Clear-cuts in production forests provide  an open, sunny environment, with an abundance of nectar, as well as exposed soil and woody debris. This makes them a potential habitat for several groups of insects that typically use open habitats like grassland, including those species that visit flowers. In the current study, we used colour pan traps to catch flower-visiting species. Study sites were selected according to age (2-8 yrs since clear-cut) and land-use history (forest or meadow 150 yrs ago). We caught and identified solitary bees (395 specimens belonging to 59 species), social bees (831/16), other Hymenoptera (367/66), Syrphidae (256/31), and beetles (Lepturinae & Cetoniinae; 11,409/12). Age of the clear-cut strongly affected species composition as well as several of the groups and species, with most species caught mainly in the younger clear-cuts. Flower abundance statistically affected several groups and species, but such effects are potentially suspect due to the flower-richness bias in pan trap catches. Bare soil and woody debris seemed irrelevant were important for the insect assemblage sampled, while bare rock sometimes positively affected flower-visiting insectswas not. Although the majority of the insects caught were forest species, about one third of the species were associated with open, agricultural sites and hence seem to be able to locate and exploit resources in clear-cuts.

Clear-cuts in production forests provide an open, sunny environment, with an abundance of nectar, as well as exposed soil and woody debris. This makes them a potential habitat for several groups of insects that typically use open habitats like grassland, including those species that visit flowers. In the current study, we used colour pan traps to catch flower-visiting species. Study sites were selected according to age (2-8 yrs since clear-cut) and land-use history (forest or meadow 150 yrs ago). We caught and identified solitary bees (395 specimens belonging to 59 species), social bees (831/16), other Hymenoptera (367/66), Syrphidae (256/31), and beetles (Lepturinae & Cetoniinae; 11,409/12). Age of the clear-cut strongly affected species composition as well as several groups and species, with most species caught mainly in the younger clear-cuts. Flower abundance statistically affected several groups and species, but inferring causation is difficult due to the flower-richness bias in pan trap catches. Bare soil and woody debris were important for the insect assemblage sampled, while bare rock was not. Although the majority of the insects caught were forest species, about one third of the species were associated with open, agricultural sites and hence seem to be able to locate and exploit resources in clear-cuts.

Burnet moths (Zygaena spp.) are day-flying Lepidoptera considered indicative of species-rich grasslands. In the present study, our aim was to clarify whether clear-cuts are habitat, supporting habitat or matrix for three species of Zygaena. We did so by sampling these species with sex pheromones on 48 clear-cuts, varying in amount of host and nectar plants, in southern Sweden. To compare the efficiency of such sampling, we also conducted transect walks on these clearcuts. Overall, host-plants on clear-cuts best explained the abundance of Zygaena spp. recorded, better than nectar-plants or connectivity with nearby grasslands. These results indicate that clear-cuts with an abundance of host plants are used as a fully functional habitat, and not a supporting habitat in the sense of only providing nectar. There is no support in these results for considering clear-cuts as an inert matrix. With about half the work-effort, pheromone traps recorded 100 times more Zygaena spp. as transect walks. The poor correspondence between observations during transects walks and pheromone trap catches suggest Zygaena spp. being difficult to monitor by transect walks. In contrast to grasslands, clear-cuts are short-term in nature requiring repeated recolonization, indicating the importance of permanent grasslands. However, clear-cuts are important temporary insect habitats due to their great acreage, and suitable management can increase the time they remain a habitat.

Management of semi-natural grasslands is essential to retain the characteristic diversity of flora and fauna found in these habitats. To maintain, restore or recreate favourable conditions for grassland species, knowledge regarding how they occur in relation to grazing intensity and soil nutrient availability is crucial. We focused on grassland plant species, i.e., species selected to indicate high natural values in semi-natural grasslands. Environmental monitoring data collected at 366 grassland sites in southern Sweden between 2006 and 2010 were used to relate the occurrence of indicator species to factors describing geographic location, local site conditions related to nutrients and moisture, and management. Site productivity, soil moisture and cover of trees and shrubs were the main structuring factors, while other factors related to management had a lesser effect (grass sward height, amount of litter, type of grazer). Not surprisingly, these patterns were also reflected in species-wise analyses of the 25 most commonly occurring indicator species, with almost all species negatively related to site productivity and most also to soil moisture. Furthermore, many species were negatively affected by increasing sward height and litter. In contrast, species-wise responses varied among species in relation to increasing cover of trees and shrubs. In comparison to cattle grazing, sheep grazing was detrimental to six species and beneficial to none, while horse grazing was detrimental to no species and beneficial to four species. When evaluating species traits, taller plant species were favoured when site productivity, grass sward height and the amount of grass litter were high. There were no strong patterns related to the flowering time, leaf arrangement, or nutrient and light requirements of species. These results highlight the importance of nutrient-poor and dry sites, e.g., when selecting sites for conservation, and the importance of the type of management executed.

During the last centuries, land use in Europe intensified, which has led to a drastic decrease in the cover of semi-natural grasslands. In Sweden, much of the lost grasslands was turned into forest. This study investigated if species typical of managed grasslands could be found in coniferous production forests more than 80 years after grassland management ceased. Species and trait composition for plants was investigated in two types of forest differing in land use history (meadow in the 1870s or continuous coniferous forest), and in reference grasslands. The average plant species richness as well as the richness of grassland indicator species were 30% higher in forests with a history as meadow compared to in forests with a history as forest, hence clear signs of historical grassland management in todays forests. Compared with forests with continuous coniferous history, vegetation in forests with a meadow history tended to be more similar to reference grassland regarding both plant species and especially plant trait composition. The study provides proof of remnant grassland populations in coniferous production as the source for the biodiversity of clearcuts, rather than seed dispersal or seed bank survival. The result highlights the importance of land use for biodiversity of clearcuts, and points to the potential value of forests with a history of meadow in grassland conservation and restoration.

