The suitability of the marine biotic index (AMBI) to new impact sources along European coasts

In recent years, several benthic biotic indices have been proposed to be used as ecological indicators in estuarine and coastal waters. One such indicator, the AZTI Marine Biotic Index (AMBI), was designed to establish the ecological quality of European coasts. The index examined the response of soft-bottom benthic communities to natural and man-induced disturbances in coastal and estuarine environments. It has been successfully applied to different geographical areas and under different impact sources, with increasing user numbers in European marine waters (Baltic, North Sea, Atlantic and Mediterranean). The AMBI has been used also for the determination of the ecological quality status (EcoQ) within the context of the European Water Framework Directive (WFD).In this contribution, 38 different applications including six new case studies (hypoxia processes, sand extraction, oil platform impacts, engineering works, dredging and fish aquaculture) are presented. The results show the response of the benthic communities to different disturbance sources in a simple way. Those communities act as ecological indicators of the ‘health’ of the system, indicating clearly the gradient associated with the disturbance.     

An overview of integrated hydro-ecological studies in the MELMARINA Project: monitoring and modelling coastal lagoons—making management tools for aquatic resources in North Africa

As landscape disturbance and climate conspire to accelerate global environmental change towards unprecedented levels in the twenty-first century, the populated coastal regions of many countries are facing major threats to sustainability. Coastal water resources are particularly vulnerable in dry regions. In view of the expected severity of future environmental change in the Southern Mediterranean Region, the European Commission supported an integrated multidisciplinary project, MELMARINA, on monitoring and modelling coastal lagoons in Morocco, Tunisia and Egypt. This is a region where water management for people and for agriculture has been intense particularly during the twentieth century, yet long-term environmental monitoring and management of wetland ecosystems are under developed. Not only are biodiversity aspects at risk in coastal lagoons and wetlands but the goods and services that affect human welfare are also generally in decline. Co-ordinated hydro-ecological monitoring at key wetland lagoons was begun in 2003 with a view to establishing environmental baselines and calibrating site-specified hydro-ecological models. This article introduces the project and its results that range from lagoon typification and hydro-ecology to the application of hydro-ecological models. Detailed results and evaluations are presented in a linked series of themed scientific articles within this special issue. The present condition of the lagoons investigated essentially results from various hydrological modifications combined with eutrophication problems, yet all still remain valuable aquatic ecosystems. Adequate monitoring data are an essential part of reliable predictive modelling and, despite several data gaps, nutrient load reduction scenarios were undertaken to help target restoration aims. Implementation of aspects of the EU Water Framework Directive for achieving good ecological status of transitional waters is advocated. Nevertheless, as the twenty-first century advances the effects of global climate change are expected to amplify current stresses making intervention restoration and adaptation management even more imperative. Long-term sustainability depends upon detecting and measuring environmental change (long-term water quality and ecological quality) and incorporating the results into appropriate hydro-ecological models to facilitate the development of appropriate management initiatives. Guest editors: J. R. Thompson & R. J. Flower Hydro-ecological Monitoring and Modelling of North African Coastal Lagoons     

Characterisation of a Tunisian coastal lagoon through hyperspectral underwater irradiance

North African coastal lagoons are unique ecosystems that often suffer degradation due to human activities. Therefore, monitoring methods are required to identify stressors and assist with the management of these valuable and often understudied ecosystems. A synthetic indicator of water ecological quality would be desirable for regular monitoring of these ecosystems under pressure. In 2008 an optical procedure was developed and applied in Ghar El Melh, a Tunisian lagoon which has been increasingly impacted by pollutant loading, especially from agriculture. In situ hyperspectral irradiance was measured at several stations, from which the apparent optical properties (AOPs), namely the irradiance attenuation coefficient K(λ) and the reflectance ratio R(λ), were obtained in order to relate them to water composition, in terms of light-attenuating substances (LASs). The significant relationships observed between R and LAS values enabled the application of a hyperspectral optical classification, which effectively highlighted threatened sectors of the lagoon. The pattern of differing water quality across the lagoon system that was derived from the hyperspectral classification agreed well with that obtained from a conventional optical classification that included AOPs and LASs. We suggest that hyperspectral analysis and classification is a useful monitoring tool for the assessment of change in coastal lagoons, and perhaps also in other shallow-water ecosystems.     

