Forest Edge Species Research Articles

Plasticity in Compensatory Growth to Artificial Defoliation and Light Availability in Four Neotropical Understory and Forest Edge Herb Species.

Simple SummaryFor monocot herbs growing in the understory of wet tropical forests face an extreme hazard in falling branches and debris from the canopy. We compared the response of two species of understory herbs to two other species of herbs growing at the forest edge or in large gaps. We made the prediction that the forest edge herb species would be better able to compensate for damage because of compensatory growth made possible in the higher light environment than that experienced by the shade-tolerant understory herbs. Our experimental studies showed that both groups of species were tolerant of defoliation under high and intermediate light conditions, but under low light growth conditions the forest edge species showed higher mortality. This finding suggests that a variety of functional growth traits may be structuring post-damage response in understory and forest edge herbs.Defoliation from falling branches is a major factor in the survival of understory herbs in tropical rainforests. Experimental studies of defoliation under three levels of light environment compared responses to partial and total defoliation in four species of tropical rainforest understory herbs. We predicted that elevated levels of light availability would help compensate for damage to through compensatory growth in both understory and forest edge species and that forest edge species would more effectively compensate under high light conditions than shade-tolerant species from the forest understory All species showed a high tolerance to defoliation under high and intermediate light conditions. Under low-light conditions survival differed dramatically with minimal mortality in forest-edge species compared to high mortality in completely defoliated understory species. Defoliation, and light × defoliation interactions, impacted multiple growth traits in understory species. In contrast, forest-edge species showed no effect of defoliation except on total biomass, and only one light × defoliation interaction was observed. Our results indicate that differences in biomass allocation, leaf ecophysiology, and other growth parameters between forest understory and edge species may be structuring post-damage response in understory and forest edge herbs.

Grassland trees and the common bulbul Pycnonotus barbatus promote Afromontane forest restoration

AbstractRestoration of Afromontane forests is critical because of their biodiversity richness and ecosystem service provision. With an evolutionary history of rapid forest migration into grassland in response to shifting climate, traits of Afromontane forests such as a high frequency of light tolerant, small fruited, and bird dispersed species may pre‐adapt them to relatively rapid recolonization of grassland protected from fire. Here, we test this hypothesis with a focus on the role of isolated grassland tree species in promoting forest regeneration. Through seed, seedling, and frugivore surveys, we found that seed rain below small, isolated grassland trees was almost 300 times that in open grassland, with 30 times more seedlings established under trees. However, these seedlings were mostly grassland or forest edge woody shrubs or small trees. Dispersal limitation was moderate to high and establishment limitation high for all other species. Ecological filtering of seed species favored some over others, which needs further exploration. Key tree traits attracting frugivore visits were distance from forest edge, height, and “leaflessness.” Across a year of sampling almost 90% of frugivore visits to isolated trees were by just two grassland / forest edge species, the common bulbul Pycnonotus barbatus (71%) and the speckled mouse bird Colius striatus (17%). Overall, our results suggest that while anthropogenic changes within Afromontane systems render any pre‐adaption Afromontane forests may have to rapid reestablishment of forest into grassland ineffectual, small, isolated grassland trees are nevertheless critical for the first stage of succession.

Grassland management and land use history shape species composition and diversity in Transylvanian semi‐natural grasslands

AbstractAimsSemi‐natural grasslands are among the most biodiverse habitats in Europe, and they are of great conservation and agricultural value. However, changes in land use like grazing intensification and the cessation of traditional management have dramatic effects on the extent and biodiversity of these ecosystems. In this study we investigated how current management practices and land use history shape species composition and diversity patterns in semi‐natural grasslands of the Eastern hills of the Cluj region.LocationEastern hills of Cluj (“Dealurile Clujului de Est” ‐ ROSCI0295) Natura 2000 conservation site and close surroundings, Transylvania, Romania.MethodsWe surveyed plots in extensively and intensively grazed grasslands, grasslands mown by hand or heavy machinery, and abandoned grasslands. To quantify grassland continuity, we analysed a series of historical cadastral and more current maps ranging from the 18th to the 21st century.ResultsSpecies composition was significantly influenced by current management, grassland continuity and environmental factors. Mown and extensively grazed grasslands had more grassland and forest edge specialists than abandoned and intensively grazed grasslands. In addition, there was a positive relationship between the number of grassland specialists, forest edge species and grassland continuity, while the number of ruderal species related negatively to grassland continuity. The highest diversity values were recorded in traditionally mown grasslands. However, diversity‐related variables were poorly reflected by grassland continuity.ConclusionsThis study provides evidence that short‐term abandonment may not be as detrimental for grasslands as often suggested, and intensive grazing results in the greatest loss in species diversity. Grassland continuity tightly influences the persistence of grassland specialist species. Thus, we recommend land use history to be included in the selection and identification of high‐nature‐value grasslands by prioritizing conservation efforts for older grasslands.

