Physiological synecology of tree species in relation to geographic distribution and ecophysiological parameters at the Atlantic forest periphery in Brazil: an overview

This paper provides a synthesis of the three papers published in the series Ecophysiology of selected tree species in different plant communities at the periphery of the Atlantic forest of SE – Brazil (Trees, this issue). We reviewed data obtained for seven tree species, belonging to the legume family and the genus Clusia of the Clusiaceae. These groups were chosen because legumes are the most abundant tree species in the Atlantic forest complex (except in the open restingas), and the genus Clusia is reportedly of utmost ecological importance as nurse plants in several habitats of the complex. These species were surveyed along one or more of several forest and open habitats at the margin of the Atlantic rain forest (open restingas, restinga dry forest, inselberg, semideciduous dry forest) and indicated the following general patterns: (1) at the intraspecific level, ecophysiological performance often (but not always) varied largely in both time and space; (2) at the interspecific level, ecophysiological performance was often (but not always) related positively to species dominance in the community; and (3) at both levels, ecophysiological performance was not related to the geographic distribution patterns, i.e., generalists and specialists did not form groups of similarly behaving plants in regard to ecophysiology. We discuss the implications of these findings, compare them with earlier studies, and suggest that ecophysiological research in the Atlantic rain forest complex could enhance its explanatory power by increasing spatial and temporal scales of observation.     

Top-down pressure by generalist and specialist natural enemies in relation to habitat heterogeneity and resource availability

Habitat heterogeneity might promote the abundance and richness of natural enemies potentially leading to higher top-down pressure on herbivorous insects. Heterogeneous habitats could provide natural enemies with more abundant and alternative resources and a greater variety of micro-habitats. Natural enemies with different searching behaviours, e.g. generalists and specialists, could be affected in different ways by habitat heterogeneity, thus affecting their pressure on herbivorous insects.To understand how top-down pressure on herbivorous insects is promoted by habitat heterogeneity, it is crucial to investigate which parameters contributing to habitat heterogeneity affect not only the abundance and richness but also the searching behaviour of different natural enemies. We investigated the relationship between heterogeneity in forest habitats and the top-down pressure exerted by generalist predators and specialist parasitoids on larvae of the European pine sawfly (Neodiprion sertifer).We used forest stands with endemic or epidemic densities of resident sawfly populations. Within each stand we selected experimental trees to create variation in tree species diversity and density in their surrounding area, i.e. habitat heterogeneity. We found that a higher tree density increased the predation by generalists on sawfly larvae in stands with endemic sawfly densities. Parasitoids were less successful in stands with endemic sawfly densities. Total mortality depended on stand character and the proportion of pine around experimental trees.The explained variation in the response variables by the models is relatively low, indicating that other measures of heterogeneity, like understory vegetation and presence of dead wood could contribute to the observed variation. Also, interference between generalist and specialist enemies could affect the realized mortality pressure. Thus, the effect of tree species diversity in combination with these other measures of heterogeneity needs to be recognized to promote the presence and the activity of natural enemies in managed habitats.     

The Use of an Invasive Species Habitat by a Small Folivorous Primate: Implications for Lemur Conservation in Madagascar

The lemurs of Madagascar are among the most threatened mammalian taxa in the world, with habitat loss due to shifting cultivation and timber harvest heavily contributing to their precarious state. Deforestation often leads to fragmentation, resulting in mixed-habitat matrices throughout a landscape where disturbed areas are prone to invasion by exotic plants. Our study site, the Mandena littoral forest (southeast Madagascar), is a matrix of littoral forest, littoral swamp, and Melaleuca swamp habitats. Here, Melaleuca quinquenervia has invaded the wetland ecosystem, creating a mono-dominant habitat that currently provides the only potential habitat corridor between forest fragments. We sought to understand the role of this invasive Melaleuca swamp on the behavioral ecology of a threatened, small-bodied folivore, the southern bamboo lemur (Hapalemur meridionalis). We collected botanical and behavioral data on four groups of H. meridionalis between January and December 2013. Our results confirm Melaleuca swamp as an important part of their home range: while lemurs seasonally limited activities to certain habitats, all groups were capable of utilizing this invasive habitat for feeding and resting. Furthermore, the fact that Hapalemur use an invasive plant species as a dispersal corridor increases our knowledge of their ecological flexibility, and may be useful in the conservation management of remaining threatened populations.     

