Residual Forest Patches Research Articles

Socio-ecological impact of forest legislations on forest and forest-people of Jhargram District, West Bengal

For thousands of years, the first settlers of the sub-continent anchored in the vast inland forest ecosystems. These first settlers are still surviving in different residual forest patches and are known as Aboriginals or tribal people. As a livelihood strategy, forest people used to tame the services of the forest ecosystem according to their needs while maintaining a narrow ecological balance. The traditional social, cultural, and religious practices and beliefs of the forest people were not devoid of the forest ecosystem. Secondary data on the overlapping of forest patches indicates their coexistence. The indigenous forest people of Jhargram district, those dependent on the services of forest ecosystems have been deeply affected by the forest policies implemented before and after India's independence. The expansion of government control over the forest resources for maximization of revenue, particularly in colonial times, paved the way to restrict forest people to access the benefits of forest ecosystem services. The main objective of this study is to analyze the impact of various regulations on forest and forest-dependent tribal people in the Jhargram District of West Bengal. The discussion has revealed some specific impacts of the forest legislation, direct and indirect in nature, on their habitat, occupation, and social and nutritional conditions. These impacts have been assessed on the basis of primary data and information generated from the field and some certain indicators. Statistical and computational techniques have been used to assess various impact. The findings attest that the effects of such legislation are consequent more upon the habitat and livelihood of the tribal groups than the non-tribal human communities.

Green tree retention as a conservation tool for the black woodpecker in managed forests

The black woodpecker, Dryocopus martius, a creator of tree cavities, is considered a keystone species and a priority in terms of forest biodiversity conservation. The aim of this paper was to understand how the structure of managed forests impacts the choice of tree for excavating cavities of the black woodpecker. The study was conducted in an extensive forest complex in northeastern Poland dominated by the pine Pinus sylvestris. The parameters of the cavity trees and surrounding forest were analyzed on different levels to determine what trees and stand types were selected by the black woodpecker. In the period from 2018 to 2021, analyses were carried out for 367 cavities excavated in trees growing in forest areas from 0 to 225 years old. The most numerous cavity trees were between 121 and 160 years old. Cavity trees were found in the stands (62%), in the residual forest patches (19%) and in the single trees remaining after logging (19%). Forty-four percent of all cavities were excavated in dead trees. Black woodpecker nesting stands were characterized by lower canopy closures and low understory and shrub layer cover. We did not find a difference between the diameters or the heights of cavity entrances among the black woodpecker nesting trees growing in different habitat types. The black woodpecker is capable of nesting in small fragments of an old stand and even in single old trees growing in clearcut areas. This is due to the high proportion of dead trees in these habitats, which are preferred by woodpeckers for excavating cavities. Leaving patches of old-growth stands in commercial forests positively affects the habitat formation of the black woodpecker and perhaps, as a consequence, that of other animal species that depend on it.

Asplenium arcumontanum (Aspleniaceae), a new species from the Eastern Arc Mountains of Tanzania

Asplenium arcumontanum (Aspleniaceae), a new terrestrial forest species from northern Tanzania, is described and illustrated. This taxon is closely related to the more widespread A. elliottii, a vicariant species with similar habitat requirements but a near-allopatric distribution. Asplenium arcumontanum fits the typical altitudinal zonation pattern of equatorial African gemmiferous ferns, and the endemism pattern of the Eastern Arc Mountains. Its restricted distribution further underscores the urgent need to conserve residual forest patches in this distinctive range.

Plant community development following reclamation of oil sands mine sites in the boreal forest: a review

