A review of dystrophic lake and pool habitat in Europe: An Irish perspective

Freshwater lakes and pools contained within peatlands are unique habitats that support rare and specialised species. Despite this, these ecosystems have been overlooked in conservation and management practices. One of these habitats, ‘3160 Natural dystrophic lakes and ponds’, is protected under the European Union (EU) Habitats Directive with a concerning proportion of these habitats having an “unfavourable-bad” or an “unfavourable-inadequate” conservation status across Europe. Our current understanding of the key physico-chemical and ecological features of this habitat is inadequate which is hindering the implementation of effective conservation measures. This review summarises the current knowledge of this protected lake habitat as defined under the EU Habitats Directive. With a focus on Ireland, we demonstrate how the current monitoring and assessment methods used to characterise and assess the structure and function and conservation status of this habitat, which relies largely on the use of macrophyte community composition and surrogate physico-chemical data collected under the EU Water Framework Directive, is ineffective. We propose the incorporation of further or alternative ecological metrics including, but not limited to, algae and macroinvertebrates which are needed to improve our understanding of the structure and function of this priority lake habitat. In addition, application of such data via ecological metrics would allow for the quantification of biodiversity and species rarity metrics which would aid in identifying sites of conservation importance.     

Vegetation influence on ectomycorrhizal inoculum Available to sub-arctic willow (Salix lapponum L.) planted in an upland Site

Summary

Restoration of scrub and woodland in deforested upland sites is an important conservation activity. However, little is known about the mycorrhizal colonisation potential of upland soils or the factors that influence the distribution of mycorrhizal inoculum. We investigated the effect of existing vegetation on mycorrhizal colonisation potential for a sub-arctic willow (Salix lapponum) by planting uninoculated cuttings into plotsrepresenting two upland habitats with either grassand herbs (‘grass’) or Vaccinium myrtillus (‘vaccinium’) and assessing mycorrhizal colonisation after 14 months using morphological and molecular techniques. From 40 willow cuttings (20 in each habitat), DNA sequences of rive ectomycorrhizal (EcM) fungal taxa were recovered: Laccaria proxima, Thelephora terrestris, Hebeloma sp., ‘Thelephoraceae sp.’ and ‘Pezizales sp.’. Cuttings in the ‘grass’ habitat were dominated by Laccaria proxima and ‘Pezizales sp.’ and in the ‘vaccinium’ habitat by Thelephora terrestris which was absent from the ‘grass’ habitat. There were no significant differences between habitats in frequency of EcM inoculum (overall percentage of cuttings colonised = 70%) or colonisation potential (overall mean percentage of root tips colonised per cutting = 20 %). These data suggest that the mycorrhizal colonisation potential and diversity of fungi available to willow in these upland soils are low and planted willow may benefit from inoculum enhancement.     

Implications of the spatial variability of macroinvertebrate communities for monitoring of ephemeral lakes. An example from turloughs

Turloughs, ephemeral water bodies associated with karstified limestone, are an important habitat found in the West of Ireland. They are a priority habitat under the European Habitats Directive (92/43/EEC) and are groundwater-dependent habitats under the European Water Framework Directive (2000/60/EC; WFD). Sampling to meet the objectives of either Directive requires discrimination of inherent natural variation from anthropogenically induced disturbances and accounting for both spatial and seasonal patterns of biotic distribution. This study reports within- (submerged grassland) and between-habitat (submerged and emergent grassland) variability of macroinvertebrate communities in six turloughs. Two different habitat types were sampled from two turloughs in April 2007, and further assessment of spatial pattern in commonly found submerged grassland habitat was determined from four additional turloughs in spring 2008. While cluster analysis and non-metric multidimensional scaling identified differences in macroinvertebrate community structures between habitats in one out of two turloughs, congruence of invertebrate communities was, nevertheless, greater within than among turloughs. Within-habitat variability of macroinvertebrate communities across sampling locations of submerged grassland habitat was sufficiently low so that samples collected at any location of a turlough can provide a reliable metric of the macroinvertebrate community of a turlough as a whole. A standardized submerged grassland sampling approach for routine turlough sampling is recommended as a pressure response method to fulfil the requirements of the WFD. For a comprehensive conservation assessment, however, as demanded under the EC Habitats Directive, we suggest a multi-habitat sampling approach to obtain a thorough assessment of turlough macroinvertebrate biodiversity.     

