Zooarchaeological remains from San Salvador, Bahamas, reveal trends in pre-Columbian exploitation of terrestrial, intertidal, and marine resources during the period A.D. 950–1500. Significant declines in quantities and weights of Gecarcinidae (land crabs), weights of mollusks, such as Cittarium pica (West Indian top shell) and Chiton tuberculatus/Acanthopleura granulata (chitons), and body sizes of both Sparisoma viride (stoplight parrotfish) and Serranidae (sea basses and groupers) all indicate prehistoric overexploitation. Declines in total number of identified marine taxa as well as average trophic levels of exploited marine vertebrates suggest reduced species diversity and “fishing down the marine food web.” These findings indicate that a relatively minor prehistoric human population (500–1000 people) can have significant environmental impacts, especially on small, vulnerable island ecosystems.
The European Union programme Natura 2000 aims at the creation of a network of Natura 2000 conservation areas in all EU member countries. Conservation areas are chosen on scientific evidence. Public expenditure for the realisation of the European initiative Natura 2000, in Austria, can broadly be estimated to amount to 75 million Euro (range 30 million Euro to 115 million Euro) for their establishment as one-off expenditure, while annual expenditure might amount to 10 million Euro (range 8 million Euro to 13 million Euro) for the conservation and maintenance of around 160 conservation areas. Significant positive regional economic effects such as value added and employment can be connected to such public expenditure.By the example of four selected model regions in Austria (Waldviertel, Steinfeld, Verwall, Karwendel), it can be demonstrated that the establishment of Natura 2000 conservation areas leads to at least small positive economic implications (local and regional value added, increased employment) which means that regions can benefit from the establishment of a Natura 2000 protection area. However, in single cases of land use conflicts, there might also be negative economic effects.The main regional development opportunities are in the fields of tourism as well as (to a smaller extent) in agriculture, forestry, hunting and fisheries. Such opportunities do not only depend solely on the establishment of a protected area, the realisation of a Natura 2000 site can initialize and support the regional economic development.The most essential recommendation for conservation policy is that instruments for information, compensation and financial support have to be expanded and adapted to the great importance of the Natura 2000 program and its agenda.
Handheld chlorophyll meters have proven to be useful tools for rapid, non-destructive assessment of chlorophyll and nutrient status in various agricultural and arborescent plant species. We proposed that a SPAD-502 chlorophyll meter would provide valuable information when monitoring life cycle changes and intraspecific variation in endangered plant populations, whereby, destruction of plants to obtain this information is impractical. Further, use of this instrument would augment leaf morphometric measurements collected during controlled studies, circumventing the need for leaf harvest. We developed a regression model relating foliar chlorophyll concentration and content to SPAD chlorophyll content indices for a genetically diverse population of the federally listed Lindera melissifolia. Application of the regression to four additional L. melissifolia populations, and to the ecologically widespread congener L. benzoin, proved the SPAD-502 to be an effective tool for non-destructive estimation of total foliar chlorophyll concentration (r2=0.8230) and content (r2=0.9029) across a range of plant ages, growing conditions, and genotypes.
Tropical rainforests have been disappearing at an alarming rate. In addition to preserving remaining tropical rainforests, we need to convert degraded and abandoned pasturelands into secondary forests. To accelerate this, human intervention in the recovery process is essential. In this review paper we (i) encapsulate some of the problems, which might surface when converting abandoned land to secondary forest. (ii) Look at some of the restoration techniques used in restoration programs and propose additional techniques for consideration. Major barriers to natural regeneration on abandoned and degraded pasturelands are: weed infestation, lack of indigenous soil seed bank, lack of seed supply/movement, soil compaction, depletion of soil nutrients and unsuitable microclimate and microhabitat. Although several restoration techniques have been recommended, most restoration programs have been carried out using native seedling transplants to accelerate natural recruitment. Most restoration groups in the tropics are still in the initial stages of determining which species or species combination to chose to gain maximum benefit. On the other hand restoration ecologists are struggling to detect which techniques are most appropriate to restore degraded and abandoned pasturelands. Our review shows that there is immediate need for further research and development on restoration techniques by examining the ecological and economic effectiveness of: direct seeding, stem cuttings using native pioneer or climax species and simple manipulation such as displacing branches of pioneer species with mature seeds on abandoned and degraded pasturelands and artificial perching to accelerate natural regeneration. These techniques are essential to successfully heal the wound humans have inflicted on the most spectacular and species-rich ecosystems on earth.
The success of MPAs in conserving fishing resources and protecting marine biodiversity relies strongly on how well they meet their planned (or implicit) management goals. From a review of empirical studies aiming at assessing the ecological effects of Mediterranean and Macaronesian MPAs, we conclude that establishing an MPA is successful for (i) increasing the abundance/biomass, (ii) increasing the proportion of larger/older individuals, and (iii) enhancing the fecundity of commercially harvested populations; also, MPAs demonstrated to be effective for (iv) augmenting local fishery yields through biomass exportation from the protected area, and (v) inducing shifts in fish assemblage structure by increasing the dominance of large predator species. However, the attraction for tourism and diving due to ecological benefits of protection can cause damages likely to reverse some of the MPA effects. Other expected effects are more subject to uncertainty, and hence need more research, such as (vi) causing density-dependent changes in life history traits and (vii) protecting the recruitment of commercially important species, (viii) protecting marine biodiversity (including genetic diversity), (ix) causing ecosystem-wide effects such as trophic cascades, and (x) increasing community and ecosystem stability, thus promoting resilience and faster recovery from disturbance. Meta-analysis of data arising from these case studies are used to establish the overall effect of MPAs, and its relationship to MPA features, such as size of no-take area or time since protection. Based on the review and the meta-analyses, specific recommendations are provided for MPA management, regarding the establishment of goals and objectives, site selection, MPA design and zoning, planning, and monitoring. Finally, a series of recommendations for MPA research are offered to drive future research in MPA issues in the Mediterranean and Macaronesia.
Spatially explicit, multi-scale models for predictions of species potential distribution can be useful tools for integrating biodiversity considerations in planning and strategic environmental assessment. In such models, the occurrences of focal species are related to habitat and landscape variables, which in urbanising areas should also include effects of urban disturbances. Moreover, the accuracy of the spatial predictive models may be affected by spatial autocorrelation, which means that a part of the variance is explained by neighbouring values. The aim of this study was to explore the effects of habitat and disturbance patterns on the distribution of two forest grouse species, Tetrao urogallus and Bonasa bonasia, and to detect and model the effects of spatial autocorrelation. The distribution of the two species could be explained in terms of reduction of a main predator, habitat quality, quantity and connectivity, including urban disturbances. The residuals of the initial regressions showed positive spatial autocorrelation that could be quantified by using a spatial probit model. The application of the spatial probit model revealed strongly significant spatial dependencies for both species. Furthermore, the model fit could be increased for T. urogallus by applying this model. The results implied that both species distributions might be affected by both reactions to the underlying land-use pattern, but also by interaction with neighbours. The use of the spatial probit model is a way to incorporate spatial interactions that otherwise cannot be captured by the independent variables.