Matrix Intensification Affects Body and Physiological Condition of Tropical Forest-Dependent Passerines

Matrix land-use intensification is a relatively recent and novel landscape change that can have important influences on the biota within adjacent habitat patches. While there are immediate local changes that it brings about, the influences on individual animals occupying adjacent habitats may be less evident initially. High-intensity land use could induce chronic stress in individuals in nearby remnants, leading ultimately to population declines. We investigated how physiological indicators and body condition measures of tropical forest-dependent birds differ between forest adjacent to surface mining sites and that near farmlands at two distances from remnant edge in southwest Ghana. We used mixed effects models of several condition indices including residual body mass and heterophil to lymphocyte (H/L) ratios (an indicator of elevated chronic stress) to explore the effect of matrix intensity on forest-dependent passerines classed as either sedentary area-sensitive habitat specialists or nomadic generalists. Individual birds occupying tropical forest remnants near surface mining sites were in poorer condition, as indicated by lower residual body mass and elevated chronic stress, compared to those in remnants near agricultural lands. The condition of the sedentary forest habitat specialists white-tailed alethe, Alethe diademata and western olive sunbird, Cyanomitra obscura was most negatively affected by high-intensity surface mining land-use adjacent to remnants, whereas generalist species were not affected. Land use intensification may set in train a new trajectory of faunal relaxation beyond that expected based on habitat loss alone. Patterns of individual condition may be useful in identifying habitats where species population declines may occur before faunal relaxation has concluded.     

Phylogenetic relationships and spatial distributions of putative fungal pathogens of seedlings across a rainfall gradient in Panama

Despite their importance in structuring plant communities, the identities and spatial distributions of the pathogens impacting wild plant communities are largely unknown. To advance our knowledge of plant-pathogen interactions in tropical forests, I identified likely fungal pathogens from forest sites across a rainfall gradient in Panama and compared the communities of fungi inhabiting a wetter, Atlantic and a drier, Pacific forest (∼45 km apart). Seedlings with symptoms of pathogen attack were collected and fungi were isolated from the symptomatic tissue. Based on internal transcribed spacer region sequences, I assigned the fungal isolates to operational taxonomic units (OTUs) and estimated their taxonomic placements. I observed 28 OTUs (defined by 95% sequence similarity); primarily, the genera Mycoleptodiscus, Glomerella, Bionectria, Diaporthe, and Calonectria. The wetter, Atlantic and drier, Pacific forest sites shared 29% of observed and 56% of non-singleton fungal OTUs, suggesting that, in these forests, the common fungal pathogens of seedlings are relatively widespread, habitat generalists.     

Generalism in the interaction of Tulasnellaceae mycobionts with orchids characterizes a biodiversity hotspot in the tropical Andes of Southern Ecuador

Biotic interactions play an important role in the assembly and stability of communities. All orchids depend on mycobionts for early establishment, but whether individual orchid species depend on a specific or broad spectrum of mycobionts is still a matter of debate. Tulasnellaceae (Basidiomycota) is the richest and most widespread mycobiont worldwide. We assessed Tulasnellaceae richness in epiphytic and terrestrial orchids in different habitats, and evaluated the degree of generalism in orchid-Tulasnellaceae interactions and the robustness of this mutualistic system to the extinction of mycobiont partners. We sampled 114 orchid individuals including all common and rare species in 56 plots of 1 m² in 3 habitats: pristine forest, regenerating forest and a landslide site in a tropical montane rainforest in Southern Ecuador. We found 52 orchid and 29 Tulasnellaceae species. The composition of Tulasnellaceae OTUs was moderately to highly similar across habitats and between orchid growth forms. A significantly nested network architecture indicated the existence of a core of generalist Tulasnellaceae OTUs interacting with both rare and common orchids. Terrestrial and epiphytic orchids showed significant differences in robustness to the extinction of their Tulasnellaceae mycobionts. Thus, generalist mycobionts may be relevant for the preservation of hyperdiverse orchid communities in the tropics.     

Succession and Micro-elevation Effects on Seedling Establishment of Calophyllum brasiliense Camb. (Clusiaceae) in an Amazonian River Meander Forest1

