Evaluation of ecosystem health for the coastal wetlands at the Yangtze Estuary, Shanghai

Despite the growing awareness of the important ecological functions and values provided by coastal and estuarine wetlands, wetland degradation continues worldwide due to increasing anthropogenic disturbances. Chongming Dongtan wetlands, adjacent to Shanghai, the largest city and industrial and trading port in China in rapid urban expansion and socioeconomic development are currently threatened with biodiversity reduction, wetland loss, contamination, and invasion of exotic plant. Sustainable protection and management of Dongtan Nature Reserve necessitate research to develop diagnostic tools and indicators for a comprehensive and objective assessment of wetland ecosystem health condition. Based on the pressure-state-response framework and ecological and environmental surveys at the Dongtan wetlands, an indicator system was established for evaluating the coastal wetlands ecosystem health, using indicators detected from satellite imagery and current field surveys. Through the establishment of health assessment units and spatial quantification of the indicators, the spatial clustering analysis, integrated with remote sensing and geographic information system technique was applied to make an accurate diagnosis of ecosystem health for Chongming Dongtan wetlands and highlight the areas in subhealthy and unhealthy condition and urgent need of conservation and management. The results from this research indicated that the ecosystem health condition at the Dongtan wetlands showed spatial variation, to a certain extent, corresponding to the distributions of elevation and land cover types. More than 75 % of the total study area was at a relatively healthy level, with 34.19 km² for the very healthy zone and 41.08 km² for the healthy zone, while the subhealthy and unhealthy zones covered 18.23 and 4.76 km², respectively. This study demonstrated the potential for this integrated approach to give objective and effective evaluation of ecosystem health for the dynamic coastal and estuarine wetlands and provide up-to-date information to assist with early warning for ecological security and management decisions for Chongming Dongtan Nature Reserve.     

Land use change and its drivers in Kurt Bahir wetland,north-western Ethiopia

The effects of land-use change on ecosystem services in Kurt Bahir wetland were investigated during 2013 to 2014 using LANDSAT satellite images from 1973, 1986, 2002 and 2013 to identify and map changes in land-use classes over time. To understand perceptions of changes in ecosystem services that resulted from observed land-use changes discussions were held with local key informants and focus group participants. Accuracy assessment was done on the 2013 classified image. In 1973, the land-use classes of the wetland comprised wetland and grazing land, with area coverages of 764.5 and 268.4 ha, respectively. The land-use classes in 1986 were wetland, grazing land and cultivated land, with area coverages of 585.7, 198.3 and 248.9 ha, respectively. The land use of the study area in 2002 was similar to that of 1986. In 2013–2014, however, there was a substantial increase in cultivation and grazing lands at the expense of the wetland, as compared to 2002. Respondents confirmed that free grazing, the harvesting of vegetation, deforestation and expansion of cultivated land were the major threats. This study indicated that land-use change is the main driver of wetland degradation and loss. It is recommended that government organisations should give due emphasis to overcome the anthropogenic effects and to develop a management plan for the sustainable utilisation of the wetland’s ecosystem services.     

Comparison of phenology trends by land cover class: a case study in the Great Basin, USA

Direct impacts of human land use and indirect impacts of anthropogenic climate change may alter land cover and associated ecosystem function, affecting ecological goods and services. Considerable work has been done to identify long‐term global trends in vegetation greenness, which is associated with primary productivity, using remote sensing. Trend analysis of satellite observations is subject to error, and ecosystem change can be confused with interannual variability. However, the relative trends of land cover classes may hold clues about differential ecosystem response to environmental forcing. Our aim was to identify phenological variability and 10‐year trends for the major land cover classes in the Great Basin. This case study involved two steps: a regional, phenology‐based land cover classification and an identification of phenological variability and 10‐year trends stratified by land cover class. The analysis used a 10‐year time series of Advanced Very High Resolution Radiometer satellite data to assess regional scale land cover variability and identify change. The phenology‐based regional classification was more detailed and accurate than national or global products. Phenological variability over the 10‐year period was high, with substantial shifts in timing of start of season of up to 9 weeks. The mean long‐term trends of montane land cover classes were significantly different from valley land cover classes due to a poor response of montane shrubland and pinyon‐juniper woodland to the early 1990s drought. The differential response during the 1990s suggests that valley ecosystems may be more resilient and montane ecosystems more susceptible to prolonged drought. This type of regional‐scale land cover analysis is necessary to characterize current patterns of land cover phenology, distinguish between anthropogenically driven land cover change and interannual variability, and identify ecosystems potentially susceptible to regional and global change.     