ContextLoss and fragmentation of semi-natural grasslands has critically affected many butterfly species in Europe. Habitat area and isolation can have strong effects on the local biodiversity but species may also be strongly affected by the surrounding matrix.ObjectivesWe explored how different land cover types in the landscape explained the occurrence of butterfly species in semi-natural grasslands.MethodsUsing data from 476 semi-natural grasslands in Sweden, we analysed the effect of matrix composition on species richness and occurrence. Additionally, we analysed at which spatial scales butterflies responded to matrix types (forests, semi-natural grasslands, arable land and water).ResultsForest cover showed the strongest positive effect on species richness, followed by semi-natural grasslands. Forest also had a positive effect on red-listed species at local scales. Responses to matrix composition were highly species-specific. The majority of the 30most common species showed strong positive responses to the amount of forest cover within 200-500m. There was a smaller group of species showing a positive response to arable land cover within 500-2000m. Thirteen species showed positive responses to the amount of semi-natural grasslands, generally at larger scales (10-30km).ConclusionsOur study showed that surrounding forest is beneficial for many grassland butterfly species and that forests might mitigate the negative effects of habitat loss caused by agricultural intensification. Also, semi-natural grasslands were an important factor for species richness at larger spatial scales, indicating that a landscape consisting mainly of supporting habitats (i.e. forests) are insufficient to sustain a rich butterfly fauna.

Quercus robur (oaks) provides an important substrate for many epiphytic lichens, and with increasing age the bark becomes suitable for some rare species. These species may respond to environmental and landscape factors differently, and at different spatial scales. We tested the effect of factors related to the individual tree and the surrounding landscape on the occurrence and richness patterns of lichens species. The study system consisted of 213 oaks selected in a grid system within a 400 km(2) heterogeneous oak-rich area in south-eastern Sweden. Oaks had been selected to be relatively uniform in size (circumference 3.1-4.1 m), and as uniformly distributed as possible in the study area. Landscape factors were calculated for various spatial scales (circles with radius ranging from 28 to 1225 m from a studied oak). One of the landscape factors stands out as of general importance oak density in the surrounding while the others (amount of forest, water, houses and arable field) had no effects, or weak effects on only some species. Among the tree specific variables, circumference was consistently important (despite ranging from only 3.1-4.1 m) while inconsistent effects were seen by sun exposure of oak trunk (Chaenotheca phaeocephala, Ramalina baltica) and density of shrubs and trees near the tree (Ch. phaeocephala). The occurrence patterns of Cliostomum corrugatum, Ch. phaeocephala, R. baltica and richness (number of eleven target lichens) were best explained by the density of oaks within radii of 401, 199, 199 and 303 m, respectively. In conclusion, our study highlighted the importance of spatial scale for understanding the occurrence of epiphytic lichens and suggests spatial scales and oak densities that could be targeted for landscape and conservation planning. (C) 2017 Elsevier Masson SAS. All rights reserved.

Old living oaks (Quercus robur) are known as a very species-rich habitat for saproxylic beetles, but it is less clear to what extent such veteran trees differ from an even rarer feature: downed trunks of large oaks. In this study, we set out to sample this habitat, using window traps, with two aims: (1) to describe the variation of assemblages among downed trunks of different type and (2) to compare beetles on downed oaks with data from veteran standing trees. The results showed that trunk volume and sun exposure better explained assemblages as well as species numbers on downed trunks than did decay stage. Furthermore, species classified as facultative saproxylic species showed weak or no differentiation among downed trunks. Species with different feeding habits showed no apparent differentiation among downed trunks. Furthermore, species composition on dead, downed oak trunks differed sharply from that of living, veteran oaks. Wood or bark feeders were more common on veterans than downed trunks, but there was no difference for those species feeding on fungi or those feeding on insects and their remains. In conclusion, for a successful conservation of the saproxylic beetle fauna it is important to keep downed oak trunks, and particularly large ones, in forest and pastures as they constitute a saproxylic habitat that differs from that of living trees.

Many saproxylic species are threatened in Europe because of habitat decline.Hollow trees represent an important habitat for saproxylic species. Artificial habitats mayneed to be created to maintain or increase the amount of habitat due to natural habitat decline.This study investigated the extent to which saproxylic beetles use artificial habitats in woodenboxes. The boxes were placed at various distances (0–1800 m) from known biodiversityhotspots with hollow oaks and studied over 10 years. Boxes were mainly filled with oak sawdust, oak leaves, hay and lucerne flour. In total, 2170 specimens of 91 saproxylic beetlespecies were sampled in 43 boxes. The abundance of species associated with tree hollows,wood rot and animal nests increased from the fourth to the final year, but species richnessdeclined for all groups. This study shows that wooden boxes can function as saproxylicspecies habitats. The artificial habitats developed into a more hollow-like environment duringthe decade long experiment with fewer but more abundant tree hollow specialists.

With steadily shrinking areas of species-rich semi-natural grasslands in Europe, the management of theremaining fragments becomes ever more crucial for the preservation of key elements of biodiversity inthe agricultural landscape. Detailed knowledge about species-wise, as well as group-wise, relationshipscan provide guidelines for conservation management and a basis for predictions about differentmanagement scenarios. In the present study, we related the occurrence of species of bumblebees (N = 12),butterflies (31) and day-flying moths (4) and their total richness in 424 sites in southern Sweden to threegrass sward attributes, (i)flower abundance, (ii) height of the grass sward and (iii) within-site variation inheight of vegetation. The abundance of nectar-bearingflowers proved overall the best predictor ofrichness and in most of the occurrence-based species-wise models. However, both high grass swardheight and high variation in grass sward height contributed significantly to species richness andoccurrence of individual species. There was a tendency for bumblebees to respond less positively toflower abundance and vegetation height than butterflies and moths. One expectation was that grasslandspecialists, red-listed species, or species decreasing in other part of Europe, would be more responsive totall vegetation orflower abundance but there was no support for this in the data. Hence, managementstrategies that promote common species will also benefit all, or most of, the rare ones as well.

QuestionsCan signs of 19th century grassland management, which can be observed in the flora immediately (2-4yrs) after clear-cutting in boreonemoral Sweden, still remain 4yrs later? Do the effects from the time since clear-cutting differ between forest and grassland plant species? LocationProvince of ostergotland, southern Sweden. MethodsTwelve contemporary clear-cut areas that were once meadows and 12 that were once forests were selected using land-use maps from the 1870s. Grasses and herbaceous plants were surveyed twice, once in 2009 and once in 2013 (2-4 and 6-8yrs after clear-cutting, respectively). Plant presence was recorded within 100 circular sample plots (radius 1m) placed evenly throughout each respective clear-cut area along transects spaced 25-m apart. The number of sample plots in which a species was present was taken as a measure of that species frequency. Random effects meta-analysis, odds ratios and ANCOVA were used to analyse species responses to clear-cutting over time. ResultsA total of 170 plant species were found in the study, of which 33 were classified as grassland indicator species and 31 as plants primarily confined to forests. Clear-cut areas with a history as meadowland had, on average, up to 64% higher total species richness and 110% more grassland indicator species than did clear-cut areas with a history as forest. The time since clear-cutting had no effect on total species richness. However, the odds of finding a grassland indicator species decreased with the time since clear-cutting, whereas the odds of finding a forest species increased. ConclusionsWe concluded that land-use history plays an important role in explaining the flora found in Swedish clear-cuts, and that its effects on species richness remain for a minimum of 8yrs after harvest (conservative estimate). This phenomenon highlights the importance of acknowledging land-use legacies in ecological research and conservation. Future studies should investigate various options for the promotion of grassland plants in clear-cuts with a history of grassland management while also acknowledging the potential conflicts between conservation and production. The results may pertain to other countries with similar land-use histories.