I investigated the effects of successional stage and micro‐elevation on seedling establishment of Calophyllum brasiliense (Clusiaceae), a common canopy tree of seasonally flooded lowland forest along the Manú River meander zone in southeastern Peru. To compare seedling establishment between microhabitat types, I planted C. brasiliense seeds in a fully crossed experimental design of three successional stages (early, mid, and mature) and two micro‐elevations (levees and backwaters). Seedling establishment success in this study was affected by both successional stage and micro‐elevation, but micro‐elevation was most important in mid‐successional habitats. In general, seedlings in early succession experienced better conditions than in mature forest; light levels were higher, herbivory lower, and seedling growth higher. In mid‐successional forest, micro‐elevation determined habitat quality; backwaters had higher light levels, lower herbivory, and higher seedling growth and survival than levees. Mid‐successional backwaters were similar in quality to early successional forest for seedling establishment, while levees in that same successional stage were the poorest microhabitats for establishment. Although mid‐successional backwaters are similar to early succession for seedling establishment, in the long run, seedlings that establish in mid‐succession have a lower chance of reaching reproductive size before their habitat ages to mature forest than members of their cohort that established in early succession. I hypothesize that successful recruitment for C. brasiliense in the Manú River meander system requires dispersal to early successional habitat.     

Four sites with contrasting environmental stress in southeastern Brazil: relations of species, life form diversity, and geographic distribution to ecophysiological parameters

Some ecophysiological parameters related to plant performance and fitness (carbon and nitrogen isotope composition and total C and N concentrations; in situ chlorophyll fluorescence measurements) were determined for over 30 species in four habitats bordering the montane Atlantic rain forest of Brazil, along a gradient of altitude and rainfall: a dry coastal forest, two areas of sandy coastal plain vegetation (restingas) , and a high altitude campo. There was a considerable diversity of ecophysiological behaviour within and between the functional groups we created based on plant life-forms. For instance, both crassulacean acid metabolism (CAM) and C₃ species were found in most life-forms sampled and throughout all habitats. Despite the variation in rainfall regimes, average overall water-use efficiency was similar between sites, particularly for C₃ species, while no clear pattern regarding nitrogen-use emerged in this respect. Acute and chronic photoinhibition were found in many species across this gradient, even in CAM plants. However, on average, chronic photoinhibition and lower energy dissipation capacity were more characteristic of plants from the restinga habitats. This suggests that, although plants colonizing these habitats have evolved features to deal with water shortage, adaptation to high light levels has not been fully achieved yet. The ecophysiological performance of some individual species in distinct habitats and in distinct microhabitats within habitats is also discussed.     

The use of fluctuating asymmetry as a measure of farming practice effects in rodents: A species-specific response

The effects of agricultural intensification on vertebrate populations could vary depending on whether species are habitat specialists or habitat generalists. Organic farming practices are generally considered to be less intensive and more environmental friendly than conventional farming practices and, as a result, these two managements may impact on habitat specialists and habitat generalists in different ways. The effect of environmental and/or genetic stress on populations can be assessed using fluctuating asymmetry (FA) and body condition of animals. We predicted that populations of a specialist species, the Pampean grassland mouse (Akodon azarae) would have higher levels of FA and poorer body condition on conventional farms compared to populations of A. azarae on organic farms. In contrast, we predicted that populations of generalist species, the corn mouse (Calomys musculinus) and the small vesper mouse (Calomys laucha) would not show differences in FA or body condition between conventional and organic farms. We examined the expression of FA in the hind foot and used the scaled mass index as a surrogate for body condition. As predicted, we found higher FA in the habitat specialist (A. azarae) on conventional farms compared to organic farms, and found no differences in FA among the two generalist species (C. musculinus and C. laucha). However, we found no differences in body condition for the three studied species between the two managements. Our results suggest that the effect of farming practices on small mammals varies between habitat specialists and habitat generalists. The results of this study provide important insights for the study of asymmetries, both from biological and methodological perspectives. Our results support the idea that the level of FA may be used as an index to assess the effects of farming practices on vertebrate populations.     

Habitat‐related patterns in phenotypic variation in a New Zealand freshwater generalist fish,and comparisons with a closely related specialist

1. Within‐species phenotypic variation is hugely variable and may play a role in determining the range of habitats a species can exploit. Our study addressed two main questions: 1. does phenotypic variation allow some species (i.e. habitat‐generalists) to use heterogeneous habitats and 2. are habitat‐generalists more variable than species occupying relatively homogeneous environments (i.e. habitat‐specialists)? 2. We examined the morphology of the common bully (Gobiomorphus cotidianus), a habitat‐generalist eleotrid fish found in lakes and rivers throughout New Zealand. We also compared the level of morphological variability in common bullies with that in the closely related redfin bully (Gobiomorphus huttoni), a habitat‐specialist of moderate‐ and fast‐flowing rivers. 3. Common and redfin bullies were collected from the South Island of New Zealand. A series of body and fin measurements were made, and cephalic dorsal head pores of the mechanosensory lateral‐line system were counted. The pores and associated canal neuromasts are important for prey detection and predator avoidance in other species, particularly, in turbulent conditions where the effectiveness of superficial neuromasts may be compromised. 4. The common bully had more dorsal head pores in fish from rivers than in those from lakes. This pattern was apparent only in adults, suggesting that selective pressures associated with adult habitat, be it rivers or lakes, are responsible. 5. As expected, there was greater phenotypic variability in the generalist common bully than in the specialist redfin bully, particularly with regard to the sensory pores, suggesting their importance for survival in turbulence. 6. We identified habitat‐related patterns in phenotypic variability in a generalist species and demonstrated a link between phenotypic variability and habitat breadth. Variation in the common bully may explain its ability to occupy a range of habitats.     