Use of biotic indices in semi-enclosed coastal ecosystems and transitional waters habitats—Implications for the implementation of the European Water Framework Directive

This study deals with the application of macrozoobenthos-based biotic indices (BI) within the frame of the implementation of the European Water Framework Directive. More precisely, this study aimed at assessing the performance of five recently developed methodologies (BI) for the assessment of ecological quality status (EcoQ) in two semi-enclosed, sheltered coastal ecosystems and in one transitional water body situated along the Western French coast, namely Marennes-Oléron Bay, Arcachon Bay, and the Seine Estuary. This study showed that these five indices rarely agreed with each other, describing very different pictures of the overall EcoQ of the three study sites. This work also clearly underlined the limitations of these approaches, notably the dependency of most of these BI and the resulting EcoQ classifications on habitat characteristics, more particularly to natural levels of sediment silt–clay content and the location of stations in the subtidal or the intertidal. The implication of our observations concerning the use of these BI for implementation of the WFD is discussed in terms of definition of habitat-specific reference conditions and necessity to adjust thresholds to the particular habitat occurring in semi-enclosed ecosystems. Meanwhile, the unmodified use of these BI severely impaired accurate assessment of EcoQ and decision-making on the managers’ point of view.     

Addressing a gap in the Water Framework Directive implementation: Rocky shores assessment based on benthic macroinvertebrates

A gap in the European Water Framework Directive (WFD) is addressed, aiming for the development of an ecological quality status assessment tool based solely on the Biological Quality Element benthic macroinvertebrates from intertidal rocky shores. The proposed Rocky shore Macroinvertebrates Assessment Tool (RMAT) was tested and validated along disturbance gradients (organic enrichment). During the whole process, the response of widely used metrics (e.g. Hurlbert index, Shannon-Wiener index, AZTI’s Marine Biotic Index; Bentix biotic index) and models (i.e., metrics combined) was compared to results provided by the Marine Macroalgae Assessment Tool to the same sampling sites.The RMAT is a multimetric index compliant with the WFD based on the benthic macroinvertebrates community, combining ‘abundance’ (Hurlbert index) and ‘taxonomic composition’ (Bentix index using density and biomass data) metrics. It performed well along anthropogenic disturbance gradients, showing ecological quality increasing from close to far away from the disturbance.The RMAT is a promising tool for rocky shore ecological assessment in the scope of the WFD or other monitoring activities worldwide.     

New frameworks for species surrogacy in monitoring highly variable coastal ecosystems: Applying the BestAgg approach to Mediterranean coastal lagoons

