Foraging behaviour of dormice Muscardinus avellanarius in two contrasting habitats.

Anatomical evidence suggests that the dormourse is a specialist feeder. Radio-tracking and direct observation confirm this, highly selective, arboreal feeding behaviour. Dormice choose flowers and fruits from a series of trees and shrubs as each becomes seasonally available. Deferred breeding and a high incidence of diurnal torper suggest that dormice experience food shortage in spring. In early summer, when flowering has ended, but fruits are not yet ripe, dormice may again suffer food shortage. At this time they appear to supplement their diet by taking insects, another high-quality food with cyclic availability. Although some tree species are particularly valuable to dormice, they may not be essential if alternatives exist. A spectrum of species which will ensure a continuum of differeing food supplies, within a small area, is essential. This im;plies a need for heterogeneous woodland structure. The implications for conversation management are discussed.     

Using Long-Term Volunteer Records to Examine Dormouse ( Muscardinus avellanarius ) Nestbox Selection

Within ecology, there are unanswered questions about species-habitat interactions, which could potentially be resolved by a pragmatic analysis of a long-term volunteer-collected dataset. Here, we analysed 18 years of volunteer-collected data from a UK dormouse nestbox monitoring programme to determine the influence of habitat variables on nestbox choice by common dormice ( Muscardinus avellanarius ). We measured a range of habitat variables in a coppiced woodland in Gloucestershire, UK, and analysed these in relation to dormouse nestbox occupancy records (by dormice, other small mammals, and birds) collected by volunteers. While some characteristics of the woodland had changed over 18 years, simple transformation of the data and interpretation of the results indicated that the dataset was informative. Using stepwise regressions, multiple environmental and ecological factors were found to determine nestbox selection. Distance from the edge of the wood was the most influential (this did not change over 18 years), with boxes in the woodland interior being selected preferentially. There was a significant negative relationship with the presence of ferns (indicative of damp shady conditions). The presence of oak (a long-lived species), and the clumped structural complexity of the canopy were also important factors in the final model. There was no evidence of competition between dormice and birds or other mammals. The results provide greater understanding of artificial dormouse nest-site requirements and indicate that, in terms of habitat selection, long-term volunteer-collected datasets contribute usefully to understanding the requirements of species with an important conservation status.     

Climate- and resource-driven long-term changes in dormice populations negatively affect hole-nesting songbirds

Global climate change has been shown to cause variable shifts in phenology in a variety of animals and unexpected outcomes across food chains are to be found. Here we examined how rising annual spring temperatures affected the interactions between seed masting, cavity nesting birds and dormice using long-term data from Eastern Czech Republic. We have shown that climate change was associated with unequal shifts in the phenology of two cavity-breeding groups: dormice and birds. Rising spring temperatures have progressively advanced the termination of hibernation for the edible dormouse Glis glis , a common bird predator, leading to an increasing overlap in the use of nesting boxes between dormice and birds. In contrast, only the collared flycatcher Ficedula albicollis , of the four cavity-nesting bird species, advanced its breeding dates in response to rising temperatures. At the same time, favourable weather conditions, coupled with good seed masting years, have been associated with a substantial rise in dormice numbers. Concurrent with the increasing dormice abundance, the number of bird nests destroyed significantly increased in three out of four bird species. We showed that while there was a significant change in the date that the dormice emerged from hibernation during the course of the study, it did not significantly contribute to predation levels when controlling for their abundance and timing of breeding in birds. We found that the increasing dormice abundance was the main factor causing high brood losses in birds, while the timing of breeding in birds had a variable effect between bird species. This study illustrates how changes in climate might affect organisms at various trophic levels with often unexpected outcomes. Limited evidence from other study organisms suggests that species most at risk are those at different trophic levels that do not shift at the same rate or in the same direction as their food resources, predators or competitors.     

