Forests regenerating after clear-cutting function as habitat for bryophyte and lichen species of conservation concern

The majority of managed forests in Fennoscandia are younger than 70 years old but yet little is known about their potential to host rare and threatened species. In this study, we examined red-listed bryophytes and lichens in 19 young stands originating from clear-cutting (30-70 years old) in the boreal region, finding 19 red-listed species (six bryophytes and 13 lichens). We used adjoining old stands, which most likely never had been clear-cut, as reference. The old stands contained significantly more species, but when taking the amount of biological legacies (i.e., remaining deciduous trees and dead wood) from the previous forest generation into account, bryophyte species number did not differ between old and young stands, and lichen number was even higher in young stands. No dispersal effect could be detected from the old to the young stands. The amount of wetlands in the surroundings was important for bryophytes, as was the area of old forest for both lichens and bryophytes. A cardinal position of young stands to the north of old stands was beneficial to red-listed bryophytes as well as lichens. We conclude that young forest plantations may function as habitat for red-listed species, but that this depends on presence of structures from the previous forest generation, and also on qualities in the surrounding landscape. Nevertheless, at repeated clear-cuttings, a successive decrease in species populations in young production stands is likely, due to increased fragmentation and reduced substrate amounts. Retention of dead wood and deciduous trees might be efficient conservation measures. Although priority needs to be given to preservation of remnant old-growth forests, we argue that young forests rich in biological legacies and located in landscapes with high amounts of old forests may have a conservation value.     

Significance of woodland key habitats for polypore diversity and red-listed species in boreal forests

Preservation of woodland key habitats has become an integral part of biodiversity-oriented forest management in northern Europe. In Finland, brook-side spruce forests constitute the most important key-habitat type in terms of total area and timber volume. Our aim was to compare polypore diversity and the occurrence of red-listed species between brook-side key habitats and comparable sites of managed forest as controls. Furthermore, we assessed the importance of stand structural features to polypore communities, and contrasted regions with different land-use history. Altogether 69 key habitats and 70 controls were inventoried in four regions across southern Finland. A total of 28,023 surveyed dead-wood units had 3,307 occurrences of 114 species of which 25 species were red-listed. Key habitats hosted on average 28% (about two species) more polypore species (mainly deciduous-specialists) than controls because of a larger average volume of dead wood and a higher proportion of dead deciduous wood. However, the average number of red-listed species was low and did not differ between the two forest categories. We detected a landscape effect connected with the intensity and length of forest management history, with the highest numbers of all and red-listed species per site in eastern Finland. Volume and diversity of dead wood were the most important variables explaining variation in species richness. Presently, key habitats in managed forests appear to contribute only little to the conservation of red-listed polypore species.     

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.     

Hidden crown jewels: the role of tree crowns for bryophyte and lichen species richness in sycamore maple wooded pastures

Tree crowns typically cover the vast majority of the surface area of trees, but they are rarely considered in diversity surveys of epiphytic bryophytes and lichens, especially in temperate Europe. Usually only stems are sampled. We assessed the number of bryophyte and lichen species on stems and in crowns of 80 solitary sycamore maple trees (Acer pseudoplatanus) at six sites in wooded pastures in the northern Alps. The total number of species detected per tree ranged from 13 to 60 for bryophytes, from 25 to 67 for lichens, and from 42 to 104 for bryophytes and lichens considered together. At the tree level, 29 % of bryophyte and 61 % of lichen species were recorded only in the crown. Considering all sampled trees together, only 4 % of bryophyte, compared to 34 % of lichen species, were never recorded on the stem. Five out of 10 red-listed bryophyte species and 29 out of 39 red-listed lichen species were more frequent in crowns. The species richness detected per tree was unexpectedly high, whereas the proportion of exclusive crown species was similar to studies from forest trees. For bryophytes, in contrast to lichens, sampling several stems can give a good estimation of the species present at a site. However, frequency estimates may be highly biased for lichens and bryophytes if crowns are not considered. Our study demonstrates that tree crowns need to be considered in research on these taxa, especially in biodiversity surveys and in conservation tasks involving lichens and to a lesser degree also bryophytes.     