基于遥感的湿地景观格局季相分析

以中国东北地区三江平原北部为研究区域,利用2012年多季相遥感影像作为数据源,结合野外调查数据,应用面向对象的分类方法,根据影像的物候、时相等特征,提取不同月份的湿地信息,进行景观格局季相分析。结果表明:(1)研究区湿地面积、类型格局在同一年不同季节不同月份会有不同幅度的变化,总体呈现缓增骤减的态势。湿地主要分布在低洼地区,主要湿地类型为草本沼泽,其次为河流,其他湿地占总面积比例较小。(2)研究区各阶段湿地都有转化,主要发生在湿地和非湿地之间,多数表现在草本沼泽和草地之间的转化。(3)湿地分布和湿地转化面积主要集中在低海拔区域和低坡度区域,其中海拔100 m和坡度5°以下范围内的湿地分布面积和湿地转化面积占湿地总面积及湿地转化面积的绝大部分。(4)年内季节性湿地转化与降水、温度和湿地植被物候关系密切。     

Zones of influence for soil organic matter dynamics: A conceptual framework for data and models

Soil organic matter (SOM) is an indicator of sustainable land management as stated in the global indicator framework of the United Nations Sustainable Development Goals (SDG Indicator 15.3.1). Improved forecasting of future changes in SOM is needed to support the development of more sustainable land management under a changing climate. Current models fail to reproduce historical trends in SOM both within and during transition between ecosystems. More realistic spatio‐temporal SOM dynamics require inclusion of the recent paradigm shift from SOM recalcitrance as an ‘intrinsic property’ to SOM persistence as an ‘ecosystem interaction’. We present a soil profile, or pedon‐explicit, ecosystem‐scale framework for data and models of SOM distribution and dynamics which can better represent land use transitions. Ecosystem‐scale drivers are integrated with pedon‐scale processes in two zones of influence. In the upper vegetation zone, SOM is affected primarily by plant inputs (above‐ and belowground), climate, microbial activity and physical aggregation and is prone to destabilization. In the lower mineral matrix zone, SOM inputs from the vegetation zone are controlled primarily by mineral phase and chemical interactions, resulting in more favourable conditions for SOM persistence. Vegetation zone boundary conditions vary spatially at landscape scales (vegetation cover) and temporally at decadal scales (climate). Mineral matrix zone boundary conditions vary spatially at landscape scales (geology, topography) but change only slowly. The thicknesses of the two zones and their transport connectivity are dynamic and affected by plant cover, land use practices, climate and feedbacks from current SOM stock in each layer. Using this framework, we identify several areas where greater knowledge is needed to advance the emerging paradigm of SOM dynamics—improved representation of plant‐derived carbon inputs, contributions of soil biota to SOM storage and effect of dynamic soil structure on SOM storage—and how this can be combined with robust and efficient soil monitoring.     

Mapping and monitoring of coastal wetlands of Çukurova Delta in the Eastern Mediterranean region

The aim of this research was to link vegetation characteristics, such as spatial and temporal distribution, and environmental variables, with land cover information derived from remotely sensed satellite images of the Eastern Mediterranean coastal wetlands of Turkey. The research method was based on (i) recording land cover characteristics by means of a vegetation indicator, and (ii) classifying and mapping coastal wetlands utilizing a Landsat Thematic Mapper (TM) image of Çukurova Deltas in Turkey. Vegetation characteristics of various habitats, such as sand dunes, salt marshes, salty plains and afforestation areas, were identified by field surveys. A Landsat TM image of 4 July 1993 was pre-processed and then classified using the Maximum Likelihood (ML) algorithm and Artificial Neural Networks (ANN). As a result of this supervised classification, the land cover types were classified with a largest accuracy of 90.2% by ANN. The classified satellite sensor imagery was linked to vegetation and bird census data, which were available through literature in a Geographical Information System (GIS) environment to determine the spatial distribution of plant and bird biodiversity in this coastal wetland. The resulting data provide an important baseline for further investigations such as monitoring, change detections and designing conservation policies in this coastal ecosystem.     

