Interior Specialists Research Articles

The impacts of agricultural windbreaks on avian communities and ecosystem services provisioning in the Bellbird Biological Corridor, Costa Rica

ABSTRACT Agricultural windbreaks are promoted to reduce the negative ecological impacts of agricultural intensification while providing ecosystem services. To improve understanding of the conditions under which windbreaks are able to provide these benefits, we evaluated the impacts of windbreaks on avian communities and ecosystem services using mixed methods. Windbreaks significantly improved air quality and temperature regulation and generated posts and lumber. While windbreaks provide habitat for certain forest bird species, forest interior specialists do not use the windbreaks. Taken together, these results suggest that windbreaks can generate both ES and habitat benefits, improving the sustainability of tropical agricultural systems.

Agricultural land in the Amazon basin supports low bird diversity and is a poor replacement for primary forest

Abstract The Amazon has a long history of disturbance under subsistence agriculture, but slash-and-burn agriculture is small in scale and has relatively low impact on resident avifauna. More recently, the Amazon has suffered extensive deforestation in favor of cattle ranching and other modern systems of agriculture. Cattle pastures, mechanized agriculture, and even tree plantations have detrimental effects on bird communities, greatly lowering diversity, especially that of primary forest interior specialists. A rising threat to the Amazon is the spread of oil palm plantations that retain few bird species and are not viable alternatives to forest. Embedded within the expanding agropastoral mosaic are forest fragments that have experienced a well-documented loss of diversity. Yet, the matrix can mitigate the recovery of fragmented bird communities depending on the type of secondary regrowth. Connectivity via matrix habitats or forest corridors is critical for the maintenance of forest avifauna. With so many types of land use developing across the Amazon, the “tropical countryside” has potential value for bird diversity. However, evidence suggests that the agropastoral mosaic harbors a small, more homogenized avifauna with few forest species, especially when primary forest is absent from the landscape. For the Amazon Basin’s bird life to be conserved into the future, preservation of large tracts of well-connected primary forest is vital. Tropical countryside dominated by agriculture simply cannot sustain sufficient levels of biodiversity.

Effects of highways on bird distribution and soundscape diversity around Aldo Leopold’s shack in Baraboo, Wisconsin, USA

In the 1940s, Aldo Leopold took extensive notes on birds and their sounds near his iconic shack in Baraboo, Wisconsin, USA. His observations, along with his land management techniques, helped frame his seminal book, A Sand County Almanac. After his death, two interstate highways were built near his property and subjected this historically significant area to traffic noise. While highways currently represent vital transportation corridors, their observed and potential impacts on biodiversity and ecosystem services are cause for concern. As the area including Leopold’s shack is now an Important Bird Area, we sought to evaluate the impact of these highways on the bird community and its related acoustic diversity. In 2011, 150 avian point counts were conducted in the three main habitats composing the landscape—upland deciduous forest, floodplain forest, and herbaceous wetland. In 2012, soundscape recordings were collected in seven floodplain forest sites using automated passive acoustic recorders. We described the local bird communities and measured their acoustic diversity. Linear models accounting for additional factors including land cover and vegetation structure characteristics showed that as the distance from highways increased, bird community descriptors (overall abundance and species richness) and acoustic diversity increased (when relationships were significant). On the species level, forest interior specialists were negatively affected by the presence of the highways, contrary to edge specialists. In addition to the direct effects of the edges produced by the highway structure, this difference might be due to the masking effect of traffic noise on interior specialists’ low-frequency vocalizations and their reliance on acoustic, as opposed to visual, communication. We conclude that while habitat structure is a principle driver of bird diversity on a broader scale, highway-induced changes in both habitat structure and soundscapes may affect bird communities.