Habitat preferences of ungulates in closed savanna of central Africa

Habitat preferences of fifteen species of ungulate were studied between July and September 1975 in dry savanna woodland of Mwabvi Game Reserve, Southern Malawi, Central Africa. Thirteen vegetation types were recognized using vegetation transects and plotless sampling techniques (but three of these are omitted from further analysis here either because of the difficulty of sampling in a representative manner or because of their infrequency). A combination of six methods was used to study habitat preferences since each had particular advantages or disadvantages, although quadrat sampling of fresh pellets/spoor counts was the most satisfactory and so used predominantly. The most common and widely distributed species was the Greater kudu, although abundance estimates in different habitats varied according to the method used. Pellet/spoor counts showed heavy use of open grassland by kudu which was not detected by daytime drives. Temporal patterns of activity indicated that the species was moving into more closed woodland during the day and only coming out into open grassland at night. Relative abundance estimates of a species may also be affected by changing group size. The mean group size of kudu increased in more open vegetation, although group size in warthog did not show this relationship. Some species, e.g. impala, reedbuck, and klipspringer showed narrow habitat preferences, occurring in only one or a few vegetation types, whilst others, e.g. kudu, sable, duiker, suni, and grysbok showed much broader preferences. Mixed Colophospermum mopane /Acacia woodland had the highest species diversity but rather low abundance. Open grassland and Acacia/Albizia woodland had high species diversity together with the greatest abundance of ungulates. Open Julbernardia/Diplorynchus, Brachystegia/Julber-nardia woodland, and particularly Pterocarpus/Diplorynchus/Combretum hill woodland had the lowest species diversity and abundance of ungulates. Ready access to cover and availability of suitable food plants probably account for the preferences of certain vegetation types over others, whilst the different behavioural ecology and food preferences of each species account for individual species differences. Access to water probably also determines habitat preferences in particular species, and studies during the wet season may show different distributions.     

The effects of agriculture and the availability of edge habitat on populations of Helmeted Guineafowl Numida meleagris and on the diversity and composition of associated bird assemblages in KwaZulu-Natal province, South Africa

We investigated the effects of agriculture and the availability of edge habitat on populations of Helmeted Guineafowl Numida meleagris and associated avian diversity and species composition in woodland and grassland biomes in the Midlands of KwaZulu-Natal province, South Africa. Study sites within woodland biome had greater species diversity than those in grassland, whereas adjacent, high-quality, protected habitat in grassland sites, enhanced diversity within this biome. Both guineafowl populations and overall avian diversity declined with increasingly intensive agriculture and disappearance of edge habitat and associated, optimally fragmented habitat mosaic. Furthermore, traditional agriculture in the form of contouring in a pesticide-free environment, resulted in extensive edge habitat that appeared to provide additional food and cover for birds. This, in turn, caused an increase in overall bird diversity, and in guineafowl populations in particular. The widespread decline in Helmeted Guineafowl populations in the Midlands that started in the 1980s, and possibly the decline in species associated with this variegated landscape, was therefore caused by the loss of the habitat mosaic to intensive, modern, monoculture, crop agriculture. Maintaining species diversity and healthy guineafowl populations within these habitats requires the persistence or re-creation of a habitat mosaic and the resulting edge habitat on a landscape scale.     

Take Only Photographs,Leave Only Footprints: Novel Applications of Non-Invasive Survey Methods for Rapid Detection of Small,Arboreal Animals

