Protecting River Corridors in Vermont1

Kline, Michael and Barry Cahoon, 2010. Protecting River Corridors in Vermont. Journal of the American Water Resources Association (JAWRA) 46(2):227-236. DOI: 10.1111/j.1752-1688.2010.00417.x Abstract: The Vermont Agency of Natural Resources’ current strategy for restoring aquatic habitat, water quality, and riparian ecosystem services is the protection of fluvial geomorphic-based river corridors and associated wetland and floodplain attributes and functions. Vermont has assessed over 1,350 miles of stream channels to determine how natural processes have been modified by channel management activities, corridor encroachments, and land use/land cover changes. Nearly three quarters of Vermont field-assessed reaches are incised limiting access to floodplains and thus reducing important ecosystem services such as flood and erosion hazard mitigation, sediment storage, and nutrient uptake. River corridor planning is conducted with geomorphic data to identify opportunities and constraints to mitigating the effects of physical stressors. Corridors are sized based on the meander belt width and assigned a sensitivity rating based on the likelihood of channel adjustment due to stressors. The approach adopted by Vermont is fundamentally based on restoring fluvial processes associated with dynamic equilibrium, and associated habitat features. Managing toward fluvial equilibrium is taking hold across Vermont through adoption of municipal fluvial erosion hazard zoning and purchase of river corridor easements, or local channel and floodplain management rights. These tools signify a shift away from primarily active management approaches of varying success that largely worked against natural river form and process, to a current community-based, primarily passive approach to accommodate floodplain reestablishment through fluvial processes.     

河西走廊临泽样区土壤系统分类研究

根据《中国土壤系统分类(修订方案)》(1995),对河西走廊临泽样区土壤进行了系统分类研究,提出了临泽样区土壤系统分类方案将土壤分为4个土纲(人为土、干旱土、潜育土和雏形土),4个亚纲,5个土类和8个亚类。同时探讨了样区土壤基层分类单元之土系的划分,初步拟定了12个土系。     

Value of Semi-Open Corridors for Simultaneously Connecting Open and Wooded Habitats: a Case Study with Ground Beetles

Abstract:  To counteract habitat fragmentation, the connectivity of a landscape should be enhanced. Corridors are thought to facilitate movement between disconnected patches of habitat, and linear strips of habitat connecting isolated patches are a popular type of corridor. On the other hand, the creation of new corridors can lead to fragmentation of the surrounding habitat. For example, heathland corridors connect patches of heathland and alternatively hedgerows connect patches of woodland. Nevertheless, these corridors themselves also break up previously connected patches of their surrounding habitat and in so doing fragment another type of habitat (heathland corridors fragment woodlands and woodland strips or hedgerows fragment heathlands). To overcome this challenge we propose the use of semi-open habitats (a mixture of heathland and woodland vegetation) as conservation corridors to enable dispersal of both stenotopic heathland and woodland species. We used two semi-open corridors with a mosaic of heathland and woody vegetation to investigate the efficiency of semi-open corridors for species dispersal and to assess whether these corridors might be a suitable approach for nature conservation. We conducted a mark-recapture study on three stenotopic flightless carabid beetles of heathlands and woodlands and took an inventory of all the carabid species in two semi-open corridors. Both methodological approaches showed simultaneous immigration of woodland and heathland species in the semi-open corridor. Detrended correspondence analysis showed a clear separation of the given habitats and affirmed that semi-open corridors are a good strategy for connecting woodlands and heathlands. The best means of creating and preserving semi-open corridors is probably through extensive grazing .     

青藏工程走廊水环境安全保护等级区划研究

采用模糊数学综合评判法和突变级数法对青藏工程水环境安全的保护等级进行分区评价与研究,结果表明:青藏工程走廊带沿线水环境分为一级、二级和三级保护区3个区域,其中一级区范围为青藏高速公路拉萨—安多段,二级区范围为青藏高速公路安多—茶错段,三级区范围为青藏高速公路茶错—格尔木段;青藏工程走廊水环境安全保护路段共计408.92 km,安全保护等级高,占路线全长的35.56%。建议拉萨—安多全段,以及安多—茶错段部分路(桥)面通过工程措施和非工程措施相结合的方式实现路(桥)面径流污染控制,有效降低路(桥)面径流对走廊带水环境的影响。     

