旅游开发影响下景观特征变化研究——以芦芽山自然保护区为例

基于不同年份的卫星像片,利用景观生态学的有关指数,对芦芽山自然保护区旅游开发影响下景观要素的基本特征和多样性进行了分析。结果表明:(1)从景观要素的基本特征看,在斑块总数、斑块总周长及其所占的比例、斑块总面积及其所占的比例上,在不同时期变化幅度不大。近期耕地的斑块数最多,草地的斑块总周长及其比例最大,灌木林地的斑块总面积及其比例最大。(2)景观要素的丰富度指数、均匀度指数、多样性指数和优势度指数在不同年份间变化都很小。结果说明芦芽山自然保护措施得力,植被景观得到比较有效的保护。居民用地和耕地的斑块数和总面积的变化,说明人为干扰对景观有一定的影响。     

旅游活动对兴凯湖自然保护区湖岗森林植被的影响——以当壁镇旅游度假区为例

以兴凯湖当壁镇旅游区为研究地,运用样方法调查了旅游相关活动影响下湖岗森林的植被状况,以植物多样性信息指数、旅游影响系数、伴人植物比例、植被盖度为评价指标分析了旅游相关活动对植被的影响,分析表明,游客的活动对湖岗森林植被有明显影响,旅游活动干扰强度与植被影响状况成正相关关系。     

山岳风景区景观格局时空变化的比较分析

以泰山的佛爷寺和竹林寺两个山岳风景区为研究对象,采用1986年和2004年两期的遥感数据,研究了两个风景区1980年代中期以来景观格局的时空变化特征以及人类活动对景观格局演变的影响。在分析景观多样性、优势度、均匀度、破碎度、扩展度、伸张度指数时间变化的基础上,对景观的空间格局变化趋势进行了对比分析。研究结果表明,两个景区的斑块数量、面积和斑块密度的变化差异明显;两个地区的景观扩展度均远大于1,说明斑块形状不规则。占据优势的森林类型18年来并未遭受严重破坏,两个景区优势度、均匀度变化趋势基本相似,佛爷寺风景区的破碎度远远高于竹林寺,也表明景区建设等人为干扰是景观格局发生变化的主要驱动力。     

北京“百万亩造林”对浅山区生物多样性的影响评价

[目的]人工造林对生物多样性恢复和城市森林功能发挥的影响深远,科学评估人工造林对生态系统恢复速度及稳定性的影响是实现生物多样性保护的基础。[方法]采用格网法获取北京浅山区276个样本单元,根据2010年、2015年和2018年土地利用类型数据,选择多样性、丰富度、均匀度和优势度4个测算指标,分别测算各期生物多样性指数及时空格局,运用OLS回归和分位点回归评价"百万亩"造林对浅山区生物多样性的影响方向和程度。[结果](1)2018年北京市浅山区林地覆盖率达到51.66%,林地面积较2015年增加了3 400hm~2,且林地二级类型间变化较大;(2)2018年北京市浅山区多样性指数、丰富度指数、均匀度指数和优势度指数均值分别为0.432、0.544、0.504和0.276,多样性和均匀度有小幅度降低,但丰富度和优势度提升明显。(3)不同分位水平下,人工造林对浅山区生物多样性的影响方向和程度并不一致,在10%分位水平下,样本单元内林地面积的快速增加均对各项生物多样性指数有显著的促进作用,但影响程度不同。[结论]人工造林应综合考虑源地物种分布状况、造林类型和优势林种等多方面因素,才能最大程度发挥其对生物多样性的修复和保护作用。     

喀纳斯景区草地景观美学价值评价及影响因素分析

[目的]自然景区的美学价值大小直接决定着其旅游开发的成败,为了解喀纳斯景区草地景观美学价值。[方法]该文选用心理物理学派的美景度评价体系,对景区内4个区域草地景观的美景度进行了定量评价,并依据上述样地植物群落α多样性和功能群结构的分析,探讨了植物多样性对喀纳斯景区草地景观美景度的影响。[结果]研究表明:喀纳斯景区草地景观美学价值整体较高,α多样性指数居中的草地美景度得分较高,α多样性指数较高的草地美景度次之,α多样性指数较低的草地美景度最差;随着功能群中一、二年生植物重要值的上升,多年生杂类草的重要值下降,美景度呈降低的趋势;美景度与平均高度、平均盖度、生物量、Shannon-Wiener指数、Margalef丰富度指数、Simpson指数和多年生杂类草重要值呈显著正相关,而与一、二年生杂草重要值呈显著负相关。[结论]因此,草地植物多样性是草地景观美学价值的重要载体,旅游活动导致草地群落植物多样性发生改变,进而深刻影响了草地景观的美学价值。     

