Use Of Ecological Indicators Research Articles

Coexistence in long-term managed lakes: Limited evidence of negative impacts of invasive macrophytes on fish communities

Invasive macrophytes are widespread and can disrupt freshwater ecosystems if not properly managed. Their impact on fish is a topic of ongoing discussion, with studies reporting contrasting results. Utilizing datasets spanning 17 years of monitoring across 34 lakes in Florida, we examined the effects of the primary non-native invaders water hyacinth (Eichhornia crassipes (Mart.) Solms), hydrilla ((Hydrilla verticillata L. f.) Royle), and water lettuce (Pistia stratiotes L.), plus the entire non-native macrophyte assemblage and abiotic variables on fish species richness, Shannon diversity, abundance, length, and biomass. Together, these indicators help assess and manage the impact of invasive species and environmental changes on freshwater ecosystems. Our study was conducted at both habitat and lake scales to ensure a more thorough understanding of potential impacts. We found evidence of a marginally positive influence of hydrilla on fish species richness and abundance, a positive influence of water lettuce on Shannon diversity, and a positive effect of water hyacinth on fish length, all at the habitat scale. Notably, these effects were largely analogous to those of native macrophytes. Water temperature of about 26 °C and dissolved oxygen levels between 5 and 10 mg/L appeared to be optimal for fish. Lakes located in northwest Florida exhibited higher fish diversity and abundance. The integrated use of ecological indicators reveals that long-term management of lakes might limit populations of non-native macrophytes, thereby reducing the adverse effects of invaders on fish communities and facilitating their coexistence. This study highlights the importance of management strategies and long-term monitoring in minimizing the impacts of invasive plants on freshwater ecosystems.

A framework for climate change adaptation indicators for the natural environment

Impacts of climate change on natural and human systems will become increasingly severe as the magnitude of climate change increases. Climate change adaptation interventions to address current and projected impacts are thus paramount. Yet, evidence on their effectiveness remains limited, highlighting the need for appropriate ecological indicators to measure progress of climate change adaptation for the natural environment. We outline conceptual, analytical, and practical challenges in developing such indicators, before proposing a framework with three process-based and two results-based indicator types to track progress in adapting to climate change. We emphasize the importance of dynamic assessment and modification over time, as new adaptation targets are set and/or as intervention actions are monitored and evaluated. Our framework and proposed indicators are flexible and widely applicable across species, habitats, and monitoring programmes, and could be accommodated within existing national or international frameworks to enable the evaluation of both large-scale policy instruments and local management interventions. We conclude by suggesting further work required to develop these indicators fully, and hope this will stimulate the use of ecological indicators to evaluate the effectiveness of policy interventions for the adaptation of the natural environment across the globe.

Restoration Trajectories and Ecological Thresholds during Planted Urban Forest Successional Development

Successfully reconstructing functioning forest ecosystems from early-successional tree plantings is a long-term process that often lacks monitoring. Many projects lack observations of critical successional information, such as the restoration trajectory of key ecosystem attributes and ecological thresholds, which signal that management actions are needed. Here, we present results from a 65 ha urban temperate rainforest restoration project in Aotearoa New Zealand, where trees have been planted annually on public retired pasture land, forming a 14 years chronosequence. In 25 plots (100 m2 each), we measured key ecosystem attributes that typically change during forest succession: native tree basal area, canopy openness, non-native herbaceous ground cover, leaf litter cover, ground fern cover, dead trees, and native tree seedling abundance and richness. We also monitored for the appearance of physiologically-sensitive plant guilds (moss, ferns, and epiphytes) that may be considered ecological indicators of succession. Linear regression models identified relationships between all but one of the key ecosystem attributes and forest age (years since planting). Further, using breakpoint analysis, we found that ecological thresholds occurred in many ecosystem attributes during their restoration trajectories: reduced canopy openness (99.8% to 3.4%; 9.6 years threshold), non-native herbaceous ground cover (100% to 0; 10.9 years threshold), leaf litter cover (0 to 95%; 10.8 years threshold), and increased tree deaths (0 to 4; 11 years threshold). Further, juvenile native plant recruitment increased (tree seedling abundance 0 to ~150 per 4 m2), tree seedling species richness (0 to 13 per 100 m2) and epiphytes colonized (0 to 3 individuals per 100 m2). These and other physiologically-sensitive plant guilds appeared around the 11 years mark, confirming their utility as ecological indicators during monitoring. Our results indicate that measurable, ecological thresholds occur during the restoration trajectories of ecosystem attributes, and they are predictable. If detected, these thresholds can inform project timelines and, along with use of ecological indicators, inform management interventions.