Aedes albopictus Populations and Larval Habitat Characteristics across the Landscape: Significant Differences Exist between Urban and Rural Land Use Types.

Simple SummaryMore than 50% of the global population now resides in cities. In addition to large human populations, some cities support large populations of vectors, such as mosquitoes. Consequently, we have seen a resurgence in urban outbreaks of mosquito borne diseases, e.g., West Nile and dengue fever, in the last 60 years. The Asian Tiger mosquito, Aedes albopictus, is an ecologically flexible species that has colonized every continent, except Antarctica, in recent decades. In this paper, we tested the prediction that A. albopictus is more abundant in human-dominated, urban, and suburban areas compared to rural areas in a temperate US city. We collected data on mosquito abundance and other aspects of the environment important for mosquitoes and that also may vary by land use type. As predicted, we found higher densities of A. albopictus in urban and suburban areas compared to rural ones. We also found few other mosquito species, higher average temperatures, lower nitrogen levels in aquatic larval habitats, and faster water evaporation in some sample weeks. We conclude that this species is thriving in human-dominated areas in this metropolitan region, and its success may be partially due to the environmental characteristic of this habitat type.One of the most profound recent global changes has been the proliferation of urban metropolitan areas. A consequence of urbanization is a reduction in abundance, or diversity, of wildlife. One exception, is the proliferation of vectors of disease; recent years have seen the emergence and resurgence of diseases vectored by species closely associated with humans. Aedes albopictus, a mosquito with a near global range and broad ecological niche, has been described as an urban, suburban, or rural vector, or a forest edge species depending on local conditions. We tested the hypothesis that abundance and phenological patterns of this species vary among different land use types in a temperate city because of the variation in the biotic and abiotic conditions characteristic of those habitat types. A. albopictus populations in urban and suburban areas were an order of magnitude larger than in rural areas and were detected several weeks earlier in the season. Additionally, we found fewer overall mosquito species, higher temperatures, lower nitrogen, higher pH, and faster water evaporation in larval habitats in urban vs. rural areas. By understanding the ecological differences that facilitate a species in one habitat and not another, we can potentially exploit those differences for targeted control.

Functional traits of broad-leaved monocot herbs in the understory and forest edges of a Costa Rican rainforest.

Broad-leaved monocot herbs are widespread and dominant components of the shaded understories of wet neotropical forests. These understory habitats are characterized by light limitation and a constant threat of falling branches. Many shaded understory herb species have close relatives that occupy forest edges and gaps, where light availability is higher and defoliation threat is lower, creating an opportunity for comparative analysis of functional traits in order to better understand the evolutionary adaptations associated with this habitat transition. We documented ecological, morphological and ecophysiological traits of multiple herb species in six monocot families from each of these two habitats in the wet tropical rainforest at the La Selva Biological Station, Costa Rica. We found that a mixture of phylogenetic canalization and ecological selection for specific habitats helped explain patterns of functional traits. Understory herbs were significantly shorter and had smaller leaves than forest edge species. Although the mean number of leaves per plant and specific leaf area did not differ between the two groups, the larger leaf size of forest edge species gave them more than three times the mean plant leaf area. Measures of leaf water content and nitrogen content varied within both groups and mean values were not significantly different. Despite the high leaf nitrogen contents, the maximum photosynthetic rates of understory herbs were quite low. Measures of δ13C as an analog of water use efficiency found significantly lower (more negative) values in understory herbs compared to forest edge species. Clonality was strongly developed in several species but did not show strong phylogenetic patterns. This study highlights many functional traits that differ between broad-leaved monocot species characteristic of understory and forest edge habitats, as well as traits that vary primarily by phylogenetic relatedness. Overall, plant functional traits do not provide a simple explanation for the relative differences in abundance for individual understory and forest edge species with some occurring in great abundance while others are relatively rare.

