基于历史数据和生物地理学确定恢复异木麻黄（Allocasuarina robusta）的未来优先事项（英文）

识别某一物种受威胁的原因有助于制定最好的物种恢复计划,基于一般概念的恢复计划可能并不适用于某个特定区域或者某个特定物种的恢复。城市扩张和土地集约化利用就被认为是威胁区域生物多样性的主要人为因素,因此厘清这个威胁过程与受威胁物种的相互作用可以指导物种的恢复工作。在南澳大利亚州,异木麻黄(Allocasuarina robusta)的变化过程为了解该地区过去的土地利用变化及其对生物多样性的影响提供了很好的机会。本文聚焦于土地利用变化与植物标本数据之间的关系,以了解常见物种和受威胁物种之间的关系。随着物种的进化和对环境的适应,所采取的生物多样性恢复保护措施(包括用于识别未来行动的方法)需要与不断变化的环境相适应。同时,不断变化的环境也会对生物多样性产生影响,并进而给土地管理者带来了许多新的问题。传统的物种恢复技术可以减缓威胁过程,例如补充种植就是有充分依据的做法,但是这种做法的意义可能还有待于进一步验证;自然再生对于种群长期生存至关重要,但是在生命力旺盛的异木麻黄中却并没有发生(自然再生情况)。调查异木麻黄的变化情况旨在探索植物标本数据与土地历史利用之间的关系,以指导未来的物种恢复工作。     

黑河流域植物物种多样性对土地利用变化的响应北大核心CSCD

黑河流域土地利用变化严重影响植物物种多样性。为了解自然、社会经济因素对黑河流域土地利用变化影响下植物物种多样性的变化趋势,本研究使用Dyna-CLUE模型,预测2050年土地利用变化,揭示多因素影响下黑河流域土地利用变化,及土地利用变化与草本、灌木物种多样性间的关系。结果表明:降水、GDP、与自然村距离等因子共同驱动土地利用变化,2050年林地、草地和水域面积的增加和未利用地面积的减小,提高了灌木、草本植物的多样性,并使之均匀度更高,种间优势度减小。耕地面积的扩张和耕地集约化导致植物分布不均、多样性减少。将模拟结果和植物物种多样性发展趋势相结合能够对未来的土地利用规划、政策及生态保护决策提供依据。应针对不同区域土地利用变化情况,制定相应的生物多样性和生态环境保护政策,促进黑河流域生态环境的恢复并支持流域可持续发展。     

广东省陆地生物多样性热点区域及其胁迫因素

生物多样性热点区域的识别及其胁迫因素的分析为生物多样性的保护和恢复提供了有效途径。当前研究大多将物种多样性及其受威胁状况结合起来确定需优先保护的热点区域,缺乏在识别生物多样性热点区域的基础上对其胁迫状况的深入分析。文章基于广东省动植物物种、生态系统林分类型、土地利用等多源数据,利用植物物种多样性、动物物种多样性和景观多样性构建陆地生物多样性热度指标,进而识别生物多样性热点区域,并在此基础上根据生物多样性面临的主要威胁分析了生物多样性受胁迫程度及主导胁迫因子。结果表明：1)广东省陆地生物多样性热度高值区主要分布在人类干扰相对较小的山区,基于热度值分区识别出云雾山、南岭、罗浮山、莲花山4个生物多样性热点区域,总面积达59 931.82 km²,占广东省陆域面积的33.58%。2)热点区域内各类保护区面积合计6 594.39 km²,约为广东省所有陆域保护区面积的61.33%,涉及广东省全部204个陆域保护区中的122个。热点区域内保护区的面积仅为热点区域总面积的11.00%,生物多样性仍有大量潜在的保护需求。3)在4个热点区域中,云雾山生物多样性...     

黄河三角洲生态系统多功能性与不同维度植物多样性的关系研究

生物多样性是生态系统多功能性的重要驱动因素,生态系统生物多样性与多功能性之间的关系是近年来生态学研究的热点。以往研究主要集中在预测物种丰富度如何影响生态系统多功能性,而不同维度生物多样性对生态系统多功能性的影响机制仍然不清楚。研究黄河三角洲不同维度生物多样性、环境因素和生态系统多功能性及其之间的关系,结果表明,黄河三角洲生态系统多功能性同时受环境因素和生物多样性因素的影响,但是,生物多样性在维持生态系统多功能性上的相对贡献明显高于环境因素;植物群落的物种丰富度、物种均匀度、谱系多样性和功能离散指数分别与生态系统多功能性显著正相关,而谱系亲缘关系指数和植物性状群落权重平均值对生态系统多功能性并无显著影响,这说明与分类多样性和谱系多样性相比,植物群落功能多样性的增加能够更有效地提升生态系统多功能性;丰富的植物功能多样性是维持黄河三角洲高水平生态系统多功能性的关键,黄河三角洲生态系统多功能性的维持主要受互补效应的驱动。     