Modern intensified agriculture has decreased farmland heterogeneity, which has led to strong negative effects on farmland biodiversity. However, partly forested landscapes seem to offer many alternative habitats for open habitat species such as butterflies, since modern forestry and development of infrastructure has created several new environments such as forest road verges and power-line corridors. The aim of the present study was to investigate the importance of power-line corridors (PLCs) as butterfly habitats by testing i) if species richness and abundance of butterflies in PLCs are affected by adjacent habitat composition (i.e. comparisons of PLCs with different adjacent habitats), ii) if PLCs act as source habitat through spill-over of individuals into adjacent forest roads and semi-natural pastures and iii) if species composition differs among the investigated habitat types. To investigate this we censured the butterfly fauna in 23 study landscapes in south-central Sweden. We found support for the hypothesis that PLCs may act as source habitats for butterflies in forest roads and pastures, since species richness and abundance were decreasing with increasing distance to PLC from 0 to 500 m. In addition, the species composition in forest roads and pastures close to and far from PLCs was similar, suggesting that this increase was not due to an increase of PLC specialists in the other two habitats. Thus, we have shown that PLCs in themselves are important butterfly habitats independently of adjacent habitat composition (adjacent mature forest, clear cuts or arable land), and they contribute to increased species richness and abundance of butterflies in surrounding areas over 10 times larger than their own width. (C) 2016 Elsevier Ltd. All rights reserved.

Synanthedon vespiformis L. (Lepidoptera:Sesiidae) is considered a rare insect in Sweden, discoveredin 1860, with only a few observations recorded until a sexpheromone attractant became available recently. This studydetails a national survey conducted using pheromones as asampling method for this species. Through pheromonetrapping we captured 439 specimens in Southern Sweden at77 sites, almost tripling the number of previously reportedrecords for this species. The results suggest that S. vespiformisis truly a rare species with a genuinely scattereddistribution, but can be locally abundant. Habitat analyseswere conducted in order to test the relationship betweenhabitat quality and the number of individuals caught. InSweden, S. vespiformis is thought to be associated with oakhosts, but our attempts to predict its occurrence by theabundance of oaks yielded no significant relationships. Wetherefore suggest that sampling bias and limited knowledgeon distribution may have led to the assumption that thisspecies is primarily reliant on oaks in the northern part ofits range, whereas it may in fact be polyphagous, similar toS. vespiformis found as an agricultural pest in Central andSouthern Europe. We conclude that pheromones canmassively enhance sampling potential for this and otherrare lepidopteran species. Large-scale pheromone-basedsurveys provide a snapshot of true presences and absencesacross a considerable part of a species national distributionrange, and thus for the first time provide a viable means ofsystematically assessing changes in distribution over timewith high spatiotemporal resolution.

Fire-favoured insects are difficult to sampleexcept opportunistically after forest fires. Here, we tested ifsmoke from a small fire could be an efficient way to samplesuch insects. Insects were sampled over ca. 10 h hours, byhand-picking and netting on screens put up around the fire.Two specimens of the rare and redlisted Hormopeza spp.(Diptera, Empididae) were caught. Large numbers([20,000) of Microsania spp. (Diptera, Platypezidae) werecaught, but none in the absence of smoke. The numbers ofMicrosania spp. clearly peaked in late afternoon, and ashort sampling period would be sufficient if targeting onlythis taxon. Of the almost 200 species of Coleoptera, 17 %were considered as fire-favoured, contributing 9 % of thespecimens, suggesting low efficiency of the method for thisgroup. Using 23 sites differing in fire history, catches ofMicrosania spp. were unaffected by numbers and area offorest fire (preceding 5 years and within 10 km radius overthe sampling sites). In contrast, there was a weak trend forthe proportion of fire-favoured Coleoptera to increase withincreasing number of fires. To conclude, smoke as producedin our study can clearly attract fire-favoured Diptera,but smoke had only a weak effect on fire-favoured Coleopterain the study area. It is still likely that selectivelypicking specimens of species attracted to smoke is a morecost-efficient method than using, e.g., Malaise traps thatcatch indiscriminately.

Butterfly conservation in Europe is mainly focused on well-defined grassland habitat patches. Such anapproach ignores the impact of the surrounding landscape, which may contain complementary resourcesand facilitate dispersal. Here, we investigated butterfly species richness and abundance in a habitatnormally regarded as unsuitable matrix: production forestry clear-cuts. Butterflies were recorded in 48clear-cuts in southern Sweden differing with regards to the time since clear-cutting and land-use history(meadow or forest based on historical maps from the 1870s). All clear-cuts had been managed as productionforests for at least 80e120 years. A total of 39 species were found in clear-cuts of both land-usehistories, but clear-cuts with a history as meadow had on average 34% higher species richness and 19%higher abundance than did clear-cuts with a history as forest. No effect of the time since clear-cuttingwas found, irrespective of land-use history, which was likely due to the narrow timespan sampled (<8years). The absence of temporal effect suggests that clear-cuts may provide butterflies with valuableresources for 10e15 years. Assuming a 100 year forest rotational cycle, this means that 10e15% of thetotal forested area are made up by clear-cuts valuable to butterflies, which corresponds to an area aboutfour times as large as that of species-rich semi-natural grasslands. The study illustrates the importance ofconsidering land-use legacies in ecological research and question the landscape-ecological view thatclear-cuts make up an unsuitable matrix for butterflies. Moreover, forest conservation management withspecial attention to land-use history may increase the quality of the landscape, thus facilitating butterflymetapopulation persistence. Given their large area and assets of nectar and host plant resources, clearcutsmust be considered as a butterfly habitat in its own right. Being a man-made environment withshort history, we might call it a neo-habitat.

