Priority Habitat Research Articles

Contrasting measures of fitness to classify habitat quality for the black-throated sparrow ( Amphispiza bilineata)

Habitat quality is an important consideration when identifying source and sink habitat and setting priority areas for avian conservation. The problem is that different measures may lead to different conclusions about habitat quality, and may also vary in the resources required to estimate them. Individual level measures, such as nest success, and fecundity, will often identify different high quality habitats than population level measures, such as abundance or the number of fledglings produced per unit area. We tested measures of fitness in the Black-throated Sparrow both at the individual and at the population level for six habitats in the northern Chihuahuan Desert, to explore their value as indicators of habitat quality. We compared clutch size, number of nestlings per nest, number of fledglings per successful nest, nest density, nest success, daily nest survival rate, season-long fecundity, number of fledglings produced per 100 ha, and adult abundance, in each habitat type. We also modeled source–sink dynamics to estimate the scale at which they operate, to infer survival rates, and to ascertain the relative source potential of each habitat. We found that fecundity is the best indicator of individual level habitat quality but a poor indicator of population level habitat quality. Nest success (or fecundity, if resources are available to adequately estimate it) plus nest density provide the most robust indicator of population level habitat quality, which is the level at which priority habitats for conservation should be identified. Mesa grassland and black grama grassland functioned as source habitats most consistently, and mesquite was consistently a sink but also probably a reservoir of individuals available to occupy other habitats.

Identification of priority habitats for conservation of the Sierra Madre sparrow Xenospiza baileyi in Mexico

The Sierra Madre sparrow Xenospiza baileyi, categorized as Endangered on the IUCN Red List, is endemic to Mexico. The subalpine bunch grasslands of the Transverse Volcanic Belt in the south of the Valley of Mexico are the last remaining habitat of this species. We conducted a detailed survey for the Sierra Madre sparrow using the point count method, and then described the species' habitat using a phytosociological approach. The two sets of information were pooled into a single analytical framework to identify priority habitats for the species. Eight vegetation communities were distinguished. The Festuca lugens-Muhlenbergia quadridentata and Stipa ichu bunch grassland communities had the highest densities of the Sierra Madre sparrow. Intensive burning and grazing activities and agricultural encroachment have restricted sparrow occupancy. Landscape analysis helped to delineate core grassland areas for the species and grassland strips and islands that could potentially act as habitat corridors. From the information generated in this study, which was shared with the local communities, we are establishing a participatory socio-ecological investigation for conservation of the Sierra Madre sparrow's habitat.

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.