Understanding how reclamation practices influence plant community assembly and succession is an important step in developing realistic indicators and targets for reclamation of oil sands mine sites to upland forest ecosystems. We currently have a poor understanding of factors affecting plant community assembly and succession in reclaimed oil sands sites. Through synthesis of research completed over the last 24 years, we identify four key findings: (i) use of surface soil and forest floor material salvaged from mined areas increases plant species cover, richness, and diversity relative to the use of various other cover soil materials (such as clay subsoil); (ii) stockpiling of salvaged surface soils decreases the abundance of native plant propagules and delays early vegetation community development; (iii) differences in plant community composition between reclaimed and adjacent mature forests remain two decades after placing cover soils; however, differences are smaller with use of forest floor–mineral mix than peat–mineral mix; and (iv) plant community assembly is in progress but communities remain different to those found in natural undisturbed conditions. Our review identified critical knowledge gaps for further research to improve understanding of: (i) long-term (60 to 100 years) plant community composition in reclaimed oil sands sites; (ii) how residual forest patches near disturbed oil sands sites act as seed and propagule sources in newly reclaimed sites; (iii) plant community assembly processes in reclamation sites; (iv) the effect of micro-topographic heterogeneity on plant community development; and (v) how soil nutrient availability in different substrates influences plant community development over the long term. Ongoing support for selected existing studies and establishment of new studies focusing on plant community development through long-term monitoring are highly recommended.

Enhancing connectivity in agroecosystems: focus on the best existing corridors or on new pathways?

Restoring or establishing corridors between residual forest patches is one of the most adopted strategies for the conservation of animal populations and ecosystem processes in fragmented landscapes. This study aimed to assess whether it is more effective to focus restoration actions on existing corridors or to establish habitats in other strategic areas that can create new dispersal pathways to enhance connectivity. We considered a real agroecosystem in northern Italy, based our analyses on graph-theory and habitat availability metrics, and focused on the Hazel Dormouse as the target species. We compared the connectivity increase resulting from (i) the simulated restoration of existing priority corridors, i.e., those with significant presence of forest but in which restoration actions would still result in considerable connectivity gains, or (ii) the simulated plantation of 30 hedgerows along new priority pathways, i.e., those areas with no current forest cover in which habitat creation would be more beneficial for connectivity. Implementing new priority pathways resulted in substantially larger connectivity gains (+ 38%) than when restoration efforts were concentrated in improving already existing corridors (+ 11%). Establishing hedgerows along new pathways allowed enhancing the complementary and functionality of the full set of landscape corridors and proved more efficient than just strengthening the areas where dispersal flows were already concentrated. We demonstrated the importance of analytical procedures able to compare the effectiveness of different management strategies for enhancing connectivity. Our approach may be applied to multiple species sensitive to fragmentation in other heterogeneous landscapes and geographical contexts.

Boreal bryophyte response to natural fire edge creation

AbstractQuestionChanges in species richness and composition in plant communities as a result of edge creation are well documented in anthropogenically modified landscapes, but what happens after natural disturbance? We investigate the responses of boreal bryophytes to edge creation in a post‐wildfire residual forest patch system.LocationBoreal black spruce–feather moss forest, western Québec, Canada.MethodsBryophyte community was sampled in 50‐m2 plots: 117 plots in 39 undisturbed forest cores (control) and 108 plots in 30 residual forest patches from wildfire, divided into 48 core plots, 30 north‐facing edge plots and 30 south‐facing edge plots. Temporal, severity, spatial and structural characteristics of the stands were also recorded to explain bryophyte community composition.ResultsResidual edges and cores were more species‐rich than undisturbed cores, particularly north‐facing edges, but community composition differed between undisturbed and residual cores. Indicator species of undisturbed cores and residual edges differed in their species traits. Spatial variables explained variations in composition, with a larger difference between core and edge communities in patches over 3 ha compared to smaller patches.ConclusionWe observed community composition change in response to natural edge creation. While edge influence is reduced in large patches, the bryophyte community remains distinct from undisturbed cores. This community change is a ‘control’ in studies of boreal bryophyte response to anthropogenic edge creation, and suggests that we should consider the natural range of variability. Finally, this study emphasizes that forest remnants do not substitute for continuous and undisturbed forests.

