Levels of polycyclic aromatic hydrocarbons in Canadian mountain air and soil are controlled by proximity to roads

Concentrations of polycyclic aromatic hydrocarbons (PAHs) were measured in soil and XAD-based passive air samples taken from a total of 22 sites along three transects (Revelstoke, Yoho, and Observation, 6-8 sites for each transect) in the mountains of Western Canada in 2003-2004. Median concentrations in air (4-ring PAHs: 33 pg/m³) were very low and comparable to those in global background regions such as the Arctic. Low median soil concentrations (16 EPA PAHs: 16 ng/g dry weight) and compositional profiles dominated by naphthalene and phenanthrene are similar to those of tropical soils, indicative of remote regions influenced mostly by PAHs from traffic and small settlements. Comparing levels and composition of PAHs in soils between and along transects indeed suggests a clear relationship with proximity to local sources. Sampling sites that are closer to major traffic arteries and local settlements have higher soil concentrations and a higher relative abundance of heavier PAHs than truly remote sites at higher elevations. This remains the case when the variability in soil organic carbon content between sites is taken into account. Both air/soil concentration ratios and fugacity fractions suggest atmospheric net deposition of four-ring PAHs to soils.     

A Comparison of Sampling Designs for Monitoring Recreational Trail Impacts in Rocky Mountain National Park

The dual goals of the Organic Act of 1916 and Wilderness Act of 1964 are to protect natural resources and provide quality visitor experiences. Park managers need metrics of trail conditions to protect park resources and quality of visitor experiences. A few methods of sampling design for trails have been developed. Here, we describe a relatively new method, spatially balanced sampling, and compare it to systematic sampling. We evaluated the efficiency of sampling designs to measure recreation-related impacts in Rocky Mountain National Park. This study addressed two objectives: first, it compared estimates of trail conditions from data collected from systematic versus spatially balanced sampling data; second, it examined the relationship between sampling precision and sampling efficiency. No statistically significant differences in trail condition were found between the 100-m interval and the spatially balanced datasets. The spatially balanced probability-based dataset was found to be a good estimate of trail conditions when analyses were conducted with fewer sample points. Moreover, spatially balanced probability-based sampling is flexible and allows additional sample points to be added to a sample.     

Atmospheric Change and Biodiversity: Co-Networks and Networking

Canada responded to the Global Biodiversity Convention by completing the Canadian Biodiversity Strategy in 1995. At the same time, Environment Canada also completed a national Science Assessment on Biodiversity. During this period, the Smithsonian Institution, in partnership with Parks and Environment Canada, initiated the implementation of a global biodiversity monitoring program in Canada. Under the auspices of the United Nations Man and the Biosphere Program, the SI/MAB monitoring protocols and plots have spread across Canada at an unprecedented rate. National champions in the science and educational sectors, working within an inter-disciplinary ecological framework, have guided the development, education, quality control and sharing of atmosphere-biodiversity observations electronically.Atmospheric-Biodiversity Networks and Networking have traditionally operated within separate mandates with little degree of integration. Air-Bio Networks were designed within an integrated framework to better understand the atmospheric stress on biodiversity and the adaptation actions, nationally and regionally. Detailed examples of the cumulative effects of climate change, stratospheric ozone depletion, acid deposition, ground-level ozone, suspended particulate matter and hazardous air pollutants on biodiversity will be discussed using a Southern Ontario case study. In addition, recommendations will be presented for future paired SI/MAB plots, linked networks and networking for adaptation within the context of climate, chemical and ecological gradients.     

The Impacts of Human Visitation on Mussel Bed Communities Along the California Coast: Are Regulatory Marine Reserves Effective in Protecting These Communities?

Rocky intertidal habitats frequently are used by humans for recreational, educational, and subsistence-harvesting purposes, with intertidal populations damaged by visitation activities such as extraction, trampling, and handling. California Marine Managed Areas, particularly regulatory marine reserves (MRs), were established to provide legal protection and enhancement of coastal resources and include prohibitions on harvesting intertidal populations. However, the effectiveness of MRs is unclear as enforcement of no-take laws is weak and no regulations protect intertidal species from other detrimental visitor impacts such as trampling. The goal of this study was two-fold: (1) to determine impacts from human visitation on California mussel populations (Mytilus californianus) and mussel bed community diversity; and (2) to investigate the effectiveness of regulatory MRs in reducing visitor impacts on these populations. Surveys of mussel populations and bed-associated diversity were compared: (1) at sites subjected to either high or low levels of human use, and (2) at sites either unprotected or with regulatory protection banning collecting. At sites subjected to higher levels of human visitation, mussel populations were significantly lower than low-use sites. Comparisons of mussel populations inside and outside of regulatory MRs revealed no consistent pattern suggesting that California no-take regulatory reserves may have limited effectiveness in protecting mussel communities. In areas where many people visit intertidal habitats for purposes other than collecting, many organisms will be affected by trampling, turning of rocks, and handling. In these cases, effective protection of rocky intertidal communities requires an approach that goes beyond the singular focus on collecting to reduce the full suite of impacts.     