Habitat disturbance can alter forest understory bird activity patterns: A regional-scale assessment with camera-traps

Despite forests are a biodiversity reservoir and a wellbeing source for the humankind, they have been largely disturbed in the past decades. Disturbed and naturally-regenerated forests and forest plantations represent 75% of the world forested area, stressing the need of managing non-pristine forests. While we know that habitat disturbance alters forest structure, reducing species richness and abundances, its effects on animal behavior remain little explored. We used camera traps to test if daily activity patterns of forest birds change along a 450-km disturbance gradient in the Valdivian temperate rainforests of southern Chile. We contrasted bird activity at four conditions: old-growth and second-growth native forests, native forests subject to selective logging, and abandoned exotic plantations with native vegetation. We contrasted habitat structure among conditions and estimated activity kernels to compare bird activity. We also made activity comparisons examining bird foraging guilds (nectarivores, frugivores, and insectivores) and habitat preference (interior vs edge). Habitat structure was different among conditions, being the old-growth native stands the most contrasting habitat. Bird daily activity patterns differed among conditions as well. We observed that bird activity reaches a peak early in the morning at the old-growth native forests, at noon in the plantations, and in the afternoon at the logged forests, while it was more variable in secondary forests. We obtained similar results among bird foraging guilds, but insectivorous birds presented the most contrasting differences. Likewise, we found a similar pattern between forest interior and edge species, which was more evident for forest interior birds. Logged forests presented the largest activity differences, despite being structurally similar to second-growth stands. Forest disturbance not only alters bird species richness and abundance, but also their behavior. Bird daily activity patterns may be directly affected by daily variations in forest microclimate conditions and indirectly affected by chantes in resource availability, which may be affecting their ecological interactions. Therefore, forest management and restoration strategies should take animal behavior into account.

Relative conservation value of Nova Scotia’s forests: forested wetlands as avian diversity hotspots

Nova Scotia’s forested landscapes are degraded and under stress. As the province moves toward an ecological forestry management approach, land managers need more complete information about the relative biodiversity value of various habitats in landscapes that they manage to fully assess conservation consequences of different management options. To begin assessing the relative conservation value of different forest types, we surveyed bird communities in 18 forested wetlands (wooded bogs, tall shrub swamps, and treed swamps), mature upland forest stands, and regenerating upland forest stands in western Nova Scotia during the breeding season in 2017 and 2018. There were distinct differences among the bird communities in each forest type. Bird species diversity, overall abundance, and abundance of several guilds and species of conservation concern were higher in forested wetlands than in mature and regenerating upland forests. Bogs and shrub swamps had the highest number of species with strong habitat affinities, but treed swamps and mature sites had unique suites of strongly associated species and guilds — several of conservation concern. Regenerating sites were occupied mainly by forest-edge species and conservation value was low. Our study highlights the importance of forested wetlands to bird conservation and supports the idea that forested wetlands are avian diversity hotspots.

Historical ecology of Mediterranean forests: Land use legacies on current understorey plants differ with time since abandonment and former agricultural use

AbstractQuestionsLand use legacies in current forest understorey vegetation, thoroughly studied in temperate regions, were investigated in a Mediterranean context. We tested the effect of three historical variables on current forest plant communities and traits: forest temporal continuity (ancient: forested before 1860, recent: reforested after 1860, and very recent forest: reforested after 1958) and type of land use in 1860 and 1958 (forest, pasture or arable land).LocationThe Regional Natural Park of Luberon (southeastern France).MethodsWe used a comprehensive vegetation plot database (473 species in 1,429 plots). Species’ response to historical variables was tested with logistic regressions, and the relationship between plant traits and historical variables was analysed with RLQ and fourth‐corner analyses.ResultsAmong all studied species, 250 responded to forest temporal continuity, 208 to 1860 land use, and 246 to 1958 land use. Species associated with ancient forests were more frequently forest specialists or forest edge species, shade‐tolerant and perennials, while species associated with recent and very recent forests were more frequently annuals, anemochorous and heliophilous species. Species exhibited different traits and ecological preferences according to the type of land use prior to forest: therophytes were more frequent on former arable land while chamaephytes were more frequent on former pasture. Trait responses to 1860 and 1958 land uses were globally consistent.ConclusionsThe effect of forest temporal continuity and past land use on forest understorey communities was consistent with other studies in northern Europe or northern America, which suggests that the same ecological processes apply in temperate lowland and Mediterranean regions. This study highlights a succession of plant communities in the long term and different trajectories of succession according to the type of former agricultural use. The long‐term legacies of past land use in current forest plant communities highlight the importance to preserve ancient forests, where typical forest species can be maintained.

