European Union Habitats Directive Research Articles

Hydrological science and wetland restoration: some case studies from Europe

Abstract. Throughout the world, wetlands are increasingly being recognised as important elements of the landscape because of their high biodiversity and goods and services they provide to mankind. After many decades of wetland destruction and conversion, large areas of wetlands are now protected under the International Convention on Wetlands (Ramsar) and regional or national legislation such as the European Union Habitats Directive. In many cases, there is a need to restore the ecological character of the wetland through appropriate water management. This paper provides examples of scientific knowledge of wetland hydrology that can guide such restoration. It focuses on the need for sound hydrological science on a range of issues including water level control, topography, flood storage, wetland connections with rivers and sustainability of water supply under climate change.

Mapping a specific class for priority habitats monitoring from satellite sensor data

The European Union's Habitats Directive aims to protect biodiversity through the conservation of habitats. If a habitat of interest corresponds to spectrally separable land cover class(es), then this activity can benefit from the production of accurate land cover maps from remotely sensed imagery. Traditionally, the image classification techniques used assume that the set of classes has been defined exhaustively, which requires all of the classes in the region to be included explicitly in the analysis. Often, however, interest focuses on just one or a small sub‐set of the classes occurring in the region that represent the habitat(s) of particular interest. Moreover, given that the size of a training set required for an image classification is typically taken to be a function of the number of classes and discriminating variables (e.g. wavebands) used in the classification, the satisfaction of the assumption of an exhaustively defined set of classes requires that much effort is directed wastefully on classes of little, if any, direct interest. Savings in training could be achieved by focusing on the class(es) of specific interest. A more appropriate approach for mapping a specific class may be to adopt a binary classification analysis that simply seeks to separate the class of interest from all others. In this way the analysis focuses on the class(es) of interest and a small training set may be used. An attractive means to achieve this is through the adoption of decision tree‐ and support vector machine‐based approaches to classification. This paper evaluates the accuracy with which a habitat of interest to the EU Habitats Directive, fen, can be mapped from Landsat ETM+ imagery of the Norfolk Broads using such classifiers as well as, for comparative purposes, a standard maximum likelihood decision rule implemented by a discriminant analysis. All analyses yielded accurate classifications, with a conventional approach based on a maximum likelihood allocation providing an overall classification accuracy of 88.4%. However, both the decision tree‐ and support vector machine‐based approaches provided classifications that were significantly more accurate than conventional maximum likelihood classification (p<0.05), with overall accuracies of 91.6 and 93.6%, respectively (table 3). The results highlight the ability to focus the analysis on the class of interest in a manner that is less wasteful of resources and effort and that yields a more accurate classification than the standard approach.

Assessing the environmental status of Mediterranean temporary ponds in Greece

Mediterranean temporary ponds (MTPs) are highly distinctive habitats with intermittent and unstable environmental conditions, inhabited by several rare and endemic plant and animal species. Temporary pond ecosystems have been classified as endangered all over the world; nevertheless, they are disappearing at a high rate, especially in the Mediterranean region. MTPs are a priority habitat under the European Union Habitats Directive and thus appropriate management and conservation efforts should be applied. Further research is needed in order to better understand the environmental characteristics and ecology of this habitat which is not always the case in many countries. In this study a range of environmental data were collected from the Greek MTP habitat sites including the altitude, the geology, the representativity, the ecological status and other biological data aiming to assess the environmental status of all known Greek MTPs. Statistical analysis were performed and thematic maps were created using a Geographical Information System (GIS). Greek MTP’s were classified according to their characteristics and habitat pressures were identified and further analysed. A comparison between the present environmental status of the MTPs in Greece with the MTPs in other Mediterranean countries was undertaken and relevant conservation and management measures were proposed. The outcome of this study was that a significant percentage of the MTP habitat sites in Greece are at risk mainly due to human activities, such as agricultural pollution, expansion of cropland and water resources over-exploitation. It was concluded that immediate restoration and conservation actions should be taken so as to prevent further ecological degradation.

Fish utilisation of managed realignments

Abstract One area of ecological benefit not yet fully evaluated in European waters is the utilisation of restored saltmarsh habitats by fish species. This study examines the utilisation of managed realignments and relic saltmarsh by fish species. Factors affecting habitat heterogeneity and fish populations are discussed, and recommendations are made with respect to scheme design and management that will maximise the biological and socio‐economic values. Fish populations in the high intertidal areas were assessed using a suite of techniques, including observations on feeding behaviour. Each microhabitat was discussed as a function of the extent of fish colonisation. A positive relationship between the degree of fish utilisation and habitat heterogeneity was ascertained using species richness, abundance and behavioural observations. This study will aid habitat valuation for economic justification of managed realignments, over and above existing drivers, such as compensatory habitat for encroachment, flood defence and the European Union Habitats Directive. The work now forms part of a wider European Interreg IIIb project, COMCOAST.