Effects of time-since-fire on ant-plant interactions in southern Brazilian grasslands

Abstract Grasslands and savannas are dynamic ecosystems, strongly regulated by environmental disturbances such as fire. Maintaining disturbance regimes in these ecosystems are of great conservation concern, and require studies with the use of ecological indicators. Biotic interactions are a major component of biodiversity that are particularly sensitive to environmental changes, and therefore should be considered in ecosystem assessment and monitoring. One of the most common interactions between insects and plants is mediated by extrafloral nectaries (EFNs), where ants use food resources from plants in exchange for protection against herbivores. Here, we explored variations on this ant-plant interaction across a post-fire successional gradient (i.e., few months to more than two years since the last fire) in eleven grassland patches in South Brazil. We evaluated time-since-fire effects on (i) the grassland habitat structure, (ii) an EFN-bearing plant population: Chamaecrista repens, (iii) the EFN-visiting ant communities, and (iv) the ant-plant ecological networks. We expected fire-induced habitat changes to benefit this plant population, and to produce positive cascading effects on interacting ants, thus influencing the structure of ant-plant networks. Freshly-burnt sites presented increased C. repens abundance, and larger individuals with more reproductive structures and EFNs in comparison with sites longer without disturbances. Plant abundance and size were inversely related to the cover of dominant grasses along the habitat gradient. The density of EFN-visiting ants, but not their species richness, increased in freshly-burnt sites, stimulated by the greater resource offer and the habitat openness, which probably facilitated ant activity. Moreover, with increasing time-since-fire, ants interacted with fewer plants, and few species formed the network generalist core. These results could further suggest that the defense service against herbivory provided by ants is also diminished in grasslands longer without disturbances. Overall, by using a series of indicators of habitat change from multiple ecological levels, this study highlights the importance of disturbance for grassland biodiversity and their ecological interactions, helping to improve management decisions.

Modeling the provision of air-quality regulation ecosystem service provided by urban green spaces using lichens as ecological indicators

The UN Sustainable Development Goals states that urban air pollution must be tackled to create more inclusive, safe, resilient and sustainable cities. Urban green infrastructures can mitigate air pollution, but a crucial step to use this knowledge into urban management is to quantify how much air-quality regulation can green spaces provide and to understand how the provision of this ecosystem service is affected by other environmental factors. Considering the insufficient number of air quality monitoring stations in cities to monitor the wide range of natural and anthropic sources of pollution with high spatial resolution, ecological indicators of air quality are an alternative cost-effective tool. The aim of this work was to model the supply of air-quality regulation based on urban green spaces characteristics and other environmental factors. For that, we sampled lichen diversity in the centroids of 42 urban green spaces in Lisbon, Portugal. Species richness was the best biodiversity metric responding to air pollution, considering its simplicity and its significative response to the air pollutants concentration data measured in the existent air quality monitoring stations. Using that metric, we then created a model to estimate the supply of air quality regulation provided by green spaces in all green spaces of Lisbon based on the response to the following environmental drivers: the urban green spaces size and its vegetation density. We also used the unexplained variance of this model to map the background air pollution. Overall, we suggest that management should target the smallest urban green spaces by increasing green space size or tree density. The use of ecological indicators, very flexible in space, allow the understanding and the modeling of the provision of air-quality regulation by urban green spaces, and how urban green spaces can be managed to improve air quality and thus improve human well-being and cities resilience.