Reliability of a Higher-Taxon Approach to Richness, Rarity, and Composition Assessments at the Local Scale

Abstract:  A promising shortcut for quantifying species patterns is to use genera and families as surrogates of species. At large spatial scales, concurrence between patterns of richness, rarity, and composition of species and higher taxa is generally high. Only a few researchers, however, have examined this relationship at the local scale, which is frequently the relevant scale in land-use conflicts. We investigated the reliability of the higher-taxon approach in assessing patterns of species richness, rarity, and composition at the local scale. We studied diversity patterns of three commonly used surrogate taxa: vascular plants, ground-dwelling beetles, and moths. We conducted year-round field surveys for these taxa in the Jerusalem Mountains and the Judean foothills, Israel. Richness and composition of species were highly correlated with richness and composition of genera for all taxa. At the family level, correlations with richness and composition of species were much lower. Excluding monotypic genera and families did not affect these relations. Rarity representation based on higher taxa varied considerably depending on the taxon, and rarity scale and was weaker compared with richness and composition representation. Cumulative richness curves of species and genera showed similar patterns, leveling off at equivalent sampling efforts. Genus-level assessments were a reliable surrogate for local patterns of species richness, rarity, and composition, but family-level assessments performed poorly. The advantage of using coarse taxonomic scales in local diversity surveys is that it may decrease identification time and the need for experts, but it will not reduce sampling effort.     

Pattern and Process in Northern Rocky Mountain Headwaters: Ecological Linkages in the Headwaters of the Crown of the Continent1

Abstract: The Crown of the Continent is one of the premiere ecosystems in North America containing Waterton‐Glacier International Peace Park, the Bob Marshall‐Great Bear‐Scapegoat Wilderness Complex in Montana, various Provincial Parks in British Columbia and Alberta, several national and state forest lands in the USA, and Crown Lands in Canada. The region is also the headwater source for three of the continent’s great rivers: Columbia, Missouri and Saskatchewan that flow to the Pacific, Atlantic and Arctic Oceans, respectively. Headwaters originate in high elevation alpine environs characterized by high snow accumulations in winter and rainstorms in summer. Most headwaters of the region contain high quality waters with few ions in solution and extremely low nutrient concentrations. Alpine streams have few species of aquatic organisms; however, they often possess rare species and have hydrogeomorphic features that make them vulnerable to climatic change. Subalpine and valley bottom streams of the Crown of the Continent Ecosystem (CCE) flow through well forested watersheds. Along the elevation gradient, the streams and rivers of the CCE flow through series of confining and nonconfining valleys resulting in distinct canyon and floodplain reaches. The alluvial floodplains are characterized by high species diversity and bioproduction maintained by the hydrologic linkages of habitats. The streams and rivers of the CCE have low nutrient concentrations, but may be significantly affected by wildfire, various resource extraction activities, such as logging or mining and exurban encroachment. Wildfire has been shown to increase nutrient loading in streams, both during a fire and then following the fire for as much as 5 years. Logging practices increase nutrient loading and the algal productivity of stream periphyton. Logging and associated roads are also known to increase sediment transport into Crown of the Continent streams directly affecting spawning success of native trout. The CCE is one of the fastest growing regions in the USA because of the many recreational amenities of the region. And, while the region has many remarkably pristine headwater streams and receiving rivers, there are many pending threats to water quality and quantity. One of the most urgent threats comes from the coal and gas fields in the northern part of the Crown of the Continent, where coal deposits are proposed for mountain‐top removal and open‐pit mining operations. This will have significant effects on the waters of the region, its native plants and animals and quality of life of the people.     