Benthic invertebrates are good indicators of aquatic ecosystem health. Yet, environmental monitoring and assessment of community changes in relation to both natural and human sources of disturbance involves considerable efforts for sample processing and time-consuming identifications of organisms, which make challenging large-scale and continuous monitoring programs required under the current regulatory frameworks at European scale. The use of higher taxa (e.g. families) as surrogates for species is a mainstream approach to reduce cost and time associated to fine taxonomic resolution in environmental studies, especially concerning macro-invertebrate communities. However, this approach of ‘taxonomic sufficiency’ simply relies on the static grouping of organisms in taxa belonging to a single higher taxonomic level irrespective of their ecological relevance or difficulties in their taxonomic identification, leading to unnecessary losses of taxonomic detail or ecological information. A new approach, namely the Best Practicable Aggregation of Species (BestAgg), has been recently developed as an alternative procedure for species surrogacy. BestAgg is based on aggregating species in the minimum number of surrogates sufficient to depict species-level community patterns consistently, while capitalizing on ecological information. Although the approach has been successfully applied to marine and freshwater invertebrate assemblages, its effectiveness in transitional water systems, where the complex and highly variable environmental conditions may affect the performance of surrogacy methods, still remain untested. Here, we applied the BestAgg approach to quantifying spatio-temporal patterns of variability of macro-invertebrate assemblages from Mediterranean coastal lagoons (Northern Adriatic Sea). Surrogates were defined using species-level data from a representative lagoon system, which served as pilot study. Then, they were used to analyze macro-invertebrate assemblages in two independent lagoons in the same geographic area. Results showed that BestAgg surrogates were effective in depicting multivariate patterns of macro-invertebrate assemblages as at species level over and beyond potential variations among the investigated lagoons. The use of families, following a more classic approach based on taxonomic sufficiency, also provided results comparable to those obtained using species. However, with respect to families, BestAgg surrogates allowed an estimated timesaving of 40% higher while still retaining an equivalent amount of information on species-level patterns. More importantly, BestAgg allowed exploiting different criteria of species aggregation, leading to a set of surrogates more aligned with ecological/functional characteristics of organisms, suggesting that BestAgg approach may provide a fresh perspective for optimizing trade-offs between pragmatism and the need for relevant ecological information in environmental assessment and monitoring.     

Application of biotic and taxonomic distinctness indices in assessing the Ecological Quality Status of two coastal lakes: Caprolace and Fogliano lakes (Central Italy)

Marine biotic indices (AMBI, BENTIX) and the statistical tool M-AMBI (Multivariate AMBI) were applied as a comparative approach in assessing the Ecological Quality Status (EcoQS) of two Mediterranean coastal lakes (Caprolace and Fogliano lakes) situated in the Circeo National Park (Central Italy). The macrobenthic community was analysed using univariate indices (community structure), correspondence analysis (CA) and taxonomic distinctness indices (Δ⁺ and Λ⁺). The community composition showed a dominance of lagoonal species in both coastal lakes, while in Caprolace lake marine taxa were also found. Diversity index (H′) complies to ranges found in Mediterranean lagoons and taxonomic distinctness indices demonstrated that taxonomy structure is in accordance with natural variability ranges. Principal component analysis (PCA) on chemical parameters of water and sediment showed that both coastal lakes differ mainly in their organic matter composition. In fact, the protein fraction of bio-polymeric carbon prevails in Fogliano lake, while the ‘refractory’ component represented by carbohydrate fraction is predominant in Caprolace lake. The difference between the two coastal lakes was also demonstrated by co-inertia analysis (COIA) performed using abundance of species and concentrations of chemical parameters. The results from the application of the three biotic indices do not highlight a clear distinction between the two lagoons. However, the AMBI index provided a more suitable evaluation of EcoQS corresponding to ‘slightly polluted’ lagoons while M-AMBI and moreover BENTIX indices indicated a worsening situation. The biotic indices are widely used in assessing the EcoQS in marine environments, but their proper application in transitional waters would depend on a resettlement; thresholds established in the biotic index scale values need to be modified according to natural variability of transitional waters referring to abiotic conditions and abundance of tolerant species.     

Ecosystem services provision today and in the past: a comparative study in two Baltic lagoons