Seasonal changes in the canopy arthropod fauna in Rinorea beniensis in Budongo Forest,Uganda

Arthropods were collected by insecticidal tree fogging on the understorey tree species Rinorea beniensis Engler (Violaceae) in Budongo Forest, a seasonal rain forest in Uganda. Eight trees were fogged in adjacent plots of primary, selectively logged and swamp forest during the wet season and again in the dry season. In all forest types, Psocoptera, parasitoid Hymenoptera, and especially Formicidae and Auchenorrhyncha were more abundant during the dry season, while Ensifera, Heteroptera, Lepidoptera, Diptera, and Coleoptera were more abundant during the wet season. Seasonal change in arthropod composition was very low in the swamp forest located near a stream, where permanent water supply is crucial for the development of the distinct swamp vegetation, with comparatively constant microclimatic conditions all over the year. Seasonal change increased in the primary forest, and shows most significant changes of athropod abundance between dry and wet season in the selectively logged forest which also had the highest heterogeneity in forest structures. Especially small and soft bodied arthropods probably accumulate along a humidity gradient in the dense canopies of Rinorea during the dry season, when the forest floor outside the swamp forest is dry. This effect, which is also strongest in the selectively logged forest, leads to a much higher density of canopy dwelling arthropods during the dry season.     

Effects of habitat area, isolation, and landscape diversity on plant species richness of calcareous grasslands

Calcareous grasslands harbour a high biodiversity, but are highly fragmented and endangered in central Europe. We tested the relative importance of habitat area, habitat isolation, and landscape diversity for species richness of vascular plants. Plants were recorded on 31 calcareous grasslands in the vicinity of the city of Göttingen (Germany) and were divided into habitat specialist and generalist species. We expected that habitat specialists were more affected by area and isolation, and habitat generalists more by landscape diversity. In multiple regression analysis, the species richness of habitat specialists (n = 66 species) and habitat generalists (n = 242) increased with habitat area, while habitat isolation or landscape diversity did not have significant effects. Contrary to predictions, habitat specialists were not more affected by reduced habitat area than generalists. This may have been caused by delayed extinction of long-living plant specialists in small grasslands. Additionally, non-specialists may profit more from high habitat heterogeneity in large grasslands compared to habitat specialists. Although habitat isolation and landscape diversity revealed no significant effect on local plant diversity, only an average of 54% of habitat specialists of the total species pool were found within one study site. In conclusion, habitat area was important for plant species conservation, but regional variation between habitats contributed also an important 46% of total species richness.     

Effects of habitat quality and landscape structure on saproxylic species dwelling in boreal spruce-swamp forests

Intensive forest management has caused loss and fragmentation of old‐growth forests and reduced the amount of dead wood throughout northwest Europe. Changes in habitat availability are reflected in occurrence patterns of habitat‐specialist species only after a certain time lag. Here we analyse the responses of wood‐decomposing fungi and saproxylic beetles inhabiting patches of spruce‐swamp forest to habitat quality, loss and isolation at three different spatial scales in eastern Finland and adjacent Russian Karelia, where forestry has been very marginal until recently. Both rare specialist species and common generalist species were included in the study to reveal whether their occurrence patterns differ. Variables describing habitat quality (density and continuity of host trees, patch area) turned out significant in explaining species' incidences (proportion of occupied host trees) in only a few cases, probably because of the relatively high quality of all study patches. Despite this fact, and consistent with our hypothesis, incidences of all the eight specialist species were higher in Russia than Finland, and the difference was significant in the two most strict habitat specialists, Pytho kolwensis and Phlebia centrifuga. In contrast, incidences of three out of four generalist species were higher in Finland than in Russia, and the difference was significant in Rhagium inquisitor. In a subset of 21 patches in Finland, we used a metapopulation model to predict the probability of each patch to be currently occupied by a species given the known spatiotemporal distribution of suitable forest stands during the last 50 years. The degree of isolation alone explained significantly the incidences of five species. However, including habitat variables into the models altered some of the effects. Moreover, inconsistent with our hypothesis, isolation appeared to also negatively affect some very common generalist species. Inclusion of these species in the study disclosed that apparently significant effects of spatiotemporal isolation should be interpreted cautiously.     