Losses of both habitat area and connectivity have been identified as important drivers of species richness declines, but littletheoretical and empirical work exists that addresses the effect of fragmentation on relative commonness of highly mobilespecies such as pollinating insects. With a large dataset of wild bee and butterfly abundances collected across Europe,we first tested the effect of habitat area and connectivity on evenness in pollinator communities using a large array ofindexes that give different weight to dominance and rarity. Second, we tested if traits related to mobility and diet breadthcould explain the observed evenness patterns. We found a clear negative effect of area and a weaker, but positive effectof connectivity on evenness. Communities in small habitat fragments were mainly composed of mobile and generalistspecies. The higher evenness in small fragments could thereby be generated by highly mobile species that maintain localpopulations with frequent inter-fragment movements. Trait analysis suggested an increasing importance of dispersalover local recruitment, as we move from large to small fragments and from less to more connected fragments. Speciesrichness and evenness were negatively correlated indicating that the two variables responded differently to habitat areaand connectivity, although the mechanisms underlying the observed patterns are difficult to isolate. Even though habitatarea and connectivity often decrease simultaneously due to habitat fragmentation, an interesting practical implicationof the contrasting effect of the two variables is that the resulting community composition will depend on the relativestrength of these two processes.

Biodiversity often suff ers from urbanization. In the present study, we focused on how the duration of urbanization aff ects therichness of 17 epiphytic lichen species and their cover on large oaks in urban environments in a city of 100 000 inhabitantsin southeast Sweden. We also surveyed trees in adjacent rural areas, selected to have similar distributions of tree trunkcircumference and surrounding oak density (within 300 m). Lichen richness and cover were lower on urban trees comparedto rural trees. Furthermore, richness and cover decreased with the length of time that urban trees had been surrounded byhouses. Most of the species that were analysed demonstrated a decline in occurrence with respect to the duration of housingdevelopment. Th e reduction in the probability of occurrence varied from 60% ( Calicium viride , Evernia prunastri ), 80%( Chrysothrix candelaris ) to 90% ( Ramalina spp.) during the considered 160-year period of urbanization. Th erefore, even ifvaluable trees survive over the course of development, their lichen biota is likely to become depleted over time.

The rare beetle Elater ferrugineus was sampled at 47 sites in the county of Östergötland, Sweden by meansof pheromone-baited traps to assess its value as an indicator species for hollow oak stands rich in raresaproxylic beetle species. In addition, Osmoderma eremita was also sampled with pheromone baits. Thesedata were then compared against species survey data collected at the same sites by pitfall and windowtraps. Both species co-occur with many Red Listed saproxylic beetles, with E. ferrugineus being a somewhatbetter indicator for the rarest species. The conservation value of a site (measured as Red List pointsor number of Red Listed species) increased with the number of specimens of E. ferrugineus and O. eremitacaught. Accuracy of sampling by means of pheromone trapping turned out to be radically different for thetwo model species. E. ferrugineus traps put out during July obtained full accuracy after only 6 days,whereas O. eremita traps needed to be out from early July to mid-August in order to obtain full accuracywith one trap per site. By using E. ferrugineus, or preferably both species, as indicator species, accuracywould increase and costs decrease for saproxylic biodiversity sampling, monitoring and identificationof hotspots.

Question

The management of species-rich semi-natural grasslands, a fragmented and threatened vegetation type in Europe, involves costs. Mowing is expensive and grazing can be difficult to achieve and maintain for logistical reasons. Is annual spring burning, which is potentially cheaper than mowing and grazing, a viable management tool for species-rich grasslands?

Location

Long-term field trials in 11 grasslands in southern Sweden.

Methods

We calculated the odds for a species being an indicator of good management, an indicator of poor management, or an indicator of nitrogen influence in spring-burned plots, grazed plots and annually mowed plots. Odds ratios contrasting spring-burned plots with grazed plots and spring-burned plots with mowed plots were subjected to meta-analyses in which we compared the odds ratios after 1, 8 and 14 spring burns. For a single trial, we also analysed data after 1, 8, 14, 28 and 39 spring burns.

Results

Compared with mowed and grazed plots, the odds of the four different indicators of good management decreased in spring-burned plots, while the odds for the two indicators of poor management increased. There was no trend in the two indicators of excess nitrogen. Therefore, the conservation value of vegetation in spring-burned plots becomes reduced over time relative to traditional management.

Conclusions

Spring burning is not an appropriate long-term management method if the aim is to maintain the conservation value of the vegetation in traditionally managed semi-natural grasslands.

• Many wood-dwelling beetles rely on old hollow trees. In Europe, oaks are known to harbour a species-rich saproxylic beetle fauna, while less is known regarding other broad-leaved tree species. Furthermore, the extent to which saproxylic insect species have specialised on different tree species remains unknown.
• In this study, we sampled beetles through pitfall traps and window traps in four different tree species in a landscape with many old oaks.
• We recorded 242 saproxylic beetle species of which 27 were red-listed. After eliminating the species recorded only on a single tree, few cases among the 171 remaining species in the data set were confined to a single tree species.
• Using odds ratios, we showed that 19 of the 171 beetle species showed significant associations with Quercus robur in at least one of the two trap types. For Acer platanoides, Fraxinus excelsior and Tilia cordata, the corresponding numbers were 6, 2 and 5, respectively. One species showed a negative association with Q. robur.
• Using meta-analysis, we quantified the degree of association between the beetle species and the tree species. The associations were most profound among species classified as obligate saproxylic rather than facultative in lifestyle. Overall, a significant association was only found with Q. robur.
• We conclude that the saproxylic fauna is dominated by non-specialist species but includes a small proportion of truly host-tree-specific species. Furthermore, other broad-leaved trees can be important as supporting habitats for many saproxylic organisms that have had presumed associations with oaks to date.