The European Biodiversity Strategy asks EU Member States for an assessment, mapping and valuing of Ecosystem Services (ES). While terrestrial ES concept is advanced and different tools are available, they are largely lacking for coastal and marine systems. We develop a stepwise methodological process to assess ES in coastal and marine systems which we name Marine Ecosystem Services Assessment Tool. We applied it to two large Baltic lagoons, the Szczecin and the Curonian Lagoons demonstrating a quantitative and qualitative assessment approach. Firstly, an initial status is defined reflecting, according to the European Water Framework Directive, a past situation when the ecosystems where in a so called good ecological state. In both Baltic lagoons, this refers to a situation around 1960. Secondly, a present state is defined, assessed and compared to the initial status. Increasing anthropogenic impacts in Szczecin Lagoon caused an overall decrease ecological status which may influence the system’s ability to provide services. Assessing ES changes semi-quantitatively via 39 indicators and 22 services, we show a decrease in provisioning and regulating and maintenance and an increase of cultural services’ provision. According to 15 expert valuations, the Curonian Lagoon displays no changes in provisioning but an increase in regulating and maintenance and cultural service provision. We discuss how these results can serve different marine management approaches and support different polices. Through our application we show how the tool can be used to assess ES changes over time and thus provide key information on sustainable use and ES for future generations.     

Effects of disturbance on phosphorus turnover and plankton dynamics

In coastal lagoons, one common type of anthropogenic disturbanceis opening of the sand barriers that isolate these lagoons fromthe sea. We investigated how a disturbance caused by an artificialopening of the sand barrier affects phytoplankton and bacterioplanktondynamics and alkaline phosphatase activities (APA) in a Braziliancoastal lagoon. We propose an index of potential phosphorusturnover time (PPTT) calculated as the ratio of total phosphorus(TP) and APA in an attempt to quantify the effect of disturbanceson phosphorus recycling within the plankton community. Openingthe barrier caused increased phytoplankton biomass, TP concentrations,APA and PPTT, and decreased bacteria to phytoplankton biomassratio. PPTT is easily calculated and may be used to detect planktonresponses to anthropogenic disturbances.     

Application of specific exergy to macrophytes as an integrated index of environmental quality for coastal lagoons

This work aims to explore the application of specific exergy on macrophytes as an integrated index to assess ecosystem health in coastal lagoons, and to analyse its possible application in view of the implementation of the Water Framework Directive of the European Union (European Commission, 2000). Exergy and specific exergy are calculated as a function of the biomass multiplied by a weighting factor (β), which express the quantity of information embedded in the biomass. Until now only few general values of β have been published. Therefore, we have extended the calculation of β-values for 244 seaweed and seagrass species which are common in Mediterranean coastal lagoons. The estimated β-values have been then compared with macrophyte-based indicators which have been recently developed, namely the Ecological Evaluation Index and the IFREMER classification scheme. Overall, we found a good agreement between β-values and macrophyte indicators. Furthermore, the specific exergy was calculated for 71 sites in coastal lagoons of Southern France and compared with existing classification schemes, finding a good agreement between them. As a result, we argue that specific exergy may be used as an integrated index that is able to synthesize and complement existing approaches.     

Macroalgae,a suitable indicator of the ecological status of coastal rocky communities in the NE Atlantic

Despite the great importance of shallow rocky communities (<30 m deep) due to their contribution to the biodiversity of coastal waters, most efforts in ecological status assessment of marine waters have been carried out in the implementation of soft bottom biotic indices. Therefore, in this paper, a methodology for the environmental evaluation of coastal rocky communities for the Bay of Biscay (NE Atlantic), the CFR index (Quality of Rocky Bottoms), is presented. This index is based on the analysis of seaweed communities throughout the depth gradient, from the intertidal to the shallow subtidal, through the combination of a multimetric approach, which combines the richness of characteristic macroalgae populations, their total cover, the presence of opportunistic species and the physiological condition of the whole macroalgae community. Quality thresholds for these indicators are based on both ecological data and expert judgment. Finally, a preliminary application of this metric to sites with theoretically good and bad environmental conditions is used to analyze the suitability of the index. As a result, the four selected indicators responded in a significant way to the pressure gradient tested, proving to be appropriate for the type of pressure analysed and obtaining coherent results in the final quality assessment with the CFR index. In conclusion, the CFR index has proved to be an effective tool for the assessment of the ecological quality of coastal rocky communities, based on the analysis of macroalgae assemblages.     