The Vegetation of Irish Machair

Machair is a highly specialised and complex sand dune habitat that is confined globally to the north west coasts of Ireland and Scotland. It comprises a flat or gently undulating sandy plain that develops in an oceanic location with a cool, moist climate. Machair systems are highly calcareous, the sediments usually containing a high percentage of shell fragments and having pH values in excess of 7. The vegetation is herbaceous, with low frequency of typical sand-binding species such as Ammophila arenaria. Irish machair is designated as a priority habitat under the EU Habitats Directive and as such Ireland has special responsibility for its conservation. The quality and extent of machair in Ireland is increasingly under threat from human pressures such as housing developments, recreation and changes in agricultural practice. This paper describes the vegetation of Irish machair and examines how climatic, edaphic, geographic and anthropogenic factors not only influence the distribution and formation of machair, but the plant communities present. A comparison between the vegetation of Irish and Scottish machair reveals a high degree of similarity, with some variation that can be explained by different land-use and/or management practices. Karen Gaynor (e-mail: karen. gaynor@environ.ie), Research Branch, National Parks and Wildlife Service, 7 Ely Place, Dublin 2. INTRODUCTION Machair is a distinct geomorphological and ecological habitat that forms as a result of a unique combination of climatic, geographic, edaphic and anthropogenic factors. Irish machair is designated as a priority habitat under the EU Habitats Directive (Commission of the European Communities 1992) (code: 21 AO). It is described therein as a 'complex habitat comprised of a sandy coastal plain resulting partially from grazing and/or rotational cultivation, in an oceanic location with a cool moist climate'. The system is highly calcareous, the sediment containing high shell fragment contents and pH values in excess of 7. The vegetation is herbaceous, with low frequency of sand-binding species. Machair is unique in that it is considered a natural landscape that is the product of cultural activities. The features of a typical machair system are presented in Fig. 1. In most cases, a small escarpment or dune ridge fronts the system. The true machair plain represents that area where wind erosion has eroded the original dune system down to a level just above the water table, where the wet consistency of the sand prevents further erosion (Pl. I). In general, the degree of flatness depends on the age of the system, as well as the underlying topography, geology, outcropping of local rocks and historical management. The machair plain is often terminated on the landward side by a lake or associated marsh/fen. There are a number of exceptions to this typical sequence. Flat machair like surfaces may form over rock platforms by the sea, bypassing the dune building phase. Where the wind is particularly strong and the direction suitable, large quantities of sand can even be deposited on the seaward face of hills inland to form hilly machair (e.g. Garter Hill, Co. Mayo) (Bassett and Curtis 1985). Scottish machair was first identified as a distinct habitat in the 1940s (Wilmott 1945; Darling 1947; MacLeod 1949) and has since been extensively described (Ranwell 1974a, 1974b; 1977; 1981; Dargie 1993; 2000; Angus 2004). Although Tansley (1939) described machair vegetation from Dog's Bay, County Galway, the habitat was not formally recognised in Ireland until 1980, when the first account of Irish machair on the Mullet Peninsula was published (Akeroyd and Curtis 1980). The criteria used to define Scottish machair were tested on a number of sites in the west of Ireland, revealing a close similarity between Irish machair sites and those found in Scotland. Further research subsequently supported this assessment (Bassett 1983; Bassett and Curtis 1985; Crawford et al. 1996). The most recent inventory of Irish sandy systems lists a total of 50 machair sites (Curtis 1991a). Following on from the work of Ritchie (1976), Curtis (1991b) used the following five criteria to define Irish machair: 1. A mature coastal sandy plain, with a more or less level surface. 2. A significant proportion of shell fragments in the sand producing a lime-rich soil (pH > 7.0). Biology and Environment: Proceedings of the Royal Irish Academy, Vol. 106B, No. 3, 311-321 (2006). ? Royal Irish Academy 311 This content downloaded from 157.55.39.225 on Thu, 09 Jun 2016 05:16:57 UTC All use subject to http://about.jstor.org/terms Biology and Environment 4-Mobile Dune-^ ^-Machair Foredune Strandline : Hummocky machair

Natura 2000 Habitat Types of Greece Evaluated in the Light of Distribution, threat and Responsibility

Natura 2000 Habitat Types of Greece Evaluated in the Light of Distribution, threat and Responsibility

Macroinvertebrate diversity and conservation status of Mediterranean ponds in Italy: water permanence and mesohabitat influence

1. In Italy small water bodies, especially temporary ones, have been little studied. As a consequence, their conservation value as a biodiversity resource is often overlooked despite Mediterranean temporary waters being listed as a priority habitat in the Habitats Directive (92/43/ EEC). 2. A monitoring programme was designed to determine which factors influence pond species richness, and to analyse the variation in macroinvertebrate community structure within and among ponds. Three main contrasting mesohabitats (macrophyte beds, littoral sediments and central sediments) were defined within 21 ponds (8 permanent and 13 temporary) along the Tyrrhenian coast of Italy near Rome, from which invertebrate macrofauna was collected in March, May and June 2002. 3. The main environmental factors influencing the number of species in ponds were hydroperiod length, depth, surface area, dissolved oxygen concentration and macrophyte species richness. Temporary ponds contained a smaller number of taxa than permanent ponds, but both types of ponds supported similar numbers of rare and threatened species. The total number of species, and in particular Coleoptera, Odonata, and Hemiptera, was higher in macrophyte beds than in both littoral and central sediments. 4. Multivariate analysis (non-metric multidimensional scaling) showed that the overall variation in assemblage composition was greater between temporary and permanent ponds than among mesohabitats, suggesting that environmental variables, such as hydroperiod, have a stronger effect on macroinvertebrate communities than substratum type. 5. In terms of species of conservation interest, this study suggests that both pond types and all mesohabitats should be considered in order to obtain a correct evaluation of pond conservation value.

