Hydraulic habitat composition and diversity in rural and urban stream reaches of the North Carolina Piedmont (USA)

The differences between urban and rural streams regarding hydrological process, channel morphodynamics and ecosystem functioning have been highlighted by a number of studies in recent decades. The need to understand lotic ecosystem functioning in these environments at scales relevant to individual organisms has led to research focusing on hydraulic composition and structure over small areas of channel bed. In this study we map and analyze the hydraulic biotope composition of two urban and two rural stream reaches in the North Carolina (USA) Piedmont to determine if urban flow regimes and attendant channel modification processes might translate into important differences in hydraulic environment, and if so, what those differences are. Hydraulic biotope assemblages were found to vary only moderately in diversity per unit stream length between sites, but were distinctly different in composition. One important control on the differences between rural and urban streams was found to be the localized incision of urban channels into bedrock and saprolite. Resistant rock outcrop in the beds of urban streams creates rapid and riffle biotopes and long stretches of upstream pool habitat by impoundment. Urban reaches were found to be more homogeneous than rural reaches in hydraulic composition and were dominated by pools. Rural reaches, characterized by copious sandy alluvium in the bed, were dominated by runs or glides. Quantitative differentiation of biotopes based on four hydraulic indices generally yields coherent associations, although these may vary in content. Comparisons between hydraulic and biotic diversities suggest relationships favoring biotic functional group aggregation over species richness‐based indices of diversity. Because the majority of published hydraulic diversity analyses are based on coarse‐bed streams, further study of hydraulic diversity in streams with finer substrate is likely to be beneficial. Copyright © 2008 John Wiley & Sons, Ltd.     

媒体群落生境——媒体生态系的设计论

21世纪初叶,随着全球化和数字化在日本的推进,以东京为中心的大众传媒主宰媒体的情况开始发生变化。但是到底朝着哪个方向变,却仍然混沌不清。我们不能把媒体的未来只交给国家或产业来决定。在此介绍运用生态学隐喻体系的"群落生境",作为市民可持续参与设计的构想。     

城市生境单元制图研究进展及其在生物多样性保护中的应用

城市生境单元制图是将原始生态环境数据和生物信息应用到城市自然保护和生态空间管理决策的有效途径.生境单元制图对于揭示城市环境与生物多样性的分布规律、探寻城市生物多样性保护与管控的生态边界具有重要意义.对城市生境单元制图的国内外研究进行综述,系统介绍了城市生境单元制图的主要步骤和方法;对比和评述了国内外典型城市生境单元制图...     

融入风景园林因子的生境单元制图法及在公园鸟类微生境研究中的应用

生境单元制图是一种能够有效表征生境质量分布、景观单元类型等信息的图示化方法,广泛应用于物种生境保护、土地利用和景观规划等领域.但在城市绿地尺度下的应用实例较少,且缺乏从风景园林师角度来构建的分类、制图体系.以北京市3个中小型公园为研究对象,以鸟类作为目标类群,构建融入风景园林因子的生境单元制图方法.对3个公园的微生境组...     

应用生境面积因子在台湾云林县的永续农业景观规划

云林地区百年来以农业产业为发展主轴,衍生出产业地景与生活地景,呈现云林生生不息的文化景观.在城乡发展过程中,将生态取向及因地制宜的土地使用方针,落实在云林县景观规划的策略推动上,通过永续性环境规划来延续云林的农业文化.藉由绿色网络(green network)的概念,提出各项绿色空间(包含自然特征的地区、公共及私人保留土地、配合保存价值的土地和其他受保护的开放空间)的改善策略来加强内部网络联结、规划及管理,让云林地方产业与地方经济在景观改造过程中兼顾社会、经济、生态各种层面下持续发展,使其从自然资源上达到景观宁适的效益.研究模拟针对各种土地使用分区,通过生境面积因子(biotope area factor)检测生态有效度,并运用绿色基础建设的理念,增加绿地面积,改善环境生态服务效能,发展云林县绿色网络,提升云林景观的健康度,在景观规划上提出未来建设的建议.     