A comparative approach of assessing ecological status in two coastal areas of Eastern Mediterranean

This work presents an assessment of the ecological quality status of two marine coastal areas in the Aegean Sea (Greece, Eastern Mediterranean) based on the benthic macroinvertebrate quality element. S. Evvoikos and Thessaloniki gulfs, two coastal areas subjected to slight and heavier anthropogenic pressures, were selected to test the biotic index Bentix developed for the assessment of the ecological status. Other ecological indicators, such as the Shannon diversity index (H′), the species richness (S) and the AMBI biotic index were also applied and evaluated comparatively. Faunistic data were also used to interpret results. The resulting classification was validated with the use of physicochemical parameters and pressure information. This work also provides an insight into the structure of the Bentix classification scheme within the scope of its use in Water Framework Directive (WFD) implementation.     

Application of an angiosperm-based classification system (BiPo) to Mediterranean coastal waters: using spatial analysis and data on metal contamination of plants in identifying sources of pressure

The Biotic Index based on Posidonia oceanica (BiPo) is a classification system for evaluation of the ecological status in Mediterranean coastal waters, developed in accordance with the EU Water Framework requirements. The aim of this study is to verify the applicability and reliability of the BiPo index to different geographical areas of the north-western Mediterranean (France, Spain and Italy), to understand whether such a classification system may be applied more extensively, as so far it has only been applied to coastal waters in Corsica. The ecological status determined for sites is verified against pressures revealed from satellite imagery and from trace metal contamination of plants, to identify the sources of pressure that may be responsible for a low ecological status. The results of this study indicate that: (i) the BiPo index responds reliably to pressures, in different areas of the Mediterranean; (ii) sites with an ecological quality ratio (EQR) close to the good/moderate boundary require particular attention to identify and reduce causes of deterioration; (iii) the support of chemical indicators, in this case metal contamination, is relevant to identify potential sources of pressure.     

Ability of phytoplankton trait sensitivity to highlight anthropogenic pressures in Mediterranean lagoons: A size spectra sensitivity index (ISS-phyto)

Size spectra exhibit common patterns of variation and predictable responses to pressures across ecosystem types, functional guilds and taxonomic groups. Here, we extend the size spectra approach to phytoplankton ecological status assessment in transitional waters by developing, testing and validating a multi-metric index of size spectra sensitivity (ISS-phyto), which integrates size structure metrics with others such as phytoplankton diversity, biomass and sensitivity of size classes to anthropogenic disturbance. The ability of various theoretical models of size spectra sensitivity to discriminate between disturbed and undisturbed ecosystems and levels of anthropogenic stress was evaluated. We used data on phytoplankton samples collected in 14 Mediterranean and Black sea transitional water ecosystems (coastal lagoons) from Italy, Albania, Greece, Bulgaria and Romania, and compared the models’ efficiency by looking at their pressure–impact response along salinity and enrichment gradients, the latter quantified as variations in dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP). Data from a fifteenth Mediterranean lagoon was used for external validation purposes. Right asymmetric models of size class sensitivity, implying higher sensitivity of smaller cell size classes, were found to contribute to the ISS-phyto multimetric tool more effectively than symmetric and left asymmetric models, distinguishing disturbed from undisturbed lagoons and disturbed from undisturbed stations within the same lagoon. When based on right asymmetric sensitivity models, i.e., those that were most efficient in identifying anthropogenic impacts, ISS-phyto also showed the best fit of pressure–response relationships along the salinity and enrichment gradients; at low to high levels of impact ISS response was driven by size class sensitivity and at very high impacts by phytoplankton biomass. A scheme for the classification of Ecological Quality Status based on ISS-phyto is proposed and validated. The validation procedure found that ISS-phyto is an effective and sensitive monitoring tool, robust, easy to apply and to inter-calibrate among laboratories.     