Are post-fire residual forest patches refugia for boreal bryophyte species? Implications for ecosystem based management and conservation

Residual patches of forest remaining after natural or anthropogenic disturbance may facilitate regeneration of fragmented forest. However, residual patch function remains unclear, especially after natural wildfire. We investigate the role of residual boreal forest patches as refugia for bryophytes and ask the question, do they house bryophyte communities similar to those encountered in undisturbed forests? Bryophytes were sampled in three habitat types in black spruce boreal forests illustrating a gradient of disturbance severity: undisturbed forests, residual patches and burned matrices. Temporal, disturbance severity, spatial and structural variables of habitats were also recorded. Bryophyte community composition differed among habitat types with residual patches characterized by higher species richness, the loss of forest specialists and the addition of disturbance-prone species. The bryophyte community found in residual patches is at the interface between the communities of undisturbed forests and burned matrices. As residual patches did not conserve all species, particularly forest specialists, they were not refugia. However, we identify temporal, spatial and structural characteristics that can maintain bryophyte communities most similar to undisturbed forests and enhance residual patch “refugia potential”. Residual patches enhance bryophyte diversity of the landscape housing species that cannot survive in the burned matrix. As conclusion we discuss the use of retention patches in harvested stands, together with the preservation of undisturbed stands that house singular bryophyte communities and especially sensitive forest specialists.

So close and yet so far away: long‐distance dispersal events govern bryophyte metacommunity reassembly

Summary Metapopulation dynamics have been used to explain bryophyte dispersal patterns and they predict that population abundances vary with the spatial distribution of habitat and with species traits. However, results from stand and landscape studies are contradictory as both distance‐dependent and distance‐independent patterns have been found. These studies have typically included only a few species, which limits interspecies comparison. It is the time to investigate bryophyte dispersal at the metacommunity scale. We studied bryophyte dispersal patterns in a system made up of burned matrices containing unburned residual forest patches. The importance of short‐ versus long‐distance dispersal was examined by comparing extant and propagule rain communities in residual forest patches of three fire sites using both species and life strategies. Extant and propagule rain communities were distinct. Several propagule rain species, of all life strategies, did not originate from the closest extant community, suggesting that regional dispersal events are important, following the inverse isolation hypothesis. Temporal, spatial and structural characteristics of the environment had a greater influence on dispersal than distance, which only influenced similarity patterns at the regional scale, highlighting the importance of propagule source attributes for the conservation of bryophyte metacommunities. Synthesis. Long‐distance dispersal may be the rule and not the exception in bryophyte metacommunities. Therefore, bryophyte metacommunity dynamics depend on several dispersal scales, and residual forest patches can contribute both to local and regional diaspore clouds. Species’ environmental tolerance during establishment and their ability to produce copious amounts of spores may be more important filters in bryophyte metacommunity dynamics than dispersal distance.

Managing Tree Diversity: A Comparison of Suburban Development in Two Canadian Cities

Is (sub)urban forest diversity shaped by previous land use? This study was designed to quantitatively assess the impacts of subdivision development on urban tree-species composition in two Canadian cities: Halifax, Nova Scotia, and London, Ontario. The main goal was to determine whether cities with contrasting pre-urbanized or pre-settlement landscapes—woodlands in Halifax and agricultural fields in London—also revealed differences in urban tree diversity losses and/or gains due to urbanization. In each city, four residential neighbourhoods representing two age categories, older and newer (40–50 years, <15 years), were examined and trees on three land types were sampled: public (street), private (residential), and remnant (woodland). All public street trees within the chosen neighbourhoods were inventoried and approximately 10% of the residential property lots were sampled randomly. Plots were examined in remnant forests in or near each city, representing the original forest habitats prior to agricultural and/or urban landscape transformations. Diameter at breast height, species richness and evenness, and proportions of native and non-native trees were measured. In both cities, streetscapes in newer neighbourhoods exhibit greater species richness and evenness, and are characterized by substantially more native trees. Despite this trend, developers and home owners continue to intensively plant non-native species on newer and smaller property lots. Older neighbourhoods in Halifax containing remnant forest stands hold the greatest number of native trees on private property, alluding to the importance of residual forest buffers and patches in promoting naturalness in the private urban forest. These results suggest that identifying and quantifying flows of species between green spaces during and after development is valuable in order to effectively promote native species establishment and enhance overall urban forest diversity.