Development of Wildlife Conservation Policy and Legislation in Ireland

Development of Wildlife Conservation Policy and Legislation in Ireland

Development of Wildlife Conservation Policy and Legislation in Ireland

The mechanisms and procedures involved in the formulation of wildlife conservation policy are discussed with particular reference to the Wildlife (Amendment) Act 2000, the European Union (EU) Habitats Directive (Directive 92/43/EEC) and the National Biodiversity Plan (2002).

Ecology, management and monitoring of grey dunes in Flanders

Grey dunes are a priority habitat type of the European Union Habitats Directive and demand special attention for conservation and management. Knowledge of the ecology of coastal grey dunes can contribute to this policy. Dune grassland succession is initiated by fixation and driven by the complex of soil formation (humus accumulation) and vegetation development. Leaching and mobilization of CaCO3. which are important in nutrient dynamics, complicate the picture. At present, grass- and scrub encroachment greatly overrules these fine scaled soil processes and causes substantial loss of regional biodiversity. Belgium has an international responsibility in grey dune conservation because of the limited range of its characteristic vegetation, flora and fauna. As biomass removal seems essential in grassland preservation, grazing is an important management tool. Evaluation of management measures focuses on biodiversity measurements on the levels of landscape, community and species.

The use of &lt;i&gt;Ranunculus Repens&lt;/i&gt; as an Indicator Species for Assessing the Extent of flooding in Turlough Basins

Turloughs are temporary water bodies that are common in the karstic areas of south Galway and the east Burren complex and are listed as priority habitats in Annex 2 of the 1992 European Union Habitats Directive. The main threat to the conservation of the turlough habitat is damage by artificial drainage. The extensive flooding of rural communities by turloughs in 1994 resulted in public demands to reduce any future threat of flooding. Flood alleviation measures that involved the removal of surplus groundwater would potentially damage vegetation communities that occur around the upper fringes of turlough basins. Due to annual fluctuations in the extent of flooding of turlough basins, it has proved difficult to determine where the turlough vegetation communities effectively stop and where the terrestrial vegetation communities begin. We investigated a transect of the Hawkhill turlough, running from a higher area subject to occasional flooding through to an area 4m above the basin floor that receives several months of flooding each year. The vegetation cover was recorded in lm x Im quadrats at intervals along this transect using the Domin scale. Distinctive zones of species were present, with an emergent aquatic community occupying the deepest zone, ephemerals occurring in the open mud community above the aquatic zone, a damp grassland community occurring at 2m from the bottom of the transect and a drier grassland community occupying the upper elevations 4-7m from the base. Ranunculus repens is one species that traverses the boundary between drier and seasonally flooded grassland; its leaf dissection, calculated as an index from digitised leaf outlines, increased with decreasing elevation. This association between leaf dissection and depth and duration of flooding could be used to identify zones within turlough basins that are governed by hydrological processes.

Cetacean distribution related with depth and slope in the Mediterranean waters off southern Spain

The northeastern section of the Alboran Sea is currently under consideration as a Special Area for Conservation under the European Union's Habitat Directive. Within this framework, the present study focuses on the distribution of cetaceans in this area and is part of the Spanish Ministry of the Environment's “Program for the Identification of Areas of Special Interest for the Conservation of Cetaceans in the Spanish Mediterranean”. Shipboard visual surveys were conducted in 1992 and from 1995 to 2001 in the north-eastern Alboran Sea, covering 14,409 km. A total of 1,134 sightings of cetaceans were made. From the data collected, the distribution of seven species of odontocete was examined with respect to two physiographic variables, water depth and slope. Analyses of χ 2 and fitting of GLMs demonstrated significant differences in distribution for all species, mainly with respect to depth. Kruskal–Wallis tests, factor analysis and discriminant function analysis showed that the species could be classified in two major groups, shallow-waters (short-beaked common dolphin and bottlenose dolphin) and deep-waters (striped dolphin, Risso's dolphin, long-finned pilot whale, sperm whale and beaked whale), respectively. Preferred habitats in terms of water depth were areas deeper than 600 m for the deep-water group, and the shallower ranges from shore to 400 m for the other. The distribution of cetaceans was further matched with that of their most common prey in order to establish which habitats could be considered important for their feeding. The resulting analysis highlighted two areas in the region as important habitats for the conservation of the most vulnerable species in the Mediterranean, the bottlenose and the common dolphin.