Riverine habitat specificity constrains dispersion in a Neotropical fish (Characidae) along Southern Brazilian drainages

Freshwater fishes often display a marked phylogeographic structure strongly associated with historical and ecological changes in the aquatic environment. Different ecological conditions in the same river drainage may act as permeable barriers to dispersion and gene flow. Previous studies recognized two discrete spatial components for the ichthyofauna in the freshwater coastal drainages of southern Brazil: the lowland fish fauna in the lagoons and the fish fauna of the rivers flowing in the valleys. In order to test if the coastal lagoons may limit the dispersion of a riverine species, we describe the phylogeographic structure among populations of Cyanocharax itaimbe, a species endemic to this region. We analysed 55 specimens characterized for two mitochondrial and one nuclear genes. Sequences were analysed using gene trees and species tree approaches, together with standard population genetics methods. Molecular analyses indicated three evolutionary groups which diverged from each other between an estimated 1,600,000 and 450,000 years before the present. However, two currently isolated river systems share the same evolutionary clade, whereas a single drainage contains two different lineages. Our results indicate strong genetic structure among populations along with generally conserved morphology. The strong genetic structure among populations living in the same drainage system may be explained by ecological differences between lagoons and rivers (or palaeochannels) that act as barriers to dispersion.     

Enzymatic survey of four populations of Atherina boyeri based on electrophoresis and the occurrence of a microsporidiosis

Biochemical genetics of a Atherinid species, Atherina boyeri were undertaken to determine variability. Among the 17 loci studied, 7 were polymorphic, of which three were retained for a more detailed comparison of populations inhabiting the French Mediterranean coastal lagoons. A microsporidiosis is present in these fishes and is limited to certain lagoons. Comparison of allelic frequencies at the polymorphic loci between fish populations of infected and healthy lagoons yielded no significant differences. Several hypotheses are discussed and attempt to agree parasite distribution with genetical results.     

The fuzzy index of ecosystem integrity (FINE): a new index of environmental integrity for transitional ecosystems

The European Water Framework Directive (WFD) (2000/60/EC) requires assessing the ecological quality status of water bodies, and gives great importance to the biological components of the ecosystem. Within this framework, a multimetric, fuzzy-based index for the evaluation of environmental quality (FINE: fuzzy index of ecosystem integrity) has been developed using data from several Italian coastal lagoons, gathered with seasonal frequency at diverse sites in each lagoon. The rationale of FINE is that certain attributes, selected on the basis of established principles of benthic ecology, are fundamental for lagoon ecosystem function. FINE is composed of seven ecosystem attributes (variables) each of which have ecological relevance for lagoon ecosystems. Individually, all these attributes are themselves useful indices of environmental conditions. However, the combination of these attributes into a single fuzzy index, provides a more robust, overall index of the response of the natural communities to environmental perturbations and avoids misleading or ambiguous results. Each variable is not represented by a single numerical value, but by several categories that describe its properties: in the present model we considered a total of seven variables: two with four modalities (low–medium–high–very high), one with three (low–medium–high) and three with two (low–high), plus a qualitative variable (yes–no), that altogether generate 768 rules. FINE is a low-cost, flexible and robust routine index of lagoon ecosystem impairment and could be of particular benefit to environmental managers and policymakers who require tools capable of expressing the degree of degradation or environmental quality of different lagoon habitats. For its relative simplicity in the application, FINE could be a good candidate to assess the environmental quality of Mediterranean transitional ecosystems. Guest editors: A. Razinkovas, Z. R. Gasiūnaitė, J. M. Zaldivar & P. Viaroli European Lagoons and their Watersheds: Function and Biodiversity     

Comparative composition and dynamics of harmful dinoflagellates in Mediterranean salt marshes and nearby external marine waters