Common and rare Swedish vertebrates — distribution and habitat preferences

Data have been compiled on the distribution, habitat preferences and population sizes of 348 vertebrates reproducing in Sweden (excluding fish) and their species richness in different habitats and regions was investigated. Furthermore, we compared the habitat preferences and distribution of rare and common vertebrates. The relative species number (corrected for area) increases from the north (the hemiarctic/boreal zone) to the south (the temperate/hemiboreal zone). The relative number of species in major habitats is highest in farmland, lakes and running waters, and possibly also in the sea. However, the absolute number of species is highest in woodland, the dominant habitat in Sweden (56% of the land area excluding sea). Within woodlands, a large proportion of species occur in southern deciduous forests, in other deciduous forests and in mixed forests, while coniferous forests are less species-rich when the habitat area is taken into account. In farmland, the most species-rich habitats are meadows and forest edges, while marshes are the most species-rich habitats amongst lakes and running waters. Nationally rare species (<1000 individuals) have a smaller European range than common species, and they also have their European distribution centres further to the south than the common species. Of the species occurring in large parts of Sweden (that is, both in the north and the south) a low proportion (4.7%) are classified as rare compared with species occurring mainly in the north (20.6% rare) or mainly in the south (31.6% rare) of Sweden. There is a positive correlation between the number of rare species and the total species number in 41 subcategory habitats, and the proportion of rare species is similar in most habitats. A more detailed analysis (including effects of both regions and habitats) suggests that the proportion of rare species in a region is a result of differences between latitudes, but also of different habitats (when corrected for latitude effects). There are differences in the proportion of rare species between the nine most species-rich orders (for example, there is a high proportion of rare species in the order Carnivora and a low proportion in the order Rodentia), but the proportion of rare species in these orders is not independent of the habitats in which they occur, making it difficult to separate the effects of habitat preferences and taxonomy on rarity. The focusing of conservation work on relatively species-rich habitats in southern and middle Sweden — such as some farmland habitats (that is, meadows and forest edges), marshes (in connection with lakes and running waters) and forests with a relatively high proportion of deciduous trees — is of high priority if the conservation of biodiversity is a main goal. These are also the habitats with a high number of rare and red-listed species.     

Vertical distribution of epiphytic bryophytes and lichens emphasizes the importance of old beeches in conservation

During storms in 2005, a number of beech trees fell over at Biskopstorp, SW Sweden, offering the opportunity to study epiphytes along entire stems. In total 16 beech trees in four beech stands representing three different age classes were included. For each tree, 2 m segments from the base to the top were surveyed. In total 115 species were found (76 lichens, 39 bryophytes), of which 30 were considered to be of conservation concern (22 lichens, 8 bryophytes). For lichens significantly more species were recorded above 2 m in height, whereas more bryophytes were recorded below 2 m in height. Certain red-listed lichens were recorded only above 2 m in height on old trees. In a second data set from the same area 140 age-determined beech trees were surveyed for species of conservation concern at the heights 0–2 and 2–5 m, respectively. These species were found almost exclusively on old beech trees, and presence at 2–5 m was recorded, with one exception, only on those trees which also had species of conservation concern at 0–2 m. Records of these species correlated significantly to microhabitat variables, i.e. the presence of rough bark and moss cover higher up the stems on the old trees. This study indicates that surveying only the base in really old beech forests can underestimate both the number of species of conservation concern and their population sizes. However, surveys restricted to the base in rather even-aged beech stands catch a large proportion of the trees with species of conservation concern.     

Habitat preferences of red-listed fungi and bryophytes in woodland key habitats in southern Sweden – analyses of data from a national survey