Uneven-aged silviculture can enhance within stand heterogeneity and beetle diversity

Uneven-aged silviculture may better maintain species assemblages associated with old-growth forests than clear felling in part due to habitat heterogeneity created by maintaining standing retention strips adjacent to harvest trails. Retention strips and harvest trails created at the time of tree removal will likely have different microclimate and may harbor different assemblages. In some cases, the resultant stand heterogeneity associated with uneven-aged silviculture may be similar to natural small-scale disturbances. For beetles, increased light and temperature as well as potential access to young vegetation and deadwood substrates present in harvset trails may harbor beetle assemblages similar to those found in natural gaps. We sampled saproxylic beetles using flight intercept traps placed in harvest corridors and retention strips in 9 replicated uneven-aged spruce stands in central Sweden. We compared abundance, species richness and composition between harvest corridors and retention strips using generalized linear models, rarefaction, permutational multivariate analysis of variance and indicator species analysis. Canopy openness doubled, mean temperature and variability in daily temperature increased and humidity decreased on harvest trails. Beetle richness and abundance were greater in harvests trails than in retention strips and the beetle species composition differed significantly between habitats. Twenty-five species were associated with harvest trails, including three old-growth specialists such as Agathidium discoideum (Erichson), currently red-listed. We observed only one species, Xylechinus pilosus (Ratzeburg) that strongly favored retention strips. Harvest trails foster both open habitat species and old-growth species while retention strips harbored forest interior specialists. The combination of closed canopy, stratified forest in the retention strips and gap-like conditions on the harvest trails thus increases overall species richness and maintains more diverse assemblages at the stand level than would otherwise be seen in less heterogeneous stand types. This suggests that uneven-aged silviculture may provide added conservation benefits for both open habitat and old-growth specialists than silvicultural approaches that reduce stand heterogeneity.

The importance of various stages of succession in preservation of biodiversity among riparian birds in northern Iran.

Every stage of succession may provide certain species with habitat requirements which are impossible in other stages of succession. This study attempts to evaluate the different stages of succession in terms of composition and structure of bird populations in Hyrcanian forests. Bird-habitat relationships were investigated by comparing vegetation characteristics in three successional stages including late, initial stage, and urban areas. Bird richness, diversity, and abundance were measured within a 25-m radius of each of the 120 sampling points in various stages of succession and urban areas from May to April (2014) in the Ziarat catchment. This study indicated that every stage of succession may support certain species. Based on bird-habitat associations along the various stages of succession, two groups were distinguished. Conventional comparative analysis separated two groups of understory birds: interior specialists and edge specialists. The interior-specialist group was positively correlated with the number of dead trees, tall trees with high values of dbh and height and canopy cover. In contrast, edge specialists groups mainly included terrestrial insectivores and were positively correlated with open area and shrub cover, and percentage of shrub cover between 1 and 2m in height. In summary, bird communities in Hyrcanian forests are highly dynamic in different vegetation covers suggesting that it is critical to increase diverse and abundant bird populations by conserving forests composed of mosaics of differently disturbed stands and mature forest patches.

