生态经济系统边缘效应的实证分析

在理论层面,从生态经济系统的生态位角度探讨省域行政边界地区的生态经济系统边缘效应的优势和特性;在实践层面,以广西玉林为例,通过探讨省域生态经济系统边缘效应的形成过程和动力机制,剖析省域生态经济系统的边缘地区玉林今后发展的优势、劣势、机遇和挑战.针对生态经济系统边缘效应的发挥提出相应对策和建议,以期为经济转型升级过程中省域生态经济系统边缘地区经济的发展和腾飞提供理论参照.     

安徽省旅游业转型升级对策研究

随着我国经济增长结构和产业增长方式调整转变,旅游业转型升级成为提高旅游业经济效益,实现旅游业可持续发展的必然要求。在全面分析安徽省旅游业转型升级背景的基础上,结合安徽省旅游业转型升级的优势条件与制约因素,提出安徽省旅游业在旅游产业结构、旅游产品、旅游企业、旅游市场、旅游人才等方面转型升级的路径与对策。     

贵州实现资源优势转换战略的途径与对策

提出了将贵州资源优势转变为产业优势,进而转变为经济优势的途径与对策.贵州实施优势矿产资源转换战略,就是要充分发挥资源比较优势,形成产业优势和经济优势,加快发展具有贵州特色的能源、原材料工业;以矿产资源开发为基础,优先发展矿产资源加工业,推进区域工业化进程,提高资源的附加值.     

资源型城市产业结构分析——以甘肃省白银市为例

基于产业结构理论,分析了白银市产业结构的演变历史与现状,以期为白银市产业结构优化提供对策依据。白银市产业结构的特征为:产业结构演变过程的非自然历史性;产业结构总体落后,发展不平衡;城市经济发展的主要动力来源于第二、三产业;城市化水平与工业化水平发展不协调;三次产业结构整体转换能力弱;产业结构单一化;产业结构与就业结构高度错位;农业是以种植业为主的传统农业结构;工业结构主要是以能源、原材料为主的重工业;服务业发展水平低,波动性大。     

欠发达地区县域经济可持续发展障碍与对策--以云南省凤庆县为例

通过对区位优势不明显,社会、经济和文化落后,但资源丰富的典型的欠发达县域凤庆县的实证研究,从思想观念、所有制结构、产业结构、基础建设、社会文化和经济,以及生态环境和农业基础等方面剖析了凤庆县经济不可持续发展的主要症结及原因,提出了该县经济可持续发展的总体思路,并作了对策探讨.     

环西宁地区旅游资源现状及开发对策

环西宁地区是青海省经济的重心,也是旅游资源丰富且特色鲜明的区域,该区旅游资源的开发对青海省旅游业的整体发展具有带动作用.在分析环西宁地区旅游资源开发的优势及存在问题的基础上,提出了旅游资源开发对策.     

地方“资源诅咒”与“生态赤字”的经济学分析——以“榆林市”等资源型城市为例

我国陕西省榆林市、甘肃省白银市、辽宁省抚顺市及四川省古蔺县等地区,依托丰富的铜、煤炭、天然气等矿产资源带动了当地经济的快速发展。然而,对资源的过度依赖和开发,使地方经济无可回避地面临"资源诅咒"和"生态赤字"问题。本文在界定"资源诅咒"和"生态赤字"概念,及其产生的经济学根源的基础上,对"榆林市"、"白银市"等典型资源型城市的"生态赤字"现状予以分析,提出基于"3E系统模型"视角下,解决资源型城市"资源诅咒"和"生态赤字"问题,实现地方经济可持续发展的路径选择。     

资源型经济转型策略探析——以山西省为例

运用资源型经济的形成机制理论及相关理论方法剖析山西省资源型经济的主要症状,运用资源型经济的规避和转型机制理论提出山西省资源型经济转型的策略和实现途径,为资源型经济地区加快转型发展提供参考与借鉴.     