Osmoderma eremita as an indicator of species richness of beetles in tree hollows

The beetle Osmoderma eremita has received much attention in the last few years, as it is among those species with the highest priority in the European Union's Habitat Directive. In this paper the species is evaluated as a potential indicator and umbrella species for the endangered beetle fauna in tree hollows. To be useful as an indicator of a species-rich fauna it should be easy to inventory and be strongly correlated with the presence of other species. An umbrella species is a species which is so demanding that the protection of this species will automatically save many others. The species richness of saproxylic beetles and occupancy of O. eremita were surveyed in tree hollows in an area in southeastern Sweden by assessing the presence/absence of living and dead adults (including fragments) and larvae. The species richness was higher when O. eremita was present, both at tree and stand level. Several threatened species were associated with the presence of O. eremita, whereas others did not correlate with the occurrence of O. eremita. As O. eremita is easy to find and identify, it is useful as an indicator of stands with a rich beetle fauna in tree hollows. Osmoderma eremita can be used as an umbrella species, because if measures are taken to conserve O. eremita, many other species in the same habitat are also conserved. However, there are some beetles in tree hollows which seem to be more sensitive to habitat fragmentation than O. eremita, and may go extinct if only O. eremita is taken into consideration.

Using Landscape Characteristics for Targeting Habitat Conservation and Restoration: a case study of ancient semi-natural woodland in the Chiltern Hills Area of Outstanding Natural Beauty, UK

Ancient semi-natural deciduous woodland is a rare and threatened habitat cited by the European Union's Habitats Directive (92/43/EEC). Current protection of this endangered habitat in the UK takes the form of site-specific reserve designations but, if the habitat is to be conserved and enhanced, a landscape-scale selective targeting system is required. In the absence of suitable species data, physical attributes of habitat patches are used as surrogate indicators of biodiversity. Using a land-use database held on a geographical information system, values of four abiotic criteria (patch area, patch shape, nearest-neighbour distance and surrounding land use) of 48 ancient semi-natural woodland patches in part of the Chiltern Hills Area of Outstanding Natural Beauty were calculated. In order to validate the findings, three lists of floral and faunal species, indicative of ancient semi-natural woodland, were compiled, and the patches ranked according to their alpha diversity using each list. Spearman's rank correlation coefficients were calculated for patch alpha diversity and patch area (0.322 to 0.482), patch shape (0.275 to 0.465) and nearest-neighbour distance ( - 0.092 to - 0.223). Multiple regression indicated that between 15 and 22% of the variation in alpha patch diversity was explained by the abiotic factors. It is suggested that spatial targeting at the landscape scale is a valuable approach to habitat conservation.

Using Landscape Characteristics for Targeting Habitat Conservation and Restoration: A case study of ancient semi-natural woodland in the Chiltern Hills Area of Outstanding Natural Beauty, UK

Ancient semi-natural deciduous woodland is a rare and threatened habitat cited by the European Union's Habitats Directive (92/43/EEC). Current protection of this endangered habitat in the UK takes the form of site-specific reserve designations but, if the habitat is to be conserved and enhanced, a landscape-scale selective targeting system is required. In the absence of suitable species data, physical attributes of habitat patches are used as surrogate indicators of biodiversity. Using a land-use database held on a geographical information system, values of four abiotic criteria (patch area, patch shape, nearest-neighbour distance and surrounding land use) of 48 ancient semi-natural woodland patches in part of the Chiltern Hills Area of Outstanding Natural Beauty were calculated. In order to validate the findings, three lists of floral and faunal species, indicative of ancient semi-natural woodland, were compiled, and the patches ranked according to their alpha diversity using each list. Spearman's rank correlation coefficients were calculated for patch alpha diversity and patch area (0.322 to 0.482), patch shape (0.275 to 0.465) and nearest-neighbour distance ( - 0.092 to - 0.223). Multiple regression indicated that between 15 and 22% of the variation in alpha patch diversity was explained by the abiotic factors. It is suggested that spatial targeting at the landscape scale is a valuable approach to habitat conservation.

Implementing EU biodiversity policy: UK experiences

This paper offers a critical review of the European Union Habitats Directive, which requires Member States to designate and protect a network of habitats of European importance. In the UK, several problems linked to implementation have already appeared at the local level. These are illustrated through two case studies where an often restrictive and static interpretation of the legal requirements of the Directive has led to management conflicts. It is suggested that the use of participatory approaches and instruments adapted to no-net-loss policies such as mitigation banking, while not entirely unproblematic, could ease some of the practical problems of implementing the Directive.