The development of appropriate wildlife survey techniques is essential to promote effective and efficient monitoring of species of conservation concern. Here, we demonstrate the utility of two rapid-assessment, non-invasive methods to detect the presence of elusive, small, arboreal animals. We use the hazel dormouse, Muscardinus avellanarius, a rodent of conservation concern, as our focal species. Prevailing hazel dormouse survey methods are prolonged (often taking months to years to detect dormice), dependent on season and habitat, and/or have low detection rates. Alternatives would be of great use to ecologists who undertake dormouse surveys, especially those assessing the need for mitigation measures, as legally required for building development projects. Camera traps and footprint tracking are well-established tools for monitoring elusive large terrestrial mammals, but are rarely used for small species such as rodents, or in arboreal habitats. In trials of these adapted methods, hazel dormice visited bait stations and were successfully detected by both camera traps and tracking equipment at each of two woodland study sites, within days to weeks of installation. Camera trap images and footprints were of adequate quality to allow discrimination between two sympatric small mammal species (hazel dormouse and wood mouse, Apodemus sylvaticus). We discuss the relative merits of these methods with respect to research aims, funds, time available and habitat.     

Characteristics of Garden Dormice That Contribute to Their Capacity as Reservoirs for Lyme Disease Spirochetes

To describe the contribution of garden dormice to the epizootiology of Lyme disease, we compared their reservoir capacity for these pathogens to that of other sympatric hosts. Garden dormice are trapped most abundantly during early spring and again during midsummer, when their offspring forage. They are closely associated with moist forests. Garden dormice serve as hosts to nymphal ticks far more frequently than do other small mammals. Spirochetal infection is most prevalent in dormice, and many more larval ticks acquire infection in the course of feeding on these than on other rodents in the study site. Mature dormice appear to contribute more infections to the vector population than juveniles do. Replete larval ticks generally detach while their dormouse hosts remain within their nests. The population of garden dormice contributes five- to sevenfold more infections to the vector population than the mouse population does. Their competence, nymphal feeding density, and preference for a tick-permissive habitat combine to favor garden dormice over other putative reservoir hosts of Lyme disease spirochetes.     

Explaining the saproxylic beetle diversity of a protected Mediterranean area

Saproxylic beetle diversity is high at the Cabañeros National Park (central Spain), where woodland habitats exhibit remarkable heterogeneity. Our aim was to explain the diversity of saproxylic beetles, focusing on species turnover among mature woodland types. We surveyed five woodland types that represented the heterogeneity of the park’s woodland habitats. Beetles were collected using window traps over a period of 20 months. The Jaccard Similarity Index was used as indirect value of beta diversity among woodlands and to test the relation between species turnover and geographical distance. We also identified the contribution of species turnover to landscape diversity by using a partitioning model. Moreover, the presence of mixed woodlands (more than one tree species) allowed us to attempt to valorise the effect of tree species (coupled with their historical management) on species turnover among woodlands. Finally, we looked for different saproxylic beetle preferences for habitat and tree species using an indicator value method. We found that saproxylic beetle species composition varied significantly among the studied woodlands. The variation in species turnover was independent from the distance among woodlands, which suggested that beetle dispersal abilities could not explain this high turnover. Tree species within woodlands were a key factor that increased diversity turnover in woodlands and, consequently, the diversity of the park. Moreover, we found saproxylic beetle species that had different habitat and tree species preferences. We conclude that woodland heterogeneity (highly affected by woodland composition) seems to be the driving force for saproxylic beetle diversity in this protected area.     

Effects of habitat configuration and quality on species richness and distribution in fragmented forest patches near Rome

Question: How important are habitat configuration, quality, history and anthropic disturbance in determining nemoral plant species richness and distribution of fragmented forest patches in a Mediterranean region? Location: Agricultural landscape north of Rome, Italy. Methods: Sixty‐nine woodland patches, identified through a stratified random sampling, were sampled for nemoral plant species. The homogeneity of woodlands was tested through a hierarchical classification of the floristic data and a Mann‐Whitney test of dependent and independent variables. The importance of habitat configuration (area, isolation, shape), quality (soil properties, forest structure, anthropic disturbance) and history (age of woodland) in determining species richness was estimated through a Poisson regression model. Presence‐absence of each species was analysed by logistic regression. Differences among plant life‐trait types (life span, dispersal mode, habitat preference) were analysed by comparing their median β‐values through ANOVA models. Results: Through hierarchical classification, two woodland types were identified that differed in species composition, habitat quality and spatial configuration. Poisson regression showed that habitat configuration and history influenced species richness. Multiple logistic regression resulted in significant fits for 88 species/variable combinations: 38 are habitat quality variables, 25 are habitat configuration variables, and 13 are anthropic factors. Dispersal strategies varied significantly with respect to area, isolation and age, while generalist and specialist species differed according to age of the woodland. Conclusion: Our results show that habitat history and configuration are the key factors determining species richness of woodland. Together with habitat configuration, habitat quality (mainly soil acidity) appeared to influence species composition.     