Patch size and vegetation structure drive changes to mixed-species flock diversity and composition across a gradient of fragment sizes in the Western Andes of Colombia

Abstract Forest fragmentation is a leading driver of biodiversity loss, yet its effects on positive species interactions remain poorly known. We examined the effects of fragmentation on mixed-species bird flocks in the Western Andes of Colombia. Using 500-m transect surveys (n = 14 transects), we sampled flocks in 8 fragments (range: 10–173 ha) and an unfragmented reference site within the same altitudinal band (1,900–2,200 m.a.s.l.) and matrix type (cattle pasture). We evaluated the relative contributions of 9 predictor variables, including patch size, distance from edge, and selective aspects of vegetation structure on the composition, size, species richness, functional diversity, and phylogenetic diversity of flocks. We found effects of both patch size and vegetation structure on flock species richness, size, and functional diversity, but no support for edge effects. Generally, flock richness and size responded differently to fragmentation than did functional and phylogenetic diversity metrics. Both flock size and richness increased with patch size, but this variable had no effect on functional and phylogenetic diversity. Flock richness and size increased in high-canopy forests with greater foliage height diversity, whereas unlogged, old-growth primary forests with large-diameter trees had lower flock richness and size, but significantly greater functional diversity. Phylogenetic diversity was not affected by patch size, edge effects, or vegetation structure. We found differences in flock composition in response to fragmentation. Richness of Furnariidae in flocks increased with increasing distance from edge and foliage height diversity, whereas that of Thraupidae and boreal migrant species increased in early successional and forest edge flocks, respectively. All flock diversity metrics differed significantly seasonally, with smaller, less diverse flocks observed in January–March than in June–August. Flocking behavior persisted in 10-ha fragments, likely because Andean flocks are “open membership” in nature, but there was extensive species turnover as forest edge and generalist species replaced forest-interior species in smaller fragments.

Effects of forestry practices on habitat variables and mammal abundance in a Japanese larch plantation

Forestry practices can lead to changes in wildlife habitat that could have lasting effects on the distribution of species. Hence, the aim of this study was to determine the effects of forestry practices on habitat variables and habitat use by mammals in three different stands (control, clear-cut and clear-cut with reserves) in a Japanese larch Larix kaempferi plantation from April to October in 2016 and 2017. We recorded the presence of field signs for the following six mammal species: Korean hare Lepus coreanus, raccoon dog Nyctereutes procyonoides, Eurasian badger Meles meles, water deer Hydropotes inermis, roe deer Capreolus pygargus and wild boar Sus scrofa. Habitat variables significantly differed among three stands. Field sign (feces, foot prints and feeding signs) abundances of mammals showed significant differences between the control and clear-cut stands. Moreover, field sign abundances of all species were highest in the clear-cut with reserves stand. We calculated the impact of clear-cutting on habitat use by mammals using GLMMs. Both clear-cutting in the models were significant and had positive coefficients on habitat use by Korean hare, raccoon dog, deer and wild boar. In Eurasian badger models, only clear-cutting with reserves show positive impacts on habitat use. Habitat selection by forest edge species such as Korean hare and deer showed dependence on understory structure. Abundant understory in the clear-cut with reserves stand may not only provide vegetative food and cover for herbivores but also small prey species for omnivores and carnivores. The results of our study show that forest understory is one of the most instrumental factors mitigating the effects of clear-cutting on habitat use by mammal and it should, therefore, be given due importance in forestry practices.

