郊野公园作为城市自然保留地的价值分析

城市自然保留地（urban natural reserved area）是指城市地区范围内具有一定面积的自然或近自然区域,具有保持生物多样性、乡土物种保护和保存复杂基因库等重要的生态功能。郊野公园作为城市自然保留地的重要组成,在生态、游憩、乡土植物、研究教育等方面具有重要的价值。本文分析了郊野公园在这些方面的价值,并介绍了香港的郊野公园建设,最后对郊野公园的建设提出了建议。     

Bird Use of Restoration and Reference Marshes Within the Barn Island Wildlife Management Area, Stonington, Connecticut, USA

/ Tidal marshes have been actively restored in Connecticut for nearly 20 years, but evaluations of these projects are typically based solely on observations of vegetation change. A formerly impounded valley marsh at the Barn Island Wildlife Management Area is a notable exception; previous research at this site has also included assessments of primary productivity, macroinvertebrates, and use by fishes. To determine the effects of marsh restoration on higher trophic levels, we monitored bird use at five sites within the Barn Island complex, including both restoration and reference marshes. Use by summer bird populations within fixed plots was monitored over two years at all sites. Our principal focus was Impoundment One, a previously impounded valley marsh reopened to full tidal exchange in 1982. This restoration site supported a greater abundance of wetland birds than our other sites, indicating that it is at least equivalent to reference marshes within the same system for this ecological function. Moreover, the species richness of birds and their frequency of occurrence at Impoundment One was greater than at 11 other estuarine marshes in southeastern Connecticut surveyed in a related investigation. A second marsh, under restoration for approximately ten years, appears to be developing in a similar fashion. These results complement previous studies on vegetation, macroinvertebrates, and fish use in this system to show that, over time, the reintroduction of tidal flooding can effectively restore important ecological functions to previously impounded tidal marshes.KEY WORDS: Estuarine; Tidal marsh; Wetland birds; Restoration     

长三角城市群旅游生态效率时空演化特征及其影响因素研究

长三角一体化是我国当前重要的国家战略之一,旅游业发展在助推长三角产业高质量一体化发展中扮演着重要角色。综合运用SBM-undesirable模型、核密度估计、空间分析等方法探索长三角城市群26个核心城市2007—2017年旅游生态效率时空演化特征,并运用面板Tobit回归模型探讨其影响因素。结果表明:(1)长三角城市群内旅游生态效率存在着显著不均衡性,研究期内旅游生态高效率城市有所减少,较高效率城市数量增加,低旅游生态效率城市增多且呈现向城市群西部敛缩的态势。(2)长三角城市群内旅游生态效率两级分化程度和地区之间的非均衡性在逐步减小。(3)长三角城市群旅游生态效率东部大于西部,北部大于南部,东西方向上非均衡性比南北方向更加显著。(4)长三角城市群旅游生态效率表现为以空间负相关为主的分布特征,空间异质性大于空间集聚性。(5)旅游经济规模、旅游产业结构、科技创新水平、城镇化发展、经济发展水平、建成区绿化覆盖率和对外开放水平对城市群整体和不同省市旅游生态效率影响的空间异质性较强。     

Computerized Map of Risk to Manage Wildlife Species in Urban Areas

For the last 20 years, human–wildlife conflicts have been rapidly increasing in towns. Although people want “greener” cities, the expansion of disliked species causes problems that are difficult to manage and to reduce. The complexity of the numerous factors involved in these human–wildlife relations needs the development of a comprehensive tool for urban planners. Today, with the development of computers and geographical information systems, it is easier to analyze and combine different spatial data as methods used for the management of risks in studies of natural hazards. Here we present a method for assessing and mapping the risk in cases of human–wildlife conflict. An application to starling management in a town in western France will show the efficiency of our methods to combine information given by a network of experts and to highlight higher risk sites. The map of risk provides a spatial result useful for comprehension, communication between people and agencies, and public education.     