土地整治项目对渭北台塬区土壤理化特性的影响

为探究土地整治项目对土壤理化特性的改良效果,本文以宝鸡市陇县河北镇兰家堡村荒草地整治项目为例,对工程实施前、实施后耕作层土壤结构和理化特性的变化进行了分析。结果表明,土地平整工程对耕作层土壤质量的改善具有显著促进作用。通过开展土地平整工程,土壤pH值显著降低,土壤耕作层土壤pH值较工程实施前降低了3.81%。整个土壤耕作层0~30cm土层深度范围内黏粒含量较整治前提高了36.34%,0~30cm土层深度范围内砂粒含量较整治前降低了5.87%。工程实施对土壤全氮、有效磷、速效钾以及有机质含量均产生了不同程度的影响,土壤全氮含量较工程实施前提高了51.16%,土壤有效磷和速效钾在工程实施后分别较之前提高了53.0%和22.97%,有机质含量较之前高出47.72%。     

定位培肥对东北黑土土壤固氮菌多样性的影响

基于10年的黑土培肥定位试验,本试验采用PCR-DGGE、克隆测序技术的方法,研究了培肥处理对大豆固氮菌多样性的影响。DGGE图谱分析表明对照土壤固氮菌多样性指数最高,其次为农肥低量处理、农化1:1处理、化肥低量处理和农肥高量处理,化肥高量处理土壤固氮菌多样性指数最低。在相似度60%水平上化肥处理聚成一群,对照、农肥处理和农化1:1处理量聚成一群。培肥处理降低了土壤固氮菌的多样性,影响了土壤中固氮菌的群落结构,其中培肥高量处理比低量处理降低土壤固氮菌多样性的效果更显著。     

松嫩草原盐碱地土壤理化性质的季节变化研究

盐碱地作为一个独特的生态系统,具有特殊的土壤理化特性,为松嫩草原植被恢复提供更为科学的数据,调查和测试了黑龙江西部松嫩草原土壤的电导率、离子组成和pH值等理化性质,结果表明:3种类型土壤的理化特征各有其特点,轻度盐碱土为非碱性钠质土,中度和重度盐碱土属于碱性钠质土;土壤的盐碱化过程与土壤理化性质变化有关,随着土壤盐碱化程度的增加,植被的种类和数量逐渐降低。松嫩平原草地是个脆弱的生态系统,必须加强对它的保护和管理。     

稻鳅共生种养模式试验研究

[目的]稻鳅共生是典型的稻田综合利用模式,符合生态农业发展方向。通过对稻鳅共生生态系统的生理生态学机制开展试验研究,为进一步推广稻鳅共生种养模式提供科学依据。[方法]采用田间试验方法,以水稻单作为对照,研究了不同泥鳅养殖密度下的稻鳅共生对水稻农艺性状、土壤理化性质、水稻产量构成的影响,并对稻鳅共生种养模式进行了经济效益分析。[结果]与对照处理相比,水稻长势在株高、有效分蘖率、根长等方面有一定提高。养殖田水稻株高增高了3%,有效分蘖率提高了8%~11%,根长提高了8.8%~31.3%。在土壤理化性质方面,与对照相比,土壤容重降低了7.1%~21.2%,孔隙度增加了4.1%~14.7%。实验前后养殖田内土壤有机质增加了3.5%~26.5%,对照田降低了2.5%~5.8%。土壤肥力(氮、磷、钾)减少,但减少幅度小于对照处理。稻鳅共生种养模式下水稻产量提高了5%~25%,同时稻田增收泥鳅1 725~3 375kg/hm2,净收入为1.836 0万~2.307 0万元/hm2,经济效益提高了3.65~4.84倍。稻鳅共生种养模式中泥鳅的养殖密度为30万尾/hm2时稻田的生态效益和经济效益最佳。[结论]稻鳅共生有效改善了土壤理化性质,促进了水稻的生长,提高了稻田产量和产值。     