发展循环经济,助推转型升级——关于仪征市循环经济产业发展的几点思考

通过对循环经济现状、可行性及制约因素分析,提出仪征市发展循环经济的思路、目标、重点及建议对策,从而助推该市经济转型升级。发展循环经济是建设资源节约型、环境友好型社会的重要抓手,也是进一步推动仪征市转变发展方式、实现"建设汽车名城、基本实现现代化"目标的有力举措。仪征是一座现代化工业城市,处在宁镇扬三大城市之间,具有较好的区位和交通条件,也拥有良好的产业形态,构建出了特色鲜明的产业链,发展循环经济产业具备一定的优势和基础。     

基于生态文明建设的滨海旅游低碳转型研究

滨海旅游作为我国海洋经济的龙头产业,在产业规模快速发展和产业地位稳步提升的同时,面临着日趋严重的资源环境约束问题.基于生态文明理念与滨海旅游转型发展的作用关系,阐述了生态文明建设与滨海旅游发展方式转变的内在关联,探讨了我国沿海地区旅游碳排放量现状特征和发展水平,提出生态文明理念下我国滨海旅游产业低碳化转型发展的对策建议.     

Conversion of temperate forests into heaths: Role of ecosystem disturbance and ericaceous plants

Fire and logging in nutrient-poor temperate forests with certain ericaceous understory plants may convert the forests into heaths. The process of disturbance-induced heath formation is documented by using examples ofCalluna in western Europe,Kalmia in Newfoundland, andGaultheria (salal) in coastal British Columbia. In a cool, temperate climate, rapid vegetative growth ofCalluna, Kalmia, and salal following disturbance results in increasing organic accumulation (paludification), nutrient sequestration, soil acidification, and allelochemicals. These are thought to be the main reasons to conifer regeneration failure in disturbed habitats. If continuation in forest is a land-use objective, then temperate forests with an ericaceous understory should not be logged unless effective silvicultural methods are devised to control the ericaceous plants and restore forest regeneration. Preharvest vegetation control may be considered as an option. Failure to control the understory plants may lead to a long-term vegetation shift, from forest to heathland, particularly in nutrient-poor sites. Successful methods of controllingKalmia andGaultheria, however, have yet to be developed. While theKalmia- andGaultheria- dominated heathlands are undesirable in Canada and the Pacific Northwest, a wide range ofCalluna heathlands of western Europe are being conserved as natural and seminatural vegetation.     

AN APPLICATION RUNOFF MODEL STRATEGY FOR UNGAGED WATERSHEDS1

ABSTRACT: Mathematical models for predicting watershed surface flow responses are available, most of which are elaborate nonlinear numerical surface and channel flow models linked with infiltration models. Such models may be used to make predictions for ungaged areas, assuming an acceptable fitting of the model to the topography and roughness of the real system. For some application purposes, these models are impractical because of their complexity and expensive computer solutions. A procedure is developed that uses a complex model of an ungaged area to derive a simpler parametric nonlinear system model for repetitious simulation with input sequences. The predicted flow outputs are obtained with the simpler model at significant savings of money and time. The procedures for constructing a complex kinematic model of a 40 acre (161,880 m²) reference watershed and deriving the simpler system model are outlined. The results of predictions from both models are compared with a selected set of measured events, all having essentially the same initial conditions. Peak discharges ranged from 3 to 118 ft³/sec (0.085 to 3.34 m³/sec), which includes the largest event of record. The inherent limitations of lumped systems models are demonstrated, including the bias caused by their inability to model infiltration losses after rainfall ceases. Computer costs and times for the models were compared. The derived simple model has a cost advantage when repeated use of a model is required. Such an applications hydrologic model has an engineering tradeoff of reduced accuracy, and lumping bias, but is more economical for certain design purposes.     

Urban ecological systems: scientific foundations and a decade of progress

Urban ecological studies, including focus on cities, suburbs, and exurbs, while having deep roots in the early to mid 20th century, have burgeoned in the last several decades. We use the state factor approach to highlight the role of important aspects of climate, substrate, organisms, relief, and time in differentiating urban from non-urban areas, and for determining heterogeneity within spatially extensive metropolitan areas. In addition to reviewing key findings relevant to each state factor, we note the emergence of tentative "urban syndromes" concerning soils, streams, wildlife and plants, and homogenization of certain ecosystem functions, such as soil organic carbon dynamics. We note the utility of the ecosystem approach, the human ecosystem framework, and watersheds as integrative tools to tie information about multiple state factors together. The organismal component of urban complexes includes the social organization of the human population, and we review key modes by which human populations within urban areas are differentiated, and how such differentiation affects environmentally relevant actions. Emerging syntheses in land change science and ecological urban design are also summarized. The multifaceted frameworks and the growing urban knowledge base do however identify some pressing research needs.     