黄河三角洲滨海湿地维管植物多样性现状及保护策略

利用公里网格法和样带群落调查相结合的方法 ,2011-2012年对黄河三角洲滨海湿地维管植物物种多样性进行了全面调查,分析了物种多样性现状和受威胁的主要因素,在此基础上提出了保护策略,为黄河三角洲滨海湿地植物多样性保护提供科学依据。     

青藏高原维管植物物种丰富度分布的情景模拟

如何充分利用离散的观测数据,通过对维管植物物种分布丰富度及其与生境因子之间的相互作用和影响机理的定量分析,实现维管植物物种丰富度的空间分布及其情景模拟,是目前生物多样性研究前沿和核心内容之一。针对这一问题,在实现青藏高原37个国家自然保护区的维管植物物种数量收集和边界数据矢量化的基础上,分别进行维管植物物种数量与土地覆盖类型、环境因子和景观生态指数等三大类生境因子之间的相关关系的定量计算和对比分析,筛选和确定最佳相关分析方程,进而构建青藏高原维管植物物种丰富度的空间模拟分析模型。该模型中,维管植物物种丰富度与生境因子之间的复相关系数为0.94,模型验证结果表明,青藏高原的维管植物物种的平均丰富度为496.79种/100 km²,其空间分布格局整体上呈东南向西北逐渐减少趋势;另外,除柴达木盆地荒漠区域以外,维管植物物种的空间分布随海拔的升高而减少。基于CMIP5 RCP 2.6、RCP 4.5和RCP 8.5三种气候情景模拟获得的青藏高原维管植物物种丰富度未来情景结果显示,在T0-T4（2010-2100）时段内,青藏高原维管植物物种丰富度整体将呈减少趋势。RCP 8.5情景下青藏高原维管植物物种丰富度的变化幅度最大,而RCP 2.6情景下的维管植物物种丰富度的变化幅度最小。研究表明,本文构建的模型能够对青藏高原维管植物物种丰富度的空间分布格局及其未来情景进行模拟分析,模拟结果可为青藏高原生物多样性及其对气候变化响应的综合评估和情景模拟提供方法和技术支持。     

退化草原轻耙处理过程中植物种多样性变化的研究

利用多年样方资料的统计分析,对退化草原群落轻耙处理后恢复过程中的生物多样性变化规律及引起这些变化的主要植物种群进行研究,结果表明:在退化群落耙地恢复过程中,整个群落的物种丰富度变化不大,物种分布的均匀性指数随演替过程呈现波动下降的趋势,多样性指数也呈现波动下降的趋势,恢复后期有所升高,且物种分布的均匀性是造成物种多样性指数变化的主要原因。羊草(Leymus chinensis)的密度和生物量的变化与多样性指数具有极显著的负相关关系。冷蒿(Aartemisia frigida)、洽草(Koeleria cristata)的密度和生物量与多样性指数具有极显著的正相关关系。隐子草(Cleistogenes squarrosa)、变蒿(A.commutata)的密度与多样性指数具有极显著的正相关关系。多样性指数与耙地处理后的恢复年限(11 a间)的关系可表示为:以密度为指标的多样性指数D_n=3.579-0.665Lnx(r=-0.9185);以生物量为指标的多样性指数D_w=4.4-0.7696Lnx(r=0.8667)。     

鄱阳湖砂山地区风沙化过程中物种多样性的变化

对鄱阳湖砂山地区土地风沙化过程中物种多样性的变化特征进行了分析,依据植物种在各类型风沙化土地的出现频率与不同风沙化阶段各生活型植物种的组成,探讨了风沙化过程中植物种绝灭与定居特点。物种多样性指数分析表明:风沙化过程是物种多样性衰减的过程,风沙化首先导致特有种的灭绝,其次为稀有种。从植物的生活型来看,多年生草本与乔木类植物受风沙化影响最大,而灌木类植物可存活风沙化过程各个阶段,在风沙化过程中植物种的绝灭速率大于定居速率。     

宁化县紫色土侵蚀区治理年限对不同治理模式植物多样性的影响

以宁化县紫色土侵蚀区4种主要治理模式的植物群落调查资料为基础,采用丰富度指数、均匀度指数和多样性指数对其进行分析。研究结果表明：1）与对照区相比,各治理样地植物群落物种多样性、丰富度和均匀度指数均有不同程度提高,植物群落结构趋于复杂稳定。2）随着演替的进展,群落多样性指数在乔灌草混交及封禁治理模式增大,但在油茶园改造模式中变化不明显。3）经济林模式治理年限短,受人为干扰强烈,植物多样性差异较大,其随治理年限的变化有待于进一步观察。4）植物多样性与植物生长型的关系：物种丰富度和多样性指数在治理初期为草本层大于灌木层,随着群落演替的进展,灌木层逐渐大于草本层;均匀度指数的变化,在油茶园改造及乔灌草混交模式中草本层大于灌木层,而在经济林和封禁模式中,多表现为灌木层大于草本层。因此,后续治理应注意：侵蚀劣地的生态恢复必须进行科学的人为干预,生物措施应合理配置乔灌草物种数和个体数,对树种单一的群落需进行补植修复;针对不同治理阶段和治理模式,生态恢复侧重点要有差异。     