基于文本挖掘的峨眉山风景区旅游形象感知

随着信息技术不断发展,社交网络逐渐普及,新技术可以更有效地研究游客对景区旅游形象的感知。以新浪微博LBS签到用户为研究对象,以微博评论为研究样本,运用Python软件获取8580条新浪微博LBS签到数据,通过ROST Content Mining、UCINET软件,采用文本分析法、社会网络分析法从景区环境、佛教文化、服务设施、户外活动、气象景观5个方面探索游客对峨眉山风景区旅游形象感知。结果显示:游客对峨眉山风景区的情感态度整体上趋于良好;对景区自然景观和宗教文化评价较高;认为峨眉山风景区是锻炼身体、休闲娱乐的好场所;对景区内基础服务设施方面存有负面评价。最后,对峨眉山及同类型景区的旅游发展提出了相应的参考建议。     

The Effect of the Structural Adjustment Program on the Output,Prices and Exports of Major Agricultural Export Crops in Nigeria

The primary objective of this paper is to examine changes in the level of output, prices and exports of major export crops resulting from the Structural Adjustment Program (SAP) in Nigeria. THere two main sources of data: the Central Bank of Nigeria (CBN) through its annual reports, Economic and Financial Review, and the Nigerian Federal Office of Statistics (FOS) through its Trade Summaries. Although the SAP led to appreciable increases in output and producer prices, its effects on exports were insignificant. The implications of these for the implementation of the program are explored.     

Revealing different understandings of soil held by scientists and farmers in the context of soil protection and management

This paper aims to analyse and draw together results from similar studies in England, Switzerland and France which investigated farmers’ understanding of soil and compared it with that of scientists, researchers and advisors (collectively called scientists in this analysis). A range of methods were used across the three studies and different theoretical approaches, looking at forms of knowledge, local practice of knowledge production and conceptions of reality, were employed to explain the results. Despite the different contexts, methodologies and theoretical approaches in the three studies, the results reveal similar patterns of difference in farmer and scientist understanding of soil. In the English study, farmers demonstrate a ‘know-how’ form or intuitive working knowledge of soil while advisors rely on scientifically established forms of ‘know-why’ and seek to understand and explain soil processes. Similarly in the Swiss study farmers’ and scientists’ differing perceptions are directed and shaped by their respective aims, methods and context of work. In the French study, farmers and researchers are shown to have different conceptions of soil, they attribute different meaning to the same activities, and use different words and language to describe the same features. In all three studies understanding is shown to be cultural and contextual, as such an integrative theoretical framework is proposed.     

森林生物多样性评价模型的改进

针对2002年的评价模型中的不足,提出了新的改进后的森林生物多样性变化的评价模型,并在我国第六次森林资源清查(1999～2003)资料的基础上,对1973～2003年我国森林生物多样性的变化进行了补充评价。评价结果表明:我国森林生物多样性的压力越来越大,压力指数由1973年的100,上升到2003年的199.10,上升了1.99倍;森林物种多样性总体的下降趋势已有一定幅度的改变,森林物种多样性指数增加了31.12%。森林生态系统多样性和森林生物多样性先逐渐上升,尔后又下降,第六次森林资源清查时又有所恢复,并分别上升了4.67个百分点和17.90个百分点。     

Trust-A monolithic panacea in land use planning?

Although trust research has been extensive and substantial, the constitution and actual merits of trust in land use planning remain nebulous. What do participants of a local land use planning process actually mean when they say they trust the planning committee? How important is participants’ trust in the planning committee in shaping their perceptions of the planning process and their cooperation in it? To explore the everyday meaning of trust in the specific context of local land use planning, semi-structured interviews with the participants of a local planning project in Switzerland were conducted (n = 9). Based on these results, the constitution and the relevance of trust in the responsible planning committee among a wider circle of participants were assessed (n = 66). The results show that participants trust the planning committee if they perceive its members as competent, honest, open, fair, reliable, reciprocating, respectful and committed. Interestingly, a considerable part of trust in the planning committee hinges explicitly on whether the committee incorporates the personal interests of the participant. Trust is indeed vital to participants’ belief that a meaningful discussion and cooperation with the members of the planning committee is possible. However, trust is neither a guarantee for people's approval of planning decisions nor for their cooperation. One implication of the findings is that in order to evaluate trust-building practice comprehensively, it is necessary to first understand the specific everyday meaning of trust for ‘real people’ in real planning processes.     