Bird community response to Marcellus shale gas development

ABSTRACTThe Appalachian shale play, which includes the Marcellus shale formation, is an important source of natural gas and underlies much of the remaining large areas of extensive contiguous forest within the eastern United States, areas that are important breeding sites for forest songbirds. Shale gas development in contiguous forest creates large disturbances and causes habitat fragmentation; the landscape matrix remains characterized by stands of mature forest. We assessed the effects of shale gas development on counts of passerines and near‐ passerine birds within an extensively forested landscape. We surveyed birds within 2 broad forest types (northern hardwood and mixed oak) at increasing distances from 49 shale gas pads established within contiguous forest habitat. We compared counts of individual species and 3 vegetation‐association groups (forest interior, synanthropic, and early successional) in relation to distance from a pad edge, and we compared community composition with distance from a pad edge. Counts of individuals and species within the forest interior group increased with increasing distance from a pad edge; counts of individuals were approximately 4 times greater at 250 m than at 0 m and 3 times greater than at 50 m. Twelve of 15 species in the forest interior group increased with increasing distance from a pad edge with no species showing a declining trend. In contrast, counts of synanthropic (i.e., human‐associated) individuals and species were greatest at the pad edge and declined with distance to a pad edge. Counts of individuals at 250 m were 92% lower than at 0 m, and counts for 4 of the 5 individual species declined with increasing distance from a pad edge. Counts of individuals and species within the early successional habitat group were greater in oak (Quercus spp.) than in northern hardwood forests, and the response to a pad edge differed among species and between the 2 forest types. In northern hardwood stands, counts were greatest near the pad edge, whereas counts in oak stands showed no trend with distance to a pad edge. Overall, the combined avian community differed with distance from a pad edge. Our results suggest that synanthropic species, which are rare in core forest, are able to rapidly exploit new development‐associated habitat. Counts of forest interior specialists declined, suggesting the habitat is becoming less suitable for this group. Our results are an early indication that shale gas development in core forest can have negative consequences for forest songbird communities as synanthropic species, which tend to be habitat generalists with wide geographic ranges, replace forest specialists. Long‐term effects will depend on the scale and extent of shale gas development, emphasizing the need for proactive planning to minimize negative effects. © 2016 The Wildlife Society.

Architecture for specific disease case study in schizophrenic patients

One of the centers that have high sensitivity for design is psychotherapy center because of special physical, mental and sentimental conditions of their patient. Design and architecture of psychotherapy centers and caring mental patients are new subjects in our country; and there was no attempt to study and design of this center by interior specialist. To start design of every usage, recognition of habitants of that place is necessary. Recognition and understanding of different needs of Schizophrenic patients and attempt to meet their needs and respect to priority of these needs in designing and improving their special spaces can be effective in improvement of its quality. Schizophrenia is a chronic and debilitating illness which is associated with impaired social and occupational skills and it affects approximately one percent of the population. Since these patients are considered one of the most disadvantaged sectors of society, and their main requirement is to help them to return home and social environment, it should be possible to step in improving treatment by identifying and using elements of environmental quality and to introduce the environment of a hospital as a healing environment not as an environment for permanent or long-term accommodation for patients, Because the main purpose of admission of a mental schizophrenic patients is maintenance of security of patients and others and above all is his stable treatment. But psychotherapy centers in Iran cannot fully respond to the needs of these patients. And most buildings in the old psychiatric institutions are without proper space and occupational therapy sectors are not efficient and effective. The subject of this paper is the eclectic and interdisciplinary, means architecture and psychology. Purposes of that are obtaining a codified agreement, design standards and present an architectural pattern for treatment and positive influences on mental disorders of schizophrenic patients and his return to a normal life.

Interior dan Branding untuk Memunculkan Identitas Natura

Nowadays, business development is accelerating and advancing rapidly because of the supports from many parties, including the government. This advancement has both positive and negative impacts on our society. In the positive side, many of the younger generations emerged to create job opportunities for those who need them. Consequently, this new jobs help strengthen our nation’s economy. In the other hand, the rising businesses are not always linearly correlated to the increase of the quality of those businesses. The quality of a business is greatly affected by the brand identity and the quality of the interior design of the business itself. Therefore, we proudly present Devita Lee Interior Specialist to be the solution of those problems above.In relation with the excellence of the business offered, Natura Resort & Villa is the perfect study case to apply the mentioned service. From multiple researches and surveys, Natura Resort & Villa emphasized the value of body and soul retreat alongside with their vision, life that enlivens. This discourse becomes the base framework for the interior design applied to the lobby area, the restaurant, and one type of villa. The most prominent design application is from the modern natural design style. The natural style implements materials from nature such as wood, bamboo, and rock with their natural colors as the interior design elements. Moreover, the materials are obtained locally, which truly in accordance with life that enlivens. While the modern style comes from the geometric shapes of the design. The next application is shown from the natural tones: dark brown, light brown, cream, and soft green, as the color accents. The next application is the election of the static or dynamic shapes, which moves uniformly.