Bird species that occupy river edge in continuous forest tend to be less sensitive to forest fragmentation

Along a distance gradient from a given river, two types of habitat can be recognized: natural river edge and forest interior, each one with its own vegetation characteristics and dynamics. In a continuous area of the Brazilian Atlantic Forest, we investigated (1) if bird communities are different between a riverbank of a small stream and an inland forest habitat; (2) if the species of the river edge habitat are the ones that persist in the most in forest fragments after deforestation of a continuous forest; (3) if the river edge habitat species are those that are less sensitive to forest fragmentation. It is expected that there are differences in the bird communities and the occupancy of some species between the two habitats. We allocated 16 sampling points in each of the habitats and sampled the birds by point counts with a short radius of 30 m. Results suggest that there is a significant difference between the composition of the bird communities of the river edge and forest interior habitats, although the species richness is similar. Six species were more likely to occupy the river edge and 14 species had a greater probability of occupancy in the forest interior. Species associated with the river edge habitat (15 species) tend not to be sensitive to forest fragmentation (12 species). In this study, we demonstrated that river-border species of continuous forest areas form a significant part of the bird communities that persist in small forest fragments, with intense edge effect. This shows that not all forest edge species are the result of the colonization from open areas. Congruently, species that occupy the most distant areas from the river vegetation in a continuous forest are those more sensitive to forest fragmentation.

Adaptation to seasonal drought in two closely related species of Neotropical Costus (Costaceae)

AbstractSeasonal drought has been shown to greatly influence the distributions and species composition of plants in tropical rain forests. By conducting a series of field, greenhouse, and growth chamber experiments, we examined how Costus villosissimus, a forest edge species, has adapted to drought and differentiated from C. allenii, its closely related species in the understory. We hypothesize that delayed seed germination and high drought tolerance may lead to habitat differentiation and thus reproductive isolation between closely related plant species in the tropics.Abstract in Spanish is available with online material.

Сhanges in the ground cover structure in the “forest –forest edge – cutover” ecotone in a bilberry spruce stand ten years after logging

Data of the vascular plant species composition in the ecotone “forest – forest edge – cutover” ten years after logging of a bilberry spruce stand in the north-taiga subzone of the Arkhangelsk Region are reported. Differences among zones of the ecotone complex regarding species percent covers and frequency of occurrence were revealed. Changes in the ground cover species abundance compared to earlier reforestation stages (2–5 years after logging) are discussed. Plant species were grouped according to their response to logging and subsequent tree layer restoration. The first group consists of typically forest-dwelling species whose phytosociological optimum corresponds to bilberry spruce forest conditions ( Goodyera repens , Listera cordata , Vaccinium vitis-idaea , V. myrtillus, Hylocomium splendens ). The second group includes the forest species that have demonstrated a negative response to logging and have been actively recovering their abundance since the time of tree layer formation in the cutover site ( Carex globularis , Chamaepericlymenum suecicum, Equisetum sylvaticum , Gymnocarpium dryopteris , Luzula pilosa , Maianthemum bifolium , Melampyrum pratense , Oxalis acetosella , Pleurozium schreberi , Rubus arcticus , Trientalis europaea ). The third group is made up of forest edge species ( Empetrum nigrum and Orthilia secunda ). The forth group comprised typically forest-dwelling apophytes, which responded positively to logging, but declined in abundance as the tree layer was forming ( Avenella flexuosa, Chamaenerion angustifolium , Polytrichum commune ). A separate group consists of the species whose response to logging and subsequent tree layer formation could not be detected by geobotanical, and has no statistic proof. It is shown that 10 years after logging, although the tree layer has formed, each zone of the ecotone complex has preserved their specific traits of the ground cover structure.

О некоторых сообществах петрофитных степей Среднего Урала

О некоторых сообществах петрофитных степей Среднего Урала

Differentiation of herb layer vascular flora in reclaimed areas depends on the species composition of forest stands