Exploring the current status of water governance and outcomes of community-based monitoring across the Oak Ridges Moraine,Southern Ontario,Canada

ABSTRACT

Community-based monitoring (CBM) activities are becoming increasingly prevalent in response to multiple factors, including reduced governmental capacity and increased public interest in environmental management. This research aims to explore how CBM has evolved in the Oak Ridges Moraine (ORM), southern Ontario, including an examination of strengths and challenges. Interviews with CBM stakeholders, provincial government staff, and conservation authority staff were combined with document analysis to explore the evolution and outcomes of ORM CBM activities. Results indicate that there is active CBM on the ORM and conservation authorities play a role in the shaping of CBM activities, although significant barriers remain to civil society participation in water governance. The case study results from the ORM were also considered in light of research emerging from the Nova Scotia experience of numerous civil society organisations involved in CBM.     

Urban Domestic Gardens (XIV): The Characteristics of Gardens in Five Cities

Domestic gardens make substantial contributions to the provision of green space in urban areas. However, the ecological functions provided by such gardens depend critically on their configuration and composition. Here, we present the first detailed analysis of variation in the composition of urban gardens, in relation to housing characteristics and the nature of the surrounding landscape, across different cities in the United Kingdom. In all five cities studied (Belfast, Cardiff, Edinburgh, Leicester, and Oxford), garden size had an overwhelming influence on garden composition. Larger gardens supported more of the land-use types recorded, in greater extents, and were more likely to contain particular features, including tall trees and mature shrubs, areas of unmown grass and uncultivated land, vegetable patches, ponds, and composting sites. The proportional contribution of non-vegetated land-uses decreased as garden area increased. House age was less significant in determining the land-use within gardens, although older houses, which were more likely to be found further from the urban edge of the city, contained fewer hedges and greater areas of vegetation canopy >2 m in height. Current UK government planning recommendations will ultimately reduce the area of individual gardens and are thus predicted to result in fewer tall trees and, in particular, less vegetation canopy >2 m. This might be detrimental from ecological, aesthetic, social, and economic stand points.     

山地自然资源的环境特征与可持续开发对策

本文通过分析山地自然资源环境的基本特征,从开发模式、利用规模和适当的开发场所三方面论述了山地自然资源可持续开发对策,并指出了在山地自然资源可持续开发过程中应重点注意的问题。     

Chemical Characteristics of Urban Stormwater Sediments and Implications for Environmental Management, Maricopa County, Arizona

On the basis of published guidelines, urban stormwater sediments do not appear to constitute a major regional environmental problem with respect to the chemical characteristics investigated here. At individual sites, high concentrations of organic compounds—chlordane, dieldrin, PCBs, and toxaphene—may require some attention. The possible environmental hazard presented by low-level organochlorine contamination is not addressed in this paper; however, high levels of toxicity in urban sediments are difficult to explain. Sediment toxicity varied significantly with time, which indicates that these tests should be evaluated carefully before they are used for management decisions.     

Lateral Hyporheic Zone Chemistry in an Artificially Constructed Gravel Bar and a Re‐Meandered Stream Channel,Southern Ontario,Canada1

Abstract: The effect of stream restoration on hyporheic functions has been neglected, although channel rehabilitation projects have a potential to alter stream‐ground‐water interactions. The present study examined the effect of an artificially constructed gravel bar and re‐meandered stream channel on lateral hyporheic exchange flow and chemistry in two lowland N‐rich streams in southern Ontario, Canada. Nitrate concentrations were relatively high, ranging from 0.5 to 1.3 mg N/l in both streams during spring through fall months. However, nitrate concentrations showed a steep decline as stream water entered the gravel bar and the meander bends. Differences between observed and predicted nitrate concentrations based on conservative ion concentration patterns indicated that 40‐100 and 68‐98% of the nitrate entering the hyporheic zone was removed in the gravel bar and meanders, respectively. Rapid depletion of dissolved oxygen concentrations along lateral hyporheic flow paths and denitrifying potentials assayed by the acetylene block technique in hyporheic sediments suggests that denitrification was an important mechanism of nitrate depletion. Despite the high rate of nitrate removal, the flux of stream water laterally entering the constructed gravel bar and meander bends was very small, and hyporheic nitrate removal was <0.015% of the daily stream load during base‐flow periods in summer and fall. The effects of restoration projects on hyporheic zone dynamics are often limited in lowland streams by low channel gradients and fine floodplain sediments with low interstitial flows that restrict the magnitude of the stream‐hyporheic connection.     

