Response of Savanna Fire Regimes to Changing Fire-Management Policies in a Large African National Park

Abstract:  Approaches to fire management in the savanna ecosystems of the 2-million ha Kruger National Park, South Africa, have changed several times over the past six decades. These approaches have included regular and flexible prescribed burning on fixed areas and a policy that sought to establish a lightning-dominated fire regime. We sought to establish whether changes in management induced the desired variability in fire regimes over a large area. We used a spatial database of information on all fires in the park between 1957 and 2002 to determine elements of the fire regime associated with each management policy. The area that burned in any given year was independent of the management approach and was strongly related to rainfall (and therefore grass fuels) in the preceding 2 years. On the other hand, management did affect the spatial heterogeneity of fires and their seasonal distribution. Heterogeneity was higher at all scales during the era of prescribed burning, compared with the lightning-fire interval. The lightning-fire interval also resulted in a greater proportion (72% vs. 38%) of the area burning in the dry season. Mean fire-return intervals varied between 5.6 and 7.3 years, and variability in fire-return intervals was strongly influenced by the sequencing of annual rainfall rather than by management. The attempt at creating a lightning-dominated fire regime failed because most fires were ignited by humans, and the policy has been replaced by a more pragmatic approach that combines flexible prescribed burning with lightning-ignited fires.     

对化工园区标准化管理体系应用实践的认识

随着全球经济一体化步伐的加快,中国的化工企业已呈现各种化工园区集聚发展的态势。化工园区作为地区化工行业集聚区域,也是一个地区工业经济发展的重要载体,已逐渐成为推动区域经济快速增长的重要支撑。本文分析了国内外先进化工园区管理模式及经验,总结了目前国内化工园区管理中存在的问题,通过借鉴国内外先进化工园区管理模式及成功经验,分析提出解决化工园区环境管理问题的建议,以期为改善园区管理现状、促进化工园区科学发展提供理论依据。     

Comparison of vegetation conditions along two backcountry trails in Mount Robson Provincial Park, British Columbia (Canada)

Vegetation conditions, i.e., plant cover, species richness, and the presence of exotic species, are compared along a high-use trail (Berg Lake Trail--BLT) and a low use trail (Mt. Fitzwilliam Trail--FWT) in Canada's Mt. Robson Provincial Park. We established 71 paired quadrats (1 m x 1 m), and assessed the amount of vegetation cover and species richness by four main lifeforms, i.e., woody species, herbaceous species, ferns, and moss, lichen and fungi. The following hypotheses were tested: (1) differences exist between control and trailside quadrats in vegetation cover, species richness and floristic diversity, and (2) differences exist between the high and low-use trails in the above-mentioned three parameters. Results show that for the majority of variables the differences between the control and trailside quadrats are statistically not significant. Variables showing significant differences are relative vegetation cover (for BLT only), exposed soil (BLT and FWT), herbaceous cover (FWT), moss, lichen and fungi cover (BLT), overall species richness (BLT), and herbaceous species richness (BLT). Ruderal and exotic species are present but only on trailside quadrats of the high-use trail. Results indicate that the Park administration's strategy to disperse use in the Mt. Robson Provincial Park should be examined critically, and some guidelines for acceptability of changes should be developed.     

Variations in the Fluoride Level in Precipitation in a Region of Human Impact

The research concerns the Wielkopolski National Park (West Poland), which suffered a huge human impact in the 1970s and 1980s owing to the nearby location of an industrial plant. Since then, fundamental technological changes that it introduced into its production of phosphate fertilizers have radically reduced the amount of pollution emitted. A three-year study (2002–2004) of fluorides in precipitation in open terrain and under tree crowns showed their concentrations to range from levels below the detection limit (0.003 mg/l) to 0.560 mg/l. Those registered under tree crowns were several times higher and indicated substantial dry deposition of fluorides on the trees. The highest values were recorded in 2003, with 43% of samples ranging from 0.01 to 0.05 mg/l, and with 51% of throughfall ranging from 0.10 to 0.50 mg/l. A strong connection was shown to exist between fluoride and sulphate concentrations in the precipitation. An analysis was made of the available data on F concentrations in the air and the dust levels around the factory, but these figures did not show an unequivocal effect on F concentrations in precipitation. A great similarity was found to occur between the fluoride content in rainwater in the Wielkopolski National Park and in the centre of the nearby Poznań metropolitan area, which indicates that there are also other F sources besides the local factory.     