Accurate and ecologically meaningful characterisation of reference conditions is a fundamental premise of restoration ecology. Restoration practice and research commonly define reference conditions in terms of compositional and structural elements. We propose a “process-centred” framework that places central emphasis on ecological functions and ecosystem processes. A wide variety of processes is central to the functioning and dynamics of ecological systems, and can be placed at the foundation of restoration research and practice. A process-centred approach allows the definition of “reference dynamics”, where spatial and temporal variability and underlying mechanisms of change are primary. We illustrate this approach using a 303-yr reconstruction of the natural surface fire regime to guide restoration of a Pinus ponderosa forest in the Jemez Mountains of southwestern North America. Fire occurrence varied over space and time during the period of record, with ecologically significant variation in fire intervals (yr fire−1) governed by process–structure interactions. We defined a variety of reference variables for reintroduction of fire as the keystone ecological process, along with related structural variation. A process-centered approach and the reference dynamics paradigm can replace a more static concept of reference conditions in defining restoration baselines and provide an improved standard of comparison for restoration ecology.
The history of the national parks in Greece involves a succession of issues pertinent to the legal framework and nature of park authorities. To date the largely state-based administration and the restrictive management practices have failed to grant effective protection and management in the designated areas largely due to organisational and institutional weaknesses, ineffective policy coordination and insufficient park authorities. The latest revision of the system of park administration and legislation in Greece heralded some changes that can improve the management of national parks. The key question is whether the creation of park boards and a number of changes in their funding possibilities and regulatory management regime are perceived by park users to contribute to genuine park improvement. Information was collected by means of a questionnaire survey in three outstanding parks in Greece. Research findings suggest that the perspectives of park users are increasingly aligned to the interests of park authorities as regards park management purposes. Park authorities’ achievements in relation to protection, management and administration were perceived as poor by the respondents in all parks. The conceptions of park users markedly reflect a situation whereby the role of the state in park administration is well anticipated and valued but visitors’ funding options are contrary to the spirit of the new law. Park users tend to reject the transfer of park administration to local authorities or private companies, recognising a continued need for both autonomy and government intervention away from direct state control. While the participants strongly recognised the importance of regulatory management in parks, the weak executive powers of park boards constitute a major administrative deficiency likely to threaten the ecological integrity of parks in the future. It is imperative that park boards acknowledge the current interaction between park users and park authorities. Otherwise, park administrators may find their task an increasingly difficult one.
Wind power is a fast-growing energy source for electricity production, and some environmental impacts (e.g. noise and bird collision) are pointed out. Despite extensive land use (2600–6000 m2/MW), it is said that most of these impacts have been resolved by technological development and proper site selection. The results in this paper suggest that: (i) wind farms kill millions of birds yearly around the world, and the high mortality of rare raptors is of particular concern; (ii) wind farms on migration routes are particularly dangerous, and it is difficult to find a wind power site away from migration routes because there is no guarantee that migration routes will not vary; (iii) according to the presented model of collision probability, the rotor speed does not make a significant difference in collision probability; the hub is the most dangerous part, and large birds (e.g. raptors) are at great risk; and, (iv) based on the field observation of squirrels’ vocalisation (i.e. anti-predator behaviour), there are behavioural differences between squirrels at the wind turbine site and those at the control site. Noise from wind turbines (when active) may interfere with the lives of animals beneath the wind turbines.US Government guidelines and the Bern Convention's report have described adverse impacts of wind energy facilities on wildlife and have put forward recommendations. In addition to these documents, the following points derived from the discussion in this paper should be noted for the purpose of harmonising wind power generation with wildlife conservation: (i) engineers need to develop a turbine form to reduce the collision risk at the hub; (ii) institute long-term monitoring, including a comparison between bird mortality before and after construction; and (iii) further evaluate impacts of turbine noise on anti-predator wildlife vocalisations.
Marginalisation of agriculture and spontaneous afforestation of abandoned land due to structural, demographic and social reasons are pressing issues in several regions of the EU and even more so in the Member State of Slovenia. Spontaneous afforestation of agricultural land is only the final and the most extreme phase of the restructuring process in agriculture. These changes have major implications for the environment and for rural development. In Slovenia, the rate of forest cover spread has been especially dramatic, making it one of the most forested countries in EU. The objective of this study was to explore possible futures of spontaneous afforestation in the Postojna region in south-western Slovenia, which is one of the regions most affected by land abandonment. This exploration was done through a scenario study based on a spatially explicit empirical model of spontaneous afforestation in relation to several physical landscape and policy relevant variables. The model was calibrated using historical data from the Postojna region. Stockbreeding intensity was used as an additional policy-relevant explanatory variable in the modelling of spontaneous afforestation.
This paper presents a practitioner's perspective of the Keren Kayemeth Leisrael's (KKL – Israel's Forest Service) forest management policy, including actions encouraging biological diversity attributes to Israel's planted conifer forests. These changes are reviewed in light of institutional changes within the KKL, recent global initiatives and scientific trends concerning biodiversity, ecologically oriented forestry and sustainable forest management.The management of Israel's planted conifer forests for biological diversity values is a relatively new phenomenon. Most of Israel's high forests were planted and consist primarily of a small core group of native and exotic Mediterranean conifers. Over time, these simplified afforestations evolved into a complex set of forest stands – a “near-native” type of forest ecosystem embodying a sum total of natural and artificial processes. They can thus serve as models to help visualise and understand how plantation-type forests can be converted into complex afforestations systems possessing a higher degree of structural, functional, compositional and genetic diversity.
