 kilometers, an average population density of 0.4 person per square kilometer on the front and of 0.04 person per square kilometer behind the front, and an average rate of frontal advance of 16 kilometers per year. For the first two centuries the maximum rate of growth may have equaled the historic maximum of 3.4 percent annually. During the episode of faunal extinctions, the population of North America need not have exceeded 600,000 people at any one time. The model generates a population sufficiently large to overkill a biomass of Pleistocene large animals averaging 9 metric tons per square kilometer (50 animal units per section) or 2.3 x 10(8) metric tons in the hemisphere. It requires that on the front one person in four destroy one animal unit (450 kilograms) per week, or 26 percent of the biomass of an average section in 1 year in any one region. Extinction would occur within a decade. There was insufficient time for the fauna to learn defensive behaviors, or for more than a few kill sites to be buried and preserved for the archeologist. Should the model survive future findings, it will mean that the extinction chronology of the Pleistocene megafauna can be used to map the spread of Homo sapiens throughout the New World.     

A proposed framework for accelerating technology trajectories in agriculture: a case study in China

Precision agriculture (PA) technologies have great potential for promoting sustainable intensification of food production, ensuring targeted delivery of agricultural inputs, and hence food security and environmental protection. The benefits of PA technologies are applicable across a broad range of agronomic, environmental and rural socio-economic contexts globally. However, farmer and land-manager adoption in low to middle income countries has typically been slower than that observed in more affluent countries. China is currently engaged in the process of agricultural modernisation to ensure food security for its 1.4 billion population and has developed a portfolio of policies designed to improve food security, while simultaneously promoting environmental protection. Particular attention has been paid to the reduction of agricultural inputs such as fertilisers and pesticides. The widespread adoption of PA technologies across the Chinese agricultural landscape is central to the success of these policies. However, socio-economic and cultural barriers, farm scale, (in particular the prevalence of smaller family farms) and demographic changes in the rural population, (for example, the movement of younger people to the cities) represent barriers to PA adoption across China. A framework for ensuring an acceptable and accelerated PA technology trajectory is proposed which combines systematic understanding of farmer and end-user priorities and preferences for technology design throughout the technology development process, and subsequent end-user requirements for implementation (including demonstration of economic and agronomic benefits, and knowledge transfer). Future research will validate the framework against qualitative and quantitative socio-economic, cultural and agronomic indicators of successful, or otherwise, PA implementation. The results will provide the evidence upon which to develop further policies regarding how to secure sustainable food production and how best to implement PA in China, as well as practical recommendations for optimising end-user uptake.     

Conservation conflicts across Africa

There is increasing evidence that areas of outstanding conservation importance may coincide with dense human settlement or impact. We tested the generality of these findings using 1 degree-resolution data for sub-Saharan Africa. We find that human population density is positively correlated with species richness of birds, mammals, snakes, and amphibians. This association holds for widespread, narrowly endemic, and threatened species and looks set to persist in the face of foreseeable population growth. Our results contradict earlier expectations of low conflict based on the idea that species richness decreases and human impact increases with primary productivity. We find that across Africa, both variables instead exhibit unimodal relationships with productivity. Modifying priority-setting to take account of human density shows that, at this scale, conflicts between conservation and development are not easily avoided, because many densely inhabited grid cells contain species found nowhere else.     

云杉天然群体基因分化与种质资源异地保存抽样策略

采用聚丙烯酰胺垂直板凝胶电泳和水平淀粉凝胶电泳对云杉全分布区10个天然群体的300个个体进行酶电泳分析,研究天然群体的等位基因数量和频率分化,共测定8种酶系统,得到17个清晰酶位点和27个等位基因.10个群体检测到的等位基因数均值为24.7个(变幅为23～27个).据基因频率进行分类,检测到全域基因和广域基因数量分别为19个和7个,分别占总基因的70.37%和25.93%;特有基因只有1个,即铁布群体的Idh-2-C,占总基因的3.7%.10个群体基因频率的均值没有太大差异,相同位点的广域基因频率在群体间均存在差异.通过计算机模拟建立云杉天然群体种质资源保存的群体和群体内个体两个层次的基因捕获曲线.群体的等位基因频率与地理生态因子的相关分析表明:Fdh-2-B基因频率与生态梯度值呈显著负相关(r=-0.661 1*).构建了云杉天然群体核心种质保存的抽样策略,经综合分析,抽取全分布区内铁布、卓尼、阿坝、小金、热务沟、凤县和曲谷7个群体,每个群体保存25个拟式无亲缘关系的个体,可以保护云杉种内95%～99%的基因资源.     