Woody Vegetation and Soil Characteristics of Residential Forest Patches and Open Spaces along an Urban-to-Rural Gradient

As the process of urbanization advances across the country, so does the importance of urban forests, which include both trees and the soils in which they grow. Soil microbial biomass, which plays a critical role in nutrient transformation in urban ecosystems, is affected by factors such as soil type and the availability of water, carbon, and nitrogen. The aim of this study was to characterize residual forest patches and open fields in residential areas in the City of Knoxville. A field study was conducted to investigate tree species diversity and determine spatial and temporal soil characteristics along an urban-to-rural gradient. Tree diversity did not differ significantly for residential urban and rural plots in Knoxville, Tennessee. Biologically, there was no indication that soils were affected by tree diversity, in terms of soil microbial biomass C/N along an urban-to-rural gradient in Knoxville residential plots. Rural soils did differ physically from urban soils, cation exchange capacity (CEC) and soil moisture content (GSM). Similarly, physical soil properties such as bulk density, both urban and rural sites were negatively correlated with tree diversity. Results indicate that although the urban-rural gradient is subject to urban environmental stressors, the urban ecosystem is resilient in maintaining the ecosystem functions of more natural systems.

Influence of residual forest patches on post-fire bird diversity patterns in jack pine-dominated ecosystems of northern Lower Michigan

Stand-replacing fires are part of the natural disturbance regime that maintain jack pine (Pinus banksiana Lamb.) forests of northern Lower Michigan. Currently, the occurrence and extent of wildfire is much reduced relative to the past and young jack pine plantations specifically managed for Kirtland’s warbler (Setophaga kirtlandii Baird) are a prominent feature on the landscape. Stringers, or patches of residual pre-fire forest, are a unique feature left behind after wildfires which are not often accounted for in plantation management. In this study, we examined the ecological value of stringers from an avian biodiversity perspective by comparing bird assemblages found within stringers to those in the surrounding forest (non-stringers). Our objective was to answer two research questions: (1) do stringers have unique bird communities relative to the surrounding vegetation (forest or plantation)?; and (2) how much of the variation in bird communities can be explained by differences in vegetation structure and composition between stringers and non-stringers? We conducted breeding and non-breeding season point counts and used abundance data to compare bird species found within stringers and non-stringers at seven sites grouped by time since disturbance. Species richness was significantly higher (P=0.01) in the stringers when the non-stringers were 30–40years old, with 32 species discovered in the stringers and 29 species in the non-stringers. During the breeding season, bird assemblages differed between stringers and non-stringers when the non-stringers were <12years old (multi-response permutation procedures; T=−10.11, A=0.07, P=<0.00), but no differences were observed when non-stringers were 30–40years old or >40years old. Non-breeding bird communities differed between stringers and non-stringers only when the non-stringer was a recently planted (<5years old) plantation (T=−2.15, A=0.09, P=0.02). Differences in bird assemblages appear to be driven by the vegetation structure of stringers and non-stringers where fires were recent, but increasing similarity in vegetation structure occurs with time since fire; over time the importance of stringers for avian biodiversity is reduced. Our results suggest that stringers are important for bird communities, especially in recently disturbed areas, and that these biological legacies should be considered where jack pine management attempts to emulate natural patterns and processes.

Forest structure and understory plant communities inside and outside tree retention groups in boreal forests

Alternatives are being sought to the widespread use of clear-cut logging in boreal forests. Group retention harvesting is a silvicultural treatment in which well-distributed but relatively small residual forest patches (ca 10 m wide) are left inside cutover sites. The objective of this study was to compare vascular plant communities, tree species regeneration, and dead wood retention in tree retention groups and adjacent clear-cuts with soil protection. Our results indicate that plant diversity is relatively similar inside tree retention groups and the adjacent clear-cut area. This result may be explained by the important spatial variability observed among the stands, which were located in different geographical locations, the fact that soils were little disturbed during harvesting in clear-cuts and few opportunities were present for the establishment of pioneer species, and the relatively short time span since harvesting. Using a functional trait approach, we found that shade tolerance still plays a significant but relatively minor role in explaining species abundance between the 2 environments. Tree retention groups also retain a greater quantity and greater variability of dead wood materials compared with clear-cuts, and a higher abundance of regenerating trees, which is likely explained in part by the direct damage caused by the harvesting operations outside tree retention groups. Overall, retention groups do not appear to confer superior protection for late-successional plants compared with traditional clear-cut logging with soil protection. Their ecological value mostly consists in ensuring a minimal input of dead woody materials for saproxylic species.