Uncertainty in site classification and its sensitivity to sample size and indicator quality – Bayesian misclassification rate in ecological risk assessment

The aim of this study was to quantify uncertainty when assigning field investigation sites according to their species community composition to either undisturbed or disturbed reference sites by use of ecological indicators. In ecological risk assessment this problem arises when selecting control investigation sites or defining reference species communities. Uncertainty is quantified using a Type II error or misclassification rate. A probabilistic Bayesian model is used to integrate a priori domain knowledge, assess the error rate and come to recommendations about an adequate sample size. Application is demonstrated using data from a case study investigating off-crop arthropod communities in German grassy field margins and consequences for impact assessment of pesticides on terrestrial ecosystems. The model allows calculating statistical power when using such a classification system. By means of stochastic simulations, recommendations about experimental design and indicator size are derived. The study shows that to develop a classification system to typify newly observed sites a well-balanced ratio of undisturbed and disturbed sites as well as a high relevance of reference sites are needed. For the given data set, a much larger number of reference sites as well as increased relevance of selected reference sites would be needed to achieve a good classification result. An optimal number of indicators is calculated allowing for a compromise between sampling error and indicator quality. Uncertainty for correct assignment of an investigation site is compared using indicators for disturbance and reference conditions. Finally, misclassification rate is proposed as a new measure for indicator quality.

Comparing social representation of water quality in coastal lagoons with normative use of ecological indicators

Coastal lagoons are important for coastal and marine biodiversity. Nevertheless, they are very sensitive and vulnerable to human impacts, which often result in a decrease of their biodiversity and degradation of their water quality. Considering recent efforts for ecological restoration of coastal lagoons, it appears appropriate to compare the social representations of users of the coastal lagoons and of inhabitants, with ecological diagnoses of biodiversity and water quality. The main question is whether there is congruence between water quality defined by environmental criteria on one hand and the social representations of these issues by lagoon users and local populations on the other hand? How can we explain the social representations of lagoons concerning landscape, water quality and biodiversity? This study was focused on two Mediterranean lagoon areas, i.e., the Palavas lagoon complex (Gulf of Lions) and Biguglia lagoon (Corsica). We have documented these changes of ecosystem states using the criteria of regional monitoring programs that anticipated the implementation of the Water Framework Directive (WFD). Accordingly, both systems have shown bad water quality in the past with recent improvements. For studying the social representations, we conducted 267 surveys with lagoon inhabitants that live close to the lagoons and users of these spaces. In general, most of the residents living close to the lagoons considered that water quality is moderate to good, that biodiversity is good to high and that the current situation is better than in the past. However, some discrepancies between social representations and ecological diagnoses were observed.

Acacia saligna: specie invasiva delle coste molisane

Abstract: Italy is one of the European countries most affected by biological invasions. In this study, we focused on the impact of Acacia saligna, an Australian invasive plant species, on the coastal ecosystem’s ecology and biodiversity along the sandy coasts of Molise (southern Italy). We analyzed data from 61 vegetation plots recorded in coastal pine forest and Mediterranean scrub habitats of Molise throughout the preparatory actions of the “LIFE Maestrale” project (NAT/IT/000262). In order to study the ecological impact of Acacia saligna comparing invaded and non-invaded areas, we first assigned the Ellenberg’s indicator values to each plant species, which were then used to relate the presence of Acacia saligna with ecological characteristics of sites through a generalized linear model (GLM). Our results showed a significant positive relationship between the presence of Acacia saligna and high levels of soil nutrients and, on the contrary, a negative relationship with the presence of mesophilic species, which are typical of the community interest habitats of pine forest (2270*). The use of ecological indicators is effective to pinpoint the ecological effects of biological invasions, as well as to evaluate habitat conservation state and to identify vulnerable native species.

Age structure: an indicator to monitor populations of large herbivores

Most populations of large herbivores are hunted over much of their distribution. The size of these populations over time must be monitored to detect responses to management actions and environmental changes. Here, I first review the limits in precision and accuracy of most methods used to estimate population size in wild herbivores. I then show how density-dependence of age structure can be used to monitor harvested populations, using simulated and empirical data. Accurate estimates of population size are difficult, costly in time and effort, and mostly impracticable at a large scale. Indices are widely used to monitor population size at a large scale, but are rarely tested, and assumptions of constant detection rates over years are questionable. In a recent approach, the effects of population density on habitat quality and individual performance were used as ecological indicators to infer changes in population size over time. Populations of large mammals are strongly age structured. In harvested populations, density-dependence and harvest affect age structure through changes in age-specific vital rates. Because age- and sex-specific vital rates are density-dependent, changes over time in age structure should reflect the response of population to changes in environmental conditions such as density and harvest rate. Time series of age-structure may be used as an ecological indicator to monitor harvested populations, and to infer their demographic trajectory, especially when used within a set of ecological indicators. However, attention needs to be paid in the use of ecological indicators because of the potential bias introduced in data collection by hunter selectivity.