Spatial technologies present possibilities for producing frequently updated and accurate habitat maps, which are important in biodiversity conservation. Assemblages of vegetation are equivalent to habitats. This study examined the use of satellite imagery in vegetation differentiation in South Africa's Kruger National Park (KNP). A vegetation classification scheme based on dominant tree species but also related to the park's geology was tested, the geology generally consisting of high and low fertility lithology. Currently available multispectral satellite imagery is broadly either of high spatial but low temporal resolution or low spatial but high temporal resolution. Landsat TM/ETM+ and MODIS images were used to represent these broad categories. Rain season dates were selected as the period when discrimination between key habitats in KNP is most likely to be successful. Principal Component Analysis enhanced vegetated areas on the Landsat images, while NDVI vegetation enhancement was employed on the MODIS image. The images were classified into six field sampling derived classes depicting a vegetation density and phenology gradient, with high (about 89%) indicative classification accuracy. The results indicate that, using image processing procedures that enhance vegetation density, image classification can be used to map the park's vegetation at the high versus low geological fertility zone level, to accuracies above 80% on high spatial resolution imagery and slightly lower accuracy on lower spatial resolution imagery. Rainfall just prior to the image date influences herbaceous vegetation and, therefore, success at image scene vegetation mapping, while cloud cover limits image availability. Small scale habitat differentiation using multispectral satellite imagery for large protected savanna areas appears feasible, indicating the potential for use of remote sensing in savanna habitat monitoring. However, factors affecting successful habitat mapping need to be considered. Therefore, adoption of remote sensing in vegetation mapping and monitoring for large protected savanna areas merits consideration by conservation agencies.
Our ability to evaluate the effectiveness of conservation interventions is primarily reliant on and often limited by the available evidence. As claimed conservation success (or failure) might merely be an artefact of the quantitative approach used for evaluation, both in terms of locating and analysing data, cross-validation of results is recommended. By cross-validation we mean using two (or more) different methods for evaluation and comparing the results. An initial assessment of the effectiveness of African wild dog (Lycaon pictus) reintroductions in South Africa was re-evaluated using a systematic review approach. This cross-validation differed from the previous evaluation in two important aspects, which define the systematic review process: comprehensive data searching; and meta-analysis. The original dataset was confirmed to be complete by an exhaustive search to locate additional data. Both the initial assessment and the meta-analysis suggested that wild dog reintroductions are successful in the short-term, with high survival rates of the released animals and their offspring. The meta-analysis corroborated the importance of pre-release socialisation in promoting post-release survival at the pack level. In contrast, the initial assessment found that additional covariates affect the survival of reintroduced wild dogs at the individual level. This study emphasises the importance of cross-validating management recommendations in endangered species recovery programmes using an evidence-based approach to assess and communicate the reliability of results.
Protected areas such as nature reserves have been found to be effective in preventing habitat destruction and protecting ecosystems within their borders. Recent studies however found extensive loss of tropical forest habitat around protected areas, vastly contributing to increase the levels of ecological isolation. Using high-resolution satellite data we investigated the isolation trend occurring in the W-Arly-Pendjari (WAP) ecological complex in West Africa. A land-cover change analysis was performed for the period 1984–2002: savanna vegetation extension and loss were derived within the complex and in a 30 km peripheral buffer. Sample regions in the buffer were also analysed using selected spatial indicators to quantify temporal trends in habitat fragmentation. Implications for change in relative capacity to conserve biodiversity were discussed through the calculation of the species richness capacity (SRC). More than 14.5% of savanna habitat was lost in the WAP peripheral areas, while 0.3% was converted inside the complex. The degree of fragmentation of remnant savanna habitat has also drastically increased. Despite the effectiveness of the park conservation programme, we found through the SRC approach that the WAP complex is decreasing its potential capacity to conserve species richness. This process is mainly due to the rapid and extended agricultural expansion taking place around the complex. A better understanding of the ecological dynamics occurring in the peripheral regions of reserves and the consideration of development needs are key variables to achieve conservation goals in protected areas.
Poverty and environmental degradation seem to be endemic in many of the former homeland territories of South Africa. The political legacy of Apartheid might have ceased, but the economic and environmental consequences thereof still have to be dealt with. In one interesting case such a poverty-stricken and environmentally degraded area (Bushbuckridge) lies adjacent to a world conservation icon, the Kruger National Park. Currently, however, the community of Bushbuckridge does not enjoy much benefit from this unique geographic location. On the contrary there seems to be increasing tension between the community in their quest for survival and the national park as a conservation enclave. This tension will not disappear automatically. The situation needs to be managed. It is proposed here that by broadening the conservation corridor through land restoration and by incorporating the Bushbuckridge communal land as an IUCN Category VI protected area (a protected area within which sustainable resource harvesting by communities is permitted) into the Kruger National Park and under the provision that the community remains the land owner, the conservation initiative could benefit the community as much as by a factor of four. For this to be successful a proper managerial and institutional system will have to be in place, including a system that will allow the trade in ecosystem goods and services.
In Switzerland, parallel to agri-environmental measures which apply directly to the field management, farmers had to convert at least 7% of their land to ecological compensation areas – ECA. Major ECA are extensified grassland, traditional orchards, hedges, and wild flower strips. In 2000, the situation shows that farmers practise the agri-environmental scheme all over Switzerland with a total of 120,000 hectares of different types of ECA. The introduction of ECA throughout the country's agricultural area can be seen as a large scale landscape restoration experiment. Its biological effects are evaluated in a monitoring programme. In a case study area of about 6 km2, in 1997, biodiversity indicators (spiders, carabid beetle and butterflies) were recorded following a stratified sampling design. Every field in the area was categorised and digitised. Habitat and landscape features that influence the indicators are analysed as well as the role of the ECA in this context. Hypothetical influencing factors are tested with the Canonical Correspondence Analysis (CCA) and partial CCA, and are categorised as follows: (1) habitat (habitat type, plant species richness); (2) landscape (habitat heterogeneity, variability, diversity, proportion of land use types in classes); and (3) space (geographical coordinates). The correlative models developed for spider and carabid beetle assemblages revealed that the most important factor is the habitat type (directly influenced by management practices). However, for spiders, land use types like ECA and natural areas in the surrounding landscape are significant factors too. The model developed for butterflies shows that species assemblages are sensitive to the habitat type and plant species richness but not to landscape features.
This paper investigates the potential of airborne lidar for recording and monitoring erosion levels in environmentally fragile upland landscapes, using an area of the Brecon Beacons National Park as a case study. Upland areas contain a rich variety of natural and cultural resources that are increasingly endangered through factors such as insensitive land-use practices, improvements in recreational access and climate change. Airborne lidar provides a highly detailed record of microtopography, in this example at a resolution of 0.5 m with a vertical accuracy of c.0.15 m and the ability to differentiate elevation changes to within 1-2 cm. The technique therefore allows the rapid and cost-effective recording of the nature and extent of erosion at a landscape scale, with the results of this analysis recording over 46 kilometres of path erosion within a 3.8 km2 area. The technique also provides the ability to highlight particular areas of risk, such as extensive braided erosion around path intersections and damage to protected SSSI habitats, providing a snapshot record of erosion at a particular point in time and an invaluable source of information for conservationists and policy-makers.
