Assessment of ecological vulnerability and decision-making application for prioritizing roadside ecological restoration: A method combining geographic information system,Delphi survey and Monte Carlo simulation

Study experience of ecologist plays an important role in assessing the contribution of different influencing factors to ecological vulnerability, helping policy makers to target measures for ecological restoration. However, uncertainty is unavoidable due to variation of study experience among experts. In this study, a new method that combines Delphi survey, geographic information system and Monte Carlo simulation was proposed to assess regional ecological vulnerability and to quantify the uncertainty of assessing result. We illustrated the capacity of this method by using a case study in northeastern Inner Mongolia, China. An index system for 13 spatial variables was established to calculate an ecological vulnerability index (EVI) from the three aspects of ecological sensitivity (ES), ecological resilience (ER) and natural-social pressure (NSP). The assessment shows that the southwestern region of the study area, especially in the counties of Sonid Left and Right, was seriously threatened by a high ES and a low ER. Onguiud county in the Greater Hinggan Mountains had a high EVI due to an intensive NSP. Based on the assessing result and regional road distribution, an EVI cost curve was created to facilitate the prioritization of allocating limited funds among the various counties for roadside ecological restoration.     

Using the Ecological Risk Index Based on Combined Watershed and Administrative Boundaries to Assess Human Disturbances on River Ecosystems

Efforts at the restoration of river ecosystems are needed not only in local habitats but are also important in terrestrial regions. Large-scale assessment of human activities can be useful in integrated watershed management. In this study, we modified the Ecological Risk Index (ERI) by considering the spatial distribution of human activities in China's Haihe River Basin (HRB). The stressor factors of human activities included population, impervious surface, cattle, agricultural land use, industry, fertilizers, pesticides, water conservation facilities, and roads. A total of 423 assessment units in the HRB were created by combining watershed and administrative boundaries to analyze the spatial distribution of human activities. Two index options, the ERI (including all stressors) and the ERI-D (excluding reservoirs and sluices), were examined for different management objectives. All the stressors and both ecological risk indices (ERI and ERI-D) were ranked in four levels: low, moderate, high, and very high. Our study demonstrated that the ERI and ERI-D can provide an overview of the spatial pattern of human stressors related to river ecosystems across a large geographic region. The approach developed in this study is useful for prioritizing management actions in targeted areas.     

Uncertainty associated with river health assessment in a varying environment: The case of a predictive fish-based index in France

Sensitive biological measures of river ecosystem quality are needed to assess, maintain or restore ecological conditions of water bodies. Since our understanding of these complex systems is imperfect, decision-making requires recognizing uncertainty. In this study, a new predictive multi-metric index based on fish functional traits was developed to assess French rivers. Information on fish assemblage structure, local environment and human-induced disturbances of 1654 French river sites was compiled. A Bayesian framework was used to predict theoretical metric values in absence of human pressure and to estimate the uncertainty associated with these predictions. The uncertainty associated with the index score gives the confidence associated with the evaluation of site ecological conditions.Among the 228 potential metrics tested, only 11 were retained for the index computation. The final index is independent from natural variability and sensitive to human-induced disturbances. In particular, it is affected by the accumulation of different degradations and specific degradations including hydrological perturbations. Predictive uncertainty is globally lower for IPR+ than for underlying metrics.This new methodology seems appropriate to develop bio-indication tools accounting for uncertainty related to reference condition definition and could be extended to other biological groups and areas. Our results support the use of multi-metric indexes to assess rivers and strengthen the idea that examination of uncertainty could contribute greatly to the improvement of the assessment power of bio-indicators.     

Analysis of over-consumption of natural resources and the ecological trade deficit in China based on ecological footprints

China has experienced unprecedented economic development in recent years and is now facing severe challenges caused by the over-consumption of resources and by ecological and environmental degradation. To assess the influence of resource exploitation and ecological trade, we have developed an index of excessive resource consumption based on the concepts of ecological deficit and ecological over-shoot, and we have used the ecological trade deficit to assess the pressure created by the export and import of resources and products. Our analysis indicated that China's consumption footprint surpassed its biocapacity in 1983, leading to an ecological deficit, and the production footprint surpassed its biocapacity in 1986, leading to an ecological over-shoot, as the over-consumption of natural resources grew. By 2010, 3.6 times the current area of bioproductive land was needed to provide sufficient resources to meet the consumption. China has been encouraging the development of exporting enterprises by implementing a series of financial and tax incentives, which have stimulated the economy in the short-term but have gradually increased the ecological trade deficit since 2000.     