The aim of this study was to identify habitat preferences of red-listedepiphytic and epixylic bryophyte, lichenized and non-lichenized fungi speciesinwoodland key habitats (WKHS) (areas less than 10 ha, where foreststructures indicate occurrence of red-listed species) in southern Sweden. Therelative importance of different groups of environmental factors was assessedwith partial canonical correspondence analysis techniques and across-validationapproach using data from 7196 selected WKHs. Different woody substrates (oldtrees, logs and snags) made up the most important variable group for occurrenceof red-listed species (30% unique explainable variation). Species associatedwith Fagus sylvatica and Picea abieshabitats, but also species associated with Quercus spp.andPopulus tremula habitats showed distinct habitatpreferences. The second most important variable group (16% unique explainablevariation) was geographical location. A west–east gradient was identified, andspecies concentrated to Baltic islands in the east were separated from otherspecies. This gradient, and an identified south–north gradient, probablyreflect differences in temperatures and rainfall between different regions.Among the remaining variable groups, historical land-use, ground conditions andforest stand composition were of similar importance (5–7% uniqueexplainable variation). Traditional management regimes resulting in semi-openforest habitats (leaf harvesting, forest grazing and selective cutting) wereassociated with the occurrence of many species, probably due to differences inmicroclimate between sites of different openness. Furthermore, a groundmoisturegradient extending from species associated with dry sites (mainly lichenizedfungi) to species associated with wet sites (mainly bryophytes), and a nutrientgradient from species associated with nutrient-poor sites to species occurringat nutrient-rich sites, were identified. Thus, conservation measures are neededin a broad spectrum of habitats with different substrates. Also sites withsimilar substrates, but situated in different regions (and climates), or withdifferent ground moisture and nutrient conditions are needed to cover the fullspectrum of habitat conditions suitable for different red-listed bryophytes andfungi.     

Epiphytic lichens and bryophytes of forest ecosystems in Tuscany (Central Italy)

The distribution of epiphytic bryophytes and lichens on three species of trees (Quercus ilex, Quercus cerris and Fagus sylvatica, representing the forest ecosystems of central Italy at low, medium and high elevations, respectively) was examined with respect to host specificity and habitat differences. Although most species were host-specific, the results suggested that habitat characteristics are more important than phorophyte properties in determining the distribution of lichens and bryophytes. Factors affecting the diversity of the epiphytic flora were different for lichens and bryophytes. In the case of lichens, climatic parameters and forest monospecificity were important factors, whereas tree cover (i.e. shade) and to a certain extent the number of available trees seemed more important for bryophytes.     

Red-listed lichens in Sweden: habitats, threats, protection, and indicator value in boreal coniferous forests

The three major threats to lichens in Sweden; forestry, air pollution, and structural changes in the agricultural landscape, are outlined. Forestry is the most serious. The majority of the red-listed lichens in forests are found in productive forests with a continuity in tree growth, but nearly 70% of the protected area in Sweden consists of alpine landscapes. Examples of important habitats with red-listed lichens are described, e.g. Alnus glutinosa marshes, alvar-vegetation, broad-leaved deciduous forests and different Picea abies forests. The use of selected indicator species of lichens and macrofungi (mainly red-listed species) in boreal coniferous forests provides information on continuity in tree growth of an area, and on earlier influences of forestry. Examples of indicator species for different types of forest are presented and discussed. In spite of the Swedish right of common accesso, collecting of lichens is forbidden without permission from the land-owner. Collecting in protected areas is allowed only with a permit obtained from the authorities.     

Monitoring of pollen rain in moss polsters and mats in view of their suitability as controls for determining the air-borne component of pollen spectra in herbivore faeces

Pollen has been extracted from six bryophyte and two lichen taxa, sampled from three habitats: upland heath, lowland bog and mixed woodland, in both west and east Scotland. The highest number of pollen taxa was recorded in bothSphagnum andThuidium; the lowest numbers of pollen taxa were recorded in two of the mosses and both lichens. For pollen rain control purposes in herbivore faecal studies, woodland species of bryophytes are not suitable due to the sheltering effects from rain provided by the overhead canopy. Open habitats such as moorland heath and bog provide polsters/mats which normally trap pollen rain more effectively for control purposes. The aim of this study was twofold: to observe the effectiveness of selected polsters and lichens as traps for pollen rain and to establish eventually, whether or not such vegetative traps could be used as controls in pollen spectra analyses of herbivore faeces for the determination of nutritional regime and habitat. From a comparison with recent studies in north west Spain of three taxa in common with Scottish samples,Polytrichum demonstrated a consistently higher number of pollen taxa trapped.Thuidium andCladonia all yielded between one and a half and three times the number of pollen taxa as in the same three bryophyte/lichen taxa sampled in Scotland. Investigation relating the pollen rain trapped in polsters to that in faecal material are continuing, and will be reported in due course. This paper is based on one given by E.C. at the 5th International Aerobiology Conference, held at Bangalore, India, August 1994.     