An Assessment of Habitat Diversity and Transformation on La Réunion Island (Mascarene Islands, Indian Ocean) as a Basis for Identifying Broad-scale Conservation Priorities

Most natural habitat in the Mascarene Islands (Mauritius, La Reunion and Rodrigues) has been transformed. Although urbanisation, agriculture and alien plant invasions have transformed large areas in La Reunion, the island has by far the greatest area of intact habitats in the Mascarenes, but remaining natural areas are under threat. We propose a protocol for defining a system of habitat types and for using these to provide a preliminary assessment of conservation priorities for La Reunion. The protocol draws on existing data and expert knowledge to map habitat types, assesses the extent of habitat transformation, and quantifies heterogeneity between habitat types based on climate, topography and geology. The pattern of habitat transformation was uneven among the nineteen habitat types identified. While three habitats have lost > 95% of their original area, four still retain> 80% of their original extent. Habitat types could be grouped into the following categories: (i) transformed habitats with low levels of plant endemism, (ii) habitats confined to homogenous geology with high levels of plantendemism, and (iii) species-rich heterogeneous habitats on diverse geological types. Priority habitats were also identified using municipalities as a basis for implementation. Urgent action is required for several habitat types where a large part of the original extent has been transformed. Three municipalities which contain more than 10 habitat types should receive conservation priority. The analysis provides the basis for setting conservation priorities in La Reunion at the regional and local scale. Implications of the results are discussed with reference to requirements for finer-scale conservation planning.

Biotic variation in coastal water bodies in Sussex, England: Implications for saline lagoons

Coastal water bodies are a heterogeneous resource typified by high spatial and temporal variability and threatened by anthropogenic impacts. This includes saline lagoons, which support a specialist biota and are a priority habitat for nature conservation. This paper describes the biotic variation in coastal water bodies in Sussex, England, in order to characterise the distinctiveness of the saline lagoon community and elucidate environmental factors that determine its distribution. Twenty-eight coastal water bodies were surveyed for their aquatic flora and invertebrate fauna and a suite of exploratory environmental variables compiled. Ordination and cluster analyses were used to examine patterns in community composition and relate these to environmental parameters. Biotic variation in the coastal water body resource was high. Salinity was the main environmental parameter explaining the regional distribution of taxa; freshwater and saline assemblages were evident and related to sea water ingress. Freshwater sites were indicated by the plant Myriophyllum spicatum and gastropod mollusc Lymnaea peregra, while more saline communities supported marine and brackish water taxa, notably a range of chlorophytic algae and the bivalve mollusc Cerastoderma glaucum. Site community differences were also related to bank slope and parameters describing habitat heterogeneity. A saline lagoon community was discerned within the matrix of biotic variation consisting of specialist lagoonal species with associated typically euryhaline taxa. For fauna, the latter were the molluscs Abra tenuis and Hydrobia ulvae, and the crustaceans Corophium volutator and Palaemonetes varians, and for flora they were the algae Ulva lactuca, Chaetomorpha mediterranea, Cladophora spp. and Enteromorpha intestinalis. One non-native polychaete species, Ficopomatus enigmaticus, also strongly influenced community structure within the lagoonal resource. The community was not well defined as specialist and associated taxa were distributed throughout the spectrum of sites surveyed. Implications for the identification and conservation of saline lagoons are discussed.