Spatial patterns of mammal occurrence in forest strips surrounded by agricultural crops of the Chaco region, Argentina

Deforestation is a major cause of biodiversity loss, and the predominant factor driving deforestation is expansion of agriculture. A key step toward successful conservation in agricultural areas is maximizing biodiversity value of remaining forest. In subtropical and tropical regions, forest often is left in narrow strips between agricultural fields under the assumption that biodiversity is sustained. We examined use of forest strips and continuous forest by medium and large-sized mammals in Argentine Chaco with camera trapping and hierarchical Bayesian zero-inflated occupancy models and assessed how use related to ecological traits of species. Almost 70% of the species cited for our study area were not detected or were detected in less than 10% of the sampling units. Ten of the 23 species that occurred in the area were absent from strips or were detected most frequently in continuous forest, including all large-bodied species and forest interior specialists. Low occurrence of mammals in strips and in continuous forest raises major concerns related to long-term persistence of mammals in Chaco. Under current development policies, agriculture will continue to expand in this region, further threatening the second largest forest in South America. Alternative configurations for the forest-agriculture landscape, as well as synergism between landscape configuration and other threats, need to be evaluated and incorporated into policy if the rich mammalian fauna of this region is to be conserved.

Breeding Bird Community of a Suburban Habitat Island: Historic Bethabara Park, Winston-Salem, NC

Habitat islands, corridors, and patches within the urban—rural mosaic provide important resources for migratory and resident species and may be crucial for breeding success and survival. In suburban areas, corridor width and patch size are strongly correlated with community composition. We assessed the breeding bird community in the Historic Bethabara Park Complex (HBPC) by territory mapping during April–July 2009 and 2010. HBPC is a 77-ha habitat island in Winston-Salem (Forsyth County), NC. We detected 109 bird species in HBPC, including 60 for which we documented at least 1 breeding territory in either year. Each year we found territories of 58 species; 57 species were the same between years. The majority of birds encountered in this study nest in the canopy, in shrubs, or in cavities. The breeding community was roughly split between migrants (32) and residents (34) and included 3 exotic species. We documented territories for 10 woodland interior specialists including Hylocichla mustelina (Wood Thrush), Seiurus aurocapilla (Ovenbird), and Piranga olivacea (Scarlet Tanager). Two of these observed bird species—Wood Thrush and Sitta pusilla (Brown-headed Nuthatch)—are designated as US birds of conservation concern by Partners in Flight (PIF). Eight of the species we documented are considered by PIF to be species of conservation concern in the Piedmont Region during the breeding season and and 3 of these are common species in steep decline: Chaetura pelagica (Chimney Swift), Megaceryle alcyon (Belted Kingfisher), and Colaptes auratus (Northern Flicker). HBPC is historically and currently species-rich and has a community composition similar to that seen in other NC Piedmont studies. We recommend periodic monitoring as the local landscape and climate change. Further research is needed to determine to what degree the park complex functions as an oasis or population sink for the bird community, especially for forest-interior obligates, Neotropical migrants, and species of concern.

Conserving natural heterogeneity is crucial for designing effective ecological networks

Large-scale ecological networks (ENs) are an important mitigation measure in agriculturally transformed landscapes. However, understanding the multitude of pressures influencing the presence/absence of species, and subsequent degree of species spatial heterogeneity, is important when planning effective ENs. We aim here to measure these pressures and determine species heterogeneity in ENs against natural reference sites. We use arthropods, as they are effective bioindicators for measuring these pressures and heterogeneity, as many are habitat sensitive. Here we use many arthropod taxa to determine how a suite of variables influences the spatially sensitive grassland interior species of both EN corridors and protected areas (PAs). At each of 48 selected sites, nine stations were sampled for arthropods, with six stations in plantation block (i.e. transformed grassland) or natural indigenous forest, as well as associated edge zone and three stations in EN corridor or PA interior. Eleven variables were measured and classed into environmental, design, and current and historical management variables. Data were split into: overall data, recording all species found in interior zones, and datasets containing only species that had >50 or >75 % of their abundance sampled in the interior zone. These datasets were split into total species and singleton-removed datasets. Overall, the richness of non-singleton species, i.e. those frequently sampled in grassland interiors, were most responsive to natural background environmental variables, while design and management variables were most important for datasets with singletons retained. This means that when planning ENs, we first need to conserve the natural range of environmental heterogeneity to conserve a range of interior specialists. This natural spatial heterogeneity then needs to be incorporated into design and management planning to conserve the full range of biodiversity in ENs, as if in PAs.