Diversity of dry forest epiphytes along a gradient of human disturbance in the tropical Andes

Question: Disturbance effects on dry forest epiphytes are poorly known. How are epiphytic assemblages affected by different degrees of human disturbance, and what are the driving forces? Location: An inter‐Andean dry forest landscape at 2300 m elevation in northern Ecuador. Methods: We sampled epiphytic bryophytes and vascular plants on 100 trees of Acacia macracantha in five habitats: closed‐canopy mixed and pure acacia forest (old secondary), forest edge, young semi‐closed secondary woodland, and isolated trees in grassland. Results: Total species richness in forest edge habitats and on isolated trees was significantly lower than in closed forest types. Species density of vascular epiphytes (species per tree) did not differ significantly between habitat types. Species density of bryophytes, in contrast, was significantly lower in edge habitat and on isolated trees than in closed forest. Forest edge showed greater impoverishment than semi‐closed woodland and similar floristic affinity to isolated trees and to closed forest types. Assemblages were significantly nested; habitat types with major disturbance held only subsets of the closed forest assemblages, indicating a gradual reduction in niche availability. Distance to forest had no effect on species density of epiphytes on isolated trees, but species density was closely correlated with crown closure, a measure of canopy integrity. Main conclusions: Microclimatic changes but not dispersal constraints were key determinants of epiphyte assemblages following disturbance. Epiphytic cryptogams are sensitive indicators of microclimate and human disturbance in montane dry forests. The substantial impoverishment of edge habitat underlines the need for fragmentation studies on epiphytes elsewhere in the Tropics.     

Monitoring of pollen rain in moss polsters and mats in view of their suitability as controls for determining the air-borne component of pollen spectra in herbivore faeces

Pollen has been extracted from six bryophyte and two lichen taxa, sampled from three habitats: upland heath, lowland bog and mixed woodland, in both west and east Scotland. The highest number of pollen taxa was recorded in bothSphagnum andThuidium; the lowest numbers of pollen taxa were recorded in two of the mosses and both lichens. For pollen rain control purposes in herbivore faecal studies, woodland species of bryophytes are not suitable due to the sheltering effects from rain provided by the overhead canopy. Open habitats such as moorland heath and bog provide polsters/mats which normally trap pollen rain more effectively for control purposes. The aim of this study was twofold: to observe the effectiveness of selected polsters and lichens as traps for pollen rain and to establish eventually, whether or not such vegetative traps could be used as controls in pollen spectra analyses of herbivore faeces for the determination of nutritional regime and habitat. From a comparison with recent studies in north west Spain of three taxa in common with Scottish samples,Polytrichum demonstrated a consistently higher number of pollen taxa trapped.Thuidium andCladonia all yielded between one and a half and three times the number of pollen taxa as in the same three bryophyte/lichen taxa sampled in Scotland. Investigation relating the pollen rain trapped in polsters to that in faecal material are continuing, and will be reported in due course.This paper is based on one given by E.C. at the 5th International Aerobiology Conference, held at Bangalore, India, August 1994.     

Tree and stand-scale factors affecting richness and composition of epiphytic bryophytes and lichens in deciduous woodland key habitats

Conservation and sustainable forestry are essential in a multi-functional landscape. In this respect, ecological studies on epiphytes are needed to determine abiotic and biotic factors associated with high diversity. The aim of the present study was to evaluate relative sensitivity of conservation targets (epiphytic bryophytes and lichens) in relation to contrasting environmental variables (tree species, tree diameter at breast height, bark crevice depth, pH, tree inclination, pH, forest stand age, area and type) in boreo-nemoral forests. The study was conducted in Latvian 34 woodland key habitat (WKH) boreo-nemoral forest stands. Generalized linear mixed models and canonical correspondence analysis showed that tree species and tree bark pH were the most important variables explaining epiphytic bryophyte and lichen composition and richness (total, Red-listed, WKH indicator species). Forest stand level factors, such as stand size and habitat type, had only minor influence on epiphytic species composition and richness. The results of the present study indicate a need to maintain the diversity of tree species and large trees, particularly Acer platanoides, Carpinus betulus, Fraxinus excelsior, Populus tremula, Tilia cordata, Ulmus glabra and Ulmus laevis in conservation of epiphytic bryophyte and lichen communities in the future.     