转变地质工作发展与服务方式的实践和建议

天津市地矿局注重加快转变经济发展方式,发挥地质工作优势,推进低碳清洁能源的开发利用创新和技术进步,紧紧依托地质工作的人才、技术和行业优势,加大清洁环保资源的勘查、研究、开发、利用。针对天津市水资源缺乏的情况,积极加强后备和应紧水源勘查。按照“两种资源,两个市场”的思路,通过实施中外合作勘查项目,以境外勘查工作为载体和平台,实施引进来和走出去战略,为天津市经济社会发展提供地质技术支撑。     

Agricultural Land in Vietnam: Markets Tempered by Family, Community and Socialist Practices

Since the late 1980s, markets involving agricultural land have emerged in the Socialist Republic of Vietnam. One major reason is that collective farms, previously a central feature of the country's political economy, ended. And a major reason for that was villagers' everyday politics gnawed the underpinnings of the collectives until they collapsed. Rural households, for the most part, wanted to farm separately. Today they do. Land is not privatized, however. Farming households have land use rights, not ownership. This tempers markets, as do other conditions arising from contending schools of thought in Vietnam about how land should be used, distributed and regulated.     

Conservation agriculture (CA) in Tanzania: the case of the Mwangaza B CA farmer field school (FFS), Rhotia Village,Karatu District,Arusha

This project was initiated to promote conservation agriculture (CA) in Tanzania so as to improve the food security and rural livelihood of small- and medium-scale farmers through the scaling-up of CA as a sustainable land management (SLM) tool as well as increasing the numbers of SLM-CA farmer field schools (FFS) in communities. The project had two phases from 2004 to 2010. It was funded by a Government of Germany trust fund and implemented by the Food and Agriculture Organization of the United Nations (FAO) and the Ministry of Agriculture in Tanzania. The project pilot districts include Arumeru (Arusha and Meru Councils), Karatu, Babati, Hanang and Moshi districts. CA has been shown to offer positive elements that could contribute to fighting hunger and poverty.     

Successful Practices in California Wine Exporting

Abstract

California is one of the world's largest wine producers, yet it has exported only a small portion of its products. Many US wineries want to pursue opportunities in foreign markets but only a few are actually doing this successfully. Therefore, this study attempts to identify the successful practices of 12 California wineries that have achieved their financial targets and other export goals. A qualitative research design of in-depth interviews was employed. Results indicate that there are 5 major success factors, with the two most important being the foreign partner relationship and top management vision and commitment to exporting.     

Time Allocation Decisions Associated with Job Market Preparation: Undergraduate Perceptions versus Market Realities

A survey of agribusiness firms identifies characteristics associated with above average starting salary offers in the allied fields of agribusiness, agricultural economics, business, and economics. A complementary survey is made of students at Texas A&M University and University of Georgia. Results show that firms value work experience and leadership experience more than students do, whereas students value raising grade point average and interview preparation more than do firms. Students seeking a firm's maximum starting salary offer will need to enhance academic performance with substantial work experience and leadership experience.     

Developments in the Doha Round and WTO dispute settlement: some implications for EU agricultural policy

Progress in the Doha Round is assessed against the changes tothe common agricultural policy (CAP) brought about by the Fischlerreforms of 2003–2004, and that proposed for sugar. Anelimination of export subsidies could place EU exports of processedfoods at a competitive disadvantage because of high sugar andmilk prices. Provided the single payment scheme falls withinthe green box, the likely new limits on domestic support shouldnot be problematic for the post-Fischler CAP. However, an ambitiousmarket access package could open up EU markets and bring pressurefor further reform. If there is no Doha agreement, existingprovisions will continue to apply, but without the protectionof the Peace Clause; and increased litigation is likely. FurtherCAP reform is to be expected.