Butterfly Community Composition Across a Successional Gradient in a Human‐disturbed Afro‐tropical Rain Forest

AbstractKnowledge of the recovery of insect communities after forest disturbance in tropical Africa is very limited. Here, fruit‐feeding butterflies in a tropical rain forest at Kibale National Park, Uganda, were used as a model system to uncover how, and how fast, insect communities recover after forest disturbance. We trapped butterflies monthly along a successional gradient for one year. Traps were placed in intact primary forest compartments, heavily logged forest compartments with and without arboricide treatment approximately 43 years ago, and in conifer‐clearcut compartments, ranging from 9 to 19 years of age. The species richness, total abundance, diversity, dominance, and similarity of the community composition of butterflies in the eight compartments were compared with uni‐ and multivariate statistics. A total of 16,728 individuals representing 88 species were trapped during the study. Butterfly species richness, abundance, and diversity did not show an increasing trend along the successional gradient but species richness and abundance peaked at intermediate stages. There was monthly variation in species richness, abundance, diversity and composition. Butterfly community structure differed significantly among the eight successional stages and only a marginal directional change along the successional gradient emerged. The greatest number of indicator species and intact forest interior specialists were found in one of the primary forests. Our results show that forest disturbance has a long‐term impact on the recovery of butterfly species composition, emphasizing the value of intact primary forests for butterfly conservation.

Multiscale impacts of forest degradation through browsing by hyperabundant moose (Alces alces) on songbird assemblages

AbstractAimSongbirds are sensitive to changes in forest structure and composition at various spatial scales, particularly during the breeding season. Habitat degradation associated with herbivore browsing may contribute to declines in songbird populations. Here, we evaluate songbird responses to herbivore‐induced habitat change at multiple spatial scales.LocationIn Gros Morne National Park (GMNP), Newfoundland, Canada, browsing by hyperabundant moose (Alces alces) has changed forest structure by reducing understorey cover and converting regenerating stands to open areas dominated by grasses and shrubs.MethodsWe conducted point count surveys to measure bird occurrence throughout GMNP during the 2010 breeding season. Using vegetation information from ground plots and remote sensing, we characterized habitat at three scales: local, neighbourhood and landscape. Following a two‐step procedure to model species occurrence with habitat, the most important habitat factors within each scale were retained for cross‐scale modelling.ResultsCross‐scale models revealed patterns in the association of songbird habitat assemblages with moose‐altered habitats. Early successional species such as mourning warbler (Geothlypis philadelphia) were positively associated with moose‐browsed habitat at the landscape scale. Forest interior specialist (e.g. black‐throated green warbler, Setophaga virens) and generalist species (e.g. boreal chickadee, Poecile hudsonicus) were negatively associated with moose‐browsed habitat at the neighbourhood scale. Local songbird species richness was independent of moose‐browsed habitat at any scale.Main conclusionsThe influence of intense browsing on forest songbirds varies by species but has the potential to extend beyond the area of immediate impact. Continued intense browsing and resulting forest alteration could cause declines in forest specialists and generalists, but may increase populations of early successional species. To maintain bird assemblages characteristic of the region, we recommend management actions that lower moose density in areas with hyperabundant populations such as GMNP to maintain forest structure and regeneration comparable to that present prior to the introduction of moose.

