Effects of anthropogenic disturbances on vegetation diversity and structure: a case study in the remnant forests surrounding the village ecosystems of Tripura,Northeast India

The types, frequency, and intensity of human interference with forests markedly affect the vegetation dynamics. Assessment of the impact of anthropogenic disturbances on forest diversity and structure is one of the central issues related to human behaviour and forest ecosystems and management. Both species diversity and density are very sensitive to local anthropogenic disturbance, which can be reduced depending on land-use systems. We used 10 line transects of 500 × 10 m to record and measure all plants ≥10 cm girth in some of the remaining forests surrounding villages in Tripura, Northeast India. To predict the effects of anthropogenic pressure on species richness and forest structure, we recorded and scored all ongoing disturbances in all transects of the forests. Although our study did not show any significant effects on the mean number of species, all diversity indices were significantly affected by disturbance. Total stem density (F = 128.60, p < 0.0001) and basal area (F = 65.30, p < 0.0001) of the forest stands were significantly affected by disturbance. Disturbance significantly (F = 84.81, p < 0.0001) impacts the abundance of mature voluminous trees removed by extensive illegal logging. Further, stem density at the middle (F = 10.01, p < 0.05) and upper (F = 131.70, p < 0.0001) canopy stories was also reduced by high disturbance intensity. The present analysis will be useful to policy-makers and planners for implementation of sustainable forest management at both the local and regional scale.     

环境规制和农业科技进步的关系分析——基于波特假说的研究

波特假说主要从动态的角度论证了环境规制和农业科技进步之间的正向变亿关系.而在安徽省1990 -2008年的农业生产数据的基础上,选择合适的环境规制和农业科技进步的指标变量,运用Johansen协整分析方法验证了安徽省农业生产中的环境规制和农业科技进步的关系也符合这一假说,Granger因果关系检验说明了安徽省环境规制是农业科技进步产生的原因,脉冲响应分析和方差分析则更深入地从定量的角度分析了环境规制对农业科技进步影响滞后的趋势和影响程度.由实证分析可以看出,只是从静态角度来分析,环境规制是不利于农业的科技进步的;但从长期效益来看,环境规制有利于农业的科技进步.因此,在农业生态环境恶化的形势下,严格对农业废弃物的排放限制,制定较严格的农产品生产标准和产品质量标准,提高农民的环境意识和科技意识,通过强化环境规制来促使农业生产者提高农业生产技术,提高农产品品质和产品的市场竞争力就显得尤为重要.     

干旱地区土地利用结构变化与生态服务价值的关系研究——以酒泉市为例

利用酒泉市1997-2006年土地利用变更调查数据和相关统计资料,计算土地利用结构异质性指数和生态服务价值,分析土地利用结构与生态服务价值的变化及其相互关系.结果表明:1997-2006年酒泉市耕地、林地、园地面积在增加,其中耕地增加最多,增加了9 803.15hm2,牧草地、水域和未利用地面积不断减小,其中牧草地减少最多,减少了207 470.56 hm2;酒泉市土地利用结构多样性指数和均匀度增加而优势度降低,土地利用趋于多样化和均匀化;各类土地的生态服务价值都有不同程度的增加,土地利用生态服务价值总体呈增加趋势;土地利用生态服务价值与土地利用结构线性相关,通过增加牧草地、水域和耕地等生态用地面积,提高土地利用集约度,调整土地利用结构促进土地利用的多样化、均匀化,可以增加生态系统稳定性和提高生态系统服务功能的经济价值.     

Study on the Comprehensive Tourism Development Pattern in Periphery Minority Area: A Case Study of Gannan Tibetan Autonomous Prefecture of Gansu Province,China

Abstract

The paper took the human-land relations as a basic point, and the theories of tourism industry system and sustainable development as the guidance, with Gannan Tibetan Autonomous Prefecture (Gannan) as the case study area. From microcosmic and macroscopic viewpoints, the author carried out function orientation and evaluation to the tourism industry development, and research on the comprehensive tourism industry development pattern of Gannan. Results show that the fragile ecological environment and the traditional economic growth pattern have restricted regional sustainable development, and made Gannan to become a representative of the periphery minority areas in Northwest China. Tourism development of Gannan is at the primary phase, with the characteristics of short industry chain and low economic efficiency. It is an inevitable choice to transform the way of regional economic growth and the development pattern of tourism industry from the traditional pattern to the pattern of sustainable development. Simultaneously, Gannan's natural, national and religious culture makes Gannan a broad prospect on the comprehensive tourism development. Gannan should choose the comprehensive tourism industry as its scientific pattern to realize sustainable development, promote harmonious social, economic and ecological development, alleviate the human-land contradictory, and realize dual goals in terms of ecology construction and economical development. For Gannan and the similar areas in China, studies on the sustainable development pattern of tourism have extremely important strategic sense with respect to tourism development and the sustainable development of regional economy.     

Study on the Comprehensive Tourism Development Pattern in Periphery Minority Area： A Case Study of Gannan Tibetan Autonomous Prefecture of Gansu Province, China

The paper took the human-land relations as a basic point, and the theories of tourism industry system and sustainable development as the guidance, with Gannan Tibetan Autonomous Prefecture （Gannan） as the case study area. From microcosmic and macroscopic viewpoints, the author carded out function orientation and evaluation to the tourism industry development, and research on the comprehensive tourism industry development pattern of Gannan. Results show that the fragile ecological environment and the traditional economic growth pattern have restricted regional sustainable development, and made Gannan to become a representative of the periphery minority areas in Northwest China. Tourism development of Gannan is at the primary phase, with the characteristics of short industry chain and low economic efficiency. It is an inevitable choice to transform the way of regional economic growth and the development pattern of tourism industry from the traditional pattern to the pattern of sustainable development. Simultaneously, Gannan＇s natural, national and religious culture makes Gannan a broad prospect on the comprehensive tourism development. Gannan should choose the comprehensive tourism industry as its scientific pattern to realize sustainable development, promote harmonious social, economic and ecological development, alleviate the human-land contradictory, and realize dual goals in terms of ecology construction and economical development. For Gannan and the similar areas in China, studies on the sustainable development pattern of tourism have extremely important strategic sense with respect to tourism development and the sustainable development of regional economy.     