塔里木河下游物种多样性恢复速率分析

通过塔里木河下游生态输水后植物群落及其环境因子的系统取样调查,采用β多样性指数,从时空维上分析了生境差异与物种的恢复速率差异.结果表明:物种多样性差异与环境水分条件有着密切的关系,在地下水埋深小于5 m时,物种恢复速率的发生率达100%,而在地下水埋深大干5 m时;多样性恢复的率达46%.生境异质性较高的群落,水分条件较好,其物种恢复速率相对较高,表现为河边低地、地表未起沙生境与人工灌溉生境具有较高的物种恢复速率.生态恢复过程中,人类的干预对局部生境中物种多样性恢复产生了一定的影响,但物种替代速率与恢复速率的大小最终决定于水分条件的可利用性与环境劣变程度.     

Place and Large Landscape Conservation along the Susquehanna River

Place theory can be used in natural resource sociology as a heuristic for identifying and incorporating differences in human and natural systems into large landscape conservation efforts. This paper draws on theories of place and applies mixed methods to understand the potential opportunities and challenges for a large landscape conservation initiative along the Susquehanna River. The research utilized key informant interviews of 62 conservation officials to develop a grounded theory of regions within the river corridor. These regions were used as the sampling frame for a telephone survey of approximately 1,000 residents. Analysis of attitudes about conservation actors, priorities, and place perceptions were layered with data acquired in key informant interviews to produce an understanding of social, physical, and symbolic aspects of the Susquehanna River landscape as a place. Identifying similarities and differences can aid in the integration of human perceptions and attitudes within large landscape conservation efforts.     

HABITAT ISLANDS AND THE PRESERVATION OF NEW ZEALAND'S AVIFAUNA*

ABSTRACT. Numerous avifauna species face extinction on New Zealand's two main islands, owing largely to forest clearance and to introduced mammals. In response, New Zealand selects certain offshore islands for the relocation of threatened native birds, first purging them of mammalian predators. Over the past few decades, this procedure has evolved to become fairly successful. Protected habitat “islands” within mainland forested areas are also being created, but with success less certain. As historic habitats are lost, small biopreservation islands may become a standard mechanism for protecting threatened species, a process that can be termed the “miniaturization” of nature.     

Driving forces of tropical deforestation: The role of remote sensing and spatial models

Remote sensing technologies are increasingly used to monitor landscape change in many parts of the world. While the availability of extensive and timely imagery from various satellite sensors can aid in identifying the rates and patterns of deforestation, modelling techniques can evaluate the socioeconomic and biophysical forces driving deforestation processes. This paper briefly reviews some emerging spatial methodologies aimed at identifying driving forces of land use change and applies one such methodology to understand deforestation in Mexico. Satellite image classification, change analysis and econometric modelling are used to identify the rates, hotspots and drivers of deforestation in a case study of the southern Yucatán peninsular region, an enumerated global hotspot of biodiversity and tropical deforestation. In particular, the relative roles of biophysical and socioeconomic factors in driving regional deforestation rates are evaluated. Such methodological approaches can be applied to other regions of the forested tropics and contribute insights to conservation planning and policy.     

Crops,trees, and birds: Biodiversity change under agricultural intensification in Uganda's farmed landscapes

Geografisk Tidsskrift, Danish Journal of Geography 106(2): 115–130, 2006

This paper examines the relationship between the intensity of agricultural land use and the abundance and richness of trees and birds in a humid tropical developing region where natural vegetation is being rapidly converted into farmland under market and population pressures. We analysed survey data on land use, birds and woody plants collected in 14 study sites situated within smallholder cropland and commercial plantations in southern Uganda. Commercial plantations had very few trees and only 10% of the original bird species. Land use intensification in smallholder systems also showed losses in bird abundance and species richness, but not nearly as much as in plantations. In both systems the impact of intensification was much bigger on the specialised and threatened birds compared to the less specialised species. This argues strongly for ‘species-sensitive’ conservation policies combining protected areas with land use regulation in areas undergoing intensification. We also found a much higher loss in bird biodiversity during the first phases of land use intensification (when larger tracts of forest are cleared) than in later phases characterised by clearing of smaller patches of vegetation and improved management of farm trees. This suggests high pay-offs to geographical targeting of conservation efforts in farmed landscapes.     