Modeling forest songbird species richness using LiDAR-derived measures of forest structure

Conservation of biodiversity requires information at many spatial scales in order to detect and preserve habitat for many species, often simultaneously. Vegetation structure information is particularly important for avian habitat models and has largely been unavailable for large areas at the desired resolution. Airborne LiDAR, with its combination of relatively broad coverage and fine resolution provides existing new opportunities to map vegetation structure and hence avian habitat. Our goal was to model the richness of forest songbirds using forest structure information obtained from LiDAR data. In deciduous forests of southern Wisconsin, USA, we used discrete-return airborne LiDAR to derive forest structure metrics related to the height and density of vegetation returns, as well as composite variables that captured major forest structural elements. We conducted point counts to determine total forest songbird richness and the richness of foraging, nesting, and forest edge-related habitat guilds. A suite of 35 LiDAR variables were used to model bird species richness using best-subsets regression and we used hierarchical partitioning analysis to quantify the explanatory power of each variable in the multivariate models. Songbird species richness was correlated most strongly with LiDAR variables related to canopy and midstory height and midstory density (R 2 = 0.204, p < 0.001). Richness of species that nest in the midstory was best explained by canopy height variables (R 2 = 0.197, p < 0.001). Species that forage on the ground responded to mean canopy height and the height of the lower canopy (R 2 = 0.149, p < 0.005) while aerial foragers had higher richness where the canopy was tall and dense and the midstory more sparse (R 2 = 0.216, p < 0.001). Richness of edge-preferring species was greater where there were fewer vegetation returns but higher density in the understory (R 2 = 0.153, p < 0.005). Forest interior specialists responded positively to a tall canopy, developed midstory, and a higher proportion of vegetation returns (R 2 = 0.195, p < 0.001). LiDAR forest structure metrics explained between 15 and 20% of the variability in richness within deciduous forest songbird communities. This variability was associated with vertical structure alone and shows how LiDAR can provide a source of complementary predictive data that can be incorporated in models of wildlife habitat associations across broad geographical extents.

Partial recovery of an African rainforest bird community 35 years after logging

Tropical rainforests suffer from fragmentation and degradation, with consequences such as the decline of interior or most selective species. For this reason, researches have been undertaken to investigate the effects of these disturbance processes, with the possibility of developing appropriate restoration plans. This research aimed to study the bird community composition of a degraded forest 33 years after intensive logging occurred in 1968- 1969. Surveys were conducted in 2003-2006 by mist netting in the Kanyawara area in Kibale National Park (Uganda) and the results were compared to those obtained by previous research in 1991–1993 at the same site and in a contiguous primary forest. We found that the ratio between forest interior specialists and forest generalists was 1.79, an intermediate value between 1.03 and 2.17 found respectively in the logged and unlogged study sites in the earlier research. We therefore suggest that about 35 years after intensive logging, our study area has partially recuperated a bird community typical of a mature forest, even though a significant alteration, probably due to the incomplete recovery of all lost ecological niches, still remains.

Edge effects created by wildfire and clear-cutting on boreal forest ground-dwelling spiders

Abstract The response of ground-dwelling spider assemblages to edges created by wildfire was compared to their response to clear-cut edges in black spruce forests in eastern Canada. For each disturbance six edge transects 100 m long were established. Spiders were collected with pitfall traps 10 m apart from 50 m inside the disturbances to 50 m in the forest interior. Measurements of the forest floor structure and the habitat around the traps were also taken. Most habitat variables varied similarly across both wildfire and clear-cut edges but two variables, coarse woody debris and shrub cover changed more abruptly at edges of clear-cuts than at wildfire edges. Two separate CA analyses of the burned and clear-cut edge transects showed that changes in spider community species composition were more abrupt at clear-cut edges than at burn edges. A species indicator analysis (INDVAL) was used to identify species that were significantly associated with specific edge zones. Eight species were significantly associated with open (disturbed) habitats, one species was significantly associated with both burned and clear-cut edges, and four species were significantly associated with the forest interior. T-tests of slope coefficients from separate simple regressions of abundance and richness over distance showed that open habitat specialist's abundance and richness changed significantly more abruptly at clear-cut edges than at wildfire edges. Locally weighted smoothed regressions showed that the extent of edge influence on ground-dwelling spider guilds (open habitat and forest interior specialist) penetrated 20–30 m into the disturbances, 30 m into the forest interior at clear-cut edges, and at least 50 m into the forest interior for wildfire edge transects. Our results suggest that a minimum width of 100 m is necessary to maintain characteristics of forest interior spider assemblages in forest remnants, riparian or road buffers, and forest strips between cut-blocks.