Bryophytes as indicators of ancient woodlands in Schleswig-Holstein (Northern Germany)

Ancient woodlands, with their long ecological continuity, frequently harbor a high number of typical, rare and threatened species, and are therefore of particular importance for nature conservation. To pinpoint these habitats, a common application is the use of plants as “ancient woodland indicators”. The occurrence of these particular species allows for evaluating the continuity of woodland cover in time. While lists of ancient woodland vascular plants have been derived for many regions, the identification and use of bryophytes as ancient woodland indicators has been widely neglected. This is a bit surprising because certain woodland bryophytes are very sensitive to varying environmental conditions or changes in land management. It therefore appeared promising to compile an ecologically grounded list of ancient woodland indicator bryophytes for practical use.In this study, we present a set of ancient woodland indicator bryophytes based on the analysis of datasets from the North German federal state of Schleswig-Holstein. To compile this list, we systematically evaluated the bryophyte distribution data from floristic surveys in relation to ancient woodland cover data from state-wide inventories. In this way, we were able to determine ancient woodland bryophytes using consistent and repeatable statistical methods.The presented list of 31 ancient woodland indicator bryophytes is ecologically sound and corresponds well with data from the sparse literature. We could distinguish two groups of ancient woodland indicator bryophytes. The first group is linked to base-rich, semi-natural deciduous woodlands with high soil and air humidity. The second group comprises acidophilic bryophytes that occur not only in acidic beech and oak woods, but also in acidic mixed or coniferous forests on ancient woodland sites. Apart from the ancient woodland indicator bryophytes, we could identify one group of recent woodland bryophytes and four groups of bryophytes that are more or less indifferent with respect to woodland continuity.Finally, we provide recommendations for the application of ancient woodland indicator bryophytes in nature conservation practice. Management suggestions for the conservation of the typical bryophyte diversity of ancient semi-natural woodlands are also given.     

Habitat change and woodland birds in Britain: implications for management and future research

There is increasing evidence that changes in habitat structure in the form of reduced understorey and loss of open habitats, both probably a result of increases in shading and deer browsing, may be responsible for causing recent changes in the composition of breeding bird communities in many lowland British woods and forests. In contrast, management of upland coniferous forests may prevent the attainment of mature and old-growth structures which would benefit community development in these new ecosystems. We suggest that the key challenge for woodland conservation policy is to create larger areas of both young-growth and old-growth habitat. These objectives need not necessarily conflict with each other, or with other multipurpose forestry objectives, provided that they inform strategic plans and are targeted at appropriate locations and scales. In the lowlands, the current large stock of middle-aged, often unmanaged and species-poor woodland provides an opportunity to restore or create new woodland habitats of high biodiversity value. The development of woodfuel markets may effectively increase the amount of young-growth but it is unclear exactly what habitat structures might be created. In the uplands, allowing more natural development of native woodland in mosaics with other habitats may provide opportunities for both old- and young-growth species. For the foreseeable future, deer impacts will continue to be widespread and probably increasingly severe in many areas. In view of the uncertainty about the implications of climate change for woodland ecosystems, a strong case can be made for attempting to buffer valued wildlife communities against damaging effects by creating and maintaining high structural diversity at a range of scales and increasing the area of woodland.     

