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Why do we need an open space map? TheAgency for Nature and Forests (ANB)only allows the hunt for partridges in an area if several conditions are met. One of these conditions is that there are enough partridges present. For this, ANB applies a minimum of 3 breeding pairs per 100 ha of open space. Therefore, a game management unit (GMU) that wishes to hunt partridge must first make an inventory of where all the partridges occur in the GMU. Based on these observations, theResearch Institute for Nature and Forest (INBO)determines the number of breeding pairs in each GMU. Finally we divide this number of breeding pairs by the area of open space to get the density of partridge (number of breeding pairs per 100 ha open space). To obtain the area of open space in each GMU, we need a map that defines what open space is. Why a new open space map? After the spring 2021 censuses, several hunters informed us that the current open space map does not always correspond to reality. Some plots were classified as open space on the map but are a built-up or forested area in reality. This overestimated the area of open space and underestimated the density of partridge. The previous version of the open space map is based on the most recent publication of thebiological valuation map (BVM). Although this version of the BVM was published in 2020, it does not mean that all the information originated from 2020. Actually, about three quarters of the information turned out to be older than 2007. For that reason, we went looking for a better source. Anopenopen space map After weighing a number of options, we choseOpenStreetMapas our source map. Like all other candidates, this map is not perfect. However, it is good enough to use. And it has the advantage that errors are relatively easy and quickly corrected. At the start of the surveys, hunters are given a preliminary version of the open space map. When hunters identify errors in the open space map, they can report the error or modify it themselves in OpenStreetMap. After calculating the number of breeding pairs, we can generate an updated version of the open space map based on the most recent information from OpenStreetMap. This update ability is an important difference between OpenStreetMap and other usable maps. Furthermore, the other maps are based on information that is at least 1 to 2 years old. For hunters, this way of working provides them the opportunity to contribute to a correct open space map themselves. Since OpenStreetMap provides the information with open use terms, everyone can enjoy an improved OpenStreetMap. Areproducibleopen space map In this report, we describe how to convert the information from OpenStreetMap to an open space map. We established the conversion as a computer program. We publish that computer program together with the open space map and the source maps that were used (OpenStreetMap and hunting area boundaries). In this way, everyone can check the rules (or have them checked), use, or implement them themselves.

Aims: Historical land-use legacies and chemical soil characteristics both explain either directly or indirectly the habitat quality of Nardus grassland, which is protected under the European habitat directive. Yet the relative importance and complementarity of both sets of variables are generally unknown. This knowledge is also relevant for practical reasons, as historical land-use variables can be used in desktop spatial analyses, whereas soil characteristics require field surveys to collect samples for laboratory analyses. To this end, we aim to disentangle the relative importance of historical land-use legacies and soil chemistry for the Nardus grassland quality, and determine the potential of habitat suitability mapping for predicting potential restoration areas. Location: Natura 2000 grasslands in Flanders (northern Belgium). Methods: We compared the model performance of three generalized additive models (GAMs), using either land-use history metrics, soil chemistry, or both as explanatory variables, with the Nardus grassland indicator species count as response. Results: All three models were able to predict areas suitable for at least three Nardus grassland indicator species with high sensitivity and specificity. However, a minimum of four indicator species are required for a favorable conservation status of Natura 2000 Nardus grasslands in Flanders. Using this threshold to detect high-priority zones, the model based on historical land-use variables resulted in a lower sensitivity than models which included soil chemistry. Conclusions: We suggest a two-step approach, with an a priori desktop spatial analysis based on historical land-use variables subdivided in a high-priority zone and a lower-priority zone. If the targeted area for restoration or conservation can be found within the high-priority zone, additional soil analyses are only required to help guide conservation and restoration measures. If additional sites are considered within the lower-priority zone, a field survey to collect additional soil data is recommended.