Abstract Spoil heaps, resulting from open-pit mining, are deprived of soil cover. A common method of reclamation for such sites is afforestation aimed at creating whole forest ecosystems. Forest stands planted on soilless areas make it possible to determine the effects of different tree taxa on the species composition of flora. The study focused on the vascular species of herb layers in young forest stands formed by Alnus glutinosa, Betula pendula, Pinus sylvestris, Quercus petraea and Robinia pseudoacacia, and mixed stands dominated by Acer pseudoplatanus or Betula pendula. The study included 227 randomly selected plots across the afforested Belchatow Brown Coal Mine spoil heap. Species composition of the herb layer was composed mainly of synanthropic species (over 70%), and was clearly related to the overstory tree species composition of forest stands. TWINSPAN divided sample plots into two groups that developed under the canopy of stands formed by: (1) Betula pendula, Pinus sylvestris or Quercus petraea, or mixed stands with Betula pendula, or (2) Alnus glutinosa or Robinia pseudoacacia, or mixed stands dominated by Acer pseudoplatanus. The first group was dominated by meadow species (25.8%), while the second had higher richness of ruderal (18.6%) and forest-edge species (14.1%). Plant species associated with fertile and moist forest habitats were more frequent in the second group (Alnus-Robinia), whereas species of acidic and dry forests occurred only in the first group (Betula-Pinus). Non-parametric tests on Ellenberg’s indicator values showed that forest stands of Betula-Pinus group created habitat conditions for light-demanding species with low fertility requirements, whereas forest stands of Alnus-Robinia group created habitat conditions for nitrophilous and shade-tolerant plant species. Our data revealed that tree species composition of forest stands is a key factor shaping herb layer conditions and – as a consequence – herb layer species composition despite of initial habitat variability on the spoil heap. These results highlight a key role of forest stand composition in the development of herb layer richness on post-industrial habitats.

Microhabitat partitioning of closely related Sarawak (Malaysian Borneo)frog species previously assigned to the genus Hylarana (Amphibia: Anura)

Microhabitats play an important role as resources that are partitioned between phylogenetically related or ecologically similar species (i.e., a guild). This hypothesis was tested by first elucidating phylogenetically closed Sarawak frog species via DNA sequencing of the 16S rRNA mitochondrial DNA gene, and later determining their microhabitat guild and partitioning via nonmetric dimensional scale. Mitochondrial 16S gene revealed 5 monophyletic groups consisting of Hylarana erythraea + Amnirana icobariensis, Chalcorana raniceps, Abavorana luctuosa, Pulchrana signata + P. picturata, and P. baramica + P. glandulosa + P. laterimaculata. On the other hand, microhabitat utilization grouped the frogs into 5 ecological guilds consisting of semiarboreal species at the forest edge (C. raniceps), ground dwellers in an unforested region (H. erythraea), ground dwellers (rock) at the forest edge (P. picturata), ground dwellers on the forest floor and forest edge species (P. signata, P. glandulosa, A. luctuosa, O. hosii), and semiarboreal forest (riverine) species (P. baramica). Thus, the microhabitats used were not influenced by the proposed phylogenetic relationships. Partitioning of microhabitat utilization, on the other hand, was clearly seen in 2 closely related species in both vertical and substrate utilization. The study supports resource partitioning by closely related species reflected by their ecological guilds, and will be useful for conservation management of the Bornean fauna.

Forest–farm edge effects on communities of ground beetles (Coleoptera: Carabidae) under different landscape structures

AbstractIn fragmented landscapes, ecological processes may be significantly influenced by edge effects, but few data are available for edge effects across forest–farmland edges. We investigated patterns of species richness, abundance, and species composition in ground beetles across forest–farm edges in two different agro‐forest landscapes in Korea. Nine and five sites were selected from Hwaseong, a fragmented landscape, in 2011 and 2012, respectively, while eight sites were selected from Hoengseong, a relatively well‐protected landscape, in 2012. Ground beetles were collected by pitfall trapping. Species richness was higher in the surrounding habitat than in the forest interior or edge in both Hwaseong and Hoengseong. However, in Hwaseong, species richness of the forest edge was similar to that of the forest interior, while in Hoengseong forest edge species richness was intermediate between that of the forest interior and surrounding areas. In addition, non‐metric multidimensional scaling based on the combined data of both locations showed that the species composition of ground beetles in the forest edge was more similar to that of the forest interior than the surrounding areas, although some open‐habitat species occurred at the forest edges. Three characteristic groups (forest specialists, edge‐associated species, and open‐habitat species) of ground beetle species were detected by indicator value analysis. In our study, ground beetle assemblages differed in the forest edges of two agro‐forest landscapes, suggesting that the edge effect on biota can be influenced by landscape structure.