Using Paleo Reconstructions to Improve Streamflow Forecast Lead Time in the Western United States

In water stressed regions, water managers are exploring new horizons that would help in long‐range streamflow forecasts. Oceanic‐atmospheric oscillations have been shown to influence streamflow variability. In this study, long‐lead time streamflow forecasts are made using a multiclass kernel‐based data‐driven support vector machine (SVM) model. The extended streamflow records based on tree ring reconstructions were used to provide a longer time series data. Reconstructed data were used from 1658 to 1952 and the instrumental record was used from 1953 to 2007. Reconstructions for oceanic‐atmospheric oscillations included the El Niño‐Southern Oscillation, Pacific Decadal Oscillation, Atlantic Multidecadal Oscillation, and North Atlantic Oscillation. Streamflow forecasts using all four oscillations were made with one‐year to five‐year lead times for 21 gages in the western United States. This is the first study that uses both instrumental and reconstructed data of oscillations in SVM model to improve streamflow forecast lead time. SVM model was able to provide “satisfactory” to “very good” forecasts with one‐ to five‐year lead time for the selected gages. The use of all the oscillation indices helped in achieving better predictability compared to using individual oscillations. The SVM modeling results are better when compared with multiple linear regression model forecasts. The findings are statistical in nature and are expected to be useful for long‐term water resources planning and management.     

Neighbourhood characteristics and urban gardens in the Toledo metropolitan area: staffing and voluntarism,food production,infrastructure, and sustainability practices

Urban gardens are important sources of sustenance for communities with limited access to food. Hence, this study focuses on food production in gardens in the Toledo metropolitan area in Northwest Ohio. We administered surveys to 150 garden managers from November 2014 to February 2015 in our attempt to better understand how neighbourhood racial composition and poverty levels are related to staffing and voluntarism, food production and distribution, the development of infrastructure, and the adoption of sustainability practices in urban gardens. The results from 30 gardens are presented in this paper. We used Geographic Information Systems to map the gardens and overlay the map with 2010 census data so that we could conduct demographic analyses of the neighbourhoods in which the gardens were located. Though the gardens were small – two acres or less – up to 46 varieties of food were grown in a single garden. Gardens also operated on small budgets. Food from the gardens was gifted or shared with friends, family, and neighbourhood residents. Gardens in predominantly minority neighbourhoods tended to have fewer institutional partners, less garden infrastructure, and had adopted fewer sustainable practices than gardens in predominantly White neighbourhoods. Nonetheless, residents of predominantly minority and high-poverty neighbourhoods participated in garden activities and influenced garden operations. Volunteering and staffing were racialised and gendered.     

Predicting deer-vehicle collisions in an urban area

Collisions with deer and other large animals are increasing, and the resulting economic costs and risks to public safety have made mitigation measures a priority for both city and wildlife managers. We created landscape models to describe and predict deer-vehicle collision (DVCs) within the City of Edmonton, Alberta. Models based on roadside characteristics revealed that DVCs occurred frequently where roadside vegetation was both denser and more diverse, and that DVCs were more likely to occur when the groomed width of roadside right-of-ways was smaller. No DVCs occurred where the width of the vegetation-free or manicured roadside buffer was greater than 40 m. Landscape-based models showed that DVCs were more likely in more heterogeneous landscapes where road densities were lower and speed limits were higher, and where non-forested vegetation such as farmland was in closer proximity to larger tracts of forest. These models can help wildlife and transportation managers to identify locations of high collision frequency for mitigation. Modifying certain landscape and roadside habitats can be an effective way to reduce deer-vehicle collisions.     