The influence of landscape matrix on isolated patch use by wide‐ranging animals: conservation lessons for woodland caribou

For conservation purposes, it is important to design studies that explicitly quantify responses of focal species to different land management scenarios. Here, we propose an approach that combines the influence of landscape matrices with the intrinsic attributes of remaining habitat patches on the space use behavior of woodland caribou (Rangifer tarandus caribou), a threatened subspecies of Rangifer. We sought to link characteristics of forest remnants and their surrounding environment to caribou use (i.e., occurrence and intensity). We tracked 51 females using GPS telemetry north of the Saguenay River (Québec, Canada) between 2004 and 2010 and documented their use of mature forest remnants ranging between 30 and ∼170 000 ha in a highly managed landscape. Habitat proportion and anthropogenic feature density within incremental buffer zones (from 100 to 7500 m), together with intrinsic residual forest patch characteristics, were linked to caribou GPS location occurrence and density to establish the range of influence of the surrounding matrix. We found that patch size and composition influence caribou occurrence and intensity of use within a patch. Patch size had to reach approximately 270 km2 to attain 75% probability of use by caribou. We found that small patches (<100 km2) induced concentration of caribou activities that were shown to make them more vulnerable to predation and to act as ecological traps. Woodland caribou clearly need large residual forest patches, embedded in a relatively undisturbed matrix, to achieve low densities as an antipredator strategy. Our patch-based methodological approach, using GPS telemetry data, offers a new perspective of space use behavior of wide-ranging species inhabiting fragmented landscapes and allows us to highlight the impacts of large scale management. Furthermore, our study provides insights that might have important implications for effective caribou conservation and forest management.

The interacting ecological effects of large-scale disturbances and salvage logging on montane spruce forest regeneration in the western European Alps

Insect outbreaks and wind storms are the most common natural disturbances affecting the northern slopes of montane Norway spruce (Picea abies (L.) H. Karst.) forests in the European Alps. The combined effects on stand dynamics, including tree regeneration, of these natural disturbances and an anthropogenic (i.e., salvage logging) disturbance were studied to assess the role of post-disturbance management practices. The study areas were in two adjacent inner valleys of the Aosta Valley Autonomous Region (western Italian Alps). Les Combes study area experienced an insect (Lymantria monacha L.) outbreak that affected 91ha in 1984–1990, while a wind storm impacted 70ha in the other valley (Parriod study area) in 1990. Salvage logging took place in both study areas 2years after the natural disturbance occurrence (i.e., in 1991–1992 in Les Combes, and in 1992–1993 in Parriod), and only dead trees were salvaged. Site characteristics, overstory and understory trees, and coarse woody debris (CWD) data were collected during the summer of 2010 in 90plots randomly distributed within disturbed portions and in control stands of the two study areas. The variability of natural regeneration structure and composition in relation to environment, forest structure, type of disturbance, and salvage logging were analyzed by univariate (i.e., ANOVA and correlations) and multivariate (i.e., MRPP, PCA, and RDA) analyses. Regeneration structure and composition were clearly different for the two disturbance types. Individuals originated mainly from seed after the insect outbreak, while an important role was played by advance regeneration in the windthrow area. Regeneration was more abundant and rich in shade tolerant species (i.e., Abies alba Mill.) after the insect outbreak, while Larix decidua Mill. and light demanding broadleaves were dominant after the windthrow. The two major factors influencing post-disturbance regeneration were the amount of the residual overstory and the amount and distribution of CWD. The presence of residual forest patches facilitated regeneration establishment by reducing herb and shrub competition, and regulating the light that penetrates to the ground. Woodpiles had a negative influence on regeneration in terms of abundance and also influenced composition. On the contrary, scattered CWD facilitated the establishment of new individuals by reducing competition with herbs and shrubs, reducing the impact of browsing, and improving substrate moisture, especially for Norway spruce.