Global change threatens the persistence of native forest ecosystems mainly by limiting the conditions for natural regeneration but also inducing tree mortality and increasing the risk of large wildfires. In this context, understanding the biotic and biotic factors that ultimately determine tree recruitment is of pivotal importance to implement adaptive forest management strategies. In this study we assess how multipurpose management strategies, including combinations of thinning intensities and prescribed burning, affect the seed emergence and seedling survival of Pinus nigra Arn. subsp. salzmannii in two different forest sites in NE Spain. We tested four overstorey and fuel treatments that combined heavy and light intensity thinnings from below with understorey clearing and two different treatments of the resulting slash: prescribed burning and lop and scatter. The results showed: (1) a lack of regeneration in control units, probably caused by the high density of canopy and understorey; (2) greater seedling recruitment in units treated with slash burning than in units treated with slash lop and scatter, probably due to the effects of prescribed burning on the herbaceous layer, soil organic layer, nutrient pools, and understorey; and (3) a different regeneration response between sites for treatments that included prescribed burning, probably due to microclimatic conditions during the experiment and differences in the characteristics of the prescribed burns. These findings indicate the potential effectiveness of combined treatments of thinning and slash burning in the context of the implementation of multipurpose management actions in endangered ecosystems adapted to low intensity fires.

Forest sustainability depends on reliable tree regeneration but seedling survival is affected by climate change and disturbance. Based on seed introduction experiments, we compared recruitment of native pine species in central Spain in totally burned, thinned, and dense stands of Spanish black pine ( Pinus nigra Arn. ssp salzmannii ). Seed sources included P. nigra from three elevations bracketing its range, as well as the fire-adapted species maritime pine ( P. pinaster ) and the mesic-adapted species Scots pine ( P. sylvestris ). In addition, seed predation effect was also tested. Small and large herbivores as well as rodents were excluded using cages. All seeds had high viability in laboratory germination tests and all displayed high emergence in field trials. However, unprotected seedlings and those that emerged in thinned or dense stands did not survive the first growing season. Surviving seedlings were only found in totally burned stands. Protected P. nigra seedlings had the highest survival, reaching 23%. Protected seedlings of P. pinaster and P. sylvestris averaged 11.5% and 10.9%, respectively. Unprotected seedlings of any species had less than 2% survival. The unexpected result of higher mortality under a sheltering canopy compared with open post-wildfire conditions may be due to wetter spring during the experiment. Overall, the results indicate that native species currently still regenerate best within the environment of their present range, even though future climate or fire disturbance may lead to distributional shifts. Protection is necessary for successful pine regeneration in the study region.

Gestandaardiseerde rapportage van de trends op basis van de Algemene Broedvogel Monitoring Vlaanderen (ABV)

Wild boar (Sus scrofa L.) reappeared in Flanders (northern Belgium) in 2006 after almost half a century of absence. Interactions between wild boar and human activities are frequent due to extensive fragmentation of the landscape in Flanders. Complaints about agricultural damage are increasing but the actual extent of crop damage remains unknown. The goal of this study was to assess the current risk and the spatial distribution of crop damage, as well as factors influencing damage distribution in the province of Limburg (eastern Flanders). An online survey was sent to farmers by email. Moreover, as we expected potential respondent bias towards farmers that already experienced damage, we also conducted a follow-up non-respondent check by telephone. Our study showed that the current crop damage probability on a farm lies between 42% (likely an overestimation due to respondent bias in the online survey) and 22% (an underestimation based on the non-respondent check). There is considerable geographical variation in the proportion of farms that report boar damage; probability for crop damage due to wild boar is relatively high for farmers in Limburg but shows a geographically heterogeneous spread. Factors explaining the crop damage probability differed strongly between the online survey and the non-respondent check and no consistent results could be found. Our results show that using the online survey, it was possible to get an initial insight in the geographical distribution of crop damage. However, as we found differences between the results of the online survey and the non-respondent check, taking management decisions based solely on online survey results without conducting a non-respondent check could lead to misguided actions. The Royal Belgian Society of Zoology acknowledges the Universitarian Foundation of Belgium and the National Fund of Scientific Research for their financial support in publishing the Belgian Journal of Zoology. We would like to thank Boerenbond for its cooperation and for providing contact details on farmers in the region. We also thank the Flemish Land Agency (VLM) for the data on the distribution of farms across municipalities in Limburg. We are very grateful to all the farmers who participated in the surveys. We are grateful to Kris Somers and Sebastien Lizin from Hasselt University for the setup of the online survey, data collection and preliminary analysis. Finally, we want to express our appreciation to dr. Dirk Maes, dr. Lucida Kirkpatrick, Bram Vanden Broecke, Frederik Van de Perre and Emma Cartuyvels for their valuable advice on the manuscript.