Urban growth and landscape connectivity threats assessment at Saguaro National Park,Arizona, USA

Urban and exurban expansion results in habitat and biodiversity loss globally. We hypothesize that a coupled-model approach could connect urban planning for future cities with landscape ecology to consider wildland habitat connectivity. Our work combines urban growth simulations with models of wildlife corridors to examine how species will be impacted by development to test this hypothesis. We leverage a land use change model (SLEUTH) with structural and functional landscape-connectivity modeling techniques to ascertain the spatial extent and locations of connectivity related threats to a national park in southern Arizona, USA, and describe how protected areas might be impacted by urban expansion. Results of projected growth significantly altered structural connectivity (80%) when compared to current (baseline) corridor conditions. Moreover, projected growth impacted functional connectivity differently amongst species, indicating resilience of some species and near-complete displacement of others. We propose that implementing a geospatial-design-based model will allow for a better understanding of the impacts management decisions have on wildlife populations. The application provides the potential to understand both human and environmental impacts of land-system dynamics, critical for long-term sustainability.     

国际自然公园环境教育评价对我国的启示

环境教育是自然公园服务和管理的核心内容,从而必然成为自然公园综合评价的重要方面。国际上,自然公园环境教育评价已经伴随着公园综合评价的发展而不断成熟,但其在我国尚处于摸索和发展阶段。本文通过世界地质公园网络、美国、澳大利亚相关自然公园环境教育评价现状的分析发现,其发展经验对我国自然公园环境教育评价中确立基本流程和基本原则,制定评价指标体系具有了一定的启示意义。     

奥林匹克公园网球中心污水处理工程中不同组件的膜生物反应器对比研究

奥林匹克公园网球中心污水处理工程主体处理工艺为两套膜生物反应器,两套膜生物反应器并联运行,膜组件分别采用板式膜和管式膜。对两套不同组件的膜生物反应器进行对比研究,结果表明:出水水质均较好;与板式膜膜生物反应器相比,管式膜膜生物反应器流程复杂、清洗过程繁琐、膜分离单元电费和药剂费高,但是维修更换简便。     

长征国家文化公园红色旅游资源网络关注度及其旅游流网络结构分析

长征国家文化公园建设面临着的现实需求和复杂问题,迫切要求开展相应的系统性研究工作。以长征国家文化公园内154处重点红色旅游资源为研究对象,基于“虚拟”与“现实”相结合的视角,使用GIS、Gephi等研究方法,对其网络关注度和旅游流网络结构进行分析。研究表明：（1）红色旅游资源网络关注度普遍偏低、差异明显,5A级景区和重要人物是最受网络用户关注的资源类型;（2）旅游流网络结构松散、小世界效应显著,在湖南、贵州、陕西省内分别形成了“△”“网状”“双核”结构模式;（3）网络关注度与旅游流网络具有关联性和差异性,据此识别了湘中、黔川、陕北等重点红色旅游区,以及川陕、闽赣等红色旅游发展潜力区。基于以上分析,长征国家文化公园建设应以重点红色旅游资源为基础,实施分类施策、分段开发、扬长补短的发展策略。围绕高高、高低、低高、低低四种不同类型资源制定相应的发展策略,并结合不同区域的发展情况分别采取“节点”“斑块”“廊道”相结合的发展模式。     

煤化工废水中硝基苯胺类污染物的HPLC测定

通过试验建立了工业废水中苯胺类污染物的液相色谱测定方法,优化了试验条件.该方法吸收值与基质质量浓度之间的线性关系非常显著,苯胺和6种硝基苯胺类成分的检出限在0.000 1～0.000 3 mg/L之间,空白加标试验的相对标准偏差(RSD)在1.8％～4.8％之间,基质加标回收率在58.6％～93.8％之间.对煤化工园排...     

Particle size distribution and characteristics of heavy metals in road-deposited sediments from Beijing Olympic Park

Due to rapid urbanization and industrialization, heavy metals in road-deposited sediments(RDSs) of parks are emitted into the terrestrial, atmospheric, and water environment, and have a severe impact on residents' and tourists' health. To identify the distribution and characteristic of heavy metals in RDS and to assess the road environmental quality in Chinese parks, samples were collected from Beijing Olympic Park in the present study. The results indicated that particles with small grain size(150 μm) were the dominant fraction. The length of dry period was one of the main factors affecting the particle size distribution, as indicated by the variation of size fraction with the increase of dry days. The amount of heavy metal(i.e., Cu, Zn, Pb and Cd) content was the largest in particles with small size(150 μm) among all samples. Specifically, the percentage of Cu, Zn, Pb and Cd in these particles was 74.7%, 55.5%, 56.6% and 71.3%, respectively.Heavy metals adsorbed in sediments may mainly be contributed by road traffic emissions. The contamination levels of Pb and Cd were higher than Cu and Zn on the basis of the mean heavy metal contents. Specifically, the geoaccumulation index(I geo) decreased in the order:CdPbCuZn. This study analyzed the mobility of heavy metals in sediments using partial sequential extraction with the Tessier procedure. The results revealed that the apparent mobility and potential metal bioavailability of heavy metals in the sediments, based on the exchangeable and carbonate fractions, decreased in the order: CdZn≈PbCu.