Environmental diagnosis: Integrating biodiversity conservation in management of Natura 2000 forest spaces

The conservation of biodiversity in Europe is defined by Directive 92/43/EEC – commonly known as the Habitats Directive – relating to the conservation of natural habitats and of wild flora and fauna. This Directive established the creation of an ecological network of European protected areas – the Natura 2000 network – , and also recognised the need to manage these areas to maintain their “favourable conservation status”.This paper proposes a methodology which enables the conservation of biodiversity to be integrated into the management of Natura 2000 forest spaces. The methodology comprises an “environmental diagnosis” in three phases. The first phase evaluates the current conservation status of habitats using the following criteria: vital functions; floristic richness; forest structure; area occupied by the habitat; and recovery capacity. The second phase assesses the fragility of the space to determine the degree of vulnerability of habitats. This involves evaluating the fire hazard, erosion hazard, and the fragility of the vegetation. The last phase combines the two previous ones to generate management areas (optimum, intermediate or unfavourable) and to prioritise management actions.This methodology was applied in a protected forest area in the Natura 2000 network, located in Avila (Spain). Different management areas were generated for biodiversity conservation, and each habitat was associated to one of them. Finally, actions were prioritised and designed to raise the habitats to a “favourable conservation status”.     

Pattern in the distribution of Britain's upland breeding birds

We use a quantitative approach to identify fifty-eight species of birds which breed in association with the British uplands. Similarities and differences between this list of 'upland birds' and previous more subjective lists are discussed. We then study pattern in the distribution of these species throughout the uplands. A high degree of regionalization is found, and interpreted in terms of the habitat composition of different regions, and known bird–habitat associations. Different regions differ widely, not only with respect to their bird species composition, but also in the number and conservation importance of their upland bird assemblages. In particular, we contrast the uplands of Wales and England with those of Scotland. The Welsh and English uplands contain a relatively low number of upland bird assemblages and are divided into a few large regions, each dominated by a single assemblage type. In comparison, the Scottish uplands are more varied, both in terms of the total number of assemblages, and the range of assemblages found at a small scale. The study provides a means of viewing any upland region within the national context.     

National and European perspectives on climate change sensitivity of the habitats directive characteristic plant species

The main goal of the Habitats Directive, a key document for European conservation, is to maintain a ‘favourable’ conservation status of selected species and habitats. In the face of near-future climatic change this goal may become difficult to achieve. Here, we evaluate the sensitivity to climate change of 84 plant species that characterise the Danish habitat types included in the Habitats Directive. A fuzzy bioclimatic envelope model, linking European and Northwest African species’ distribution data with climate, was used to predict climatically suitable areas for these species in year 2100 under two-climate change scenarios. Climate sensitivity was evaluated at both Danish and European scales to provide an explicit European perspective on the impacts predicted for Denmark. In all 69–99% of the species were predicted to become negatively affected by climate change at either scale. Application of international Red List criteria showed that 43–55% and 17–69% would become vulnerable in Denmark and Europe, respectively. Northwest African atlas data were used to improve the ecological accuracy of the future predictions. For comparison, using only European data added 0–7% to these numbers. No species were predicted to become extinct in Europe, but 4–7% could be lost from Denmark. Some species were predicted to become positively affected in Denmark, but negatively affected in Europe. In addition to nationally endangered species, this group would be an important focus for a Danish conservation strategy. A geographically differentiated Danish conservation strategy is suggested as the eastern part of Denmark was predicted to be more negatively affected than the western part. No differences in the sensitivity of the Habitats Directive habitats were found. We conclude that the conservation strategy of the Habitats Directive needs to integrate the expected shifts in species’ distributions due to climate change.     