城市居民区配套设备噪声频率特性分析

对绵阳市某居住区典型的配套设备噪声源进行分析,选取变配电房噪声、车库噪声、电梯井噪声、电梯控制室噪声、家用空调室外机、水泵房等6种典型噪声源。分析这些噪声源的频谱及低、中、高频段的能量比率。结果表明,各声源最大声压级所在频段以低频段最多（6种典型噪声中占5种）,最大能量分布频段也是以低频段最多（6种典型噪声中占5种）,因而低频噪声已经成为居住区中影响最大的噪声源。     

The Influence of Urban Density and Drainage Infrastructure on the Concentrations and Loads of Pollutants in Small Streams

Effective water quality management of streams in urbanized basins requires identification of the elements of urbanization that contribute most to pollutant concentrations and loads. Drainage connection (the proportion of impervious area directly connected to streams by pipes or lined drains) is proposed as a variable explaining variance in the generally weak relationships between pollutant concentrations and imperviousness. Fifteen small streams draining independent subbasins east of Melbourne, Australia, were sampled for a suite of water quality variables. Geometric mean concentrations of all variables were calculated separately for baseflow and storm events, and these, together with estimates of runoff derived from a rainfall-runoff model, were used to estimate mean annual loads. Patterns of concentrations among the streams were assessed against patterns of imperviousness, drainage connection, unsealed (unpaved) road density, elevation, longitude (all of which were intercorrelated), septic tank density, and basin area. Baseflow and storm event concentrations of dissolved organic carbon (DOC), filterable reactive phosphorus (FRP), total phosphorus (TP) and ammonium, along with electrical conductivity (EC), all increased with imperviousness and its correlates. Hierarchical partitioning showed that DOC, EC, FRP, and storm event TP were independently correlated with drainage connection more strongly than could be explained by chance. Neither pH nor total suspended solids concentrations were strongly correlated with any basin variable. Oxidized and total nitrogen concentrations were most strongly explained by septic tank density. Loads of all variables were strongly correlated with imperviousness and connection. Priority should be given to low-impact urban design, which primarily involves reducing drainage connection, to minimize urbanization-related pollutant impacts on streams.     

京津冀城市群土地利用效率时空演变及影响因素研究

本文对京津冀城市群土地利用效率展开测度并分析其时空格局演变特征,探析土地利用效率的影响因素,通过提高城市土地利用效率助力京津冀协同发展。以京津冀城市群13个城市的市辖区为单元,建立土地利用效率以及影响因素评价指标体系,分别使用超效率SBM-Undesirable模型、Tobit模型展开测算和分析,使用Malmquist指数研究土地利用效率时空格局演变特征。结果表明:①2002-2020年京津冀城市群土地利用效率整体处于高水平利用,但是土地利用效率呈下降趋势。北京市土地利用效率增长明显,但受到“虹吸效应”影响,周边城市呈现不同程度的土地利用效率下降,冀中南地区大部分城市土地利用效率保持增长。②研究区内,低效率城市在投入方面存在较大冗余问题,其中固定资本存量和能源消费总量的冗余问题最为突出,造成资源浪费。③城市经济增长、城市医疗水平、城市教育水平、城市经济地位对土地利用效率具有正向作用;城市交通道路、人口密度则具有负向作用。在京津冀协同发展背景下,应着眼高新技术产业布局,优化城市国土空间结构,提高资源配置效率,严格保护生态环境,坚定不移走生态优先、绿色发展之路,贯彻落实可持续发展战略。     

Use of Standardized Visual Assessments of Riparian and Stream Condition to Manage Riparian Bird Habitat in Eastern Oregon

The importance of riparian vegetation to support stream function and provide riparian bird habitat in semiarid landscapes suggests that standardized assessment tools that include vegetation criteria to evaluate stream health could also be used to assess habitat conditions for riparian-dependent birds. We first evaluated the ability of two visual assessments of woody vegetation in the riparian zone (corridor width and height) to describe variation in the obligate riparian bird ensemble along 19 streams in eastern Oregon. Overall species richness and the abundances of three species all correlated significantly with both, but width was more important than height. We then examined the utility of the riparian zone criteria in three standardized and commonly used rapid visual riparian assessment protocols—the USDI BLM Proper Functioning Condition (PFC) assessment, the USDA NRCS Stream Visual Assessment Protocol (SVAP), and the U.S. EPA Habitat Assessment Field Data Sheet (HAFDS)—to assess potential riparian bird habitat. Based on the degree of correlation of bird species richness with assessment ratings, we found that PFC does not assess obligate riparian bird habitat condition, SVAP provides a coarse estimate, and HAFDS provides the best assessment. We recommend quantitative measures of woody vegetation for all assessments and that all protocols incorporate woody vegetation height. Given that rapid assessments may be the only source of information for thousands of kilometers of streams in the western United States, incorporating simple vegetation measurements is a critical step in evaluating the status of riparian bird habitat and provides a tool for tracking changes in vegetation condition resulting from management decisions.     