Mowing of semi-natural grasslands is an important management method to maintain the conservation value and species-richness of this habitat. Mowing using cutting instruments, e.g. sickle bar mowers, is thought to be superior by practitioners compared with other mechanical instruments that tears off the plant material, e.g. grass trimmers. However, almost no studies exist that supports this assumption. We analysed a 12-year field trial in a semi-natural grassland in south-eastern Sweden, with the aim of determining which mowing technique best maintains the conservation value of semi-natural grasslands. Two mowing techniques were compared: mowing using a hand-pushed sickle bar mower (a type of knife mower), or mowing using a grass trimmer at a 5-cm or 0-cm cutting height. The odds that a recorded species belongs to a group of indicator species were calculated for sample plots, and odds ratios were calculated contrasting treatments. Three types of indicator species classification systems were used: (i) indicators of management for species richness, (ii) indicators of excess nitrogen and (iii) indicators of lack of management. The odds ratios were calculated for years 1–5, 7 and 12 of the trial. In addition, Principal Response Curve analysis was performed to analyse the change in vegetation composition over time and ANOVA for plant species richness in plots. The results showed that over time there were no differences in the odds of finding indicators of any of the three types, for any of the mowing techniques. Furthermore, there were no apparent change in vegetation composition and only a small effect on richness. These results suggest that mowing using a sickle bar mower or a grass trimmer had the same effect on the floristic composition of grasslands, and both techniques can be recommended for use in semi-natural grasslands.

Plant species richness in central and northern European seminatural grasslandsis often more closely linked to past than present habitat configuration, which isindicative of an extinction debt. In this study, we investigate whether signs ofhistorical grassland management can be found in clear-cuts after at least80 years as coniferous production forest by comparing floras between clear-cutswith a history as meadow and as forest in the 1870s in Sweden. Study sites wereselected using old land-use maps and data on present-day clear-cuts. Speciestraits reflecting high capacities for dispersal and persistence were used toexplain any possible links between the plants and the historical land use. Clearcutsthat were formerly meadow had, on average, 36% higher species richnessand 35% higher richness of grassland indicator species, as well as a larger overallseed mass and lower anemochory, compared to clear-cuts with history asforest. We suggest that the plants in former meadows never disappeared afterafforestation but survived as remnant populations. Many contemporary forestsin Sweden were managed as grasslands in the 1800s. As conservation of remaininggrassland fragments will not be enough to reduce the existing extinctiondebts of the flora, these young forests offer opportunities for grassland restorationat large scales. Our study supports the concept of remnant populationsand highlights the importance of considering historical land use for understandingthe distribution of grassland plant species in fragmented landscapes, aswell as for policy-making and conservation.

One of the main natural disturbances that affects the structure of rain forests is treefalls, frequently resulting in gaps. Tree-fall gaps can bring drastic changes in environmental conditions compared with the undisturbed understory. We investigated the effect of tree-fall gaps on fruit-feeding butterfly (Nymphalidae) species assemblages in an undisturbed lowland rain forest in southeastern Peru. We used fruit-baited traps suspended 2 m above ground in 15 tree-fall gaps ranging in area from 100 to 1000 m² and in adjacent undisturbed understory. Our data support the hypothesis that tree-fall gap and understory habitats are utilized by different butterfly species assemblages. There were morphological differences between gap and understory species, where the understory species had a larger wing area to thoracic volume. Vegetation structure and composition were important factors affecting the butterfly assemblages. Most of the butterfly species showed an avoidance of vines and a strong association with the presence of trees and shrubs in gaps. There were also differences among gap assemblages that increased with gap size. Some of the species that were associated with gaps have been considered as canopy species. Other gap species in the present study, however, are known to feed on fruits and/or use host plants mainly, or only, occurring in gaps, implicating that the gap assemblage is a mix of canopy species and those unique to gaps. This indicates that, in an undisturbed Amazon forest, tree-fall gaps may contribute to maintain species diversity by creating a mosaic of specific habitats and resources that favors different butterfly assemblages.

Assessing ecological sustainability involves monitoring of indicators and comparison of their states with performance targets that are deemed sustainable. First, a normative model was developed centered on evidence-based knowledge about (a) forest composition, structure, and function at multiple scales, and (b) performance targets derived by quantifying the habitat amount in naturally dynamic forests, and as required for presence of populations of specialized focal species. Second, we compared the Forest Stewardship Council (FSC) certification standards’ ecological indicators from 1998 and 2010 in Sweden to the normative model using a Specific, Measurable, Accurate, Realistic, and Timebound (SMART) indicator approach. Indicator variables and targets for riparian and aquatic ecosystems were clearly under-represented compared to terrestrial ones. FSC’s ecological indicators expanded over time from composition and structure towards function, and from finer to coarser spatial scales. However, SMART indicators were few. Moreover, they poorly reflected quantitative evidence-based knowledge, a consequence of the fact that forest certification mirrors the outcome of a complex social negotiation process.

The European red click beetle, Elater ferrugineus L., is associated with wood mould in old hollow deciduous trees. As a result of severe habitat fragmentation caused by human disturbance, it is threatened throughout its distribution range. A new pheromone-based survey method, which is very efficient in detecting the species, was used in the present study to relate the occurrence of E. ferrugineus to the density of deciduous trees. The latter data were from a recently completed regional survey in SE Sweden recording >120,000 deciduous trees. The occurrence of E. ferrugineus increased with increasing amount of large hollow and large non-hollow trees in the surrounding landscape. Quercus robur (oak) was found to be the most important substrate for E. ferrugineus, whereas two groups of tree species (Carpinus betulus, Fagus sylvatica, Ulmus glabra, vs. Acer platanoides, Aesculus hippocastanum, Fraxinus excelsior, Tilia cordata) were less important but may be a complement to oak in sustaining populations of the beetle. The occurrence of E. ferrugineus was explained by the density of oaks at two different spatial scales, within the circle radii 327 m and 4658 m. In conclusion, priority should be given to oaks in conservation management of E. ferrugineus, and then to the deciduous trees in the genera listed above. Conservation planning at large spatial and temporal scales appears to be essential for long-term persistence of E. ferrugineus. We also show that occurrence models based on strategic sampling might result in pessimistic predictions. This study demonstrates how pheromone-based monitoring make insects excellent tools for sustained feedback to models for landscape conservation management.

Autocorrelation within ecological time series and synchrony between them may provide insight into the main drivers of observed dynamics. We here present methods that analyse autocorrelation and synchrony in ecological datasets using a spectral approach combined with Bayesian inference. To exemplify, we implement the method on dendrochronological data of the pedunculate oak (Quercus robur). The data consist of 110 years of growth of 10 live trees and seven trees that died during a synchronized oak death in Sweden in c. 2002-2007. We find that the highest posterior density is found for a noise colour of tree growth of gamma approximate to 0.95 (i.e. pink noise) with little difference between trees, suggesting climatic variation as a driving factor. This is further supported by the presence of synchrony, which we estimate based on phase-shift analysis. We conclude that the synchrony is time-scale dependent with higher synchrony at larger time-scales. We further show that there is no difference between the growth patterns of the alive and dead tree groups. This suggests that the trees were driven by the same factors prior to the synchronized death. We argue that this method is a promising approach for linking theoretical models with empirical data.