Vertical Profiles of Soil Properties and Microbial Activities in Peatbog Soils in Slovakia

Peatlands are unique ecological communities that represent long-term terrestrial carbon sinks with enormous organic substance supply. Soil organic substance represents the main source of organic carbon in the biosphere, and depending of conditions, it is able to eliminate or sequestrate greenhouse gasses in the environment. Current methods of peatbogs assessment rely on the use of ecological indicators, but often lack an in-depth analysis of soil parameters. The objective of this study was to examine vertical profiles of selected soil properties (soil reaction, soil organic carbon content, soil moisture) and various types of microbial activity (soil basal respiration, microbial biomass carbon, activity of soil urease, phosphatases and catalase). Soil samples were collected from three sites (centre of peatbog, edge of peatbog and site closely surrounding peatbog) on the peat soil at three depth intervals (0–0.10 m, 0.10–0.20 m and 0.20–0.30 m) in northeast of Slovakia. Enzyme and microbial activities decreased with depth, but significant correlation was found with alkaline phosphatase. Average values of most soil biochemical indices were highest at the centre of peatbog with the exception of urease and catalase activity. Our results indicated that enzymatic and biological potential for organic matter mineralization was strongly correlated to soil pH, soil moisture and soil organic matter content.

Dung beetle persistence in human-modified landscapes: Combining indicator species with anthropogenic land use and fragmentation-related effects

Identifying and making use of ecological indicators becomes an essential task in the conservation of tropical systems, mainly in fragmented landscapes where land use intensification and habitat loss are confounding factors in the detection of species’ responses to human-caused disturbance. We aimed to analyze the importance of anthropogenic land use and fragmentation-related effects on dung beetle (Coleoptera: Scarabaeinae) persistence according to the interior–exterior non-linear gradient (forest+matrix) in a fragmented Atlantic Forest landscape used to sugar cane production and cattle ranching/farming. We offer scores for a comprehensive set of community-level attributes, from beetle abundance to taxonomic and ecological composition (i.e. species body size), including a list of indicator species of different forest habitats and adjacent matrix. Dung beetles were surveyed by traps across forest interiors (i.e. core forest areas) and edges of a primary forest, small fragments, sugar cane fields and pastures in a total of 60 sites. Indicator analyses were conducted across the landscape, using two well-established methods (IndVal and SIMPER). Our results suggest that (1) cross-habitat taxonomic distinctness is associated with the presence of indicator species, (2) some species benefit or are dependent of open habitats created by human-disturbances, such as forest edges (e.g. Canthon nigripennis) and matrices (e.g. Canthon aff. piluliformis, Dichotomius nisus and Trichilum externepunctatum), (3) although landscape habitats exhibit reduced beta diversity, dung beetle assemblages are spatially organized in response to the presence of both forest habitats and matrix and fragment area, (4) forest interior supports beetle assemblages biased toward large-bodied species, (5) accordingly forest interior, forest edges and matrix support taxonomically distinct assemblages, both contributing to the bulk of species richness at landscape level, (6) the response of dung beetles to the interior–exterior non-linear gradient (i.e. forest edge+matrix) reveals a similar pattern regardless of the nature of the matrix, and (7) there is no within-habitat variation in beetle abundance and species richness associated with distance from forest edge. Given that there is a high number of forest-dependent or forest-interior specialist species (e.g. Aphengium aff. sordidum, Ateuchus aff. alipioi, Dichotomius mormon, Ontherus aff. erosus and Onthophagus aff. clypeatus) dung beetle persistence in human-modified landscape is highly dependent on the presence of core areas, although edge-affected and matrix habitats may be complementary. This information is essential to permit a better prospect for dung beetle persistence in human-modified landscapes as they continue to move toward edge-dominated landscapes with intensively managed matrices.