Exploitation over the last 50 years has altered the Fennoscandian boreal forest landscapes quite considerably. The situation in our two study areas in Lierne (Berglia and Raudberga) in central Norway in three periods, the 1950s, the 1970s and 1999, exemplifies this development. The ecological consequences of the landscape alterations identified during this period are illustrated by tracing the trend of the bird guild associated with old-growth forest. We have used existing and estimated density data for this guild, theories on landscape ecology and Geographical Information System (GIS) analyses. At Berglia, the area covered with old-growth forest was reduced by a further 19% in 1999 compared with the “pristine” situation where 65% of the landscape was forested. At Raudberga there has been a further 36% reduction from the original 72% coverage, leaving just 36% of this area covered by old growth. Given our assumptions (e.g. a 100-metre edge effect), the old-growth bird guild has been declining at ratios of 1.23–1.49 at Raudberga and 1.60–1.93 at Berglia relative to the reduction in the proportion of areas covered by old-growth forest stands, a significantly higher rate of decline than the one-to-one relationship expected if the loss of habitat areas had been the only effect. The difference in the spatial habitat configuration between these two areas can explain some of the variation as Raudberga shows a more coarse-grained fragmentation pattern. If the current trends, according to our best-fit models, are allowed to continue until 2050, only 30–44% of the population sizes at the “pristine” state will survive at Berglia and 22–32% at Raudberga. For some of the species involved, this certainly implies that the critical threshold value for maintaining viable population sizes will be exceeded, not least because the long-established practice of clear-felling will lead to a lack of important habitat features such as dead wood and large trees in the landscape. The boreal forest is, however, a natural, dynamic system whose resilience should be quite good and, as shown by our best possible scenario, a significantly improved situation can be achieved by 2050. However, this presupposes that the current alarming trends are taken seriously by the management authorities, and that the multi-professional knowledge available is applied in future planning processes for our rural areas.
South America is blessed with both world-leading levels of biodiversity, and world-record breaking levels of habitat conversion in some areas. Under this highly dynamic context, sound conservation planning is needed and one component of effectively prioritising conservation interventions is through the assessment of threats to natural ecosystems. Here we present a continent-wide and spatially explicit threats assessment to natural ecosystems. A conceptual framework is presented which quantifies threat as a function of both the magnitude of the impacts of specific damaging human activities, and the variable response of different ecosystems to those impacts. The framework is then applied on seven different threat layers (accessibility, conversion to agriculture, fires, grazing pressure, infrastructure, oil and gas, recent conversion) to map out and spatially quantify the level of threat expected over the coming 2–5 year period. An aggregate threat layer is calculated, and the threats to major habitat types are evaluated. Tropical and Subtropical Grasslands, Savannas and Shrublands and Flooded Grasslands and Savannas are found to be under the greatest threat (0.36 and 0.35 aggregate threat respectively), both threatened most by fires (0.96), the former by accessibility (0.72) and the latter by grazing pressure (0.62). Tropical and Subtropical Moist Broadleaf Forests are the least threatened of all ecosystems (0.13), closely followed by Montane Grasslands and Shrublands (0.14). Overall, accessibility is shown to be a major issue across much of the continent, and fires are a significant threat in some identified regions. The results are being used by The Nature Conservancy to target conservation efforts in the region, and also to drive policies for threat abatement. Furthermore, the conceptual framework and methodology is applicable to any region and presents a useful means of prioritising conservation interventions across broad geographic regions.
To identify thresholds in the relationship between the number of species in viable populations and habitat availability is useful for nature conservation. However, to obtain such empirical data may be extremely laborious. Many saproxylic (wood-living) species are under threat because there is little coarse woody debris (CWD) in managed forests. Based on computer simulations of CWD dynamics, and information about the substrate requirements of red-listed saproxylic species, we conclude that it is unlikely that any specific quantity of CWD can be defined as the extinction threshold for large numbers of species, since different species are specialists in utilising different types of CWD. In our analysis, we identified a curvilinear relationship between total CWD and the number of red-listed species in viable populations, even assuming that there were sharp extinction thresholds for individual species. Thus, it is highly unlikely that it will ever be possible to identify simple targets for maintenance of CWD based on extinction thresholds for the whole community of saproxylic species. Instead other strategies are necessary when formulating conservation targets.
In 1997–1999, 411 red foxes Vulpes vulpes were collected from all over Denmark. Among these 205 were used for a univariate craniometrical investigation on six skull traits. 308 of the foxes were analysed by horizontal starch gel electrophoresis. Of the studied 18 enzymes, 14 were monomorphic and four polymorphic. Of the latter ones three were used for further analysis, as one enzyme system was difficult to score. No genetic heterogeneity within samples between sexes was revealed. However both genetic and morphometrical differentiation were found between the regions, with the foxes from Copenhagen significantly deviating from all other samples, including those from the remaining part of Zealand. Thus, our data suggest that the foxes from Copenhagen may be considered as an isolated population with limited amount of gene flow with the other populations in Denmark. Possible causes of such limited gene flow are discussed.
Tropical forest animals are at high risk worldwide as a result of over-exploitation and forest clearing. Zooarchaeological studies of animal use by the ancient Maya of the southern lowland regions of Guatemala, Honduras, Belize, and Mexico provide long-term historical information on animal populations under conditions of human population growth and climatic change that is valuable to both archaeology and conservation biology. In this paper, zooarchaeological data from 35 chronologically defined faunal sub-samples recovered from 25 ancient Maya archaeological sites are used to assess the effects of ancient hunting on animal populations of the Maya region between the Preclassic and Colonial periods (2000 BC–AD 1697). The variations in species abundance are used as a proxy for describing changes in ancient Maya hunting practices and hunted animal populations, interpreted on the basis of hunting efficiency models from foraging ecology. A significant reduction in the proportion of large mammals, particularly Odocoileus virginianus, in zooarchaeological assemblages between the Late Classic (AD 600–850) and Terminal Classic/Postclassic periods (AD 850–1519) suggest that over-hunting during the Late Classic may have led to a reduction in availability of these animals to the ancient Maya hunters in the later periods. This finding is discussed in relation to important social and environmental variations to evaluate the impact of hunting and other factors such as forest clearance and climate on ancient animal populations in the Maya region.