The soil quality concept as a framework to assess management practices in vulnerable agroecosystems: A case study in Mediterranean vineyards

Land management aiming to sustain ecosystem services is an important issue, especially in biodiversity hot spots such as found in Mediterranean areas. In Mediterranean areas, viticulture is an important land use. Vineyards are frequently found on inherently poor soils and are submitted to intensive management practices, which threaten soil functioning and associated ecosystem services. To encourage winegrowers and stakeholders to be reflective and adapt their vineyard practices, we evaluated the effects of three soil management practices (inter row plant cover duration, weeding and fertilization strategies) on soil functioning in 146 commercial plots distributed in Southern France, by a complementary set of biological and physico-chemical indicators. We used the concept of soil dynamic quality to evaluate some soil management practices on soil functioning. The influence of inherent soil properties derived from pedogenesis on soil dynamic indicator response was accounted for by considering the response of soil indicators for three soil groups differing in their stoniness and Ca carbonate content. The three soil management practices systematically influenced some nematode-based indicators, whereas other indicators were ascribable to a specific soil type or practice. We demonstrated that the potential of soil management practices to enhance soil functioning is restricted by soil type. In particular for calcareous soils, the soil functioning is very stable limiting effects of soil management practices. The presence of a cover crop, even temporary, in the inter row, is the only practice which benefits soil functioning whatever the soil type whereas organic fertilization and chemical weeding exhibit contrasting results on soil functioning.     

国家尺度自然保护地生态系统联网监测指标体系构建与应用研究

自然保护地是维护国家生态安全, 提升生物多样性保护成效的重要载体, 对保护地生态系统进行实时、高频、多尺度的监测是认知其动态变化的有效手段, 也是实现自然保护地生态系统健康管理的基石。由于目前我国没有形成自然保护地生态系统监测网络, 缺少统一的联网监测指标体系, 导致多数自然保护地生态系统组成家底不清、动态不明, 应对生物多样性保护新问题的能力不足, 并且在国家尺度上的自然保护地生态系统健康状况及保护成效评估缺乏联网监测数据支撑。因此, 亟需构建国家尺度的自然保护地生态系统组成和动态监测网络, 以及一套科学、系统、规范的自然保护地生态系统联网监测指标体系。该文针对自然保护地生物多样性和生态系统监测的目标和内容, 参考国内外现有的生态系统监测网络的指标体系, 确定了自然保护地生态系统联网监测指标体系建立和选取的基本原则, 建立了一套适用于国家尺度的自然保护地生态系统联网监测指标体系, 并在6个国家级自然保护区进行示范。构建的指标体系针对构成生态系统的6类关键要素(生境要素、生物要素、气象要素、土壤要素、大气和水环境要素、景观要素)制定了30个监测指标, 有效应用于森林、草地、荒漠、湿地等生态系统类型的自然保护地, 能够实现对不同类型自然保护地生态系统组分和结构的现状和演变特征进行长期、动态化监测, 并可为自然保护地保护成效评估和健康管理提供规范化、标准化的基础数据。     

Exploring ecosystem health of wetlands in Rarh tract of West Bengal through V-O-R model

Monitoring and assessing ecosystem health(EH) is crucial for ecosystem management on a local and global scale. The current study uses the V-O-R (Vigor-Organization-Resilience) model (Peng et al.,2015) to assess the ecosystem health of wetlands in the Rarh tract of the Murshidabad district. Water depth, landscape matrices, and land use and land cover (LULC) data were used to quantify vigor, organization, and elasticity. According to the findings, built-up areas increased from 2.11% in 1990 to 8.91% in 2020 and agricultural lands increased from 57.01% in 1990 to 81.53% in 2020.Wetlands, on the other hand, dropped by 3.43% in 2020 from 15.32% in 1990. From 1990 to 2020, EH dropped from 0.95 to 0.17 and good EH declined from 35.62% to 1.58%. Weak EH, on the other hand, grew to 30.52% throughout this time. The fast agricultural land growth and urban area expansion are to blame for the worsening of EH in the wetlands. Finally, the study's findings give a better knowledge of EH in the Rarh tract wetlands, which will aid policymakers in creating eco-environmental management strategies.     