农村劳动力流动过程中的人力资本效应研究

农村剩余劳动力向城市流动是我国从二元经济走向同质经济,实现现代化的一个必然过程。人力资本投资是实现这个历史转变的关键所在。人力资本投资不仅能够改变中国农村人力资源的结构,提高农村人力资本的含量,也是加大农村劳动力转移、改善转移的层次和效果的关键。本文主要探讨了劳动力流动对农村人力资本投资的增长效应,现行城乡隔离的教育资源分配和就业机制对农村人力资本投资的不利影响,以及加大农村人力资本投资的对策建议等问题。     

当前我国农村人力资源开发路径探析

人力资源管理着眼于提升和开发人力资源,全面提升人口素质,因而在经济和社会发展中的作用和地位日益彰显。分析我国农村人力资源现状及存在的问题,并提出农村人力资源开发的有效路径。     

China's demographic history and future challenges

On 28 April 2011, China's state statistics bureau released its first report on the country's 2010 population census. The report states that the total population of mainland China reached 1.3397 billion in 2010, with an annual average population growth rate of 0.57% during the previous 10 years. The share of the total population aged 0 to 14 declined from 22.9% in 2000 to 16.6% in 2010, whereas the proportion aged 65 and above grew from 7.0% to 8.9% during the same period. This indicates that China's population is aging rapidly. The report also shows that China is urbanizing, with nearly half of the population--665.57 million people, or 49.7%--living in urban areas, an increase of 13 percentage points over the 2000 figure. Moreover, about 260 million Chinese people are living away from where they are formally registered, and the overwhelming majority of them (about 220 million) are rural migrants living and working in urban areas but without formal urban household registration status. China is at a demographic turning point: It is changing from an agricultural society into an urban one, from a young society to an old one, and from a society attached to the land to one that is very much on the move.     

中国农村剩余劳动力转移问题及对策研究

中国是世界上人口最多的农业大国,也是世界上农村人口最多的国家,同时也是世界范围内农村人口就业压力最大的国家,因此研究农村剩余劳动力转移具有极强的现实意义。解决好农村剩余劳动力转移问题,有利于中国经济的发展、城乡差别的缩小、"三农"等问题的解决,有利于中国劳动力资源的合理配置,有利于促进中国由人力资源大国向人力资源强国的转变。深化对农村剩余劳动力转移问题的认识,即农村劳动力自身的文化教育程度低、乡镇企业吸纳能力下降、农业自身发展不足、户籍制度和土地制度制约、劳动力市场不完善等,并根据存在的问题提出相应的对策建议。     

武夷山国家级自然保护区森林土壤涵水量估测及空间分析

以福建省武夷山国家级自然保护区为研究对象,以2003年24块固定样地数据、2003年生态定位站气候观测数据、2003年10月5日LandsatTM遥感数据为主要信息源,采用INVEST模型,对区域内的森林土壤涵水量进行估测和空间分析。结果表明：2003年研究区森林土壤平均涵养水源深度为204．135mm,土壤涵养水源总量为10518．72万m3;2003年森林土壤涵水深度呈空间聚集型分布,随着海拔的降低、人为干扰活动的增强,核心区、缓冲区、实验区森林土壤涵水深度的空间聚集性减弱、破碎化趋势增强;森林土壤涵水深度较高的林分位于海拔较高、坡度较陡、土壤湿度较大、植被生长状况较差的立地;森林土壤涵水深度在空间分布上呈现出从东北向西南倾斜的带状分布趋势;森林土壤涵水深度与海拔、坡度、土壤湿度指数的平均相关系数分别为0．2065、0．6295、0．3570,表明森林土壤涵水深度与3个因变量呈正相关关系。     