崇明岛绿色河流廊道景观格局

绿色河流廊道作为一种重要的生态基础设施,在改善生态环境质量,维持生物多样性,提高景观多样性等方面发挥着关键作用。以崇明岛为例,探讨绿色河流廊道景观格局定量研究的方法,针对绿色河流廊道景观格局存在的问题,提出相应的绿色河流廊道建设建议。利用GIS处理河流廊道基础数据,以景观生态学原理为基础,以景观格局指数为依据,从崇明岛绿色河流廊道景观构成和廊道网络结构两方面详细分析崇明岛内各行政区域的不同绿色河流廊道的景观格局。结果表明：绿色河流廊道总长为 952.26 km,廊道建设率基本在80%以上;绿色河流廊道普遍较窄,平均宽度仅为 9.96 m,不利于生物多样性的保护;崇明岛绿色河流廊道比较缺乏,总密度仅 0.75 km/km2;各行政区域相比,城镇区域绿色河流廊道建设率高,绿色廊道质量高;农场区域的绿色河流廊道建设不及城镇区域,但绿色廊道较城镇区域要宽。崇明岛河流廊道网络结构简单,网络线点率,连通性偏低,网络中缺乏回路,严重影响滨水生态系统的发展.     

循环流廊道湿地中氮归趋过程模拟研究

针对新型高效脱氮循环流廊道(CFC)湿地,构建了涵盖6种氮形态、3类介质、10种代谢途径的N循环模型,探索了湿地内N迁移转化模式.结果表明,沸石吸附(53.3%)、植物吸收NH+4-N(27.6%)、NO-3-N反硝化(10.2%)、植物吸收NO-3-N(2.9%)和NO-2-N短程反硝化(1.5%)对TN去除贡献依次降低.NH+4-N去除机制存在季节差异,其中1月NH+4-N主要通过沸石吸附去除(84.5%);4~6月通过植物吸收去除(76.4%~85.3%);7月通过沸石吸附(36.1%)、亚硝化(45.8%)及植物吸收(21.4%)共同去除.此外,定期收获植物、按期再生沸石及种植水生植物可分别提升TN去除率1.7%~7.7%、43.1%~72.2%和19.8%~36.2%.综之,CFC湿地去除途径多样性保障了TN的长期高效去除.     

沿江开发中生态建设问题的探讨

沿江经济迅速发展的同时也将导致一些环境问题的出现。文中分析沿江经济发展过程中占用岸线和河流湿地等对生态环境造成的破坏情况，进而从生态建设的要求出发，提出如何通过建设生态廊道和生态斑块等措施来减缓沿江的生态环境恶化问题。     

退化滨水景观带植物群落生态修复技术研究进展

滨水带是重要的生态交错带,物质、养分和能量流动速率高,具有较高的生态、经济和美学价值。近年来,由于缺乏科学合理的生态规划意识,我国滨水带多被建成近直立人工护岸,加之自然、人为干扰力度的加强,滨水岸线生境破坏,生物群落丧失,滨水带退化,水岸生态环境日趋恶化。通过对滨水带生态景观功能分析,研究滨水带退化原因与机理,系统归纳了国内外退化滨水景观带植物群落生态修复相关技术的研究现状,深入探讨了生境恢复、生物廊道恢复、景观格局美化和水岸生态系统结构与功能优化等方面的研究内容,并提出今后滨水带生态修复技术研究方向,以及基于生态学、景观学、水力学、土力学、生物学、经济学等多学科背景的滨水景观带植物群落定量分析、配置方法。最后指出,滨水景观带植物群落生态修复技术研究需进一步分析我国水岸生态系统退化机理、细化滨水深槽-浅滩序列、量化滨水植被配置宽度与生物多样性关系、深化稳定化长效管理技术等,为我国退化滨水生态景观带植物群落生态修复集成技术的研究与实践提供参考,以全面有效的提高生态环境质量。     

廊道效应与城市景观结构

根据景观学原理，本文将城市廊道分为两类，人工廊道与自然廊道，并着重分析城市廊道的场效应，研究表明，廊道效应产生的实质在于廊道效益是距离的函数，因而可用指数衰减曲线表示，从理论上分析，人工廊道与自然廊道场效应的分界点即综合效益极大点，自然廊道在两条人工廊之间存在的合理依据是：至少存在两个分别与两条指数衰减曲线相交的综合效益极值点。根据廊道效应原 文对北京古代传统规划格局进行分析，发生在天人鸽 与择中     

河西走廊绿洲城市化及可持续对策

本文分析了河西走廊绿州城市化现状 ,认为经济基础薄弱、产业结构不合理、水资源匮乏、生态环境脆弱是河西走廊绿洲城市化的主要限制因素 ,指出河西绿洲加速城市化应加大产业结构调整力度 ,系统规划城市建设 ,加强水资源统一管理和节水建设 ,大力发展教育事业和提高农业产业化水平