First record of Branchinella spinosa (Milne-Edwards) (Crustacea: Branchiopodacolon; Anostraca) from Greece

As the result of a first screening of temporary inland water habitats,Branchinella spinosa is here recorded for the first time in Greece. This finding extends the circum-Mediterranean part of its vast distribution. The species was collected from a shallow astatic coastal salt-marsh that is mainly fed by rainwater, where it coexists but rarely co-occurs withArtemia parthenogenetica. Branchinella spinosa is only the fourth anostracan species currently known from Greece. The poor knowledge of anostracan richness and abundance is mainly due to limited sampling efforts in this area. As temporary aquatic habitats are threatened by several anthropogenic activities, especially agriculture and land clearing for urbanisation and tourism, there is an urgent necessity for further monitoring and protection of these precious habitats.     

塔里木河下游土地沙漠化及其原因探讨国家

土地沙漠化作为极其重要的环境和社会问题正困扰着当今世界,威胁着人类的生存和发展。塔里木河下游地区是我国沙漠化最严重的地区之一,作为内陆河流下游地区的沙漠化典型代表,不少学者对塔里木河下游沙漠化的成因、发展及相关问题进行过讨论。在实地考察和前人研究的资料基础上,对塔里木河下游土地沙漠化及其成因、沙漠化对下游地区可持续发展的危害进行了探讨。     

Does outmigration lead to land degradation? Labour shortage and land management in a western Nepal watershed

In Nepal, changing demographic patterns are leading to changes in land use. The high level of outmigration of men in the hills of Kaski District, Western Development Region of Nepal, is affecting the household structure but also land management. Land is often abandoned, as the burden on those left behind is too high. How do these developments affect the state of the land in terms of land degradation? To find out, we studied land degradation, land abandonment caused by outmigration, and existing sustainable land management practices in a subwatershed in Kaski District. Mapping was done using the methodology of the World Overview of Conservation Approaches and Technologies (WOCAT). While previous studies expected land abandonment to exacerbate slope erosion, we demonstrate in this paper that it is in fact leading to an increase in vegetation cover due to favourable conditions for ecosystem recovery. However, negative impacts are several, including the increase of invasive species harmful to livestock and a decline in soil fertility. Traditional land management practices such as terraces and forest management exist. To date, however, these measures fail to take account of the changing population dynamics in the region, making the question of how migration and land degradation are linked worth revisiting.     

Variation between bee communities on a sand dune complex in the Great Basin Desert,North America: Implications for sand dune conservation

Sand dunes across the Mojave and Great Basin Deserts house rich bee communities. The pollination services these bees provide can be vital in maintaining the diverse, and often endemic, dune flora. These dune environments, however, are threatened by intense off-highway vehicle (OHV) use. Conservation efforts adopted by land managers often consist of setting aside a portion of a dune system that is off-limits to OHV use, but little work has been done showing the extent to which this protects native bee communities. A two-year study of bee communities on a Great Basin sand dune complex in Dugway Proving Ground located in northwestern Utah revealed low similarity index values between closely situated collecting plots (1–40 km apart). Similarity values ranged from 0.13 to 0.70 for species composition, and from 0.07 to 0.57 when similarity was weighted by abundance. Distance between plots had no significant relationship to similarity when richness and abundance were considered. Bee similarity between plots was significantly correlated with floral similarity. These results indicate that dune conservation strategies that preserve “representative” portions of dune systems may be insufficient to protect bees and the pollination services they provide.     

西双版纳不同山地长果桑及食果动物

热带雨林是大自然赋予人类的珍贵资源宝库 ,有着久远的发展历史 ;认识其间的动植物关系以及人类影响下的动态变化 ,不仅有重要学术意义 ,而且对热带山地生态系统的保护、恢复 ,山区的持续发展有现实指导作用。我们在长果桑果期研究了西双版纳不同强度人为影响的热带山林摄食动物种群结构 ,对地区的发展和热带山地生态系统的维护有了新的认识。     

Classifying Geographical History*

Although the term “historical geography” has been the subject of a sustained and critical debate, that of “geographical history” has not. Usage of the latter term has been variable and the epistemological status of geographical history has been ambiguous. An examination of the usage of the term “geographical history” during the past 100 years or so reveals both that it has been employed little but confusingly and that there have recently been calls for its wider adoption. Two key themes are identified in the literature: first, that of geographical history as the study of changing geographical distributions; and second, geographical history as the study of geographical (in the sense of physical environmental) influences in history. In theory it is possible to distinguish geography from history and historical geography from geographical history, but in practice it is often difficult to do so. Nonetheless, examining usage of the term matters as a contribution to the history of ideas, and identifying its common usages allows scholars to communicate with mutual understanding.