Capturing ecological complexity: OCI,a novel combination of ecological indices as applied to benthic marine habitats

The novel Overall Complexity Index (OCI) is proposed to measure ecological complexity, incorporating four complexity indices: (1) exergy and (2) throughput as extensive metrics, (3) specific exergy and (4) information as intensive metrics. Exergy and specific exergy estimate structural complexity while throughput and information functional complexity. OCI was applied to benthic habitats in a coastal marine tract encompassing a Marine Protected Area (MPA) in north-western Italy. The four individual indices did not always show homogeneous results in assigning complexity to different habitats. On the contrary, the additive measure provided by OCI showed that seagrass meadows and coralligenous reefs are in all the most complex habitats. Applying OCI provided results consistent with traditional approaches based on expert judgement, which usually attach more interest to seagrass meadows and hard bottoms with respect to soft bottoms, but expressed a synthetic, objective and quantitative approach. OCI can be mapped for management purposes, resolving the discordances evidenced by the individual indices. Ecological complexity in the study area is concentrated in some hot spots, as mapped by OCI, while the greatest part of the seafloor is occupied by low complexity habitats. Only some of these complexity hotspots are included within the Marine Protected Area, while this study suggests that high complexity areas, adjacent to the existing MPA, should be considered for protection possibly reshaping MPA's limits.     

影响江苏省道地药材野马追产量的生态因子分析

野马追是江苏省著名的道地药材之一,全草入药,是祛痰、止咳、治疗慢性支气管炎效果显著的天然药物,在临床上具有很重要的应用价值.市场上该药材的需求量很大,目前主要依靠人工栽培来满足市场的需求.通过对江苏省野马追主要生产地区的生长环境与野马追生物量之间相关性的分析,探讨了土壤氮钾含量、pH、间种等环境因素都对野马追生物量的影响规律.结果显示,野马追适宜在微酸环境中生长,以pH6.0左右为最佳,不适与其他作物间种,土壤中碱解氮含量为28～30 mg/kg,速效钾含量230～240mg/kg时有利于其生物量增加.人工栽培过程中应尽量满足野马追生物量增加的最适条件,提高野马追引种驯化成功率,确保人工栽培野马追的药材品质和产量.     

小城镇土地利用变化的生态效应分析

采用系统生态学方法,尤其是应用了Simpson生物多样性指数法,前后相隔10年为时间跨度,对小城镇发展典型地区浙江省绍兴县某镇土地利用变化导致的生态效应进行了初步定量分析与研究.结果表明,由于土地使用功能的改变,导致了以绿色植物为计数的Simpson指数增加近2倍,而以土壤微生物为参照的工业和居住用地的Simpson指数均高于农业用地,反映该小城镇发展过程中生物多样性明显降低,并出现了局部气候的恶化(表现为镇区内年平均气温上升,而年平均相对湿度下降)等不良生态效应.     

Purification processes, ecological functions, planning and design of riparian buffer zones in agricultural watersheds

Two international meetings on ecological engineering, with a focus on riparian buffer zones, served as the source for selected papers in this special issue: (1) an International Workshop on Efficiency of Purification Processes in Riparian Buffer Zones: Their Design and Planning in Agricultural Watersheds, jointly organised by Hokkaido University, Japan, the National Agricultural Research Center for Hokkaido Region, Japan, Civil Engineering Research Institute of Hokkaido, Japan, and the Institute of Geography, University of Tartu, Estonia, and held from 5 to 9 November 2001 in Kushiro City, Hokkaido, Japan; and (2) an International Conference on Ecological Engineering for Landscape Services and Products, jointly organised by the International Ecological Engineering Society (IEES) and Lincoln University, Christchurch, New Zealand, and held from 25 to 29 November 2001 in Christchurch, New Zealand. At these two meetings, altogether 94 oral presentations (17 from invited speakers) and 15 posters by representatives from 21 countries were presented. The editorial paper highlights trends in investigation of the purification processes in riparian buffer zones as well as planning, design and management aspects of riparian buffers regarding the wide spectrum of their ecological functions; it characterises the two international meetings which served as sources for the selected papers and briefly explains the main aspects of these papers.     

Assessment of ecological risks in weed biocontrol: Input from retrospective ecological analyses

Prediction of the outcomes of natural enemy introductions remains the most fundamental challenge in biological control. Quantitative retrospective analyses of ongoing biocontrol projects provide a systematic strategy to evaluate and further develop ecological risk assessment. In this review, we highlight a crucial assumption underlying a continued reliance on the host specificity paradigm as a quantitative prediction of ecological risk, summarize the status of our retrospective analyses of nontarget effects of two weevils used against exotic thistles in North America, and discuss our prospective assessment of risk to a federally listed, threatened species (Cirsium pitcheri) based on those studies. Our analyses quantify the fact that host range and preference from host specificity tests are not sufficient to predict ecological impact if the introduced natural enemy is not strictly monophagous. The implicit assumption when such use is made of the host specificity data in risk assessment is that population impacts are proportional to relative preference and performance, the key components of host specificity. However, in concert with shifting awareness in the field, our studies demonstrate that the environment influences and can alter host use and population growth, leading to higher than expected direct impacts on the less preferred native host species at several spatial scales. Further, we have found that straightforward, easily anticipated indirect effects, on intraguild foragers as well as on the less preferred native host plant species, can be both widespread and significant. We conclude that intensive retrospective ecological studies provide some guidance for the quantitative prospective studies needed to assess candidate biological control agent dynamics and impacts and, so, contribute to improved rigor in the evaluation of total ecological risk to native species.