Analysis of historic changes in regional ecosystem service provisioning using land use data

Land use change has a major impact on goods and services that our environment supplies for society. While detailed ecological or biophysical field studies are needed to quantify the exact amount of ecosystem service supply at local scales, such a monitoring might be unfeasible at the regional scale. Since field scale monitoring schemes for ecosystem services or ecosystem functioning are missing, proxy based indicators can help to assess the historic development of ecosystem services or ecosystem functioning at the regional scale. We show at the example of the historic development (1964–2004) in the district of Leipzig/Germany how land use/land cover data can be used to derive regional scale indicators for ecosystem functions. We focus thereby on two hypotheses: (1) the ecosystem functioning has degraded over time and (2) changes in land use configuration play an important role in this degradation. The study focuses on indicators for ecosystem functions related to (i) water purification by riparian buffer strips, (ii) pollination, (iii) food production and (iv) outdoor recreation. Each indicator builds on the analysis of land use configuration and land use composition information and is tested on sensitivity/robustness with respect to parameters which had to be estimated based on expert knowledge. We show that land use composition is an important aspect in our ecosystem service assessment. Although our study region is faced with a maximum land use change of 11% in the major land use classes between 1964 and 2004, we see a decrease of ecosystem function indicators up to 23%. The regional assessment shows an overall trend for degradation of ecosystem functioning from 1964 to 1984. This trend is reversed between 1984 and 1994 but the process slowed down until 2004 without reaching the level of 1964.     

Spatio-temporal variations of ecosystem health in the Liuxi River Basin,Guangzhou, China

Ecosystem health is an important research topic. Several studies have mainly focused on ecosystem health assessment (EHA) on a large or medium scale, with only a few studies using small grids as research units. Based on the Vigor–Organization–Resilience–Services (VORS) model, which can adequately compute multiple ecosystem values for each land use type, this study used a scale with a 250 m × 250 m grid as the spatial research unit to quantitatively and dynamically assess the ecosystem health and analyze its spatial implications in the Liuxi River Basin, Guangzhou, China. The results showed that the ecosystem health level of each land use type is ranked as follows: water areas > shrublands > grasslands > wetlands > broadleaf forests > drylands > construction land. The amount of construction land area rapidly increased from 2005 to 2018 at the cost of a substantial loss of broadleaf forests, shrublands, and wetlands, which led to a decline in ecosystem health values. Thus, anthropogenic activities such as urbanization and deforestation were the main driving factors affecting land use changes and spatial distribution of ecosystem health. Furthermore, the correlation between ecosystem services (ES) and ecosystem health was the strongest, indicating that ES was a key indicator contributing to ecosystem health in the Liuxi River Basin. The ecosystem health of the Liuxi River Basin had a significant positive spatial aggregation effect which gradually increased from 2005 to 2018. The high–high aggregation areas were mainly clustered in water areas and grasslands, and the low–low aggregation areas were mainly clustered in construction zones and paddy fields. This study provides an important reference for evaluating ecosystem health based on the VORS model, ecological conservation, and the management of small basins in the context of rapid urbanization.     

图们江下游湿地生态系统健康评价

湿地是世界上具有独特结构与功能的生态系统,图们江流域湿地生态系统的健康对该区乃至东北亚地区综合生态系统网络的建设具有重要意义。选择图们江流域下游为研究区,基于压力-状态-响应(PSR)模型,在压力系统、状态系统、响应系统三个层面选取30个指标构建了图们江下游湿地生态系统健康评价指标体系,运用层次分析法和多级模糊综合评判法对研究区湿地生态健康状况进行综合评价,其结果为0.5878,处于亚健康状态。其中,压力系统的健康指数为0.5292,响应系统的健康指数为0.6866,状态系统的健康指数为0.5116,各等级隶属度S=(16.83%, 25.37%, 16.76%, 16.97%,24.07%)。主要表现在研究区域湿地的补水水质差,导致湿地水质污染加重,富营养化现象严重;并且由于人为因素,湿地大面积退化,景观破碎化加剧,功能逐渐丧失,生产力水平下降;急需对本区域湿地进行保护与管理。     