Spatio-temporal forest changes can have a progressive negative impact on the habitat of species that need forest continuity, i.e. the continuous presence of forest. Long-term species data that demonstrate such an impact are often not available. Instead we applied a spatial analysis on maps of the historical and present-day forests, by calculating landscape indices that explain forest plant species diversity. We digitized for this purpose, forests in Flanders (northern Belgium, ~13,500 km2) at four time slices (1775, 1850, 1904–1931, 2000) and created a map of forest continuity in 2000. The ecological relevance of the analysis was further enhanced by a site classification, using a map of potential forest habitat types based on soil–vegetation relationships. Our results indicated that, between 1775 and 2000, forests occupied 9.7–12.2 % of the total study area. If continuity was not taken into consideration, forest fragmentation slightly increased since 1775. However, only 16 % of the forest area in 2000 remained continuously present at least since 1775 and is therefore called ancient forest (AF). Moreover, connectivity of forest that originated after 1775, called recent forest, was low and only 14 % was in physical contact with AF. The results were habitat-specific as forest on sites that are potentially suitable for a high number of slow-colonizing species, e.g. ancient forest plants, were affected most. We discuss that a GIS analysis of this kind is essential to provide statistics for forest biodiversity conservation and restoration, in landscapes with a dynamic and heterogeneous forest cover.

Spatio-temporal forest cover changes often cause a change of forest plant species diversity. Slow colonizing ancient forest plant species (AFS) can be negatively affected, as they depend to a certain degree on the continuity of the forest cover in space and time. The implementation of conservation and restoration strategies for AFS can be supported by a map that represents the actual AFS diversity of the current forest, as well as the potential AFS diversity that open land can achieve when converted to forest. To create such a map for Flanders (northern Belgium), an empirical model was constructed using spatially explicit data on habitat suitability and continuity. The model calculated a high AFS diversity for suitable mesophilous sites covered by forest in 1775 and in the early 20th century. Sites near a concave edge of a forest patch in 2000, either inside or outside forest, were also rated high. This is the first operational landscape model on AFS diversity that can be used to select hotspots of AFS diversity in the present-day forest and sites with a high restoration potential in the open landscapes. Application of the AFS diversity map on a local scale should include additional information on linear landscape elements, soil conditions and forest management, as we assume that these factors account for a high proportion of the unexplained deviance.

To study the impact of provenance selection of planting stock in (re)forestation and landscape plantings, the variation in bud and flower phenology, height increment and shrub morphology was examined within and between the local and non-local provenances of Crataegus monogyna in a provenance trial. Seven Belgian provenances were included, five in Flanders and two in Wallonia, completed with three commercial provenances originating from Italy, Hungary and the United Kingdom. A completely randomized design (single tree plots) was adopted. Data were processed using mixed modelling techniques. South European provenances flushed up to 7 days earlier than the Flemish provenances, whereas the Walloon provenances flushed 4 days later. Compared to the Flemish provenances, Southern provenances and Walloon provenances flowered 4 days earlier and 2 days later respectively. Height increment and shrub morphology did not vary significantly between the Belgian and commercial provenances. Bud burst varied less than flowering among the Flemish and the Walloon provenances. This possibly indicates a higher selection pressure on bud burst than on flowering. The higher time lag between the different provenances for bud burst in comparison to flowering indicates a stronger plastic response for the latter. The results point out the importance of bud burst as an indicator of local adaptation to geo-climatologic components. Finally, it appeared that old hedges are likely to be good sources of locally adapted seed.