A key aspect for understanding species distributions is how they respond to habitat factors at different spatial scales. In this study we used a dataset mapping 33,000 large/hollow oaks, habitat for a guild of saproxylic beetles specialised on oaks at an extent of 10,000 km². A total of 16 oak-dependent saproxylic species, out of 35, showed a clear relationship with substrate density at scales ranging from 52 m to ⩾5200 m. The characteristic scale of response for species richness of oak specialist species was 2284 m. At this scale, there was a tendency for richness to plateau at about 0.15 oaks ha⁻¹, in which case about 250 hollow or large (circumference 310 cm) oaks would be needed in an area of 1600 ha to ensure a rich saproxylic oak fauna.

The main general conclusions were: (i) a multi-scale approach is especially valuable to identify the characteristic scale of response; and that assuming a joint, single scale for all species may result in very poor decision support. (ii) The variation in species’ responses to substrate density at different scales means that habitat loss and fragmentation as well as management and restoration may have very different effects upon different species. (iii) Some species respond both to local and landscape scales, indicating that species occurrences in fragmented oak landscapes are affected both by short-term dynamics of the beetles and long term dynamics of the oak substrate. (iv) Maps, useful as decision support, can be constructed based on resource availability (in our case oak density) and characteristic scales.

The landscape matrix is suggested to influence the effect of habitat fragmentation on species richness, but the generality of this prediction has not been tested. Here, we used data from 10 independent studies on butterfly species richness, where the matrix surrounding grassland patches was dominated by either forest or arable land to test if matrix land use influenced the response of species richness to patch area and connectivity. To account for the possibility that some of the observed species use the matrix as their main or complementary habitat, we analysed the effects on total species richness and on the richness of grassland specialist and non-specialist (generalists and specialists on other habitat types) butterflies separately. Specialists and non-specialists were defined separately for each dataset. Total species richness and the richness of grassland specialist butterflies were positively related to patch area and forest cover in the matrix, and negatively to patch isolation. The strength of the species-area relationship was modified by matrix land use and had a slope that decreased with increasing forest cover in the matrix. Potential mechanisms for the weaker effect of grassland fragmentation in forest-dominated landscapes are (1) that the forest matrix is more heterogeneous and contains more resources, (2) that small grassland patches in a matrix dominated by arable land suffer more from negative edge effects or (3) that the arable matrix constitutes a stronger barrier to dispersal between populations. Regardless of the mechanisms, our results show that there are general effects of matrix land use across landscapes and regions, and that landscape management that increases matrix quality can be a complement to habitat restoration and re-creation in fragmented landscapes.

In Swedish boreal landscapes, the loss of species-rich semi-natural grasslands is largely due to a longhistory of agricultural abandonment. Large areas historically managed as meadows have become matureconiferous forest. This study focused on the potential biological legacy following a long period of grasslandabandonment. The butterfly fauna in clear-cuts which was historically meadows and abandoned longenough to allow a generation of conifers to mature (70–90 years) was compared with clear-cuts whichwere historically coniferous forest. The results showed that clear-cuts historically managed as meadowswere: (i) much richer in individuals, (ii) more species-rich, and (iii) contained many more grasslandspecialists than clear-cuts with a history as forest, with many of these species threatened in other partsof Europe.The results from our study demonstrate for the first time, to our knowledge, that the legacy of historicalland-use in remnant plant communities can affect butterfly diversity in clear-cuts and hence the largescaledynamics over a timescale of a full tree rotation. The results of this study have implications for forestmanagement practices. Replanting clear-cuts on land that was previously meadows with deciduous treesor allowing the forest to regenerate naturally instead of planting conifers would make it possible topreserve a greater diversity of habitats for butterflies and other organisms.

Background and purpose A complex interplay between biotic and abiotic factors is believed to be responsible for several oak declines in pedunculate oak (Quercus robur L.). This study aims to clarify the temporal process of oak declines, as well as identifying individual tree and environmental variables that affects growth rate and that may increase the risk of mortality. The study was performed in southern Sweden at three sites. Findings Cross-dating revealed that most trees had died during the last decade and that the growth rates of the dead oaks were affected long before death. Averaged growth chronologies of dead and control trees reaching 150 years back in time illustrated an excellent match up until around 1992, when a severe drought occurred after which the dead trees started to express reduced growth. Precipitation the previous year during August-September and during March-June this current year was of significant importance for oak growth. Site-specific results that showed that dead trees: included fewer small-sized trees, grew on non-clay soils, were more likely to have shelf fungus and cavities and were exposed to less sunshine. Conclusion The results support the theories that oak mortality is a long process that may be induced decades before the actual death.

Species are differentially affected by habitat fragmentation as a consequence of differences in mobility, area requirements, use of the matrix, and responses to edges. A quantitative understanding of these differences is essential not only for conservation biology but also for basic ecological theory. Here, we examine density responses by butterflies to patch size and use a quantitative theory on the scaling of population density with patch size to interpret results. Theory suggests that the density distribution of mobile species along a patch size gradient should depend on the scaling of net migration rates, whereas the density distribution of less mobile species should depend more on local growth. Using data from 11 localities in three European countries, we calculated the slope in the relationship between patch size and population density. These slopes were evaluated in relation to butterfly traits and matrix composition. As estimates of butterfly mobility we used both wing span and expert mobility rankings. The slope of the density–area relationship changed as predicted with wing span and the association of species to grasslands. Large and highly mobile species had a negative slope, similarly for grassland specialists and generalist species, and the slope matched quantitative predictions based on the scaling of net migration rates. Small and less mobile grassland specialists had a slope that was less negative than the slope of large and mobile grassland specialists, whereas the slope did not change with size for generalist species. These analyses suggest that the variability in response among butterfly species to patch size could be explained by accounting for body size/mobility and habitat associations among species. A caveat is that edge effects are not explicitly included in the model analysis, and future research should aim to combine area and edge effects in a common theoretical framework.

This article briefly describes the success of the knowledge-transfer reform within medicine known as evidence-based medicine. In this field, the idea is that any decision about an intervention, or lack thereof, should be based on the best available knowledge. The current move towards a similar reform within nature conservation is reviewed, and its differences with medicine discussed. If "evidencebased conservation" is broadly accepted among researchers, practitioners and NGOs, it might lead to a more consistent protocol for reporting case studies trying interventions and, in the long run, a more efficient use of limited resources for conservation.