The effect of coppice management on moth assemblages in an English woodland

Coppice woodlands in Britain may become the target of increased management due to the rise in demand for woodfuel. The biodiversity value of sweet chestnut (Castanea sativa) coppice and the effect of coppice management upon this has received limited study. Moths were the focus of this study in an actively coppiced sweet chestnut woodland in southern England. Coupes, with between one and 20 years of coppice regrowth, were systematically sampled for night flying micro- and macro-moths and coppice structure and ground vegetation were described. Using differences in moth assemblage, three stages of coppice development were distinguished: with one-four, five-nine and more than 10 years of coppice regrowth. Differences in moth assemblage related to habitat conditions within each coppice stage. The young coppice stage moth assemblage was characterised by species typically associated with open habitats; moths of the middle coppice stage assemblage fed on trees and were species typically associated with open woodland and scrub habitats; moths of the mature coppice stage assemblage were species typically associated with closed canopy woodland and contained specialist species whose larval food consists of material such as lichen and decaying leaves. All three coppice stages supported species of listed conservation status; the mature coppice stage contained a distinctive range of scarce and threatened species. The study showed that active coppicing promotes a change in moth assemblage but consequently will temporarily eliminate many species of mature stage coppice. Management which provides a range of coppice age classes within a woodland, appears key in promoting moth diversity.     

Ant assemblages in isolated trees are more sensitive to species loss and replacement than their woodland counterparts

Isolated trees possess an arthropod assemblage different to that found in woodland trees. While isolated trees become an increasingly dominant part of many landscapes, with ‘off reserve’ habitat conservation potential, we know little about the drivers of their assemblage structure. While sampling bimonthly for 12 months in the seasonally dry tropics of Mexico, we characterized the ant species most likely to occupy isolated trees in comparison to small woody patches (‘matorral’; 0.13–0.74 ha), and examined the influence of environmental variables on the respective ant assemblages at both canopy and ground level. Isolated trees possessed a predictable ant assemblage: when compared to the woodland patches, isolated trees were characterised by a lack of specialised arboreal species and an increase in generalised terrestrial species reaching the canopy. Arboreal woodland ant species were as affected by tree isolation as the terrestrial woodland ant fauna. Ant assemblages at isolated trees correlated with a series of microenvironmental (microclimate and biophysical) variables, but this was not the case for the ant assemblages in woodlands. This suggests that at very small habitat sizes (e.g., isolated trees), microenvironment influences assemblage composition by favouring more environmentally tolerant or opportunistic species. Although we were unable to identify alternative variables (e.g., patch area, connectivity) which correlated with assemblage composition in larger habitat patches, it appears that in such patches, local microenvironment is less closely associated with assemblage structure, and variables such as patch and landscape configuration become increasingly important. In a practical sense, micro-habitat restoration aimed at augmentation of vegetation surrounding isolated trees may therefore be an effective means of increasing matrix habitat quality and increasing the partitioning of the arboreal and terrestrial faunas, thereby conserving a broader range of species. More generally, movement of matrix species into habitat patches appears to apply universally over a range of scales and taxa, and provides a distinct contrast to the predictions based on the Theory of Island Biogeography.     