Contains fulltext : 179174.pdf (Publisher’s version ) (Open Access)

Missing observations in water bird censuses are commonly handled using the Underhill index or the birdSTATs tool which enables the use of TRIM under the hood. Multiple imputation is a standard technique for handling missing data that is rarely used in the field of ecology, but is a well known statistical technique in the fields of medical and social sciences. The purpose of this paper is to compare these three methods in terms of bias and variance. The bias in the Underhill method depends on the algorithm and starting values. birdSTATs and multiple imputation are unbiased in the case of missing values that are missing completely at random; more missing values implies less information, and so wider confidence intervals are expected as the missingness increases. The Underhill method and birdSTATs tool underestimate the variance; omitting data from a complete dataset and applying the Underhill index or birdSTATs tool results in smaller confidence intervals. Multiple imputation with an adequate imputation model provides wider confidence intervals. Biased parameter estimates with underestimated variance can potentially lead to incorrect management and policy conclusions. Hence, we dissuade the use of Underhill indices or the birdSTATs tool to handle missing data, rather we suggest that multiple imputation is a more robust alternative, even in suboptimal conditions.

Helminth infections are the cause of morbidity in Cambodian cattle but other factors such as nutritional deficiencies and concurrent diseases may enhance the effects of parasites. The present study aimed to investigate the impact of anthelmintic treatment, feed supplementation, or both on gastrointestinal strongyle (GIS) and trematode infections as well as on morbidity parameters in Cambodian village cattle. At the beginning of the dry season, cattle populations in six villages were randomly assigned to a group: (A) receiving anthelmintic treatment (ivermectin+clorsulon) at week 0; (P) feed pellet supplementation during week 0-13 or both (AP). On five visits (week 0-29), faecal and blood samples were obtained for parasitological examination and haematocrit determination, respectively. Body condition (BCS), hind quarter fouling (HQFS), diarrhoea (DS), and conjunctiva colour (FAMACHA©) were scored and heart girth circumference was determined. To investigate the impact of treatment over time (week 0-29), a mixed model was used with treatment, time, and their interaction as fixed effects, and animal and village as random factors. At baseline, the proportion of GIS positive animals was high (67.9%), whereas trematode infections were low (Paramphistomum: 8.8%; Fasciola: 2.6%). Very thin to emaciated cattle (BCS 1-2) were more prevalent (11.4%) and FAMACHA© scores of ≤3 or below (65.8%) less prevalent than in an earlier study in the region. A Time ⨯ Treatment interaction was present for faecal egg counts (FEC) of GIS, GIS prevalence (both p

Aim Invasive alien species (IAS) are recognized as major drivers of biodiversity loss, but few causal relationships between IAS and species declines have been documented. In this study, we compare the distribution (Belgium and Britain) and abundance (Belgium, Britain and Switzerland) of formerly common and widespread native ladybirds before and after the arrival of Harmonia axyridis, a globally rapidly expanding IAS