1. Habitat requirements and occurrence patterns of three species of burnet moths (Zygaena filipendulae, Zygaena lonicerae and Zygaena viciae) were studied at different life stages and different scales on the Baltic island of Oland, Sweden. 2. Larvae of all three species were more likely to occur in small-scale patches (i.e. 1 m2) with a greater cover of their most important host plants, Lotus corniculatus, Trifolium medium/pratense, or Vicia spp., than were pupae or adults, and were also observed on significantly larger than random plants. Pupation of Z. filipendulae took place in taller vegetation than preferred by feeding larvae and adults. 3. Adults of all species preferred different nectar plants of Asteraceae and Dipsacaceae, growing in sunny conditions. 4. A large-scale analysis of occupancy patterns was made, evaluating the relationship between burnet occurrence and the area of meadows and pastures within 10 x 10 km grid cells in Sweden. All three species showed a significant positive relationship with the area of semi-natural grassland. The area required for a 50% probability of burnet occurrence was 454 ha for Z. filipendulae, 925 ha for Z. lonicerae and 2055 ha for Z. viciae. 5. Conservation work should aim at preserving and restoring open areas rich in the respective host plants and nectar sources, with light grazing or mowing late in the season. At the landscape scale, burnet moths were favoured by a high density of semi-natural grassland and management priorities should be directed to these regions.

Monitoring of butterflies is often directed only towards grassland fauna. Species associated with other habitats, as well as the impact of the surrounding landscape, are often neglected. The aim with this study was, in contrast, to perform and evaluate a landscape-based monitoring method for butterflies in diverse habitats and more specifically to (i) evaluate the impact of environmental variables on butterfly abundance; (ii) compare the distribution of butterflies in different habitats; and (iii) analyse data from the study with the aim of improving the method. Eight randomly placed study sites (750 m x 750 m) located in south-eastern Sweden were used. The vegetation composition (tree cover, percentage of coniferous and deciduous forest, shrubs, dry, mesic, damp and wet land) inside the squares was analysed using aerial photos and habitats along transects were categorised in the field. The butterfly composition varied depending on the landscape composition. Tree cover had the largest impact on butterfly abundance with a negative relationship between abundance and increasing tree cover. The most species-rich habitats were other grasslands (abandoned fields and fallows), clear-cuts, semi-natural grasslands, and bogs, each habitat also harbouring unique species. Clear-cut was the habitat harbouring the highest abundance and other grasslands the highest diversity of butterflies. Semi-natural grasslands, where the nationally based monitoring of butterflies in Sweden currently is being performed, constitutes andlt;1% of the total land area in Sweden, indicating a current bias in monitoring directed towards only a part of the species pool. The landscape-based form of monitoring presented here can, if performed regularly, increase our knowledge of how structural changes of landscape affect butterflies and thereby improve conservation efforts.

The saproxylic beetle fauna on old oaks was sampled in four regions of southern Sweden using two methods: window and pitfall trapping. The aim was to test a way of finding indicator species which can be used to identify sites with high species number or that scored high on a conservation priority species index, based on occurrence of red-listed species. From 92 sites surveyed, in total 164 species of saproxylic beetles were identified. Different sets of indicator species were selected based upon 22 sites from a centrally located region. Predictions of species number and the index for 30 other sites from the same province were made. The correlation between observed and predicted species number and the index increased with increasing number of indicators. When comparing different treatment of species indata, the explanatory power of predictions was strongest for presence/absence data. Indicator sets of species effectively caught with pitfall traps gave overall the best predictions of both species number and the index. Predictions of species number and the index worked well within the same regions but gave varied result for the three other regions which shows that transferability of indicators between regions may be doubtful.

The butterfly fauna was monitored in six semi-natural grasslands in southeastern Sweden. The aim was to evaluate monitoring criteria for wind, sunshine, temperature and time of day for butterfly species richness and abundances when using the line transect method. A total of 30,111 butterflies belonging to 46 species were recorded. Data from this study suggests somewhat stricter criteria for temperature and sunshine than stated in the widely used "Pollards walk". A sharp decline in butterfly numbers were detected at temperatures below 19A degrees C if the proportion of sunshine of the transect walk was below 80-85%. No effect of wind speed, up to five on the Beaufort scale, on observed numbers of species or individuals were found. Several butterfly species showed well-defined diurnal rythms of flight activity, and the results indicated that transect walks can be performed between -4.5 and +4 h from the time when the sun reached its highest point. The results of this study can be used to adjust general criteria in national monitoring and also for detailed regional and local monitoring where it may be important to adjust for diurnal rhythm and weather related bias.

Oaks (Quercus robur) can reach a considerable age, which makes them an important substrate for many epiphytic lichens, including several red-listed species. We studied the importance of tree size and other environmental factors for the occurrence of six epiphytic lichens at two sites, in southeastern Sweden, differing in quality as judged by tree size distribution and number of old trees. The effects of tree circumference, light availability, trunk inclination and site were analysed. Results showed that different lichen species responded differently to these factors, but, overall, tree size was most important for lichen occurrence. Five species showed a positive relation to tree size, but the 50% probability of occurrence was reached at different tree sizes among these species and there were also site differences. This study shows that the maintenance of old trees is crucial for several lichen species, which highlights the importance of long-term management plans.

Oaks (Quercus robur) can reach a considerable age, which makes them an important substrate for many epiphytic lichens, including several red-listed species. We studied the importance of tree size and other environmental factors for the occurrence of six epiphytic lichens at two sites, in southeastern Sweden, differing in quality as judged by tree size distribution and number of old trees. The effects of tree circumference, light availability, trunk inclination and site were analysed. Results showed that different lichen species responded differently to these factors, but, overall, tree size was most important for lichen occurrence. Five species showed a positive relation to tree size, but the 50% probability of occurrence was reached at different tree sizes among these species and there were also site differences. This study shows that the maintenance of old trees is crucial for several lichen species, which highlights the importance of long-term management plans.