High occurrence of red-listed bryophytes and lichens in mature managed forests in boreal Sweden

Successful biodiversity conservation needs to be based on reliable data regarding the distribution and abundance of species. Red Lists summarize the status of rare and declining species. Here we present the first detailed survey (10 m × 10 m resolution) of nationally red-listed bryophytes and lichens at stand level in boreal forests. 30 managed forest production stands in boreal Sweden, soon to be harvested, were surveyed in detail regarding red-listed bryophytes and lichens. On the 180 ha totally investigated, 33 red-listed species were found, representing 35% of all forest red-listed bryophytes and lichens so far recorded from this part of Sweden. The mean number of red-listed species per stand was 10 and varied between 5 and 16. Excluding three species which were so common that, given the time-limit, it was not possible to record all of their occurrences, there were on average 6 number of observations ha⁻¹. The presence and density exceed those earlier found in ‘key habitats’, defined as hot-spots for red-listed species. Almost all observations were made on trees, with 48% on living trees and 52% on dead. Altitude, area and stem volume explained 67% of the red-list species density. The results highlight the importance of unprotected areas for rare and declining species and point to a hitherto unacknowledged high biodiversity value of mature managed boreal forest stands, shaped by a less intense forestry than today's. It also raises questions regarding the use of red-listed species to identify areas of importance to biodiversity. Objective and systematic surveys of red-listed species in the forest landscape, including younger stands, are urgent.Der erfolgreiche Schutz der Biodiversität muss auf verlässlichen Daten über die Verbreitung und Abundanz der Arten basieren. Rote Listen fassen den Status seltener und abnehmender Arten zusammen. Hier präsentieren wir die erste detaillierte Erfassung (10 m × 10 m Auflösung) von Bryophyten und Flechten der nationalen Rote Liste auf Bestandsniveau in borealen Wäldern. Im borealen Schweden wurden in 30 bewirtschafteten Produktionswälder, die bald geerntet werden sollen, die Bryophyten und Flechten der Roten Liste im Detail erfasst. Auf den insgesamt untersuchten 180 ha wurden 33 Arten der Roten Liste gefunden, die 35% aller Wald-Bryophyten und-Flechten der Roten Liste repräsentieren, die bisher in diesem Teil Schwedens erfasst wurden. Die mittlere Anzahl derRote-Liste-Arten pro Bestand war 10 und variierte zwischen 5 und 16. Unter Ausschluss von drei Arten, die so gewöhnlich waren, dass es bei dem gegebenen Zeitlimit nicht möglich war alle ihre Vorkommen zu erfassen, gab es im Durchschnitt 6 Beobachtungen ha⁻¹. Vorkommen und Dichten übertrafen die früher in “Schlüsselhabitaten” gefundenen, die als ‘hot spots’ bezeichnet werden. Fast alle Beobachtungen wurden auf Bäumen gemacht, mit 48% auf lebenden und 52% auf toten Bäumen. Die Höhe, das Gebiet und das Stammvolumen erklärten 67% der Dichte der Rote-Liste-Arten. Die Ergebnisse heben die Wichtigkeit nicht-geschützter Gebiete für seltene und abnehmende Arten hervor und weisen auf einen bisher nicht wahrgenommenen hohen Biodiversitätswert von alten bewirtschafteten borealen Waldbeständen hin, die von einer weniger intensiven Forstwirtschaft als der heutigen geformt wurden. Es stellen sich ebenso Fragen, die die Verwendung der Rote-Liste-Arten betreffen, um für die Biodiversität wichtige Gebiete zu identifizieren. Objektive und systematische Erfassungen der Rote-Liste-Arten in Waldlandschaften inklusive der jüngeren Bestände sind dringend.     

Disturbance effects on diversity of epiphytes and moths in a montane forest in Ecuador

We sampled the diversity of epiphytes (lichens, bryophytes, vascular plants) and moths (Geometridae, Arctiidae) in mature and recovering forest and in open vegetation in the montane belt in Ecuador. No uniform pattern of change in species richness was detected among the different taxonomic groups with increasing disturbance. Species richness of epiphytic bryophytes and vascular plants declined significantly from mature forest towards open vegetation. In contrast, species richness of epiphytic lichens did not change with increasing forest alteration, while that of geometrid moths was significantly higher in recovering forest compared with mature forest and open habitats. Arctiidae were significantly more species-rich in recovering forest and open vegetation than mature forest. Hence, for some organisms, modified habitats may play an important role for biodiversity conservation in the Andes, whereas others suffer from habitat disturbance. However, trends of changes in species composition following deforestation were surprisingly concordant across most studied epiphyte and moth taxa.     