Ecosystem-based assessment of a prawn fishery in coastal Kenya using ecological indicators

The study aimed to describe and assess indicators that can potentially contribute to the development of Ecosystem-based Approach to Fisheries Management (EAFM) of prawn stocks in the Malindi-Ungwana Bay, the most productive coastal ecosystem in Kenya. A comprehensive EAFM is required to holistically manage fisheries resources and their associated habitats. The study assessed ecological indicators based on objectives of harvest sustainability and biodiversity conservation. Analyses were performed on data sourced from the State Department of Fisheries, and research databases. Trends in historical landings (1985–2010) of penaeid shrimps from the Malindi-Ungwana Bay were analyzed using LOWESS. Number-size spectra analysis was used to assess the exploitation status of the shrimps, while biomass-trophic level spectra (BTLS) analysis was applied as a potential tool for analyzing multifactor effects on the bay. IndiSeas-based ecosystem indicators were used to assess impact of the prawn trawl fishery on biodiversity of the bay. Results indicate long-term series with two peaks (1997 and 2000) in historical landings of penaeid shrimps and a monotonous decline in catches during 2002–2010. Slopes of number-size spectra suggested increased fishing mortality with time (2008–2012), while patterns of intercepts indicated a general increase in fisheries productivity of the bay. BTLS analysis using demersal fish survey and fish by-catch data suggested reduced levels of biomass across trophic levels and a temporal decline in trophic levels of fish species caught, however, the short time span constrains robust conclusions from the BTLS analysis. Biodiversity and conservation based indicators (e.g. fish sizes, trophic levels and proportion of predators in catches) adopted from the IndiSeas program showed the Malindi-Ungwana Bay to be ecologically degraded. There is need to initiate long-term monitoring programs to strengthen temporal scale of analysis of the datasets and to support use of ecological indicators for resource management and development of an EAFM in data-poor WIO countries.

VEGETATION OF INDUSTRIAL WASTE LANDFILLS WITHIN THE AGGLOMERATION OF THE CAPITAL CITY OF WARSAW

This study presents the results of examination of the vegetation on the waste landfill of ArcelorMittal-Warszawa steel mill and the furnace waste landfill of Siekierki Power Station, both sites in Warsaw. The presented analyses of the field research contain detailed floristic-phytosociological data as well as botanical and ecological evaluation of the identified plants. The vegetative structures, together with the suc cession trends of the vegetation cover of two examined landfills, have been shown. Ecological habitat adaptations of plants and their spatial structure have been evaluated. The inventoried flora has been subjected to taxonomic, syntaxonomic and eco logical classification. 154 plant species from 48 taxones in the range of families have been identified. Families characterized by the biggest abundance of species were: Compositae, grasses and Fabaceae. More than half of the live forms indentified were hemicryptophytes. The vegetation of two landfills has been dominated by synantrop hic communities (Stellarietea mediae, Artemisietea vulgaris, Molinio-Arrhenatheretea), with apophytes being in the largest number. With the use of ecological indicators a broad ecological tolerance of the majority of species toward ecological factors has been observed.

Defining quantitative stream disturbance gradients and the additive role of habitat variation to explain macroinvertebrate taxa richness

Most studies dealing with the use of ecological indicators and other applied ecological research rely on some definition or concept of what constitutes least-, intermediate- and most-disturbed condition. Currently, most rigorous methodologies designed to define those conditions are suited to large spatial extents (nations, ecoregions) and many sites (hundreds to thousands). The objective of this study was to describe a methodology to quantitatively define a disturbance gradient for 40 sites in each of two small southeastern Brazil river basins. The assessment of anthropogenic disturbance experienced by each site was based solely on measurements strictly related to the intensity and extent of anthropogenic pressures. We calculated two indices: one concerned site-scale pressures and the other catchment-scale pressures. We combined those two indices into a single integrated disturbance index (IDI) because disturbances operating at both scales affect stream biota. The local- and catchment-scale disturbance indices were weakly correlated in the two basins (r=0.21 and 0.35) and both significantly (p<0.05) reduced site EPT (insect orders Ephemeroptera, Plecoptera, Trichoptera) richness. The IDI also performed well in explaining EPT richness in the basin that presented the stronger disturbance gradient (R2=0.39, p<0.001). Natural habitat variability was assessed as a second source of variation in EPT richness. Stream size and microhabitats were the key habitat characteristics not related to disturbances that enhanced the explanation of EPT richness over that attributed to the IDI. In both basins the IDI plus habitat metrics together explained around 50% of EPT richness variation. In the basin with the weaker disturbance gradient, natural habitat explained more variation in EPT richness than did the IDI, a result that has implications for biomonitoring studies. We conclude that quantitatively defined disturbance gradients offer a reliable and comprehensive characterization of anthropogenic pressure that integrates data from different spatial scales.