湿地生态系统健康评价指标体系Ⅰ.理论

湿地生态系统健康是一个新的研究领域。主要从湿地生态系统指标的概念出发,阐述了选择生态系统指标的基本理论,分析了湿地生态特征指标体系,湿地功能整合性指标体系和湿地社会政治环境指标体系所包含的基本内涵,特别强调了生态系统结构和内在功能是生态特征的主要表现。功能整合性是湿地生态系统健康的外在表现,同时,社会政治环境因素中,政策法规,总体规划,政策保障,公众参与程度,代际周期的社会公平性,个人接受能力,团体接受能力等是影响湿地生态系统健康的重要因素。     

哈尼梯田湿地生态系统健康评价指标体系构建

为了获得梯田湿地生态系统健康评价的指标体系,以云南红河哈尼梯田湿地为例,基于对该湿地维持机制的分析,构建了包括生态特征、功能整合、社会与政治3个方面共20个指标的健康评价指标体系以及各个指标的健康阈值分级表。同时,利用AHP层次分析法确定了各指标的权重,运用综合评价法对梯田湿地生态系统的健康状态进行评价。本研究构建的评价指标体系解决了哈尼梯田湿地生态系统缺乏健康评价指标体系和支持理论的问题,为评价该类型湿地生态系统的健康状态提供指导方法,能够依据其评价结果为后续湿地健康质量的提升及湿地的可持续利用发展提出改进策略。     

长江三峡库区生态环境变化遥感研究进展

长江三峡库区是我国最重要的生态敏感区之一,受三峡水利工程和相关人类活动影响,其生态环境变化显著.揭示三峡库区生态系统结构、功能和生态过程的变化对于维护库区生态安全具有重要意义.生态环境遥感为此提供了关键途径,并在三峡库区生态环境研究中受到重视.现有的三峡库区生态环境变化遥感研究往往存在较大差异,难以有效反映生态环境变化和响应特征,加之生态本底和人类干扰活动的复杂性,三峡库区生态环境变化遥感研究仍面临诸多挑战.本文对库区环境变化遥感研究的发展阶段、研究尺度、遥感数据和方法等进行了系统总结,并从土地利用/覆盖变化、植被变化、水土安全、生态服务价值评价、生态系统健康与生态规划5个方面对库区生态环境变化遥感研究进展进行综述,在此基础上探讨了当前三峡库区生态环境变化遥感研究存在的问题,并提出未来研究中需重点关注的主要科学问题,以期为三峡库区生态环境管理和类似地区生态环境变化遥感研究提供参考.
     

A comparison of wetland characteristics between Agricultural Conservation Easement Program and public lands wetlands in West Virginia,USA

In West Virginia, USA, there are 24 conservation easement program wetlands enrolled in the Agricultural Conservation Easement Program (ACEP). These wetlands are located on private agricultural land and are passively managed. Due to their location within fragmented agricultural areas, wetlands enrolled in ACEP in West Virginia have the potential to add wetland ecosystem services in areas that are lacking these features. We evaluated ACEP wetlands compared to reference wetlands on public land in West Virginia by using surrounding land cover, vegetative cover, and wetland features and stressors such as the presence or absence of erosion, upland inclusion, algal mats, and evidence of impacts from the surrounding landscape as surrogate measurements of wetland function on 13 ACEP wetlands and 10 reference wetlands. ACEP wetlands had higher percentages of tree coverage and a higher proportion of agricultural land in the areas immediately surrounding the wetland. Reference wetlands had higher percent coverage of emergent vegetation and had a higher proportion of forest in the immediate landscape. Our findings suggest that ACEP wetlands provide valuable early successional and forested wetland cover in a state that is largely forested. Because of this, it is important to maintain and even expand ACEP in West Virginia to continue providing a valuable source of early successional wetland habitat.     