Groundwater and wetland management in the Shannon river basin (Ireland)

Abstract This paper examined groundwater and wetlands in the Shannon river basin in the context of implementation of the European water framework directive (WFD). The particular wetland example of turloughs (groundwater fed temporary lakes in karst areas) was examined in the context of defining river basin district boundaries and in the delineation of their catchment areas for risk assessment as required by Articles 3 and 5, respectively of WFD. Groundwater dependent terrestrial ecosystems such as turloughs are particularly challenging in terms of delineating their catchment areas for the purposes of risk assessment and implementation of measures. Turloughs are a habitats directive Annex I priority habitat, which occur mainly in Ireland and consequently, many turloughs in Ireland have been designated as special areas of conservation. Better understanding of such complex systems with high degrees of groundwater–surface water interaction will be required to ensure their protection in river basin management plans.

Conservation implications of grazing practices on the plant and dipteran communities of a turlough in Co. Mayo, Ireland

Turloughs, which are classified as priority habitats under the European Habitats Directive, are seasonally flooded depressions found almost exclusively in Ireland. In 2001, three adjacent fields with different stocking densities were selected and plant/dipteran communities within the same vegetation zone of each field (site) were investigated using quadrats and sweep netting, respectively. There was a significant positive relationship between Diptera morphospecies richness/Diptera abundance and mean vegetation height (P < 0.001). However, no significant relationship between Diptera morphospecies richness and plant species richness was found. Median Diptera morphospecies richness per sweep was lower at the site with the highest stocking density (17) than at the other two sites (22 and 31, respectively). Total species richness of Sciomyzidae was greater at the least grazed site (7) than at the more heavily grazed sites (2 and 1, respectively). The results suggest that an evaluation of turlough management practices based on plant communities alone is not sufficient and that at least some areas within the turlough basin remain ungrazed on a rotational basis to ensure maximum diversity of Diptera.

Delineating priority habitat areas for the conservation of Andean bears in northern Ecuador

We sought to identify priority areas for the conservation of Andean bear (Tremarctos ornatus) habitat in the northern portion of the eastern Andean cordillera in Ecuador. The study area included paramo and montane forest habitats within the Antisana and Cayambe-Coca ecological reserves, and unprotected areas north of these reserves with elevations ranging from 1,800 to 4,300 m. We collected data on bear occurrence along 53 transects during 2000–01 in the Oyacachi River basin, an area of indigenous communities within the Cayambe-Coca Ecological Reserve. We used those data and a set of 7 environmental variables to predict suitability of Andean bear habitat using Mahalanobis distance, a multivariate measure of dissimilarity. The Mahalanobis distance values were classified into 5 classes of habitat suitability and generalized to a resolution of 1,650-m × 1,650-m grid cells. Clusters of grid cells with high suitability values were delineated from the generalized model and defined as important habitat areas (IHAs) for conservation. The IHAs were ranked using a weighted index that included factors of elevation range, influence from disturbed areas, and current conservation status. We identified 12 IHAs, which were mainly associated with paramo and cloud forest habitats; 2 of these areas have high conservation priorities because they are outside existing reserves and close to areas of human pressure. The distribution of the IHAs highlighted the role of human land use as the main source of fragmentation of Andean bear habitat in this region, emphasizing the importance of preserving habitat connectivity to allow the seasonal movements among habitat types that we documented for this species. Furthermore, the existence of areas with high habitat suitability close to areas of intense human use indicates the importance of bear–human conflict management as a critical Andean bear conservation strategy. We suggest that a promising conservation opportunity for this species is linked to its occurrence in highland habitats, which play a key role in the maintenance of long-term water supplies.

Plant invaders, global change and landscape restoration

Modifications in land uses, technology, transportation and biogeochemical cycles currently influence the spread of organisms by reducing the barriers that once restricted their movements. We provide an overview of the spatial and temporal extent for agents of environmental change (land and disturbance transformations, biogeochemical modifications, biotic additions and losses) and highlight those that strongly influence rangeland ecosystems. Restoration may provide a mechanism for ameliorating the impacts of invasive species, but applications of restoration practices over large scales, e.g. ecoregions, will yield benefits earlier when the landscape is prioritised by criteria that identify locations where critical restoration species can grow and where success will be high. We used the Great Basin, USA as our region of interest where the invasive annual grass, cheatgrass (Bromus tectorum), dominates millions of hectares. A landscape-level restoration model for sagebrush (Artemisia tridentata ssp. tridentata and ssp. wyomingensis) was developed to meet the goal of establishing priority habitat for wildlife. This approach could be used in long-range planning of rangeland ecosystems where funds and labour for restoration projects may vary annually.