Differences in leaf‐litter invertebrate assemblages between radiata pine plantations and neighbouring native eucalypt woodland

Abstract We investigated the structure, composition and environmental correlates of leaf‐litter invertebrate assemblages in Pinus radiata plantations and in neighbouring native eucalypt woodland in the Jenolan Caves Karst Conservation Reserve, south‐east Australia. Invertebrate assemblages of plantations were compared with remnant eucalypt woodland located well away from the influence of plantations to determine the direct effects of plantations as a result of habitat‐replacement with a non‐native plantation species. We also included in our comparisons edge habitat of eucalypt woodland located immediately adjacent to plantations. This unique edge habitat is exposed to the intrusion of large volumes of pine leaf‐litter from plantations, which has the potential to affect indirectly invertebrate assemblages of surrounding woodland. We found that species richness of invertebrates was significantly lower in pine plantations compared with remnant eucalypt woodland. There was a complete absence of species from 12 invertebrate orders that were found in surrounding eucalypt woodland. A rich and abundant native plant understorey that provides increased habitat heterogeneity is the most likely explanation for the richer invertebrate assemblage found in remnant eucalypt woodland. The total abundance of all invertebrate taxa in pine plantations in winter was significantly higher than in remnant eucalypt woodland, pine‐litter edges and pine‐free edges. Plantations were characterized by particularly high abundances of species in two orders, Acari and Collembola. High abundances of acarine and collembolan species in plantations were associated with a decompositional environment represented by comparatively higher moisture contents and higher C : N ratios of both leaf‐litter and soil, higher soil conductivity and lower soil pH. We suggest that implementation of The Plantation Biodiversity Benefits Score will be a fruitful way forward to assess the environmental benefits that can be gained from pine plantations in this region of south‐eastern Australia.     

The effect of supplementary food upon the activity patterns of wood mice, Apodemus sylvaticus, living on a system of maritime sand-dunes

The wood mouse is primarily a woodland species but it also occurs on maritime sand-dunes. The mice living on the sand-dunes leave their nests earlier in the evening and spend more time out of the nest than those animals living in woodlands. Here we test the hypothesis that this difference is because woodland provides substantially more food than do sand-dunes. Our experimental approach was to provide supplementary food in the form of wheatgrain to a sand-dune population and compare activity patterns with a control population. The mice on the supplemented area were strictly nocturnal and spent less time above ground than the controls. Their activity pattern was essentially the same as that of wood mice living in deciduous woodland.     

Regional distribution patterns predict bird occurrence in Mediterranean cropland afforestations

Part of the abandoned cropland in Mediterranean landscapes is being subjected to afforestation dominated by pines. Here we simultaneously evaluate the effect of three categories of factors as predictors of the interspecific variation in bird habitat occupancy of fragmented afforestations, namely regional distribution, habitat preferences, and life-history traits of species. We use the “natural experiment” that highly fragmented pine plantations of central Spain represent due to the prevailing pattern of land ownership of small properties. Many species with marked habitat preferences for woodland habitats were very scarce or were never recorded in this novel habitat within a matrix of deforested agricultural landscape. Interspecific variability in occurrence was mainly explained by regional distribution patterns: occurrence was significantly and positively associated with the proportion of occupied 10 × 10 UTM km squares around the study area, habitat breadth, and population trend of species in the period 1998–2011. It was also positively associated with regional occupancy of mature and large pine plantations. Other predictor variables related to habitat preferences (for woodland, agricultural and urban habitats) or life-history traits (migratory strategy, body mass, and clutch size) were unrelated to the occurrence of species. Thus, small man-made pinewood islands funded by the Common Agrarian Policy within a landscape dominated by Mediterranean agricultural habitats only capture widespread and habitat generalist avian species with increasing population trends, not contributing to enhance truly woodland species.     