Managing Tree-of-Heaven (Ailanthus altissima) in Parks and Protected Areas: A Case Study of Rondeau Provincial Park (Ontario, Canada)

The Carolinian Life Zone in southwestern Ontario, Canada is valued because it represents an almost disjunct ecosystem (i.e., one that is typical of the mid-Atlantic United States, rather than the rest of Canada or the nearby states in the United States). The landscape of the Carolinian Life Zone has undergone dramatic transformation, especially in recent decades as agriculture, urbanization, and recreation have intensified. One of the most apparent changes is the invasion of exotic plant species that exacerbates the need for mass restoration efforts. Within the Carolinian Life Zone, Rondeau Provincial Park has experienced an influx of nonindigenous, invasive species in recent years. Tree-of-heaven (Ailanthus altissima) is one example. The infestation is still relatively localized to (mainly) the park, slowly spreading, and manageable as long as something is done immediately. We examined the effects of hand-pulling and mulching, cut stump and glyphosate application, cut stump alone, and the EZJect Capsule Injection System (using glyphosate) on the management of A. altissima within the park. Cut stump and glyphosate treatment was most effective and efficient in its control of young A. altissima shoots because it limits disturbance and has acceptable capital and operating costs. Hand-pulling and mulching was the second choice, mainly because of the risk of additional disturbance that increased shoot densities 1 year after treatment. Cut stump alone was not effective, worsened the infestation, and is not recommended for this species. The EZJect system was effective at managing mature, seed-producing shoots, although the somewhat higher capital costs mean that the system probably should be purchased for management of several invasive tree species to make it more cost-effective.     

泸州市城市空气自然降尘和硫酸盐化速率的探讨

本文以1992－2001年泸州市城市空气质量数据为依据，指出了该市自然降尘和硫酸盐化速率的变化规律，并对防治对策进行了探讨。     

珠三角城市群人居环境高质量发展时空演化特征及影响因素

综合运用熵权法、协调度研究了2010—2019年珠三角城市群人居环境高质量发展时空演化特征,并采用障碍度分析了该城市群影响人居环境高质量发展的障碍因子。结果表明:①珠三角城市群人居环境高质量水平呈上升的态势,空间分布呈“屋脊”式格局,区域差异明显。②在人居环境高质量五大准则层中,除生态环境外,其他四大准则层均表现为波动上升态势,协调度呈现高质量低协调和低质量高协调两种差异。③公共基础服务、社会经济和居住环境对珠三角城市群人居环境高质量发展障碍度较大。     

Floodplain management in London,Ontario, Canada: Assessing implementation of section 28 of the conservation authorities act

An assessment of floodplain regulation by the Upper Thames River Conservation Authority in the City of London for the period 1978–1989 was undertaken. Utilizing a mix of data sources available through the conservation authority office, questionnaires administered to flooplain residents, interviews with relevant government officials, and housing statistics, the study concludes that regulations have been administered in an equitable and efficient manner. However, regulations have had some problems in controlling all development activity and in addressing policy objectives. Problems arise from weaknesses in the Conservation Authorities Act, an ensuing lack of judicial and participating municipal support in prosecuting violations, and inadequate monitoring and enforcement of development activity. Without addressing these issues, the basic problems associated with floodplain management in Ontario will remain.     