 Föreliggande rapport är slutrapporten inom projektet ”Landskapsekologiska effekter av vägar och järnvägar på ryggradslösa djur” som pågått 2001-2003. En övervägande majoritet av alla studier av vägars/järnvägars effekter på djur har tidigare gjorts på större däggdjur och fåglar, men även groddjur och smådäggdjur fanns relativt väl representerade. För ryggradslösa djur fanns dock få studier och kunskapen var dålig om effekterna på denna grupp som är den absolut artrikaste. Projektet har fokuserat på dagfjärilar och odlingslandskap. En av de bäst kända grupperna av ryggradslösa djur är dagfjärilar. Odlingslandskapet som de framförallt finns i är också ett intressant landskap gällande infrastrukturproblematik. Det här projektet ligger under paraplyprojektet EKLIPS (ekologisk infrastrukturplanering med fjärranalys). Målet med EKLIPS är att utveckla och förbättra trafikverkens hantering av natur- och kulturvärden i de olika delarna av planeringsprocessen.

Projektet bestod av två delar: 1) att undersöka arealkrav på landskapsnivå hos en grupp ryggradslösa djur (dagfjärilar) för att i förlängningen kunna identifiera värdefulla odlingslandskap. 2) att studera den eventuella barriäreffekt en väg kan ha på flygande ryggradslösa djur. Även här är det dagfjärilar som studerats.

De huvudsakliga slutsatserna av den här studien av dagfjärilar som verktyg i infrastrukturplanering är att:

• Dagfjärilar kan användas för att identifiera biologiskt rika odlingslandskap. Totalt undersöktes 62 områden och 12 170 individer av 57 fjärilsarter identifierades.
• Landskapet ska studeras i relativt stor skala. Den skala som påverkar fjärilssamhällets sammansättning handlar om kilometrar snarare än hundratals meter. Mängden hagmarker och lövskogar inom 500 m och 2000 m kunde inte förklara fjärilsfaunans sammansättning, däremot mängden inom 5000 m.
• Det finns kritiska tröskelvärden för mängden av habitat i landskapet och infrastruktur har troligen sin största negativa påverkan kring dessa värden. Tröskelvärdet för att ett artrikt område (>20 arter dagfjärilar) med >50% sannolikhet ska kunna finnas i ett område var i denna studie 570 ha (7,3%) hagmarker/lövskog inom en radie av 5000 m.
• Tröskelvärdena för enskilda arter varierade mellan 130-950 ha, det vill säga 1,6-12.1% av landskapet ska bestå av passande habitat.
• Indikatorarter kan användas för att identifiera rika landskap. Våra studier pekar på att flera arter och två artgrupper kan vara användbara. De två artgrupperna är pärlemorfjärilar och bastardsvärmare. Totalt 13 arter eller artgrupper påträffades främst i rika landskap, t ex skogsnätfjäril, vitgräsfjäril, midsommarblåvinge, brunfläckig pärlemorfjäril och silverstreckad pärlemorfjäril.
• Vägar kan fungera som barriärer för vissa arter. För två av arterna hade vägen en signifikant barriäreffekt. För luktgräsfjäril minskade flödet med 74% och för slåttergräsfjäril med 43%.
• Potentiellt rika landskap ska gå att identifiera från flygbilder och satellitdata utan att göra omfattande fältinventeringar i framtiden baserat på våra resultat. Fortfarande är dock resultaten för osäkra (ej upprepade i andra landskap) för att appliceras i större skala.
• När vägplaneringsprocessen kommit fram till vägutredningen kan indikatorarterna användas för att identifiera för artrikedomen viktiga områden och för att precisera målsättningarna för vilken naturhänsyn som skall tas i arbetet. Indikatorarterna kan också användas i uppföljningsarbete för att uppskatta om projektmålen uppnåtts.

Metapopulation theory has generally focused only on the stochastic turn-over rate among populations and assumed that the number and location of suitable habitat patches will remain constant through time. This study combines in a PVA both the deterministic landscape dynamics and the stochastic colonisations and extinctions of populations for the butterfly Lopinga achine in Sweden. With data on occupancy pattern and the rate of habitat change, we built a simulation model and examined five different scenarios with different assumptions of landscape changes for L. achine. If no landscape changes would be expected, around 80 populations are predicted to persist during the next 100 yr. Adding the knowledge that many of the sites are unmanaged and that the host plant will slowly deteriorate as canopies close over, and adding environmental variation and synchrony, showed that the number of populations will decrease to around of 4.3 and 2.8 respectively, with an extinction risk of 34% - quite different from the first scenario based only on the metapopulation model. This study has shown the importance of incorporating both deterministic and stochastic events when making a reliable population viability analysis. Even though one can not expect that the long-term predictions of either occupied patches or extinction risks will be accurate quantitatively, the qualitative implications are correct. The extinction risk will be high if grazing is not applied to more patches than is the case today. The simulations indicate that an absolute minimum of 10-30 top-ranked patches needs to be managed for the persistence of the metapopulation of L. achine in the long term. The same problem of abandoned and overgrowing habitats affects many other threatened species in the European landscape and a similar approach could also be applied to them.

The red-listed butterfly Lopinga achine was studied by mark-recapture methods in southern Sweden for three seasons. We examined movement within and between populations and egg production in relation to age. The majority of the movements were small with mean movements between recaptures of 45-54 m for males and 94-116 m for females. There were few movements between sites, 20 of 996 recaptured males moved and 36 of 391 recaptured females, even though the distance to other sites was in many cases < 100 m. The distance moved and the number of females moving between sites increased with increasing age. On average, a female that moves does so after laying two-thirds of its eggs in its natal site. It is therefore important to take account of the proportion of reproductive effort involved in dispersal when estimating colonisation ability. The males did not move more with increasing age. Female behaviour can be seen as a "spread-the-risk" strategy, an adaptation to the successional habitat of L. achine, whose natal site sooner or later will deteriorate. Butterflies like L. achine living in successional habitats may exhibit mobility that is intermediate between butterflies living in ephemeral habitats (very mobile) and in long-lived habitats (sedentary). ⌐ 2002 Elsevier Science Ltd. All rights reserved.

The distribution of occupied and vacant sites and migration of the threatened butterfly Lopinga achine were studied in the province of ╓sterg÷tland, Sweden. The probability of occupation increased with increasing patch area and decreasing distance to the nearest occupied patch, presumably due to different probabilities of colonisation and survival of the populations inhabiting the patches. Probability of female emigration from and immigration to a patch increased with decreasing area. Middle-sized patches produced the largest number of female migrants, although the highest fraction was noted for the smallest patches, and the greatest number of females was marked in the largest patch. The fraction of resident females, but not males, increased with increasing area. The observed occupancy and migration pattern have important conservation implications: all but two populations comprising three or more individuals were within 740 m of the nearest neighbour, indicating the need for networks of suitable, closely situated patches. ⌐ 2001 Elsevier Science Ltd. All rights reserved.