ORAL VACCINATION AGAINST RACCOON RABIES: LANDSCAPE HETEROGENEITY AND TIMING OF DISTRIBUTION INFLUENCE WILDLIFE CONTACT RATES WITH THE ONRAB VACCINE BAIT

Aerial distribution of oral vaccine baits is one of the available strategies for controlling the spread of infectious wildlife diseases. This technique has commonly been used to control rabies in wild carnivores and, together with other techniques, was used to immunize wild populations of raccoons (Procyon lotor) and striped skunks (Mephitis mephitis) after the detection of the first rabid raccoon in the province of Quebec, Canada, in 2006. Vaccine bait distribution was conducted over large areas where agricultural land is dominant but interspersed with residual forest patches. Our objective was to evaluate the effect of habitat (forest vs. agricultural crops) in space and time on the contact rate between wildlife and the ONRAB(®) vaccine bait, a recent alternative to the V-RG(®). Four transects of eight vaccine baits each were installed parallel to, and at different distances from, the forest's edge (under forest cover, at field-forest edge, and at 50 and 200 m from forest edge in agricultural crops) at three sites composed of various crop types interspersed with forest patches. This experiment was conducted during three periods (late spring, 1-7 June; summer, 27 July-2 August; and fall, 24-30 October) in 2009. Contact rates with vaccine baits were monitored for 7 days in each period to evaluate the potential temporal variations generated within the habitat types. Contact rates with ONRAB vaccine baits were highest under forest cover and in the fall. Of 13 species observed in proximity to the vaccine baits, raccoons were the most frequent (49.5%, n=55 visits). Our study underlines the importance of taking into account landscape heterogeneity and timing of distribution when planning the distribution of vaccine baits to control rabies in raccoons.

Landscape-scale disturbance and boreal forest birds: Can large single-pass harvest approximate fires?

Boreal forest birds have adapted to changes caused by natural disturbances such as fire and this adaptation forms the basis for the Natural Disturbance Paradigm (NDP) underlying recent proposed changes in forest harvesting practices in western Canada. To date, this paradigm has been evaluated primarily at the stand level and within conventional harvesting systems. The potential for improvements in avian conservation at the landscape scale by adopting the NDP approach is largely unknown. We examined the effects of landscape-scale disturbances on forest bird communities by contrasting richness and abundance of birds in (1) 16 single-pass harvest sites with residual forest patches, (2) 29 multi-pass harvest sites with residuals; and (3) 15 salvage-logged post-fire sites with variable harvest intensity. We contrasted bird communities in these treatments with those in unsalvaged post-fire sites of similar age. Post-fire sites were used to provide a metric of the Natural Range of Variation (NRV) to be expected in bird communities. Sites were surveyed for avian community composition and abundance 1–5 years post-disturbance. Redundancy analysis indicated that bird communities differed from the NRV in all of the harvest treatments. However, single-pass harvests provided a somewhat better fit to NRV than did multi-pass harvesting. Avian community similarity was influenced by non-linear responses to area harvested, amount of residual retention, residual composition and pre-disturbance forest composition. An optimization routine created from a General Linear Model, suggests that community similarity to NRV can be maximized by using single-pass harvests over multi-pass harvests, harvesting 66–88% of the timber in the planning unit, and retaining 5–19% of the disturbance area as live residual patches, with 50% of harvests having at least 9% of the area in residuals.

Attributes of forest strips used by snowshoe hare in winter within clear-cut boreal landscapes

The snowshoe hare (Lepus americanus Erxleben) is an important prey for many predators in the boreal forest. In this biome, clear-cut landscapes are generally large and consist of aggregated cutting blocks separated by narrow forest strips (typically 60–100 m wide). To identify attributes of forest strips that are important for snowshoe hares, we measured the use of strips using track counts over two winters in six clear-cut landscapes (23–256 km2) in south-central Quebec. Surveys were conducted in 20 riparian strips (RS), 20 upland strips (US), and 15 control sites (CO) at the periphery of clear-cut landscapes. Overall, 392 signs of hare presence were recorded along 50 km of transects. Snowshoe hares were present in one-third of the strips surveyed and were five times less abundant in US and RS than in CO. The species avoided strip edges. Hares were more common in the wider strips (&gt;100 m), in the strips adjacent to residual forest patches (≥25 ha), or in those having a denser shrub canopy, which is often associated with a greater basal area in balsam fir (Abies balsamea (L.) Mill.). To maintain snowshoe hare at moderate densities in large clear-cut landscapes, we suggest leaving uncut forest strips &gt;100 m wide in areas having a good shrub cover with presence of balsam fir.