Development of a Bird Integrity Index: Measuring Avian Response to Disturbance in the Blue Mountains of Oregon, USA

The Bird Integrity Index (BII) presented here uses bird assemblage information to assess human impacts to 28 stream reaches in the Blue Mountains of eastern Oregon. Eighty-one candidate metrics were extracted from bird survey data for testing. The metrics represented aspects of bird taxonomic richness, tolerance or intolerance to human disturbance, dietary preferences, foraging techniques, and nesting strategies that were expected to be positively or negatively affected by human activities in the region. To evaluate the responsiveness of each metric, it was plotted against an index of reach and watershed disturbance that included attributes of land use/land cover, road density, riparian cover, mining impacts, and percent area in clearcut and partial-cut logging. Nine of the 81 candidate bird metrics remained after eliminating unresponsive and highly correlated metrics. Individual metric scores ranged from 0 to 10, and BII scores varied between 0 and 100. BII scores varied from 78.6 for a minimally disturbed, reference stream reach to 30.4 for the most highly disturbed stream reach. The BII responded clearly to varying riparian conditions and to the cumulative effects of disturbances, such as logging, grazing, and mining, which are common in the mountains of eastern Oregon. This BII for eastern Oregon was compared to an earlier BII developed for the agricultural and urban disturbance regime of the Willamette Valley in western Oregon. The BII presented here was sensitive enough to distinguish differences in condition among stream riparian zones with disturbances that were not as obvious or irreversible as those in the agricultural/urban conditions of western Oregon.     

ICCLP: An Inexact Chance-Constrained Linear Programming Model for Land-Use Management of Lake Areas in Urban Fringes

Lake areas in urban fringes are under increasing urbanization pressure. Consequently, the conflict between rapid urban development and the maintenance of water bodies in such areas urgently needs to be addressed. An inexact chance-constrained linear programming (ICCLP) model for optimal land-use management of lake areas in urban fringes was developed. The ICCLP model was based on land-use suitability assessment and land evaluation. The maximum net economic benefit (NEB) was selected as the objective of land-use allocation. The total environmental capacity (TEC) of water systems and the public financial investment (PFI) at different probability levels were considered key constraints. Other constraints included in the model were land-use suitability, governmental requirements on the ratios of various land-use types, and technical constraints. A case study implementing the system was performed for the lake area of Hanyang at the urban fringe of Wuhan, central China, based on our previous study on land-use suitability assessment. The Hanyang lake area is under significant urbanization pressure. A 15-year optimal model for land-use allocation is proposed during 2006 to 2020 to better protect the water system and to gain the maximum benefits of development. Sixteen constraints were set for the optimal model. The model results indicated that NEB was between $1.48 × 10⁹ and $8.76 × 10⁹ or between $3.98 × 10⁹ and $16.7 × 10⁹, depending on the different urban-expansion patterns and land demands. The changes in total developed area and the land-use structure were analyzed under different probabilities (q _i ) of TEC. Changes in q _i resulted in different urban expansion patterns and demands on land, which were the direct result of the constraints imposed by TEC and PFI. The ICCLP model might help local authorities better understand and address complex land-use systems and develop optimal land-use management strategies that better balance urban expansion and grassland conservation.     

Spatial distribution of particulate matter (PM10) in Warri metropolis,Nigeria

This study examined the spatial distribution of particulate air pollution in the Warri metropolis. This was done to ascertain the differences between the distribution of particulate matter (PM10) in the urban area and the surrounding rural areas. To achieve this, the study generated data from field measurement of PM10 levels for the year 2003. Analysis of variance, the U-test, and simple regression statistical techniques were used to analyze the data. The major finding of the study was that the Warri metropolitan area is polluted with PM10 levels of over 126 μg/m³, which is 81% over the 70 μg/m³ threshold of the World Health Organization. However the built-up area of the Warri metropolis is 150% more polluted with PM10 particulates than the surrounding rural areas. While the traffic-clogged area of Enerhen, Jakpa, Deco, and Estate Junctions are the most polluted areas with levels of 151 μg/m³, traditional areas had the lowest levels of 128 μg/m³. The daily distribution of PM10 showed that Mondays were the most polluted days with levels of 145 μg/m³ and Fridays were the least polluted days with levels of 141.5 μg/m³ in the built-up area, whereas in the rural area Wednesdays were the most polluted days with levels of 57.1 μg/m³ and Sundays were the least polluted days with levels of 53.5 μg/m³. Mondays generally recorded the highest PM10 values because of the large amount of industrial operation, heavy vehicular traffic in the peak period, and increased commercial activities. The study also showed significant variation in the level of PM10 particulates within the urban areas of the Warri metropolis with a calculated F-value (3.29), which is greater than the critical F-value of 3.14 at the 0.05 significance level. It is therefore recommended that urban environmental management policy should be vigorously pursued to curb the adverse consequences of increased PM10 levels in urban areas of the Warri metropolis.