生态单元制图在城乡生物多样性保护中的研究

生态单元制图是基于生态单元分类系统划分和记录不同土地使用类型或土地覆盖类型的过程。文章旨在通过分析融入植被结构因子的生态单元制图模型在城乡生物多样性保护中的研究,以期为我国以生物多样性为导向的城市绿地规划提供理论依据和实践方法。     

Ecohydraulic modelling of anabranching rivers

In this paper we provide the first quantitative evidence of the spatial complexity of habitat diversity across the flow regime for locally anabranching channels and their potential increased biodiversity value in comparison to managed single‐thread rivers. Ecohydraulic modelling is used to provide evidence for the potential ecological value of anabranching channels. Hydraulic habitat (biotopes) of an anabranched reach of the River Wear at Wolsingham, UK, is compared with an adjacent artificially straightened single‐thread reach downstream. Two‐dimensional hydraulic modelling was undertaken across the flow regime. Simulated depth and velocity data were used to calculate Froude number index, known to be closely associated with biotope type, allowing biotope maps to be produced for each flow simulation using published Froude number limits. The gross morphology of the anabranched reach appears to be controlling flow hydraulics, creating a complex and diverse biotope distribution at low and intermediate flows. This contrasts markedly with the near uniform biotope pattern modelled for the heavily modified single‐thread reach. As discharge increases the pattern of biotopes altered to reflect a generally higher energy system, interestingly however, a number of low energy biotopes were activated through the anabranched reach as new subchannels became inundated and this process creates valuable refugia for macroinvertebrates and fish, during times of flood. In contrast, these low energy areas were not seen in the straightened single‐thread reach. Model results suggest that anabranched channels have a vital role to play in regulating flood energy on river systems and in creating and maintaining hydraulic habitat diversity.     

塔指生活小区分质供水研究

研究了塔指生活小区的给水系统现状，表明目前系统存在着净化站超负荷运行的问题，同时高成本的净化水使用不合理，提出并论证了分质供水方案。     

基于城市生物多样性保护的环滇池鸟类生境识别与网络构建

生物多样性是人类赖以生存和发展的重要基础,城市生物多样性是其重要组成部分。鸟类是城市生物多样性的指示物种和伞护物种,具有重要研究价值。基于城市生物多样性保护的目的,利用MaxEnt模型预测识别滇池沿岸鸟类适宜生境,完成生境制图,并利用最小成本距离模型和电路理论构建及优化鸟类生境网络。结果表明：1)MaxEnt模型识别环滇池湖滨水陆相交区域为鸟类高适宜区生境,距滇池一级保护区距离与植被覆盖度是影响鸟类生境适宜性的主要因子;2)生境制图结果显示,高适宜区生境以湿地与林地为主,两者占比分别为39.34%和28.67%;3)基于最小成本距离模型构建了滇池沿岸及昆明城市范围内的鸟类生境网络;4)基于电路理论识别了生境网络的生态“夹点”和“障碍点”,改进网络的连通性。研究成果形成鸟类生境识别和网络构建的系统方法,为城市生物多样性保护提供科学依据与参考。     

Long‐reach Biotope Mapping: Deriving Low Flow Hydraulic Habitat from Aerial Imagery

Understanding of the type and distribution of hydraulic habitat along watercourses is valuable from an ecological and a morphological perspective. The data quantify system state and may be used against benchmark criteria to define system status level and degradation. Current mapping techniques are subjective, time consuming and expensive when carried out over long reaches often requiring specialist field skills. This paper proposes a novel approach to hydraulic habitat mapping using readily available aerial imagery (GoogleEarth and Bing maps) to generate long‐reach digital elevation models, which are subsequently used in a 2D modelling domain (JFlow+) to predict hydraulic habitat in the form of biotope types and distribution from Froude number classification. The approach is tested on a 1‐km reach of the river Wharfe, England, a morphologically and hydraulically varied watercourse. Biotope mapping of the study reach recorded a distribution of 49% pools, 33% glides and 17% riffles, compared with an observed 54% pools, 32% glides, 13% riffles and 1% broken standing waves/chutes, suggesting that gross biotope distribution may be reliably mapped using the technique when compared with field mapping but that depth estimation error leads to classification issues around transition zones. The improved spatial detail and objective mapping achieved by the technique also provide valuable sub‐feature detail on hydraulic habitat variation not picked up by conventional survey. The ease of digital elevation model construction allows for rapid assessment of extended reaches offering an efficient mechanism for whole river ecological assessment, flagging critical sites that would benefit from more detailed field assessment. Copyright © 2016 John Wiley & Sons, Ltd.