Conservation priority of Italian Alpine habitats: a floristic approach based on potential distribution of vascular plant species

In the European Union, the Directive 92/43/EEC defines a number of species and habitats of community interest that are worthy to be preserved because in danger to disappear or because they are representative of the different European bio-geographical regions. In the light of the limited economic resources generally allocated to conservation efforts, there is the necessity to prioritise conservation actions in order to avoid deterioration of protected areas. To this aim, in the present study the most representative habitats of the Italian Alps are compared on the basis of vascular plant biodiversity and a conservation priority index is proposed for each habitat taking into account the potential distribution of 252 threatened vascular plant species. Rocky slopes, screes and alpine grasslands resulted to have the greatest percentage of endemic plant species so reflecting the general distributional pattern of endemic plant species at high altitudes in Eurasian mountains. The relationship between the conservation priority index and the corresponding habitat extent within the Natura 2000 network suggests that peatlands, arid grasslands, wet meadows and freshwater habitats deserve a higher priority in conservation actions. Although vascular plant biodiversity is not necessarily a surrogate of overall biodiversity of Alpine habitats, the results here reported can be used as an initial reference framework for prioritising conservation actions, so as to accomplish the provisions of Article 6 of Habitats Directive.     

Climate change and pollutant impacts on Scottish vegetation

Summary

By the 2050s the UK is projected to be about 1.6°C warmer, when the atmospheric CO₂ concentration will be 525 ppmv. These changes will have profound effects on the Scottish flora and fauna. Vegetation primary productivity will increase, except in dry regions, and the productivity of upland forest plantations may increase by several Yield Classes. The spread of plant species may be less than expected, but a number of slow-growing ‘stress-tolerant’ species, including montane/alpine species, are likely to be lost. Nitrogen deposited as a result of emission of NO_X from vehicles and NH₃ from agriculture is now a major source of acidity, and problems of acidification and eutrophication are linked. Despite reductions in sulphur emissions, critical loads of acid deposition are likely to be exceeded for soils in most of the Scottish uplands until at least 2005. Critical levels affecting tree growth may be exceeded where forests are in cloud for 10% of the time in areas of the Great Glen. Much of the Scottish uplands receives 25–30 kg N ha^-1 yr^-1, which may be causing change in species composition. Background tropospheric ozone concentrations are increasing. Much of the Scottish uplands experiences mean summer ozone concentrations exceeding those in southern England, but with fewer exceedances of critical levels. However, many crops and some sensitive native species are probably being adversely affected.     

What are palm groves of <Emphasis Type="Italic">Phoenix</Emphasis>? Conservation of <Emphasis Type="Italic">Phoenix</Emphasis> palm groves in the European Union

There are three species of Phoenix (Arecaceae) in the territory of the European Union, P. canariensis, P. dactylifera and P. theophrasti, found in wild-native populations, feral, planted and intermediate states, accounting each for thousands of individuals. The EU Habitats Directive has addressed the conservation of P. theophrasti and P. canariensis under the habitat type 9370, ‘Palm groves of Phoenix,’ but neglected to include the wild-growing populations of P. dactylifera palms in southern Spain. In this paper, we survey the habitats and status of both representative native and naturalized populations of Phoenix, in total 103, through fieldwork, image analysis and review of literature. We underline the significance of feral populations and palms originating from ancient abandoned plantations, existing in protected areas as a reservoir of genetic variation. We conclude that, in order to improve their conservation status by adequate protection and conservation management, the concept of Phoenix palm groves in the Habitats Directive should be redefined to include the western group of P. dactylifera and the various habitats of P. canariensis and P. theophrasti that do not appear in the current definition.     

Natura 2000 habitats in Tuscany (central Italy): synthesis of main conservation features based on a comprehensive database

We analyse and report a synthesis of a long-term project leading to the creation of a database of habitats of conservation interest in Tuscany (Italy). All available floristic and vegetation literature from 1960 to date and relating to the Tuscan territory, and all terrestrial and inland water (non-marine) Habitats of European Community Interest as listed in Annex I of the EU Habitats Directive present in Tuscany have been identified and taken into account. A total of 2,691 sites were attributed to 82 different conservation interest habitat types and were geo-localised and uploaded to the database. For each habitat site, threat and pressure factors are indicated and a quick expert-based assessment made on the basis of three parameters: rarity, vulnerability and a quality estimate. For the analysis, all database information was referred to a vectorial 10 × 10 km grid. The territorial distribution of habitats is discussed with respect to: the level of information available, the numbers of reports and the habitat-type concentration. The major threats and pressures affecting these Tuscan habitats are highlighted and discussed. Vegetation dynamics proved to be the most important natural/seminatural threat. Another important threat is invasion by/competition with other organisms, mainly invasive alien species. Among anthropic threats, the management of riparian and aquatic vegetation together with water management all strongly affect many habitat types with links to wetlands. Infrastructures, particularly those connected with tourism and recreation, are an important threat factor especially in coastal areas. Some positive effects of certain anthropic pressures are also illustrated. Lastly, some actions to improve habitat knowledge, evaluation and conservation are suggested.     