水土匹配、空间效应及区域农业经济增长——基于中国2003-2013的经验分析

水资源和土地资源是非常重要的自然资源,是农业经济发展不可或缺的物质要素。水资源与土地资源的合理匹配能够促进区域的资源优势转化为经济增长,从而促进区域农业经济发展。我国是一个人口众多的农业大国,同时也存在水资源与土地资源短缺的问题。本文结合我国农业水土资源自然禀赋与实际利用情况,首先利用中国2003-2013年的分省数据,选取单位耕地面积的广义农业水资源量测度方法和当量系数描述了我国农业水土资源匹配的现实,发现我国农业水资源与土地资源在空间上匹配程度不高,农业生产受到水土资源约束较强,农业水土资源的形成区域与消耗区域在空间上不相匹配;然后,在邻接权重矩阵下采用Moran’s I指数验证我国区域农业经济增长的空间关联性,结果显示我国各省农业经济增长存在显著的空间关系,呈现出高度的集聚性和非均质性。为避免估计结果有偏,本文在此基础上采用空间计量建模及估计方法,加入农业生产人、财、物等控制变量,测度水土匹配度对区域农业经济增长的空间溢出效应。结果显示,水土匹配度对区域农业经济发展的区域内和区域间的溢出效应都显著为正,总体上水土匹配度对区域农业经济发展具有正向的溢出效应,即水土匹配度对本地区农业经济增长具有促进作用;同时,由于相邻区域的水土资源自然禀赋条件类似,而且农业生产中存在"示范效应"和"模仿效应",水土匹配度对相邻地区农业经济增长也具有一定的促进作用。因此,采取相关措施优化农业水土资源匹配关系,对促进我国区域农业经济增长,保障我国粮食安全非常重要。     

老年人旅游消费与影响因素关联度分析——基于京津冀地区2006-2013年面板数据

我国现阶段65岁以上老年人享有较好的社会保障体系,具有一定的物质基础和精神需求,对出行旅游具有强烈的欲望.在我国人口老龄化趋势逐渐加重的驱使下,刺激老年人出行旅游能够极大的促进消费,带动内需增长.为了科学制定拉动老年人旅游的政策措施,本文从《中国统计年鉴》(2006-2013年)中选取65岁以上人口比、老年抚养比、城镇人口比重、城镇基本养老保险基金支出、文盲人口占15岁及以上人口、接受高等教育人数、以及地区最终消费支出作为主要的比较指标;从《中国旅游统计年鉴》(2006-2013年)中选取65岁以上旅游人数比与65岁以上人口旅游消费支出作为主要参考指标,分别对相关数据进行了灰色关联分析.分析结果显示,选取的比较指标与参考指标之间呈现了中等以上强度的关联性,关联度均在0.6以上,65岁以上人口、老年抚养比、城镇人口比重相对2个参考指标关联度最强,城镇人口数量与受教育情况业是影响65岁以上旅游人数的重要因素,分析结论可以作为国家和地方政府在制定养老产业相关政策时的重要参考.本研究的最后,提出了完善社会福利保障体系和旅游业法律法规,提高养老保险水平,保障老年人旅游市场安全及制定差异化价格战略等措施.     

秸秆还田对稻田温室气体排放的影响:Meta分析——以长江中下游地区为例

全球气候变暖是人类面临的严峻挑战,稻田生态系统在全球气候变暖中起到重要的作用。目前已有许多学者通过大田试验的方法研究了不同秸秆还田方式下温室气体排放的特征,但由于试验地点等因素的不同导致最终的结果差异很大。通过整合这些结果来研究区域内不同秸秆还田方式(翻耕秸秆还田(CTS)、免耕秸秆还田(NTS)和旋耕秸秆还田(RTS))下稻田温室气体排放的特征,能够准确地反映一定区域内稻田生态系统的净减排潜力。本文基于长江中下游地区32篇关于秸秆还田对稻田温室气体排放的文献收集173组数据,利用Meta分析方法研究了3种秸秆还田方式下稻田CH_4和N_2O排放的特征,并估算出不同秸秆还田方式下稻田的全球增温潜势和净增温潜势。结果表明,CTS、NTS和RTS处理下稻田CH_4周年排放的效应值分别为0.76、0.37和0.68,稻田N_2O周年排放的效应值分别为0.44、0.36和0.52;在两熟制下,不同秸秆还田方式下稻田CH_4周年排放的效应值的大小为RTSCTSNTS,但N_2O周年排放的效应值的大小为RTSNTSCTS。在三熟制下,三种秸秆还田方式下稻田CH_4的周年排放的效应值的高低为CTSRTSNTS,而N_2O周年排放的效应值的高低为RTSNTSCTS。在相同的秸秆还田方式下,三熟制稻田温室气体周年排放的效应值都高于两熟制。此外,不同的还田秸秆种类影响稻田温室气体的排放;结合前期研究,估算出CTS、NTS和RTS处理下稻田的净增温潜势分别为12 375.55、11 232.36和15 982.87 kg CO_2-equivalent·hm~(-2)。因此,免耕秸秆还田是长江中下流地区稻田净减排条件下适宜的秸秆还田方式。