Leaving forest strips in large clearcut landscapes of boreal forest: A management scenario suitable for wildlife?

Riparian forest strips (RS) along lakes and streams have been incorporated in regulations on clearcuts to protect water quality and fish habitat. As well, upland strips (US) are used to limit the size of clearcut patches. We conducted a three-year study to evaluate if RS and US between adjacent cutovers in large clearcut landscapes could be useful for certain terrestrial wildlife. Our study was conducted in southcentral Québec on six landscapes (23–256 km2) originating from black spruce (Picea mariana) forests that were recently logged (≤ 9 years). Residual uncut forest, mostly strips (width = 51–132 m), made up 31% of the productive forest area within these landscapes. RS and US were suitable habitat for red squirrel (Tamiasciurus hudsonicus) and many species of birds including spruce grouse (Falcipennis canadensis). They provided marginal habitat for snowshoe hare (Lepus americanus) and were not preferred by moose (Alces alces) over clearcut areas in winter. One bird species, bay-breasted warbler (Dendroica castanea), was absent in forest strips during the last year. We concluded that leaving RS and US is a management scenario that enables maintaining certain wildlife species within clearcut landscapes, but that larger residual forest patches are needed to accommodate area-sensitive and forest-interior species. A portion of these patches should be allowed to develop into mature and overmature stages for old-growth forest species. Green tree and dead tree retention should also be incorporated in logging practices to accommodate species that need snags for nesting or feeding. In areas where wildlife use has a high priority, large clearcuts should be intermixed with dispersed patch cutting in order to gain social acceptance. Key words: black spruce, forest strip, clearcutting, ecosystem management, Picea mariana, riparian strip

Carabid beetle assemblages (Coleoptera, Carabidae) across urban-rural gradients: an international comparison

We studied communities of carabid beetles in residual forest patchesalong urban-suburban-rural gradients in three cities (Helsinki, Finland; Sofia,Bulgaria and Edmonton, Canada) to examine their responses to urbanisation. OnlyFinnish carabids showed a marked division of community structure along thegradient. In Bulgaria and Canada, carabids did not separate into distincturban,suburban and rural communities. Our results provide some support for thepredictions that species richness will decrease, that opportunistic specieswillgain dominance, and that small-sized species will become more numerous underdisturbance such as that provided by urbanisation. The rather weak and variedresponse of carabids to this disturbance suggests that local factors and theirinteraction are of primary importance for community composition. Occurrence ofreasonably similar carabid communities across the gradient at each of the threelevels of urbanisation suggests that habitat changes commonly associated withurbanisation have not affected the ecological integrity of carabid assemblagesin residual urban forest patches.

Short-term response of wildlife to clear-cutting in Quebec boreal forest: multiscale effects and management implications

We studied the short-term response of wildlife to clear-cutting in four blocks (52-114 km2) that were logged in 100- to 250-ha clustered patches. Surveys were conducted, 2 years before and 2 years after logging, to determine the relative abundance of 12 wildlife species, and telemetry data were also gathered on four species. Small mammals, species with the smallest home ranges ([Formula: see text]1 ha), either remained in the clearcut patches or had replacement habitat in the buffer strips. Most species with home ranges up to 25 ha (spruce grouse, Falcipennis canadensis Linné; snowshoe hare, Lepus americanus Erxleben) were excluded from clearcut patches. Species with home ranges [Formula: see text]5 km2 (marten, Martes americana Turton; moose, Alces alces Linné) remained in some residual forest patches scattered throughout clearcuts and in the adjacent uncut forest. In their home range, these two species avoided clearcut patches where the shrub layer and coniferous regeneration were scattered. Because many wildlife species depend on residual forest, the important issue is not the size of clearcut patches but the extent and configuration of the remaining forest. Instead of a clustered distribution of clearcut patches, we propose two harvest scenarios more compatible with integrated wildlife-forest management objectives on a local scale.