Quantifying the climate exposure of priority habitat constrained to specific environmental conditions: Boreal aapa mires

Climate velocity is an increasingly used metric to detect habitats, locations and regions which are exposed to high rates of climate change and displacement. In general, velocities are measured based on the assumption that future climatically similar locations can occur anywhere in the study landscape. However, this assumption can provide a biased basis for habitats which are constrained to specific environmental conditions. For such habitats, a set of selected suitable locations may provide ecologically more realistic velocity measures. Here, we focus on one environmentally constrained habitat, aapa mires, which are peat-accumulating EU Habitats Directive priority habitats, whose ecological conditions and biodiversity values may be jeopardised by climate change. We assess the climate exposure of aapa mires in Finland by developing velocity metrics separately for the whole ≥10 ha aapa mire complexes (‘aapa mires’) and their wettest flark-dominated parts (‘flark fens’). Velocity metrics were developed for six bioclimatic variables (growing degree days (GDD5), mean January and July temperatures, annual precipitation, and May and July water balance, based on climate data for 1981–2010 and for 2040–2069 as derived from global climate models for two Representative Concentration Pathways (RCP4.5 and RCP8.5). For the six variables, velocities were calculated based on the distance between climatically similar present-day and nearest future mire, divided by the number of years between the two periods, and by excluding the unsuitable matrix. Both aapa mires and flark fens showed high exposure (>5 km/year) to changes in January temperature, and often also considerably high velocities for GDD5 and July temperatures. The flark fens showed significantly higher climate velocities than the aapa mires and had a smaller amount of corresponding habitat in their surroundings. Thus, many of the studied mires, particularly the flark fens, are likely to face increased risks of exposure due to changes in winter and summer temperatures. Moreover, considerable changes in precipitation-related conditions may occur at the southern margin of the aapa mire zone. Our results show that specifically tailored climate velocity metrics can provide a useful quantitative tool to inform conservation and management decisions to support the ecosystem sustainability of this EU Habitats Directive biotope and targeting restoration towards the most vulnerable aapa mires.     

Identifying important bird habitats in a sub-arctic area undergoing rapid land-use change

Capsule Habitats in lowland South Iceland sustain bird populations of international importance, with highest densities in wet habitats.

Aims In areas important for biodiversity there is an urgent need to assess large-scale variation in the biodiversity value of habitats to inform management. We carried out a large-scale survey to assess the conservation value of sub-arctic, Icelandic bird habitats.

Methods Bird counts were carried out on 200 transects in the five most common vegetated habitat types in South Iceland. Based on these counts, breeding bird density and diversity were compared between habitats and total population sizes of common species in these habitats were calculated.

Results Overall, eight species (seven waders and Meadow Pipit) composed over 95% of all birds counted. The combined density of those species exceeded 275 birds/km² in all habitats. The two wettest habitat types had the highest density of birds.

Conclusion Wet habitats in lowland South Iceland held particularly high densities of breeding birds, notably waders, which constitute populations of international importance. Wet habitat types are generally of higher value for more species, than dryer ones.     

Conserving Scotland's raised bogs

Summary

Raised bog was always a relatively rare habitat in Scotland and, being mainly found in lowland areas, the habitat has had a long history of land-use and exploitation associated with it. Today, raised bogs are considered as one of Britain's rarest and most endangered habitats. As a consequence the Scottish Wildlife Trust ran a conservation programme (the Scottish Raised Bog Conservation Project) between 1993 and 1995 to set up a strategy which could conserve the remaining bogs. A major landcover survey executed under the auspices of the project revealed widespread damage although 9% of the resource remained in a ‘near-natural’ state. However, the continuing cumulative effects of centuries of small scale activities and the effects of past and present air-pollution places all sites under considerable threat. One way to counter such threats is to enact positive conservation management on sites. To date, most work has concerned vegetation and hydrological management on the mire surface. Initial analyses of monitoring programmes suggest this type of conservation management is having little impact across the whole site. It is suggested that more comprehensive programmes of management should now be undertaken to restore the hydrological system of the whole site including the surrounding lagg fens.     