In the 1980s the Nature Conservancy Council created an ancient woodland inventory showing all woods in Great Britain (GB) greater than 2 ha that were believed to have had woodland habitat cover continuously from 1600. Subsequently these lists have been maintained as three separate inventories by NCC's successors, English Nature (now Natural England), Countryside Council for Wales and Scottish Natural Heritage. This paper outlines the concept of ancient woodland as it has developed in GB, and how this idea gave rise to the ancient woodland inventories. The criteria used in compiling the inventories are discussed, including the inception dates and the threshold size, and the difference between ancient woodland and parkland. The inventories have been digitised for use with Geographic Information Systems (GIS), which has made them more accessible to planners and nature conservation bodies; however, the digitising process is more precise than the original definition of the boundaries of the ancient woodland. The three different countries have approached this issue slightly differently, taking account of the differing landscapes within which their ancient woodland exists. As the inventory developed, new legislation has also been brought into play to protect ancient woodland further. The inventory currently lacks detailed information concerning the condition or type of wood, beyond its semi-natural or plantation status. Ascertaining, and then maintaining, the condition of ancient woodland in Great Britain will be a major challenge for the future.
Two methods were used to separate free-ranging mink Mustela vison into wild mink and escaped farm mink. Analysis of stable carbon isotopes was performed on teeth and claws of 226 free-ranging mink from two areas in Denmark. A classification based on empirical data resulted in three groups (n=213); 47% were newly escaped farm mink and another 31% had been born in farms and lived in nature for more than ca. 2 months. The remaining 21% may or may not have been born in nature, but they had been free ranging for more than a year and were thus considered wild. A genetic analysis by means of microsatellites was performed on a subsample of the trapped mink (86 individuals) and on 70 farm mink, in order to assess the proportion of escaped farm mink in the free-ranging population. Strong genetic evidence for a high percentage of escaped farm mink in the free-ranging population (86%) was found, in agreement with the carbon isotope results. Both methods can be used to distinguish between farm and wild mink, but whereas microsatellites can only say whether a given mink originated from a farm or not, carbon isotopes can give some more detail on the period of time that a farm mink has been living in natural habitats. The high proportion of escaped farm mink in the Danish nature could have serious implications for the preservation of other vulnerable species and should be carefully considered when designing conservation strategies.
Atlantic Forest mammals are still poorly known and very few localities have been properly surveyed and/or studied. Protected reserves are of paramount importance for the conservation of native flora and fauna. Hereby we provide a survey of mammals captured and/or observed in Poço das Antas Biological Reserve, the largest lowland Atlantic Forest reserve in Rio de Janeiro state, southeastern Brazil. A total of 77 species were recorded, several of them endemics and/or listed as threatened either by IUCN's Red List, by the Brazilian Red List or by the regional Red List of Rio de Janeiro State. Mammals are threatened in several ways in this area: (1) habitat loss and fragmentation, (2) road mortality, (3) fires, (4) poaching, (5) cattle grazing, (6) pollution, (7) exotic species, and (8) feral populations of dogs Canis familiaris and cats Felis catus. Despite all threats, this is an important site for biodiversity conservation and scientific research. Better management and more investment would surely improve its effectiveness in protecting Atlantic Forest mammals.
Heterogeneous landscapes are biodiversity ‘hotspots’. Degradation resulting from acidification, desiccation and eutrophication not only decreases habitat quality, but also causes heterogeneity to decline. While restoration measures aim at restoring habitat quality, they can further reduce heterogeneity when they affect large parts of an area (large scale) or cause disturbance (high intensity). Successful restoration of biological diversity therefore requires knowledge of the mechanisms underlying the relation between landscape heterogeneity and species diversity. This paper addresses two questions:
Inland wetlands are worldwide distributed and have been heavily impacted in recent decades by human activities such as commerce, recreation, and food sources. The direct consequences of these activities on aquatic systems are changes in hydrology and salinity alterations, and the introduction of exotic species. Recent large-scale ecological and genetic studies across several countries and continents indicate that population structure, regional endemism, and geographic speciation patterns are common in passively dispersed aquatic invertebrates contradicting previous predictions of homogeneous genetic distribution. This essay discusses the main processes that shape these patterns and determine the biodiversity and geographic distribution of diapausing aquatic invertebrates in inland wetlands. Large-scale geographical studies to describe general patterns and to understand genetic and ecological processes determining the biogeography of cosmopolitan species are needed. Further knowledge of these issues should provide invaluable information allowing development of appropriate conservation management policies for inland waters across entire ecosystems, landscapes, and geographic regions.
Ecological restoration of native woodlands and wooded pastures on former agricultural land is an important topic in modern conservation practice. The introduction of large herbivores is increasingly used to achieve these aims. We investigated how grazing, resistance traits of plants (concerning herbivory) and associational resistance interact and affect the establishment pattern of woody species on abandoned arable land (N-Belgium, W-Europe). In these early successional tree assemblages, we tested whether grazing increased or decreased spatial heterogeneity, which is supposed to be a crucial factor for biodiversity.
The scientific and management perception of artificial surface-water provision has swung like a pendulum from being to the benefit of herbivores, to being to the detriment of many vegetation and herbivore species. Using simulations, this study explores in a GIS how the water-landscape may change for water-dependent grazers under different surface-water management policies and climatic conditions in the Kruger National Park, South Africa. The simulations revealed that the addition or removal of artificial water sources in Kruger will only significantly change the water-landscape during drought episodes, emphasising the importance of considering artificial water provision in a spatio-temporal context. More generally, this illustrates how climatic conditions and time-lags can often confound the effects of management intervention in highly variable systems, demostrating the importance of continuous and long-term monitoring for evaluating management actions. Furthermore, it was shown how the wide-scale provision of water suppressed variability in surface-water availability, reducing spatial and temporal heterogeneity that is important for coexistence in, and resilience of, naturally fluctuating, non-equilibrium systems. This was especially evident during drought periods. Considering the results, water provision policies of semi-arid conservation areas supporting large water-dependent herbivore species should explicitly recognise and consequently aim to mimic spatio-temporal variability in surface-water availability.
Strategies have been suggested by many conservationists to conserve biodiversity at regional, national and global levels. However, conservation strategies developed in the past were mostly based on qualitative attributes or one or two attributes. In the Himalayan region biodiversity varies from aspect to aspect, habitat to habitat and community to community therefore, location specific studies are required for its conservation and management. In the present study an approach has been developed to prioritise species at local level using six conservation attributes. Threat categorisation of the floristic diversity was undertaken based on Conservation Priority Index. Of the total 637 species of vascular plants recorded, 10 species were categorised as critically endangered; 15 species as endangered and 31 species as vulnerable. Two species as critically endangered, seven species as endangered and three species as vulnerable according to IUCN have been also recorded which indicated the importance of the sanctuary. Maximum threatened species were found in altitudinal zones 2000–2800 m and sites dominated by Betula utilis and Rhododendron campanulatum in forest and alpine zones, respectively. The two factors of over exploitation and habitat degradation have been identified as major threats to the floristic diversity. Therefore, monitoring of population and habitats, development of conventional protocol; establishment of species in-situ conditions and akin habitats and replication of this approach in other parts of Indian Himalayan Region have been suggested.