喀斯特山地高校苔藓植物多样性及环境响应——以贵州大学为例

以贵州大学喀斯特山地校园为对象,调查其苔藓植物物种多样性及其生境特征,探讨苔藓植物生长与环境的关系。结果表明,研究区域内苔藓植物共12科27属51种。优势科是丛藓科(Pottiaceae)、青藓科(Brachytheciaceae)和灰藓科(Hypnaceae);主要生活型为丛集型、交织型和垫型;不同功能区域的苔藓植物生物多样性从高到低依次为行政办公区、休闲游憩区、教学科研区、体育运动区、宿舍休息区;不同生境物种丰富度从高到低依次是疏林草坪、林下、草坪环境、灌丛花池、道路;人为干扰程度与光照、湿度是影响苔藓植物多样性组成的重要因子。研究区域内苔藓植物多样性较低,多为土生藓类。在苔藓生长的微生境中,人为干扰低、空气湿度大的林地、疏林草坪更利于苔藓生长。     

Hollow oaks and beetle conservation: the significance of the surroundings

In this study we investigated hollow oaks (Quercus robur, Q. petrea) situated in open landscapes and in forests in Norway in northern Europe, and compared their importance for rare and threatened beetles (Coleoptera). Old, hollow oak trees, both in parks and in forests, were extremely rich in red-listed beetles, and hosted a high proportion of threatened species. The proportion of oak associated species and the mean number of red-listed beetle species per tree was similar in the two site types, but rarefaction showed that for a certain number of individuals, oaks in forests had more threatened and near-threatened species than oaks in parks. The species composition also differed between site types: Park oaks had a higher proportion of species associated with hollows and animal nests, whereas in forests, there was a higher proportion of species depending on dead oak wood in general. Four factors were significant in explaining the richness of red-listed beetles in our study: Tree circumference, cavity decay stage, proportion of oak in the surroundings, and coarse woody debris (CWD) in the surroundings. Forest oaks were smaller, but they still trapped a species richness comparable to that of the larger park oaks—probably a result of high amounts of CWD in the surroundings. We show that oaks in open landscapes and oaks in forest have only partly overlapping beetle assemblages and, thus, cannot be substituted in conservation. Planning for conservation of red-listed beetles associated with this key habitat demands a large scale perspective, both in space and time, as the surroundings have important effects on associated threatened and near threatened species.     

Positive edge effects on forest-interior cryptogams in clear-cuts

Biological edge effects are often assessed in high quality focal habitats that are negatively influenced by human-modified low quality matrix habitats. A deeper understanding of the possibilities for positive edge effects in matrix habitats bordering focal habitats (e.g. spillover effects) is, however, essential for enhancing landscape-level resilience to human alterations. We surveyed epixylic (dead wood inhabiting) forest-interior cryptogams (lichens, bryophytes, and fungi) associated with mature old-growth forests in 30 young managed Swedish boreal forest stands bordering a mature forest of high conservation value. In each young stand we registered species occurrences on coarse dead wood in transects 0-50 m from the border between stand types. We quantified the effect of distance from the mature forest on the occurrence of forest-interior species in the young stands, while accounting for local environment and propagule sources. For comparison we also surveyed epixylic open-habitat (associated with open forests) and generalist cryptogams. Species composition of epixylic cryptogams in young stands differed with distance from the mature forest: the frequency of occurrence of forest-interior species decreased with increasing distance whereas it increased for open-habitat species. Generalists were unaffected by distance. Epixylic, boreal forest-interior cryptogams do occur in matrix habitats such as clear-cuts. In addition, they are associated with the matrix edge because of a favourable microclimate closer to the mature forest on southern matrix edges. Retention and creation of dead wood in clear-cuts along the edges to focal habitats is a feasible way to enhance the long-term persistence of epixylic habitat specialists in fragmented landscapes. The proposed management measures should be performed in the whole stand as it matures, since microclimatic edge effects diminish as the matrix habitat matures. We argue that management that aims to increase habitat quality in matrix habitats bordering focal habitats should increase the probability of long-term persistence of habitat specialists.