Developing a classifier for the Habitats Directive grassland types in Denmark using species lists for prediction

Abstract. This paper describes the use of supervised methods for the classification of vegetation. The difference between supervised classification and clustering is outlined, with reference to their current use in vegetation science. In the paper we describe the classification of Danish grasslands according to the Habitats Directive of the European Union, and demonstrate how a supervised classification can be used to achieve a standardized and statistical interpretation within a local flora. We thereby offer a statistical solution to the legal problem of protection of certain selected habitat types. The Habitats Directive protects three types of Danish grassland habitats, whereas two remaining types fall outside protection. A classification model is developed, using available Danish grassland data, for the discrimination of these five types based on their species composition. This new Habitats Directive classification is compared to a previously published unsupervised classification of Danish grassland vegetation. An indicator species analysis is used to find significant indicator species for the three protected habitat types in Denmark, and these are compared to the characteristic species mentioned in the interpretation manual of the Habitats Directive. Eventually, we discuss the pros and cons of supervised and unsupervised classification and conclude that supervised methods deserve more attention in vegetation science.     

The Seascape of Demersal Fish Nursery Areas in the North Mediterranean Sea,a First Step Towards the Implementation of Spatial Planning for Trawl Fisheries

The identification of nursery grounds and other essential fish habitats of exploited stocks is a key requirement for the development of spatial conservation planning aimed at reducing the adverse impact of fishing on the exploited populations and ecosystems. The reduction in juvenile mortality is particularly relevant in the Mediterranean and is considered as one of the main prerequisites for the future sustainability of trawl fisheries. The distribution of nursery areas of 11 important commercial species of demersal fish and shellfish was analysed in the European Union Mediterranean waters using time series of bottom trawl survey data with the aim of identifying the most persistent recruitment areas. A high interspecific spatial overlap between nursery areas was mainly found along the shelf break of many different sectors of the Northern Mediterranean indicating a high potential for the implementation of conservation measures. Overlap of the nursery grounds with existing spatial fisheries management measures and trawl fisheries restricted areas was also investigated. Spatial analyses revealed considerable variation depending on species and associated habitat/depth preferences with increased protection seen in coastal nurseries and minimal protection seen for deeper nurseries (e.g. Parapenaeus longirostris 6%). This is partly attributed to existing environmental policy instruments (e.g. Habitats Directive and Mediterranean Regulation EC 1967/2006) aiming at minimising impacts on coastal priority habitats such as seagrass, coralligenous and maerl beds. The new knowledge on the distribution and persistence of demersal nurseries provided in this study can support the application of spatial conservation measures, such as the designation of no-take Marine Protected Areas in EU Mediterranean waters and their inclusion in a conservation network. The establishment of no-take zones will be consistent with the objectives of the Common Fisheries Policy applying the ecosystem approach to fisheries management and with the requirements of the Marine Strategy Framework Directive to maintain or achieve seafloor integrity and good environmental status.     

Lichen conservation in Scotland

Summary

The significance of the Scottish lichen flora is outlined within the context of the British Isles and Europe, prompting a cautionary note on an over-reliance of assessing conservation importance using national Red Data Book categorisations. The conservation needs of lichens and their habitats, from ‘gardening’ to landscape management are discussed.     

Habitat conservation prioritization: A floristic approach applied to a Mediterranean wetland network

The importance of plant communities for conservation purposes is recognized in their inclusion in the “Habitat Directive” (92/43 EEC), that relates habitat types to plant community syntaxonomic units. However, habitat definitions in the Habitat Directive lead to several inaccuracies in local habitat characterization. Several wetland plant communities (and their corresponding habitats), rare in the Mediterranean basin, are not included in the Habitat Directive. This study proposes criteria for assessing the conservation importance of habitats. It deals with plant community types at the alliance level, as promising units for setting conservation priorities. The principle criteria considered as drivers for setting alliance conservation values are the distribution and abundance of plant species of conservation interest and their fidelity to a plant community. Multivariate methods were used, and a quantitative floristic index of alliance conservation priority was created. This procedure was applied to an important wetland in central Italy. Results emphasize: (i) high conservation values of some alliances not listed in the Habitat Directive, confirming various gaps in the current conservation law affecting Mediterranean wetlands; (ii) that habitats widely distributed in other biogeographical areas, may greatly underestimate their conservation importance in Mediterranean region; (iii) need to consider regional peculiarities when setting conservation priorities.     