A model of a natural wooded landscape in Britain as influenced by large herbivore activity

Summary The generally accepted view of the natural forests that once covered much of Britain has been of largely closed-canopy woodland with regeneration in gaps created by the death or destruction of small groups of trees, or occasional catastrophic blow-downs. An alternative view has recently been promoted in which large herbivores grazed open areas that eventually went through scrub and woodland phases. Regeneration within the woodland phase was prevented by grazing so that, when the trees died, open areas formed again. For regions where the herbivore-driven process predominated a model of possible landscape structures was developed for an area of 5 � 5k m (2500 ha) over a 500-year cycle. Different combinations of open and closed landscapes resulted, depending on the assumptions made about how long, for example, the closed woodland or open park phases lasted and whether patches of a particular phase were clumped or scattered. Possible implications for different species groups are illustrated. The balance between open and closed areas depends on assumptions made about the duration of the different phases. However, a predominantly wooded landscape (50 per cent in the woodland phase, 25 per cent in the park phase, with the balance as scrub (15 per cent) or break-up (10 per cent) stands) is compatible with a herbivoredriven dynamic process. Continuity of both open conditions and old trees over time and space can be achieved in this wooded landscape with an intimate mix of habitats at the scale of a few hundred metres. Modern conservation priorities in Britain are set against a background of 3000 years (at least) of a cultural landscape and controlled agricultural-type grazing is part of the management used to maintain some priority habitats and species. Under modern conditions free-range grazing regimes may not produce the same effect and so cannot, a priori, be assumed to be better in biodiversity terms than controlled grazing in all circumstances. However, the model results suggest that over large spatial scales and a long time period varied habitat mosaics may be generated by naturalistic grazing regimes. Naturalistic grazing regimes should be trialled therefore to determine what range of habitats and species they can now support and as a way of improving our understanding of how the former natural landscape might have functioned. There are practical issues including animal welfare and public liability that need to be resolved if such trials are to be taken forward.

Loss of palsa mires in Europe and biological consequences

Palsa mires are northern mire complexes with permanently frozen peat hummocks. These are degrading throughout their distribution range, probably because of regional climatic warming. This review of the current understanding of the geographical, climatic and biological characteristics of palsa mires focuses on Europe. Recent studies have reported a drastic decrease in the extent of palsa mires in Fennoscandia; in Finland, the distribution of palsas was formerly about three times that at present. With continued or accelerated warming, as predicted for high latitudes, further extensive degradation or the wholesale disappearance of palsa mires seems inevitable. Palsa mires are known to be biologically heterogeneous environments with a rich diversity of bird species, and they are listed as a priority habitat type by the European Union. However, their role as habitats for other organisms is still poorly understood. There is urgent need for research and monitoring to assess the ecological and biological consequences of the decline of palsa mires in Europe.

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.

Experimental management of Mediterranean temporary pools for conservation of the rare quillwort Isoetes setacea

Mediterranean temporary pools represent unique species-rich habitats with many rare and endangered species. The Roque-Haute Natural Reserve is one of the few sites in France with Isoetes setacea Lam., a very rare Mediterranean quillwort, considered as a keystone species determining a priority habitat for the European Union. Land uses changes have favoured the invasion of the pools by several shrub and tree species (e.g., Ulmus minor, Fraxinus angustifolia subsp. oxycarpa). Clearing shrubs in an experimental area of one pool resulted in the increase of I. setacea as compared to control, combining a higher cover in previously occupied quadrats and more quadrats occupied. Litter accumulation had a negative effect on the population of Isoetes but this effect was detectable only in the cleared area. Light attenuation was shown experimentally to be detrimental to the vegetative and regenerative production of I. setacea. Clearing of the shrubs and removal of the litter led to an increase in the I. setacea populations and therefore appears to be an effective technique for restoring these plant communities invaded by shrubs. Long-term shrub control should be ensured by reintroducing sheep grazing in order to enhance the sustainable conservation of this oligotrophic habitat.