MANGANESE CYCLE IN IMPOUNDMENT WATER

Manganese entering impounded water will undergo a cyclic transformation. Oxidation precipitates manganese from top waters. At the bottom of the lake, biological activity will render manganese soluble by both intracellular as well as extracellular activity. The study was made to demonstrate that biological reduction and transformation, organometallic complexation, together with the presence of carbon dioxide and the lowering of pH all have some effect on the solubility of manganese. Dissolved manganese may be brought back to top waters during the lake overturn and therefore deteriorates the water quality.     

Biodiversity and biotechnology

The maintenance of biodiversity is urged from many quarters and on grounds ranging from aesthetic considerations to its usefulness, particularly for biotechnology. But regardless of the grounds for preserving biodiversity, writers are generally in agreement that it should be preserved. But, in examining the various references biodiversity, such as species diversity, genetic diversity, and habitat diversity, it is apparent that we cannot aim to preserve biodiversityas such, since there are a number of conflicts in any such undertaking. In preserving one aspect of biodiversity, we damage another aspect. Five arguments which attempt to ground our moral concern for biodiversity are reviewed and critiqued, not only for their consistency but also for their power to move us to action. The final section of the paper shows how conflicts in the values of personal and environmental health can impair ethical action and especially policy formation.An earlier version of this paper was read at the conference on Agriculture, Food, and Human Values: Tradition and Change, Orlando, Florida, October 7–9, 1987.     

Sources and Transport of Phosphorus to Rivers in California and Adjacent States,U.S., as Determined by SPARROW Modeling

The SPARROW (SPAtially Referenced Regression on Watershed attributes) model was used to simulate annual phosphorus loads and concentrations in unmonitored stream reaches in California, U.S., and portions of Nevada and Oregon. The model was calibrated using de‐trended streamflow and phosphorus concentration data at 80 locations. The model explained 91% of the variability in loads and 51% of the variability in yields for a base year of 2002. Point sources, geological background, and cultivated land were significant sources. Variables used to explain delivery of phosphorus from land to water were precipitation and soil clay content. Aquatic loss of phosphorus was significant in streams of all sizes, with the greatest decay predicted in small‐ and intermediate‐sized streams. Geological sources, including volcanic rocks and shales, were the principal control on concentrations and loads in many regions. Some localized formations such as the Monterey shale of southern California are important sources of phosphorus and may contribute to elevated stream concentrations. Many of the larger point source facilities were located in downstream areas, near the ocean, and do not affect inland streams except for a few locations. Large areas of cultivated land result in phosphorus load increases, but do not necessarily increase the loads above those of geological background in some cases because of local hydrology, which limits the potential of phosphorus transport from land to streams.     

Surface applied water treatment residuals affect bioavailable phosphorus losses in Florida sands

Water treatment residuals (WTR) can reduce runoff P loss and surface co-application of P-sources and WTR is a practical way of land applying the residuals. In a rainfall simulation study, we evaluated the effects of surface co-applied P-sources and an Al-WTR on runoff and leacheate bioavailable P (BAP) losses from a Florida sand. Four P-sources, namely poultry manure, Boca Raton biosolids (high water-soluble P), Pompano biosolids (moderate water-soluble P), and triple super phosphate (TSP) were surface applied at 56 and 224kgPha(-1) (by weight) to represent low and high soil P loads typical of P- and N-based amendments rates. The treatments further received surface applied WTR at 0 or 10gWTRkg(-1) soil. BAP loss masses were greater in leachate (16.4-536mg) than in runoff (0.91-46mg), but were reduced in runoff and leachate by surface applied WTR. Masses of total BAP lost in the presence of surface applied WTR were less than approximately 75% of BAP losses in the absence of WTR. Total BAP losses from each of the organic sources applied at N-based rates were not greater than P loss from TSP applied at a P-based rate. The BAP loss at the N-based rate of moderate water-soluble P-source (Pompano biosolids) was not greater than BAP losses at the P-based rates of other organic sources tested. The hazards of excess P from applying organic P-sources at N-based rates are not greater than observed at P-based rates of mineral fertilizer. Results suggest that management of the environmental P hazards associated with N-based rates of organic materials in Florida sands is possible by either applying P-sources with WTR or using a moderate water-soluble P-source.