Interior Design Specialist: Adding Another Member to the Interdisciplinary Team

&lt;h4&gt;EXCERPT&lt;/h4&gt; &lt;p&gt;Interdisciplinary teams have long been used for review of cases or sentinel incidents in health care settings. When a conventional team consisting of a registered nurse, a physician, and a physical therapist met to review the case of an older woman who fell in her apartment at a retirement community, team members realized that understanding what characteristics of the environment contributed to the fall incident required the addition of a new team member. That new member was a specialist in interior design with experience in designing and evaluating housing environments for older adults.&lt;/p&gt;

The avifauna 23 years after logging in Kibale National park, Uganda

The bird fauna of logged and unlogged forest in Kibale National Park, western Uganda were studied and comparisons made. Species diversity and richness were higher in the logged areas. A single species, the Yellow-whiskered Greenbul Andropadus latirostris dominated in the logged compartment. However, the majority of individual birds found in the logged forest were generalist or forest-edge species. Over 84% of the forest interior specialist species that occurred in primary forest had recolonized or persisted in the logged forest; however, there were seven out of 48 understorey forest specialists that had not done so. Although there was moderate species overlap between the two habitats, the logged forest compartment had not fully recovered from logging after 23 years.

Incidence of Xylechinus pilosus and Cryphalus saltuarius (Scolytidae) in forest-clearcut edges

The incidence of two bark beetle species, Xylechinus pilosus (Ratzeburg) and Cryphalus saltuarius Weise, in forest-clearcut edges was studied using 100-m sample plot transects perpendicular to the stand edge and penetrating the forest interior. The presence/absence data on species occurrence was analyzed using logistic regression models. Both species showed clear edge avoidance in the 1st 30-m zone from the stand boundary. Distance from the stand boundary, density of breeding material (suppressed spruces), and density of dominant spruces showed positive effects on species incidence in the logistic regression models. The present results show that forest interior specialists occur in the family Scolytidae, and may be useful for predicting indirectly the edge effect on threatened wood-living beetle species related to old-growth forests.

Diversity, abundance and seasonality of birds in a Caribbean pine plantation and native broad-leaved forest at Trinidad, West Indies

SummaryMonoculture plantations of exotic Caribbean pinePinus caribaeahave been planted extensively in many tropical countries, but little is known about the bird communities inhabiting them. From October 1995 to September 1996, we compared bird populations in a 37-ha stand of mature Caribbean pine forest (planted in 1972) with an adjacent, similar-sized stand of native broad-leaved forest at Mount Saint Benedict, Trinidad, West Indies. Ten censuses, each including 10 fixed-radius point counts (25 m radius, 10 minutes duration), were conducted simultaneously during different months of the year in each habitat. Both species richness and species diversity were significantly lower in the pine forest, but the overall abundance of individual birds did not differ between the two forests. Seasonal variation in bird populations was more pronounced in the pine forest, where fewer birds (and presumably food resources) were present during the dry season. The pine forest bird community was dominated by forest edge specialists and the native forest by forest interior specialists at both the individual and species levels. At the individual level, nectarivores, aerial foragers and understorey foragers were proportionately more common in the pine forest; insectivores and canopy foragers were more common in the native forest. At the species level, more aerial foragers occurred in the pine forest and more understorey foragers in the native forest. The diversity of bird communities in pine plantations may be promoted by increasing habitat heterogeneity.