Shrub cover has visible effects on Pinus nigra Arn ssp. salzmannii seedling emergence, but only in drier years under moderate basal area (25–30 m 2 ha −1 ). In the wetter year, shrub cover favours seedling survival without basal area influence. Shrubs are known to favour tree seedling recruitment in difficult climate environments, but facilitation may prove optimal in intermediate-level rather than harsh conditions, although such an effect remains to be specified. The main aim of this work was to evaluate the influence of stand basal area (15–20, 25–30 and 35–40 m2 ha−1) × with/without shrub facilitation on seedling recruitment in Spanish black pine (P. nigra Arn. ssp. salzmannii), which has been struggling to regenerate natural forests since the late nineteenth century, sometimes jeopardizing stand persistence. In spring 2012 and 2013, 72 subplots of 25 × 25 cm were established in Cuenca Mountains, central-eastern Spain (four replicates, each counting three subplots × 2 shrub conditions, both under and outside shrub cover, in three different stand basal areas). All plots were randomly distributed at least 500 m apart within each stand basal area. Each subplot comprised 20 seeds previously collected at the experimental forest site. Seedling emergence and early survival were monitored every month in 2012 and 2013. Seedling recruitment was strongly influenced by year. The year 2012 was drier and warmer than 2013. In 2012, seedling emergence was higher under the 25–30-m2 ha−1 stand basal area and favoured by shrub cover, whereas in 2013, neither basal area nor shrub cover had significant effects. No seedling survived the summer in 2012. Higher seedling survival was found outside shrub cover at every basal area interval in 2013 with living seedlings until the end of the year. Climate is the main factor controlling seedling emergence and survival. Shrub facilitation has visible effects on seedling emergence, but only in drier years under moderate light (moderate basal area). Facilitation collapses at extreme stress levels. In wetter years, shrub cover does not promote seedling survival and basal area is not an influential factor.

Despite a growing catalogue of eradication projects, documented successful vertebrate eradications on the mainland remain scarce. Reporting on successful campaigns is crucial to counter pessimism on ambitious programmes to tackle invasive species and to allow conservation practitioners, wildlife managers and scientist to learn from previous experience. Moreover, there is a need for basic information on the effectiveness of control methods and management strategies that can be used. In this note we report on a successful lowtecheradication campaign of a local population of Pallas’s squirrel Callosciuruserythraeus, a species of tree squirrel with documented ecological andsocioeconomic impacts in its invasive range. The population was eradicated from a suburban park of about 15 ha using baited mesh wire life traps, in five consecutive capture campaigns between October 2005 and January 2011. Using maximum likelihood estimation from catcheffort data we calculated initial densities in the park at 3 squirrels ha. Although control started quickly and the extent of the invasion was limited, the campaign took over 5 years and required an estimated investment of over €200,000 including 1.5 years of posteradication surveying. We provide basic data on the methods used to eradicate this invasive rodent. Critical success factors and possible improvements with respect to the specific context of this case are discussed. Adding this species to the list of species of EU concern currently under development could provide incentive to minimise impact of this tree squirrel at the continental scale.

Prior to the construction of an offshore wind farm at the Belgian Thorntonbank, local seabird abundance was studied by means of ship-based surveys. ‘Seabirds at sea’ count data, however, exhibit extreme spatial and temporal variation, impeding the detection of human impacts on seabird abundance and distribution. This paper proposes a transparent impact assessment method, following a before–after control–impact design and accounting for the statistical challenges inherent to ‘seabirds at sea’ data. By simulating a broad range of targeted scenarios based on empirical model coefficients, we tested its efficacy in terms of power and investigated how the chance of statistically detecting a change in numbers is affected by data characteristics, monitoring period and survey intensity. Because of high over-dispersion and/or zero inflation, the power to detect a 50% decrease in numbers was generally low, but did reach 90% within less than 10 years of post-impact monitoring for northern gannet (Morus bassanus) and common guillemot (Uria aalge).

Through before–after control-impact designed ship-based seabird surveys, seabird displacement occurring after the installation of an offshore wind farm at the Belgian Bligh Bank in 2010 was studied. Results demonstrate that northern gannet (Morus bassanus), common guillemot (Uria aalge) and razorbill (Alca torda) avoided the wind farm area, and decreased in abundance with 85, 71 and 64%, respectively. Lesser black-backed gull (Larus fuscus) and herring gull (Larus argentatus) were attracted to the wind farm, and their numbers increased by a factor 5.3 and 9.5. Other gull species too were found to frequent the turbine-built area, most notably common gull (Larus canus), black-legged kittiwake (Rissa tridactyla) and great black-backed gull (Larus marinus). The ecological incentives behind the observed attraction effects are still poorly understood, but on top of the increase in roosting possibilities it is plausible that offshore wind farms offer enhanced feeding opportunities. Importantly, attraction of seabirds to offshore wind farms implies an increased collision risk.