Scale and ecological dependence of ecosystem services evaluation: Spatial extension and economic value of freshwater ecosystems in Italy

Using land cover datasets derived from satellite imagery as a proxy for ecosystem services (ES) mapping and evaluation generates a series of technical problems mainly related to the resolution at which spatial data are acquired. Small sized and highly fragmented ecosystems such as wetlands, streams and rivers are particularly underestimated when coarse resolution land cover datasets are used. However, even at finer resolution, a large fraction of the economic value provided by freshwater ecosystems may not be adequately captured by remote sensed data because, other than technical and methodological problems, the provision of many freshwater services is strictly dependent on the interactions and contacts of these ecosystems with contiguous environments. The paper analyzes and discusses the effectiveness of the CORINE land cover (CLC) dataset to represent the spatial extension and, indirectly, the economic value of freshwater biomes in Italy, with emphasis on rivers and streams. Using a georeferenced national hydrographic network database and applying a stream buffer of variable width to more than 20,000 water courses, we demonstrated that less than 10% of the estimated surface is captured by the CLC dataset with heavy negative consequences on the overall evaluation of ES at local, regional and national scale. Our approach, easily applicable also to other geographical and spatial contexts, may contribute to improve proxy-based methodologies in ES mapping/evaluation and may help to limit errors in the estimation of freshwater services.     

西南喀斯特石漠化生态系统土壤有机碳分布特征及其影响因素

喀斯特石漠化已成为制约我国西南地区社会经济可持续发展最严重的生态地质环境问题,其恢复重建已成为我国社会经济建设中一项重要内容。土壤有机碳作为土壤质量评价的重要指标,可以综合反映土地生产力、环境健康功能,另一方面土壤有机碳也间接影响了陆地生物碳库,是陆地生态系统碳平衡的主要因子,它的转化和积累变化直接影响全球碳循环动态,已成为生态科学领域研究的热点之一。系统的总结了西南喀斯特石漠化地区不同土地覆被/土地利用、不同等级石漠化环境土壤有机碳的空间和季节分布特征。结合前人研究成果,进一步分析了影响喀斯特石漠化地区土壤有机碳分布的自然(气候、地形与土壤性质、植被等)和人为(土地覆被/土地利用变化、农业管理措施等)各因素,并提出增加喀斯特石漠化地区土壤有机碳含量的对策。研究结果为喀斯特石漠化退化生态系统恢复重建、石漠化地区土壤综合利用、增加碳截存应对全球碳循环减源增汇等提供了重要的科学参考。     

Agricultural Legacies in the Great Basin Alter Vegetation Cover, Composition, and Response to Precipitation

The land-use history of an ecosystem influences current structure and possibly response to modern disturbances and stresses. In semiarid systems the nature of land-use legacies is poorly understood, confounding efforts to establish sustainable management approaches. We compare previously cultivated and non-cultivated lands in Owens Valley, California, where cultivation once extended to 34% of the valley floor but was largely discontinued by 1940, to measure the influence of past disturbance on modern vegetation. We combined historic maps of cultivated and non-cultivated land with an extensive vegetation survey, historic aerial photographs, and satellite measurements of vegetation response to precipitation variability to examine the importance of land-use history in determining the sensitivity of vegetation to annual variations in precipitation. Remote sensing analysis showed that total plant cover on previously cultivated lands was lower and fluctuations in cover were marginally more dependent on precipitation compared with plant cover on non-cultivated lands. We then compared modern plant assemblages within cultivated and non-cultivated land to determine if compositional differences could explain the current patterns of vegetation cover. We found lower species richness on previously cultivated parcels, and higher frequency and cover of perennial grasses on non-cultivated lands. Therefore, we showed differences in land-cover patterns, isolated a mechanism that could account for the differences (species differences), and developed a method for remotely analyzing land regions that have experienced historic anthropogenic disturbance.     

滨海红树林湿地生态系统健康的诊断方法和评价指标

健康的红树林湿地生态系统是指系统组分之间及系统整体维持动态的平衡,在适度的自然与人为干扰下,红树林生态系统服务功能发挥正常。本文筛选并评述了包括指示物种法、结构功能指标法、生态系统失调综合症诊断法、生态系统健康风险评估法、生态脆弱性和稳定性评价、生态功能评价法等6种可用于红树林湿地生态系统健康的诊断方法,分析了各自的应用前景。以压力-状态-响应模型为主线,构建了红树林湿地生态系统健康评价指标体系。在未来研究中,需进一步加强指标的筛选、评价标准与权重的确定,将生态系统健康水平与其生态服务功能相关联,开展具体案例分析。