Analyzing the ecological footprint at the institutional scale – The case of an Israeli high-school

One way in which institutions can implement the idea of sustainability is through the use of ecological indicators that will characterize the current situation and help determine where to focus efforts in order to achieve the goal of sustainability. The use of the ‘Ecological Footprint Analysis’ (EFA) represents an innovative attitude to calculate the load that an institution imposes on the natural environment. The goal of this study is to illustrate the benefits of using EFA at the institution scale. Our case study is the ecological footprint of one high school in the city of Haifa, Israel. We present a unique method integrating between institutional and individuals’ sourced data concerning consumption patterns at the institutional level. We then present the breakdown of the school footprint into four main components: electricity, transportation, food and materials. The results of our research reveal an overall footprint of 314 global hectares (gha), from which food and electric power are the main components followed by materials and transportation. Based on the results, we developed scenarios for potential future reduction of the high school ecological footprint.

Use of ecological indicators to assess the quality of Great Lakes coastal wetlands

Over 2000 coastal wetland complexes have been identified in the Laurentian Great Lakes watershed, each providing critical habitat for numerous aquatic and terrestrial species. Research has shown there is a direct link between anthropogenic activities (urbanization and agricultural development) and deterioration in wetland health in terms of water quality and biotic integrity. In this study, we evaluate coastal marshes throughout the Great Lakes basin using a suite of published ecological indices developed specifically for coastal wetlands of the Great Lakes (Water Quality Index (WQI), Wetland Macrophyte Index (WMI), and the Wetland Fish Index (WFI Basin)). We surveyed 181 wetlands, including 19 in Lake Superior (11%), 11 in Lake Michigan (6%), 13 in Lake Huron (7%), 92 in Georgian Bay and the North Channel (51%), 18 in Lake Erie (10%), and 28 in Lake Ontario (15%), over a 13 year period (1995–2008). Water quality parameters were measured at every site, while paired fyke nets were used to assess the fish community (132 sites) and macrophytes were surveyed and identified to species (174 sites); all of this information was used to calculate the associated index scores. One-way ANOVA results showed that there were significant differences in wetland quality among lakes. According to the WQI, we found that over 50% of marshes in Lakes Michigan, Erie, and Ontario were in degraded condition, while over 70% of marshes in Lakes Superior, Huron, and Georgian Bay were minimally impacted. Georgian Bay had the highest proportion of wetlands in very good and excellent condition and least number of wetlands in a degraded state. The WMI and WFI showed similar results. This is the largest bi-national database of coastal wetlands and the first study to provide a snapshot of the quality of coastal habitats within the Great Lakes basin. We recommend this information be used to guide conservation and restoration efforts within the Laurentian Great Lakes.

From fronds to fish: the use of indicators for ecological monitoring in marine benthic ecosystems, with case studies from temperate Western Australia

Ecological indicators are used for monitoring in marine habitats the world over. With the advent of Ecosystem Based Fisheries Management (EBFM), the need for cost effective indicators of environmental impacts and ecosystem condition has intensified. Here, we review the development, utilisation and analysis of indicators for monitoring in marine benthic habitats, and outline important advances made in recent years. We use the unique, speciose benthic system of Western Australia (WA) as a detailed case study, as the development of indicators for EBFM in this region is presently ongoing, and major environmental drivers (e.g. climate change) and fishing practices are currently influencing WA marine systems. As such, the work is biased towards, but not restricted to, indicators that may be important tools for EBFM, such as biodiversity surrogates and indicators of fishing pressure. The review aimed to: (1) provide a concise, up-to-date account of the use of ecological indicators in marine systems; (2) discuss the current, and potential, applications of indicators for ecological monitoring in WA; and (3) highlight priority areas for research and pressing knowledge gaps. We examined indicators derived from benthic primary producers, benthic invertebrates and fish to achieve these goals.