The taxonomic structure of phytoplankton populations in two Mediterranean coastal lagoons were compared with those of nearby marine waters (external waters). Mediterranean confined lagoons remain isolated for most the year and concentrate phytoplankton to a very high biomass. Coastal lagoons on the Mediterranean may, therefore, act as accumulators of neritic phytoplankton (including species related to harmful algal blooms). We examined whether coastal lagoons act as concentrators of marine toxic dinoflagellates during confinement periods, and the common environmental factors that favour growth of specific harmful species in the two ecosystems considered: coastal lagoons and external waters. An alternation between the dominance of diatoms and dinoflagellates was observed, coinciding with that described in Margalef's mandala, occurring in external waters as well as in coastal lagoons. Moreover, the temporal patter was different in the two ecosystems. Dinoflagellate species composition and their bloom period were highly variable in time and space, thus, species had to be analysed individually. Most of the dinoflagellate species found in this study were potentially harmful and high biomass producers. Harmful dinoflagellate species performed well in both, external waters and lagoons, but the specific species-dependent affinity to each of these environments determined which organisms bloom there. Thus, expansion of harmful algal blooms (HAB) to inland waters is not likely and some environmental factors such as the oxidised state of available nitrogen, became determinant to the success and bloom of a species in the coastal lagoon ecosystem.     

An ecological quality status assessment procedure for soft-sediment benthic habitats: Weighing alternative approaches

An assessment procedure for determining the ecological quality status of soft-sediment benthic habitats requires the following aspects: (1) habitat assignation of the samples (habitat approach), (2) reference or target conditions for the benthic parameters (reference approach), and (3) the selection of indicator tools to assess the relative quality status (indicator approach). For all these aspects, different approaches exist, and the indicator selection and reference approaches are largely documented. The aspect of the habitat approach is sometimes neglected, but is essential in determining the reference conditions per habitat type. Benthic habitats differ in structure and function, and as such will show wide variations in statistics or measures between habitats. A major problem, mainly in coastal soft-bottom systems, is to track the deviation lines within data of the different benthic habitat types. This study shows that both a classical community analysis and the use of habitat suitability maps seem to be appropriate tools, but further fine-tuning is necessary. For the second assessment step, an objective assessment of reference conditions is a challenge in areas lacking pristine or minimally disturbed sites, and areas of which historic data are not available. This can be remedied by using a dataset of the area with a good spatial and temporal coverage of the benthic data, thereby avoiding data originating from highly impacted areas. For the third aspect in the assessment procedure, we recommend the use of different indicators with different properties (parameters, algorithms) since it indicates their weaknesses and strengths in the local region.In general, this study showed us that it is valuable to test different existing approaches for EcoQ assessment in a local area, revealing strengths, weaknesses and shortcomings within the assessment regarding data, habitat identification, monitoring strategy, reference settings and indicator use. All these aspects need to be taken into account within an ecological quality status assessment of an area in order to improve its confidence.     

基于探索性空间数据分析的海坛岛土地利用生态风险评价

生态风险评价作为一种新型环境管理工具,提供了定量化评估土地利用变化生态效应的新视角.本研究以福建海坛岛为案例区,基于1990年Landsat TM与2010年SPOT5遥感影像、2030年平潭综合试验区总体布局规划图和野外调查等数据,构建度量生态终点的生态风险表征指数,运用探索性空间数据分析中的空间自相关和半方差分析方法,对海坛岛过去 现在 未来不同土地利用情景下生态风险进行评价,分析其潜在的风险性及其变化趋势.结果表明： 海坛岛生态风险指数存在明显的尺度效应,在3000 m范围内表现出较强的正相关,生态风险指数空间分布以高 高聚集和低 低聚集类型为主;生态风险指数具有显著的各向同性特点,且其空间分布与对应时期局部空间自相关指数分布模式一致;各生态风险等级区年际变化较为剧烈,波动态势与波动幅度均有所不同;低生态风险区呈先增后降趋势,中、高生态风险区呈先降后升趋势.规划期的人为扰动强烈,高生态风险区在整个区域扩展蔓延.为减低土地利用生态风险、维护区域生态安全,可采取的生态风险控制策略包括：优化土地资源空间格局、保护关键生态区域、控制建设用地规模.