Environmental values and forest patch conservation in a rural Costa Rican community

Although conservation attention has generally focused on large forest tracts, there is increasing evidence that smaller forest patches are important for both conservation and rural development. A study of forest patch conservation in a rural Costa Rican community found that, although forest patch conservation was influenced by landholding size, material factors did not account for all the variation in forest patches conservation behavior or conservation orientations of farmers. A qualitative interpretive approach, using semi-structured interviews, found that environmental values were influenced by at least three factors. First, colonist farmers with direct experience with environmental degradation in other regions of Costa Rica were more likely to be concerned about environmental degradation. Second, childhood exposure to conservation played an important role in influencing conservation orientations. Third, the environment was frequently discussed in relation to the moral and social values present in religious doctrines. The study also found general support for forest conservation laws, and a clear indication that interest in forest conservation has grown in recent years. The study highlights the importance of environmental values, in conjunction with material factors, in influencing forest conservation in rural communities.     

白洋淀流域生态系统服务评估及其调控

政策制定者在制定土地利用相关政策时需要权衡各方面的利益关系,协调资源保护和经济发展之间的关系.由于缺乏有效的评价与权衡办法,目前对这方面研究还较少.采用InVEST模型,评价了白洋淀流域7种服务功能指标,分析了其空间分布特征.通过情景(政策情景与保护情景)分析,较好的反映了农业直接经济收入与服务功能之间的关系.结果表明:生物多样性、水源涵养、土壤保持和固碳重要区域主要分布在流域西部、北部和流域中部山区;水质保护和授粉重要区域主要分布于流域东部、南部和中部平原区.政策情景下,产水量第二,农业产出有所下降,固碳能力较保护模式差,N/P输出最少.保护情景下产水量最大,农田产出价值不变,氮磷保持与政策情景差不多,但固碳效果最好.通过权衡不同情景下服务功能得失,筛选既不损害流域居民实际经济收入,又能使得水文服务功能得到提高的管理模式.研究表明InVEST模型可以很好的用于对自然资本评估和空间化特征分析,通过建立不同情景,评价结果可以用于权衡不同管理策略下服务功能得失,是一种评价和预测自然资本变化的有效方法,对政策制定和策略筛选具有重要的指导意义.     

江苏云台山物种多样性及保护

在实地调查的基础上，对云台山的物种多样性保护现状作全面分析。初步确定区域物种多样性保护的关键树种，计18种，隶属15科，18属，这些树种在本地区不仅珍贵稀少且科学研究意义重大。调查表明，云台山物种多样性以种类丰富、过渡性明显、滨海区系成分复杂和明显带有岛屿区系色彩为特征。由于人为破坏、病虫害流行和旅游压力，目前云台山物种多样性受人为扰动严重，建议加强就地保护和迁地保护。     

基于回归模型的县域建设用地集约程度影响因素分析——以吉林省为例

通过对土地利用现状的研究以及影响集约利用水平因素的相关分析,并根据研究区域内建设用地利用的实际情况,定性和定量地对吉林省内全部县域建设用地进行集约利用水平分析,运用SPSS软件进行回归模型分析,得出影响吉林省县域范围建设用地集约利用水平的主要因素。结果表明:城乡建设用地人口密度、建设用地地均固定资产投资、建设用地地均地区生产总值、单位地区生产总值消耗新增建设用地量和单位固定资产投资增长消耗新增建设用地量等因素,对县域建设用地集约水平有非常显著的正向影响;单位地区生产总值耗地下降率、地区生产总值与建设用地增长弹性系数和地区生产总值与城乡建设用地增长贡献度,对县域建设用地集约水平有较为显著的正向影响;单位人口增长消耗新增城乡建设量、人口与城乡建设用地弹性系数和人口与城乡建设用地增长贡献度等因素,对县域建设用地集约水平影响不明显。