Continental and insular Southeast Asia were originally endowed with vast areas of luxurious Tropical Evergreen Forest. Mainly since the sixties of the last century these tropical rainforests have been under a steadily increasing pressure due to intensive logging for commercial purposes and the increasing number of people depending on the given environment for more agricultural land and for fuel wood.One innovative approach to combine the necessities of rural development, safe natural resource management and biodiversity restoration was developed under the acronym “Rainforestation Farming” on the island of Leyte in the Philippines. More than 100 different local forests and fruit tree species were tested and planted in a near-to-nature planting scheme concerning species composition in a former degraded area covered by Imperata cylindrica.The recommended planting scheme includes both sun-requiring trees and shade-loving trees, highly valuable timber trees and fruit trees. During the first year of planting, nursery grown sun-loving trees were planted at close distance of 2×2 m to quickly reach the condition of a closed canopy and therefore shading out of the grass. During the second year, shade-loving trees, coming from either the nursery or from the natural forest in the form of seedlings sitting under mother trees, were planted under the established first year pioneers.To support the protection of the remaining forest, particularly the mother trees as resource for seedlings and to spur biodiversity rehabilitation efforts through people's participation a support system with community organisers was established. Already after four years some highly endangered species like the herbivorous Flying Lemure, Gynocephalus volans, and the insectivorous nocturnal ape, Tarsius syrichta, moved back into parts of the reforested closed canopy areas of the research and model farm.
Large, dead and dying European aspens (Populus tremula L.) host many threatened species in Fennoscandian boreal forests. Large aspen trees have mostly disappeared and are being harvested from the managed forests that cover 95% of the forest area in Finland. Due to the small area protected (4.1%), the aspen-associated species may encounter major difficulties in the protected areas if aspen trees disappear due to natural forest succession. The availability of aspens was assessed in the old-growth conservation area network in eastern Finland. We mapped all the living and dead aspens in 15 protected old-growth forests. The total number of counted trees was 32 903 individuals. Current amounts of living (2.7 m3/ha) and especially dead aspens (2.8 m3/ha) in the protected areas were higher than in the surrounding managed forests (1.1 and 0.1 m3/ha for living and dead trees, respectively). However, while saplings (dbh<5 cm) occur in most of the areas (12 individuals/ha on average) they survive poorly and young aspen cohorts (5 cm <dbh<15 cm) are lacking or are very rare. The most likely reason for the poor sapling survival is high browsing pressure by the mammalian herbivores, especially the moose. The moose population has increased many times in Finland during the past decades. The poor regeneration of aspens implies that the value of the old-growth conservation areas for aspen-associated species will face a serious bottleneck within a few decades when the currently middle-aged tree cohorts disappear. If the current high browsing pressure and lack of natural disturbances continue the obligatory aspen-associated species may disappear both locally and regionally from the network of the protected areas.
Trends in international policy show improvement in integration of biodiversity concerns in other sectors, movement from development and implementation of biodiversity policy to evaluation of effectiveness, and development of entirely new policies. There is an increasing need to assess and quantify the impacts of policies on biodiversity. Biodiversity research as well as monitoring has a strong role to play to suit this need.
Proneness to extinction varies naturally and continuously according to the ecological phenomena that compound rarity even before anthropogenic effects may play a role. This is particularly obvious in islands, where populations are often (and naturally) small and fragmented and, consequently, conservation priority lists may have a large number of species clustered unhelpfully in the higher threat categories. In this study we propose a simple model of threat based on natural descriptors of rarity and taxonomic distinctiveness (area of occupancy, population abundance and trend, and endemicity), assess its correlation with ecological features of the species (habitat preferences and body size) and check whether the Spanish Red data Book and a normative conservation priority list (the Canary Islands Catalogue of Threatened Species and its administrative revision) includes these ecological bases for birds. We found that a large variation in threat (48.2%) was explained by phylogeny, habitat breadth and preference for urban areas (with a negative effect), and preference for agricultural environments (a positive effect). The Spanish Red data Book and the administrative lists tested are poorly related to descriptors ordering the extinction risk and loss of taxonomic singularity, so some changes would make their categories more coherent. We contend that the ecological bases of rarity should be taken into account to understand why some populations/species are at higher extinction risk whereas others remain relatively safe, as this would provide firmer grounds on which to base conservation priorities.
The Donau-Auen National Park in Austria is situated partially within the area of the city of Vienna, and is exposed to high-use pressure including off-trail use and off-leash dog walking. Management measures are based on, among other things, the knowledge of the user groups’ perceptions of the impacts of their own behaviour on park wildlife, in particular, problematic behaviour. On-site visitors were interviewed using a standardised questionnaire during the winter of 2002 (N=271) in order to assess their awareness of the disturbance of wildlife due to different anthropogenic uses, including recreational ones. Only 40% of the respondents were aware that wildlife is disturbed, and merely 12% believed that they could have potentially disturbed wildlife on the day of the interview. In contrast, the wildlife experts interviewed assigned greater negative impacts on wildlife to some recreational uses. No differences were found between visitors with unproblematic behaviour and regular off-trail walkers and dog walkers – even those whose dogs were unleashed – in regard to their own potentially impacting behaviour. Some management implications are discussed, taking the specific situation of a small national park on the urban–rural fringe into consideration.
Human-induced pressures are known to be one of the main causes of biodiversity loss. In order to readily assess policy impacts on biodiversity, a cost-effective evaluation tool is developed, using species sensitivity scores. We demonstrate the potential effects of a selected policy option, being woody bioenergy crop production, on a wide range of species groups in Europe. Large-scale expansions of woody biofuel plantations would have a net negative effect on the species set covered in our study, with little variation among biogeographical regions, but with considerable differences among species groups. The evaluation tool enables policy makers to assess the potential impact of decisions on future biodiversity.
The rapid assessment of tropical plant biodiversity has become an important tool for the quantitative investigation of regional scale (between location) biogeographical patterns. However, the analysis presented here of local scale (within location) variation in a Mexican tropical dry forest suggests that a significant part of regional scale variation in this forest type may be an artefact of the undersampling of sites within locations. Such undersampling is common but is shown to have potentially serious implications for regional conservation assessment in tropical dry forest. It is argued that several sites within each location need to be sampled before the plant diversity at those locations can be meaningfully compared.