Which habitats of European importance depend on agricultural practices?

The aim of this paper is to identify the habitat types listed in the Habitats Directive Annex I that require low-intensity agricultural management for their existence. We assessed the link between the Annex I habitat types and agricultural practices in order to identify habitat types that depend on the continuation of agricultural practices or whose existence is prolonged or spatially enlarged via blocking or reducing the secondary succession by agricultural activities. 63 habitat types that depend on or which can profit from agricultural activities—mainly grazing and mowing—were identified. They are classified into 2 groups: (1) habitats fully dependent on the continuation of agricultural management; (2) habitats partly dependent on the continuation of agricultural management. This paper also briefly discusses habitat types for which either doubts remain on their dependence on agricultural management, or the relation to extensive farming practices exists only in part of their area of distribution in Europe or under certain site conditions, respectively. Assessments of the conservation status of habitats of European Importance by 25 EU Member States in 2007 showed that habitats identified by us as depending on agricultural practices had a worse status than non-agricultural habitats.     

A relic wood of Juniperus turbinata Guss. (Cupressaceae) in Sicily: Structural and ecological features,conservation perspectives

Abstract

Juniperus turbinata Guss. (Cupressaceae) is a threatened tree species occurring in the Mediterranean area. It is listed as a vulnerable species in the Red Book of Italian plants and its various communities are included in Annex I of the Habitats Directive 92/43/EEC as a priority habitat for conservation. During field investigations carried out to analyse the plant biodiversity of coastal habitats in southern Sicily, a new interesting population was found. This study aims to characterize this relevant new finding with a marked focus on demography and synecology of the plant community in question in order to define its habitat, assess its conservation status and propose conservation measures. Our data highlight that the juniper is characterized by low turnover population dynamics. In order to understand the role of J. turbinata in sandy soil communities of south-eastern Sicily, comparisons of 21 plots (relevés) with 25 established plots in south-eastern Sicily were carried out using cluster analysis and canonical component analysis. This has allowed three different plant communities with different ecological features to be identified.     

Focal species diversity patterns can provide diagnostic information on plant invasions

In Europe, coastal sandy habitats are considered highly endangered among those included in the EC Directive 92/43/EEC (Habitats Directive). Among the different threats which affect coastal communities, the spread of alien plants has been claimed to induce changes in community diversity and structure. We therefore set out to analyse diversity patterns of native and focal species (diagnostic and characteristic of coastal dune habitats of European conservation interest) in sandy coastal habitats invaded by Carpobrotus aff. acinaciformis, a widespread alien plant. Focal species are a major conservation target for the Habitats Directive and their decline should be considered a serious threat for the whole habitat. The study was performed in the Central Western coast of Italy. We randomly sampled the vegetation of the holocenic dune by 2 m × 2 m plots. First we split the collected data in two sets: invaded and non-invaded. We compared overall native and focal species richness patterns of the two sets by rarefaction curves. Then, in order to describe the singular aspects of species diversity (e.g. richness, Shannon index, Simpson index, Berger–Parker index), we also compared Rènyi's diversity profiles and we tested the significance of the differences between invaded and non invaded sets using a bootstrap procedure. Rarefaction curves of the non-invaded set rise quickly and reach higher accumulation values than the invaded set, but differences between the two curves were not significant. With respect to Rènyi's profiles, the profile for the invaded dataset was always below the non-invaded one, but differences in diversity were significant only when specifically considering the focal species (Shannon, Simpson and Berger–Parker indices). In the analysed case, the invasion is significantly associated with changes in focal species diversity, instead those differences are not evident on the all native species pool. In the case of recent invasions, a consistent decline on focal species diversity may represent an early alarm sign of diversity loss and may help define specific conservation actions to prevent the decrease of overall diversity.