How ecological indicators construction reveals social changes—The case of lakes and rivers in France

Social and scientific factors are deeply enmeshed in each other within the development and the use of ecological indicators (EI). Yet low research has assessed which factors contribute to selecting ecological indicators on the long-term. This article proposes to study the historical construction of EI by examining ecological, political, and social background of specific places where EI were developed, in France on lakes and rivers. Our major findings in France were that ecological indicators were never optimised for the present market or political arena. Instead EI development was typically recycling previous tools that were elaborated for other purposes by environmentally committed outsiders, without regular funding. We found that regular funding for monitoring an EI was only provided when it matched an institution's goal. Beyond the geographically limited relevance of the case studies, these results therefore improve the theoretical framework we deploy when constructing or relying on indicators.

Selecting terrestrial arthropods as indicators of small-scale disturbance: A first approach in the Brazilian Atlantic Forest

The growing pressure placed by human development on natural resources creates a need for quick and precise answers about the state of conservation of different areas. Thus, identifying and making use of ecological indicators becomes an essential task in the conservation of tropical systems. Here we assess the effects of small-scale disturbance on terrestrial arthropods and select groups that could be used as ecological indicators in the Brazilian Atlantic Forest. Arthropods were sampled within a continuous forest in the Serra do Mar State Park, southeastern Brazil, both in disturbed and undisturbed areas of the reserve. The abundance of exotic species was higher in the disturbed site, and this pattern seems to be an adequate indicator of anthropogenic disturbance. Species richness of Araneae, Carabidae, Scarabaeidae, Staphylinidae, and epigaeic Coleoptera (pooled) was higher in the undisturbed site, while that of fruit-feeding butterflies was higher in the disturbed site. Species richness was not significantly correlated between any pair of taxa. In contrast, species composition was significantly correlated among most groups, and clearly discriminates the disturbed from the undisturbed site. Moreover, fruit-feeding butterflies and epigaeic Coleoptera composition discriminated disturbed and undisturbed sites even when species were grouped into higher taxonomic levels, which may be a way of overcoming the difficulty of identifying arthropod species from poorly studied, species-rich ecosystems. Potential applications for these indicators include the choice and evaluation of sites for the establishment of natural reserves, elaboration of management plans, and the assessment of ecological impacts due to human activities, either for the purposes of licensing or legal compensation.

Comparison of biotic indices for water quality diagnosis in the Duero Basin (Spain)

Several methods for water quality assessment have been proposed for European rivers. The EU Water Framework Directive requires the use of ecological indicators for stream monitoring networks and has encouraged research on biological indices. However, there is a lack of integrative studies comparing the efficiency of such methods in the determination of the ecological status in rivers. The present work, carried out in the Spanish side of the Duero Basin, the largest in the Iberian Peninsula, aimed at comparing different water quality indices. The survey was conducted during autumn 2003 and summer 2004 in 95 sites covering the entire basin. Epilithic diatoms and benthic macroinvertebrates were sampled and analysed following standard methods for the calculation of the macroinvertebrate index IBMWP and 18 different diatom indices. Additionally, water physical and chemical variables were measured and Habitat (IHF) and Riparian (RQI) indices were determined in situ. In general, both diatom and macroinvertebrate indices were strongly correlated with each other and with abiotic factors. The highest correlation coefficients between water physical and chemical data (especially with the concentrations of phosphates and N-derived compounds) were obtained for the diatom index SPI and the IBMWP, though no biotic method detected changes in the concentrations of toxicants (Zn 2+ , Cr III). The use of diversity metrics as monitoring indices is not recommended. The results indicated that several different biotic indices, based on a wide range of biotic communities, must be integrated in water quality surveillance protocols, in order to reflect complementary aspects of the ecological status in river ecosystems.