Environmental effects of brushwood harvesting for bioenergy

Sweden aims to increase the proportion of renewable energy sources, ultimately to be able to phase out fossil fuels. To achieve this, new energy sources need to be explored. In this multi-disciplinary article, we examine the technical, economical, ecological and legal possibilities to commercially and sustainably harvest brushwood for bioenergy, while simultaneously gaining positive environmental effects, both for biological diversity, the cultural heritage, and the climate.The Swedish open landscape is becoming covered with secondary brushwood regrowth through natural succession, except where it is kept open. Brushwood is spreading along roads, railway lines, edge zones, in power line corridors, abandoned semi-natural grasslands, nature reserves, and in marginal land in urban areas. Such brushwood consists of saplings, bushes and young trees of a range of deciduous plant species, e.g. birch, aspen, alder and goat willow, sometimes mixed with conifers, often forming dense thickets.Such secondary brushwood regrowth could be systematically utilised as a new source of renewable bioenergy. Commercial brushwood harvesting in Sweden may contribute 26 PJ of energy annually, which may be a small but significant contribution, considering the favourable energy ratio (Er=28), indicating that large emission reductions can be achieved, if fossil fuels are replaced. Growing brushwood does not require fertilizers or pesticides, soil tillage or crop management, and it does not compete with any other potential land use. Many brushwood habitats are already being managed to clear brushwood, for other purposes, minimizing the added harvesting cost.Apart from providing bioenergy, it has also been suggested that brushwood harvesting would benefit biological diversity. A large number of nationally redlisted species are dependent on the active management of open habitats, including semi-natural grasslands, and man-made habitats such as road verges and power line corridors.Our literature review shows that brushwood harvesting could benefit both biological diversity and the cultural heritage, and contribute to the management of the open cultural landscape. There are however certain limitations. Brushwood harvesting would favour a certain set of species, including many redlisted, but it may also threaten another set of species, especially species associated with early successional stages of forest regeneration, as well as forest edge species, depending on how and where it is applied. Harvesting may be affected by legislation imposing limitations regarding habitats of particular importance for biodiversity. The environmental and legal constraints would probably reduce the profitability of brushwood harvesting in certain areas, as well as the annual production of bioenergy.

Forest birds respond to the spatial pattern of exurban development in the Mid-Atlantic region, USA.

Housing development beyond the urban fringe (i.e., exurban development) is one of the fastest growing forms of land-use change in the United States. Exurban development’s attraction to natural and recreational amenities has raised concerns for conservation and represents a potential threat to wildlife. Although forest-dependent species have been found particularly sensitive to low housing densities, it is unclear how the spatial distribution of houses affects forest birds. The aim of this study was to assess forest bird responses to changes in the spatial pattern of exurban development and also to examine species responses when forest loss and forest fragmentation were considered. We evaluated landscape composition around North American Breeding Bird Survey stops between 1986 and 2009 by developing a compactness index to assess changes in the spatial pattern of exurban development over time. Compactness was defined as a measure of how clustered exurban development was in the area surrounding each survey stop at each time period considered. We used Threshold Indicator Taxa Analysis to detect the response of forest and forest-edge species in terms of occurrence and relative abundance along the compactness gradient at two spatial scales (400-m and 1-km radius buffer). Our results showed that most forest birds and some forest-edge species were positively associated with high levels of compactness at the larger spatial scale; the proportion of forest in the surrounding landscape also had a significant effect when forest loss and forest fragmentation were accounted for. In contrast, the spatial configuration of exurban development was an important predictor of occurrence and abundance for only a few species at the smaller spatial scale. The positive response of forest birds to compactness at the larger scale could represent a systematic trajectory of decline and could be highly detrimental to bird diversity if exurban growth continues and creates more compacted development.

Butterfly fauna in Mount Gariwang-san, Korea

The aim of this study is to elucidate butterfly fauna in Mt. Gariwang-san, Korea. A field survey was conducted from 2010 to 2015 using the line transect method. A literature survey was also conducted. A total of 2,037 butterflies belonging to 105 species were recorded. In the estimation of species richness of butterfly, 116 species were estimated to live in Mt. Gariwang-san. In butterfly fauna in Mt. Gariwang-san, the percentage of northern species was very high and the percentage of grassland species was relatively higher than that of forest edge species and forest interior species. Sixteen red list species were found. In particular, Mimathyma nycteis was only recorded in Mt. Gariwang-san. When comparing the percentage of northern species and southern species including those recorded in previous studies, the percentage of northern species was found to have decreased significantly whereas that of southern species increased. We suggest that the butterfly community, which is distributed at relatively high altitudes on Mt. Gariwang-san, will gradually change in response to climate change.