The future of food security in the Three Areas of Sudan

Currently, the pace of recovery in the 'Three Areas' is moving faster than the implementation of the Comprehensive Peace Agreement (CPA). This gap is leading to greater imbalances in income, unsustainable urbanization, overexploitation of the environment and resource based conflict. Unless regulated, the likely result will be chronic poverty and an undermining of the success of the CPA. Agencies must be mindful of how they provide assistance so that they support the CPA. The analysis of food security should take place in the context of a larger political, social and economic analysis of the emerging situation. The least developed areas should be prioritised and interventions should provide benefits to the full range of socioeconomic groups. WFP must identify its role in the wider and integrated response. It should support the emerging peace process and the key reforms. If WFP chooses to consolidate its activities, it will require capable strategic partners. If it chooses to invest more in building the capacity of government and community structures, it must improve its skill base and field presence     

长白山不同生态系统地下部分生物量及地下C贮量的调查

论文在收集已有资料的基础上,补充调查了长白山自然保护区中沿不同海拔高度形成的不同森林生态系统的细根生物量和一些森林类型的根系总生物量,并且对自然环境因子对根系生物量的影响进行了相关分析。研究表明,由高海拔到低海拔(岳桦林、苔藓岳桦暗针叶林、暗针叶林过渡带、苔藓红松暗针叶林、红松针阔混交林)树木细根(<2mm)生物量分别是458.92gm^-2、537.42gm^-2、390.35gm^-2、397.25gm^-2和660.21gm^-2;根系总生物量分别是2578.00gm^-2、2794.00gm^-2、2680.00gm^-2、3459.25gm^-2和5155.00gm^-2。分别对细根生物量和根系总生物量与降水量和活动积温之间进行相关性分析时,发现细根生物量与不同海拔高度的活动积温和降水量没有明显的相关性;而根系生物量与这些因子存在着指数相关关系。该研究同时对不同海拔高度根系中的C、N含量和土壤中有机质的含量进行了分析和测定。结合已有的倒木和凋落物的资料,估算了长白山自然保护区中沿不同海拔高度形成的不同森林生态系统地下C的贮量。在长白山自然保护区内,由高海拔到低海拔,林地C贮量分别是15493.88gm^-2、21005.74gm^-2、19819.24gm^-2、14232.51gm^-2和7344.02gm^-2。     

恢复力视角下秦岭贫困山区乡村振兴潜力研究

恢复力概念为秦岭贫困山区乡村发展研究提供了新的视角,从恢复力视角研究乡村振兴潜力,对于提高贫困山区乡村内生发展动力、实现乡村有效振兴具有重要意义。以秦岭贫困山区商洛市为案例,在理论构建的基础上,建立贫困山区乡村恢复力评价体系测度恢复力指数,采用空间主成分分析法识别恢复力关键影响因素,据此提出三区县乡村振兴潜力类型分类。研究结果表明：（1）商洛市三个区县各镇办的恢复力指数呈集聚分布态势,恢复力整体上处于偏低水平状态。（2）环境因素、经济因素对乡村社区恢复力起到决定作用。（3）三区县乡村振兴潜力可分为四种类型：均衡发展潜力区、农业主导潜力区、农业旅游兼营潜力区和地理环境限制潜力区,根据其资源禀赋和现状发展条件提出针对性的乡村振兴策略。     

多重资本驱动下西安市秦岭北麓S村的空间生产与收缩——基于布尔迪厄理论的管窥

引入布尔迪厄的资本理论,构建多重资本概念模型;以西安市秦岭北麓S村为例,对其在不同类型资本综合影响下的空间生产与收缩过程及机制进行质性研究和可视化分析。结果表明：（1）经济资本的三级循环推动S村物质空间商品化程度不断加深,商户金融资本的差异造成村内经济阶层分化与空间分异,外来经济资本的进入则易诱致社会风险。（2）新生的业缘关系与亲缘、地缘关系交织而成的社会网络等结构性社会资本的变化,引致S村社会空间的混杂和地方认同的分化;社会信任等认知性社会资本的下降造成村民交往空间的内移,并促成新的空间治理秩序。（3）商户个人品味等身体化文化资本创造出多样化的文化空间,政府赋予村庄的集体称号等制度化文化资本推动形成农家乐专业村品牌。（4）元资本主导下,村内三大旅游项目被拆除,S村由空间持续再生产转向空间收缩。（5）自然垄断地租、小规模集体行动优势、元资本的间接调控与直接影响以及双重锁定效应,共同构成S村空间生产与收缩的机制。