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.

The creation and characterisation of a bioclimatic classification for Britain and Ireland

The paper discusses the creation of a bioclimatic classification for Britain and Ireland, which aims to provide discrimination between areas of conservation importance. The work used the UKCIP98 baseline data, which was supplemented with additional climate data for Irish stations to define a 21 class classification based on a 10 km square grid. The hierarchical classification was based on 89 monthly climate variables and bioclimate indices, chosen to reflect limits to species distribution. The classes were characterised by relating their distributions to the area of protected sites contained within each class and to the presence/absence of selected Habitats Directive Annex 1* Priority Habitats. The principal components analysis undertaken prior to the classification shows that the principal bioclimatic variables that discriminate areas across Britain and Ireland are (in order of explanatory power) related to rainfall, mean temperature and growing season, wind speed and the drying power of the air. The classification shows good discrimination between the small, dissected classes of upland areas and the more contiguous classes of lowland Britain and Ireland. The number of classes in northern and upland areas appears to be a reflection of the diversity of habitats within these areas.

Effect of track spacing and data interpolation on the interpretation of benthic community distributions derived from RoxAnn™ acoustic surveys

Abstract A 150 mile2 (388 km2) area in the South Minch on the Scottish west coast was surveyed acoustically using the seabed discrimination system RoxAnn™. This site was chosen from BGS seabed sediment maps because of the wide variety of substratum types present within a relatively small area. The work presented here investigates different combinations of survey track spacing in relation to interpolation of acoustic data for mapping benthic biodiversity. Three different survey track spacings (4, 2 and 1 km) and three pixel sizes (1000, 500 and 250 m) were utilised. The results indicated considerable variations in the fine scale variations of the substratum maps produced and their accuracy in relation to ground truth data. Depending on the track spacing and level of interpolation utilised, the survey site could be considered relatively important under the UK Biodiversity Action Plan in terms of priority habitat types present or completely insignificant. These variations have serious implications for the use of this technology in site identification, conservation and management.

A comparison of the ecological quality of land between an English agri-environment scheme and the countryside as a whole

A survey of 451 Countryside Stewardship Scheme (CSS) agreements was carried out across England in 1998–1999 to characterise the ecological quality of the land. The land within the agreements was mapped using the UK Biodiversity Action Plan Broad and Priority Habitats and the vegetation of the agreements was sampled using random quadrats. By far the most widespread Broad Habitat was Improved Grassland, accounting for around 50% of all agreement land. Of this, the majority was semi-improved. Priority Habitats accounted for 15% of all agreement land (equivalent to around 18,500 ha). In addition to the 15%, there was also land within habitat mosaics containing one or more Priority Habitat. The analysis of vegetation revealed that 53% of all randomly-placed quadrats were categorised as Infertile Grassland and 24% as Fertile Grassland. Survey data were compared with results from the Countryside Survey 2000, a national assessment of vegetation undertaken in 1998. In the lowland areas of England, CSS land had a much higher proportion of grassland habitats and was much more likely to be typical of low fertility situations than the countryside as a whole. In the marginal uplands and uplands, CSS agreement land contained a greater proportion of grassland, but with a reduced proportion of important upland Broad Habitats, such as Dwarf Shrub Heath and Bog, although these do tend to be found more in the Environmentally Sensitive Areas. The differences between the CSS and the countryside as a whole clearly reflect the priorities of the CSS, especially the high proportion of grassland. The CSS has targeted Broad and Priority Habitats and in this respect has been successful.