A tidal barrage across the Severn Estuary (UK) was first proposed in the 1970s and similar ideas have re-emerged in recent years as the pressure for sources of renewable energy increase. Claims that the barrage would deliver ecological and flood defence benefits based on the tidal power project at La Rance in France are examined. This analysis suggests that the range and scale of ecological and geomorphological impacts will be considerably more deleterious than has hitherto been documented. Monitoring of the Eastern Schelde tidal barrage, constructed to reduce flood events in Holland, provides important pointers about the possible effects of a barrage across the Severn Estuary. The published outcomes of detailed monitoring on the Eastern Schelde provide a robust analogue that suggests significant detrimental effects on nature conservation are likely and that some of the functional changes also have important implications for flood defence structures around the estuary and its tributaries.
The integration of spatial information concerning animal species into static, rule-based spatially explicit non-probabilistic models for decision-making regarding the planning of landscapes and regions provides generalised habitat-described landscape-structural parameters. As a basis for an individually developed model, a discussion is first of all presented which involves general data and parametric requirements, necessary for the development of a species-referenced, spatially explicit model for analysis and evaluation. The parameters necessary for an assessment of habitat characteristics of birds in Central Europe will be discussed on the basis of landscape and structural information, using the Corn Bunting (Emberiza calandra) as an example. A spatial analysis and assessment procedure supported by geographical information system (GIS) for this species has been developed for the definition of regulations and assessment categories and subsequently applied to the example of an open agricultural landscape in Saxony-Anhalt. Within the area of examination of approximately 42.4 km2, 56 songbird perches were located (density of 1.34 territories/km2). A comparison with the 45 mapped territories from the year 2004 indicated a good correlation with the model assumptions. Indeed, 16 of these 45 territories were only briefly occupied and the establishment of breeding pairs was ascertained in only 17 territories. The analysis and assessment model as presented yielded reality-based results after the utilisation of relatively little landscape-structural entry data, and is well suited for support of the decision-making process for spatial planning. The model framework presented in this paper can be modified and transferred to other species.
Since 1999, SPVS has been involved in three projects that combine two fundamental goals over the course of 40 years: the conservation of one of Brazil's most important remnants of Atlantic Forest and the implementation of projects for carbon sequestration. In addition, there is an interest in replicating these projects in order to restore other degraded areas, protect the Brazilian biomes, and help to diminish deforestation and forest fire, therefore reducing carbon emissions. The acquisition of 19,000 ha of degraded areas of high biological importance in southern Brazil was the first step towards the implementation of the projects. These areas are owned by SPVS, a Brazilian NGO, and are being restored, conserved and transformed into Private Natural Reserves, in partnership with the NGO – The Nature Conservancy, and financed by the companies – American Electric Power, General Motors and Chevron Texaco. The process of forest restoration involves several stages: soil studies, surveying the region's native plants, planning for restoration by means of a Geographical Information System, production of seedlings, application of different techniques for planting (such as manual or mechanised planting with seedlings and stakes), and biomass and biodiversity monitoring. To guarantee the survival of the seedlings on the planted areas, during the first three years, there is a continuous and systematic maintenance programme including weeding of undergrowth, crowing and organic fertilisation. The three projects already planted around 500,000 seedlings of native species until September 2004, and aim to plant a further 300,000 until 2008.
Arable land in Switzerland harbours low biodiversity and lacks permanent species-rich structures. To remedy this situation,improved field margins(IFMs)will be introduced as a new ecological compensation type in the Swiss Lowlands. IFMs are extensively managed, sown species- and flower-rich vegetation strips which provide both habitats for a wide range of species and valuable structures for the ecological
network. However, the success of ecological compensation measures depends strongly on their acceptance by farmers and the general public. In summer 2004, we investigated in a case study the attitudes of 108 Swiss people to IFMs directly in the field. Study participants were asked to rate the attractiveness of IFMs of different species richness and composition that were presented to them, to explain their rating and to estimate the number of species present. In addition, they were asked to imagine a field margin of their particular liking, to describe it, and to state their opinion on several aspects of IFMs. Study participants responded very positively to species-rich vegetation. The more species-rich an IFM was perceived to be, the more it appealed to them. Species richness and general diversity were named as the main reasons for a positive rating. Study participants strongly approved the establishment of improved field margins. The positive rating and high acceptance of IFMs in this study indicate that they may be a successful new tool for biodiversity enhancement in intensively used agricultural landscapes.
Topsoil removal is an effective, but also expensive method of nature restoration on fens and fen meadows. The high cost is a factor limiting the application of this method, especially in Central European countries, where investments in nature restoration are low.Can we partly balance the high costs of restoration with the method of topsoil removal, by utilising the degraded soil? We explore and roughly assess the benefits from re-using the removed soil. The cost limitation lies mainly in the transport. This is due to the difficulties of moving the soil within the project site and the often high costs of transporting and storing soil out of the site. The soil substrate can be utilised in forestry or horticulture, but is of rather poor quality, compared to commercially sold garden soil. In general, the respondents were not willing to pay for the substrate, pay much less than the price of commercial soil or they were not directly interested in using it. The assessment of possible gains in our case study indicated that, even if the soil is utilised in some way, the high costs cannot be fully balanced.
We describe an improved mathematical model for the relationship between the population of giant pandas (Ailuropoda melanoleuca) and bamboo (Bashania spanostachya) developed by Smith (1979) and Yuan et al. (1989), by adding a correction term which takes into account the effect of a sudden collapse of bamboo as a food source. The values for the co-efficients were based on field data collected in 1994 and 1995 in Yele Nature Reserve (Mianning county, Sichuan Province). The model reflects the dynamic relationship between giant pandas and bamboo in Xiangling Mountains. It is more realistic than earlier models. The density dependent co-efficient for bamboo in the model, Parameter a, decides whether the positive equilibrium point B is a stable or an unstable focus as a changes. The branching value a0 exists in a very narrow interval. The fundamental structure of the phase graph of the model changes significantly and one stable limit cycle is obtained.
The UK has until very recently been through a phase of significant development, in particular for housing and transport networks, but currently compensation for ecological impacts is often carried out poorly, if at all. Over the last 15 years support for habitat banking in environmental policy has grown rapidly, defined as the restoration, creation or enhancement of habitats for the purpose of providing similar resources through compensation for development impacts. It is an incredibly flexible tool, as demonstrated by the wide variety of situations in which it is applied, and it has already brought disparate parties together, including landowners, biologists, consultants, planners, and developers. A common concern with the concept relates to the risk and uncertainty surrounding the restoration of habitat functions after the original habitat has been lost. Other concerns relate to the regulation of habitat banks, and the calculation of compensation requirements such as what should be the ratio of new habitat or resource created to environmental impact caused. We address these and other issues and propose two models for habitat banking in the UK, which could also be adapted for use elsewhere in Europe. We highlight numerous potential advantages for biodiversity, human welfare, and the economy, and argue that the most effective way to address doubts surrounding the habitat banking concept would be through one or a number of pilot projects, which need to be implemented now.