The effects of restoring a conifer Plantation on an Ancient Woodland Site (PAWS) in the UK on the habitat and local population of the Hazel Dormouse (Muscardinus avellanarius)

The common dormouse is a European protected species that is considered at risk during forest management operations in the UK. Historically, they were believed to exist principally in scrub and broadleaved woodlands, especially hazel coppice, but recent evidence has shown that they are present in some conifer sites at low density. Operations to restore conifer plantations on ancient woodland sites (PAWS) with native broadleaves may be especially hazardous to dormice populations, since dormouse densities are generally lower here so sudden perturbations may cause local extinction. Recent policy for restoring PAWS to broadleaved and the need to comply with European legislation has emphasised the need to devise appropriate but pragmatic forest management protocols involving the phased removal of conifers over time. Dormice were handled and individually marked on a single 12?ha conifer PAWS site from 2000 and a density index calculated from 2002 to 2007. In four adjacent study areas, a different form of PAWS restoration was carried out in 2003 to remove c. 33% of conifers. The effects on dormouse numbers, damage to artificial hibernation nests, and regeneration of suitable habitat were recorded. Monitoring indicated that dormouse populations were sustained in each study area after management, suggesting that at this site, conifer removal operations did not have a significant detrimental effect on the dormouse population. Damage to artificial hibernation nests was significantly different between the four study areas. The least damage occurred in the study area containing large group fells due to potential refuge areas, and worst in the traditional standard overall thinning. Measured differences in shrub vegetation throughout each study area showed that numerous small group fells or a few larger group fells subsequently regenerated to form a better vegetation structure for dormice than the traditional standard overall thinning. The implications for forest managers of the results from this single site are discussed.     

Dispersal of common dormiceMuscardinus avellanarius in a habitat mosaic

In the eastern part of Saxony (Germany), common dormiceMuscardinus avellanarius (Linnaeus, 1758) were found in very small woods (average area of 10 woods was 2.9 ± 1.4 ha) isolated within agricultural fields for more than 100 years (average distance to the next, larger wood 268 ± 84 m). Dormice reproduced even in wood islands smaller than two hectares. Altogether 6 marked dormice were recorded migrating across the open landscape. Of these, 5 were juveniles. Minimum and maximum distances in treeless areas between points of capture and recapture were 250 and 500 m respectively. These migrations over open ground seem to be rare but normal events and explain the presence of common dormice in very small patches of woodland in habitat mosaics.     

Nest losses of cavity nesting birds caused by dormice (Gliridae, Rodentia)

Mammals are common predators on bird nests. However, their species identity frequently remains unknown. Here we present long-term data (1975–2005) from a central European woodland on the predatory effect of three dormice species (Rodentia, Gliridae) on cavity-nesting birds. Dormice are mostly frugivorous during the active late-summer season, but shortly after they terminate hibernation, they frequently depredate cavity-nesting-bird nests. The seven bird species studied, lost on average between 2.9 to 18.4% of their broods. MigratoryFicedula flycatchers suffered the highest brood losses, while the residentParus titmice and the nuthatchSitta europaea had much lower brood losses. The three dormice species differed significantly in their predatory effect during different avian breeding stages. The edible dormouseGlis glis (Linnaeus, 1766) depredated both eggs and nestlings equally, while the common dormouseMuscardinus avellanarius (Linnaeus, 1758) and the forest dormouseDryomys nitedula (Pallas, 1778) destroyed more nests during egg laying and the incubation period. Among adult birds, females were taken more frequently by dormice than males. Among avian species, adultFicedula flycatchers were more often depredated than the titmice and nuthatch. Our study provided further evidence, that among the traditional studies on the costs of reproduction, parental mortality at the nests needs to be considered and that incubating or brooding females might be under higher predation risk than the males.     