The Relative Lengths of Seashore Substrata Around the Coastline of Ireland as Determined by Digital Methods in a Geographical Information System

Coastal zone management requires standardized and quantitative information on the distribution of natural habitats. For example, the European Union Habitats Directive requires member states to protect habitats in relation to their proportion within that state's territory. Basic information on sea-bed types is available on marine charts. However, gaining an overview of, or analysing patterns within it, is difficult because of the many charts at different scales and projections. In this paper a methodology is described using a geographical information system (GIS), by which the high tide mark of Ireland was labelled with the dominant sea-bed types. The counties with the longest coastlines are Cork, Mayo, Donegal, Galway, Kerry and Clare. They have the most mud, sand, gravel, rocks, cliff and marsh respectively. The 7524km coastline is 41% rock, 34% sand and 11% mud. How the statistics are derived can provide a basis for comparison between coastal areas at both a national (e.g. islands vs mainland, between counties) and international (e.g. comparison with coasts of France) level and be used to extrapolate the amount of natural resources and predict how much time field surveys would take, is demonstrated. This approach is applicable to any coastal area for which basic seabed information exists. It can be analysed for management and research purposes and provides a baseline on which additional datasets may be added (e.g. climate, bathymetry, tides, natural resources, conservation importance) to produce a GIS of greater value than the sum of its parts.

Threatened vascular flora of Sierra Nevada (Southern Spain)

An analysis is made of the floristic richness of the Sierra Nevada (southern Spain), where more than 2100 vascular plants were catalogued, thus making it the area with the richest and most varied flora in the western Mediterranean region, including a considerable number of endemic species. In a study of the endangered flora and its protection, 116 taxa are listed as having the most restricted distribution and as being under threat of extinction. Field work for these taxa was undertaken in order to improve knowledge of their habitats, populations, chorology and main threats. Using the new IUCN categories of threat, an analysis was made for each of the taxa, especially those that are critically endangered with a very low number of individuals or very narrow areas of occupancy. Mention is made of the problems posed by the practical application of the new IUCN categories. The main types of environmental impact affecting the flora are also described, including grazing, natural causes, wetland desiccation and water pollution. The highest-lying areas (oro- and cryoro-Mediterranean belts) are where most of the threatened plants are to be found. Since these same plants are mostly endemic to the Sierra Nevada, the need to protect the high peaks of the area is paramount. Reference is made to current legislation protecting threatened plants and the gaps in the European Union Habitats Directive with relevance to the protection of the Sierra Nevada flora. A number of key strategies for protection are proposed.

Landscape ecology of calcareous fens (Caricion davallianae) and the Cladietum marisci in the lowlands of NE-Germany and their relevance for nature conservation in the European Union Habitats Directive

Landscape ecology of calcareous fens (Caricion davallianae) and the Cladietum marisci in the lowlands of NE-Germany and their relevance for nature conservation in the European Union Habitats Directive

Changes in dewpond numbers and amphibian diversity over 20 years on chalk downland in Sussex, England

The fate of dewponds, the only substantive wetland habitat on the chalk Downs of southern England, was monitored over an area of 150 km2 between 1977 and 1996 together with changes in use by the five species of amphibians that inhabit them. Despite a proactive pond restoration programme there was an overall net loss of seven pools (21% of the initial number of 33) by 1996, although a higher proportion and absolute number of surviving ponds were in good condition in 1996 (58%, 15 ponds) compared with 1977 (24%, eight ponds). Anurans (common frogs Rana temporaria and toads Bufo bufo) were more widespread on the Downs in 1996 compared with 1977, probably because they colonised new ponds effectively, whereas urodeles (smooth newts Triturus vulgaris, palmate newts T. helveticus and crested newts T. cristatus) all declined over the same period. T. cristatus, a species ceded maximum protection under the European Union Habitats Directive, occurred in nine sites in 1977 but in just three by 1996. Total destruction of ponds was the most common cause of crested newt extinction, but at two sites the species disappeared following the establishment of fish populations. Various indices of amphibian diversity in dewponds are also compared.

Imminent extinction of the Nore freshwater pearl mussel Margaritifera durrovensis Phillips: A species unique to Ireland

AbstractThe last population of the Nore freshwater pearl mussel Margaritifera durrovensis was surveyed each year from 1990 to 1994 in the River Nore, southern Ireland.The population has fallen from a ‘flourishing colony’ in the 1920s to an estimated 2000 in 1990 and 420 in 1994. No juvenile mussels were observed in any of the surveys.If life history data for Margaritifera margaritifera are applicable to M. durrovensis, the population would need to be 20 times greater for successful recruitment.Although given special mention in the Bern Convention, M. durrovensis was omitted from the European Union Habitats Directive, perhaps due to uncertainty regarding its taxonomic status as it shares characteristics with both M. margaritifera and M. auricularia.Immediate measures are required to prevent the extinction of M. durrovensis including, (a) a captive breeding programme, (b) habitat restoration, and (c) formal recognition of its priority status within the Habitats Directive.