Although maintenance of species-rich plant communities in ditch banks seems possible with agri-environment schemes, in general these schemes have not delivered an increase in species richness in these habitats. This could be related to an emphasis in the existing management guidelines on preventing extinction of desirable plant species as opposed to encouraging their colonisation. We investigated germination, establishment, survival and reproduction of nine target species on ditch banks and determined how differences in vegetation productivity (biomass) and management regime affect the outcome of these processes. Our results suggest that ditch bank target species are more limited by colonisation (seed and microsite limitation) than by extinction (site limitation). Since target species are often lacking from the soil seed bank, restoration of populations of these species in ditch banks should focus on improving colonisation opportunities and promoting dispersal from nearby sources. Introduction by the sowing of seeds could be considered, especially in instances where natural colonisation appears unlikely. Although microsite limitation is always a limiting factor, the relative importance of microsite limitation compared to seed and site limitations greater in high-productivity ditch banks. This provides support for the ‘shifting limitation hypothesis’ postulating that the major factor regulating species richness shifts from regional to local processes under increasing productivity. For effective ditch bank restoration, it is essential to improve the conditions for germination and establishment, particularly at high-productivity ditch banks. We conclude that extensive management strategies advocating late first cuts appear suboptimal, regardless of the productivity of ditch bank systems. Current management recommendations in agri-environment schemes need to be revised and defined separately for low- and high-productivity situations in order to achieve largest conservation gain. Continuous monitoring and adaptation of the implemented management to fit individual circumstances will be required.
Effective conservation management is dependent on accessing and integrating different forms of evidence regarding the potential impacts of management interventions. Here, we explore the application of Bayesian Belief Networks (BBN), which are graphical models that incorporate probabilistic relationships among variables of interest, to evidence-based conservation management. We consider four case studies, namely: (i) impacts of deer grazing on saltmarsh vegetation; (ii) impacts of burning on upland bog vegetation; (iii) control of the invasive exotic plant Rhododendron ponticum; and (iv) management of lowland heathland by burning. Each of these themes is currently a significant conservation issue in the UK, and yet the potential outcomes of management interventions are poorly understood. Through these examples, we demonstrate that BBNs can be used to integrate and explore evidence from a variety of sources, including expert opinion and quantitative results from research investigations. Incorporation of such information in BBNs enables different sources of evidence to be compared, the potential impacts of management interventions to be explored and management trade-offs to be identified. BBNs also offer a highly visual tool for communicating the uncertainty associated with potential management outcomes to conservation practitioners, and they can also be readily updated as new evidence becomes available. Based on these features, we suggest that BBNs have outstanding potential for supporting evidence-based approaches to conservation management.
Population viability and metapopulation theory and models are heuristic tools that can be used to plan restorations and assess their success. Using examples from South Florida, USA, we review background information and ongoing reintroduction experiments with the federally endangered coastal perennial vine, beach jacquemontia, Jacquemontia reclinata (Convolvulaceae). All known wild populations are declining in isolated habitat fragments varying in size, occupied area, and degree of isolation. Eleven reintroduction sites ranging in size from 422 to 4800 m2 within the extant species’ range have been identified that have characteristics suitable for J. reclinata introductions and have land managers amenable to restoration efforts. Previous RAPD analysis indicated that genetic diversity of natural populations was positively correlated with population size; the two largest populations had the highest genetic diversity and the smallest populations had relatively low genetic diversity. Despite habitat fragmentation and large distances between some populations, migration rates were very high among populations (m=4.05). Experimental crosses indicated the species has a mixed mating system. From 2001 to 2005, we have introduced 935 J. reclinata in seven experiments in five locations using plants propagated ex situ at Fairchild Tropical Botanic Garden. Reintroductions have dramatically increased the number of plants in the wild by 72%. Survival from the time of transplant to 2005 ranged from 2% to 97%, was not significantly correlated with metapopulation parameters, such as, founding population size, patch size, or connectivity to extant populations. Reintroduced plants are contributing seed and pollen to the wild populations, but no recruited seedlings have yet been observed. Although it may take decades before we can consider the reintroduced populations to be self-sustainable, we argue that planning restorations for rare species based on predictions from ecological theory is advisable to allow a higher probability of success.
Good distribution maps based on adequate sampling of a number of taxonomic groups are required to provide reliable conservation strategies. Nevertheless, it is common that inventories of many animal groups, particularly insects, are incomplete or nonexistent, with large gaps appearing once all available information of insects is mapped, especially when wide spatial scales are considered. Due to the lack of resources and manpower, the accomplishment of future field campaigns in these generally poorly surveyed areas should be directed so as to maximise the information obtained with the minimum survey effort. Using an exhaustive database of Iberian water beetles (which was relatively scarce and biased), we aim to prioritise areas to propose a planned survey design able to generate more accurate geographical representations of species distributions. For this, a prediction on the geographic distribution of the species richness of this group in the Iberian Peninsula was first obtained using the information coming from seven sets of well-surveyed grid cells determined by using progressively more exigent completeness values. Both observed and estimated by accumulation curves, species richness values of these different cell groups were subsequently used as the dependent variable in the modelling procedure. We used generalised linear models and 18 environmental variables as predictors. In this manner, 14 species richness predictions were obtained whose predictive power was assessed by a Jackknife procedure. The best model explained 57.5% of total deviance with a high mean Jackknife predictive error (29.9%). The overlay of these predictions with the survey effort map allows us to locate those areas where more sampling effort is necessary (areas of high predicted species richness that are not well inventoried).
A distinctive feature of ecological restoration is that the human presence in the natural landscape can be perceived as beneficial and not necessarily as harmful. Consequently, negotiations between heterogeneous actors involved and reactions to developments in different ecosystems become part of the scientific practice of restoration. This paper discusses some implications of restoration practice for the science of ecology in connection with recent debates about a new mode of knowledge production in science. I illustrate how different types of expertise from several backgrounds can be fed into each step of restoration implementation via alternate phases of selection and of corroboration by use to expose it to further observation in order to develop more scientifically and socially robust restoration strategies.
A variety of social and physical impacts are attributed to mountain biking. In many cases, the perception of these impacts differs from the reality of on-site experiences. This distinction is explored in two ways. First, a brief review of impact issues associated with mountain bikes is carried out. Second, results are presented from a survey of 370 walkers on a multi-day natural track where biking has been allowed on a trial basis. Walker opinions are surprisingly positive toward bikes. These opinions are found to be more positive among those walkers who had actual encounters with bikes. By contrast, more negative opinions were found among those who had no such encounters. Such distinctions between perception of a conflict and the actual outcome from an experience have important implications for park managers responsible for providing a range of different recreation opportunities.