Macro‐ and microclimatic interactions can drive variation in species' habitat associations

Many species are more restricted in their habitat associations at the leading edges of their range margins, but some species have broadened their habitat associations in these regions during recent climate change. We examine the effects of multiple, interacting climatic variables on spatial and temporal patterns of species' habitat associations, using the speckled wood butterfly, Pararge aegeria, in Britain, as our model taxon. Our analyses reveal that this species, traditionally regarded as a woodland‐dependent insect, is less restricted to woodland in regions with warmer winters and warmer and wetter summers. In addition, over the past 40 years of climate change, the species has become less restricted to woodland in locations where temperature and summer rainfall have increased most. We show that these patterns arise mechanistically because larval growth rates are slower in open (i.e. nonwoodland) habitats associated with colder microclimates in winter and greater host plant desiccation in summer. We conclude that macro‐ and microclimatic interactions drive variation in species' habitat associations, which for our study species resulted predominantly in a widening of habitat associations under climate change. However, species vary in their climatic and nonclimatic requirements, and so complex spatial and temporal patterns of changes in habitat associations are likely to be observed in future as the climate changes.     

The effect of woodland area on avian community composition in a fragmented southern UK landscape and associated management recommendations

ABSTRACT

Capsule: Smaller woodlands not only support fewer species but also show different avian community composition due to loss of woodland interior and an increase in edge habitat.

Aims: To use observed community composition changes, rather than traditional total species richness-area relationships, to make area-specific management recommendations for optimizing woodland habitat for avian communities in fragmented landscapes.

Methods: 17 woodlands were selected in Oxfordshire, UK, with areas between 0.2 and 120 ha. Three dawn area searches were conducted in each woodland between 1st April and 28th May 2016 to record encounter rates for each species. The impact of internal habitat variation on woodland comparability was assessed using habitat surveys.

Results: Woodlands with area less than 3.6 ha showed a significant positive relationship between total avian species richness and woodland area. Woodlands with area over 3.6 ha were all consistent with a mean (± se) total richness of 25.4?±?0.6 species, however the number of woodland specialists continued to increase with woodland area. Woodland generalists dominated the total encounter rate across the area range, however the fractional contribution of woodland specialists showed a significant positive correlation with woodland area, while the fractional contribution of non-woodland species significantly decreased. Non-woodland species numbers peaked in mid-sized woodlands with enhanced habitat heterogeneity.

Conclusions: Community composition analysis enabled more targeted recommendations than total species richness analysis, specifically: large woodlands (over 25?ha) in southern UK should focus conservation efforts on providing the specific internal habitats required by woodland specialists; medium-sized woodlands (between approximately 4 and 25?ha) should focus on promoting internal habitat variety, which can benefit both woodland species and non-woodland species of conservation concern in the surrounding landscape; small woodlands (under 4?ha) should focus on providing nesting opportunities for non-woodland species and on improving connectivity to maximize habitat for woodland generalists and facilitate movement of woodland specialists.     

Development of secondary woodland in oak wood pastures reduces the richness of rare epiphytic lichens

Wooded pastures with ancient trees were formerly abundant throughout Europe, but during the last century, grazing has largely been abandoned often resulting in dense forests. Ancient trees constitute habitat for many declining and threatened species, but the effects of secondary woodland on the biodiversity associated with these trees are largely unknown. We tested for difference in species richness, occurrence, and abundance of a set of nationally and regionally red-listed epiphytic lichens between ancient oaks located in secondary woodland and ancient oaks located in open conditions. We refined the test of the effect of secondary woodland by also including other explanatory variables. Species occurrence and abundance were modelled jointly using overdispersed zero-inflated Poisson models. The richness of the red-listed lichens on ancient oaks in secondary woodland was half of that compared with oaks growing in open conditions. The species-level analyses revealed that this was mainly the result of lower occupancy of two of the study species. The tree-level abundance of one species was also lower in secondary woodland. Potential explanations for this pattern are that the study lichens are adapted to desiccating conditions enhancing their population persistence by low competition or that open, windy conditions enhance their colonisation rate. This means that the development of secondary woodland is a threat to red-listed epiphytic lichens. We therefore suggest that woody vegetation is cleared and grazing resumed in abandoned oak pastures. Importantly, this will also benefit the vitality of the oaks.