Trophic Niche in a Raptor Species: The Relationship between Diet Diversity,Habitat Diversity and Territory Quality

Recent research reports that many populations of species showing a wide trophic niche (generalists) are made up of both generalist individuals and individuals with a narrow trophic niche (specialists), suggesting trophic specializations at an individual level. If true, foraging strategies should be associated with individual quality and fitness. Optimal foraging theory predicts that individuals will select the most favourable habitats for feeding. In addition, the “landscape heterogeneity hypothesis” predicts a higher number of species in more diverse landscapes. Thus, it can be predicted that individuals with a wider realized trophic niche should have foraging territories with greater habitat diversity, suggesting that foraging strategies, territory quality and habitat diversity are inter-correlated. This was tested for a population of common kestrels Falco tinnunculus. Diet diversity, territory occupancy (as a measure of territory quality) and habitat diversity of territories were measured over an 8-year period. Our results show that: 1) territory quality was quadratically correlated with habitat diversity, with the best territories being the least and most diverse; 2) diet diversity was not correlated with territory quality; and 3) diet diversity was negatively correlated with landscape heterogeneity. Our study suggests that niche generalist foraging strategies are based on an active search for different prey species within or between habitats rather than on the selection of territories with high habitat diversity.     

Local species immigration,extinction, and turnover of butterflies in relation to habitat area and habitat isolation

Temporal dynamics of insect communities in terrestrial habitat fragments have been rarely studied. Here it was tested whether immigration, extinction, and turnover of butterfly species change with area and isolation of 31 calcareous grasslands. The area ranged from 0.03 to 5.14 ha, the isolation index from 2,100 to 86,000 (edge-to-edge distance 55–1,894 m). In both study years (1996, 2000), the total number of individuals (16,466, 15,101) and species (60, 54) sampled across all sites were similar and number of species increased with area in both years indicating an equilibrium. Rates of extinction (38% for habitat specialists vs. 20% for generalists) and turnover (51% vs. 35%) were higher, and rates of immigration (11% vs. 30%) were lower for habitat specialists than for generalists. Extinction and turnover rates decreased with increasing fragment size for both specialist (n =25 species) and generalist (n =36) butterflies, but specialists showed a significantly steeper decrease with increasing fragment size than generalists. Immigration rates increased with area. As a result, species number of habitat specialists declined in small habitats but not in large habitats between 1996 and 2000. No significant impact of habitat isolation on the butterfly community was found. The data suggest that large habitat fragments are of special importance for the conservation of the specialized, most endangered butterfly species. Habitat isolation appears to be less important, as butterflies can cope with the habitat mosaic in our study region.Due to an error in the citation line, this revised PDF (published in December 2003) deviates from the printed version, and is the correct and authoritative version of the paper.     

Morphological plasticity and ecophysiological response of ground ivy (Glechoma hederacea,Lamiaceae) in contrasting natural habitats within its native range

Abstract

Some species intrinsically have a high invasiveness capacity, shown by high phenotypic plasticity and rapid growth, enabling a wide distribution across their native habitats and successful invasion in the introduced range. For such species, information from native habitats is critically important. An example is Glechoma hederacea, native to Eurasia but introduced and widespread in the USA. Our main objective was to investigate variation in traits of native G. hederacea populations across contrasting habitats: open, forest edge and understory. Vegetation was sampled and the ecophysiological and morphological traits were measured with accompanying environmental parameters. Results showed that in native habitats environmental conditions cover wide gradients of light and soil moisture. Plants had the highest cover in nutrient-rich, shaded habitats, representing the optimal habitat, indicating shade tolerance of G. hederacea. Plants from forest understory exhibited strong similarities in investigated traits to plants from the forest edge, even though this was a drier, sunnier habitat. Plants from open, sunny habitats experienced stress as indicated by the quantum efficiency of PSII and significantly higher sexual reproduction. Results show that G. hederacea is moderately tolerant simultaneously to shade and drought, a characteristic that has been reported for numerous invasive species, while at the same time it shares some characteristics with weedy plants.     

Habitat Use and Body Mass Regulation among Warblers in the Sahel Region during the Non-Breeding Season

Migratory birds face significant challenges across their annual cycle, including occupying an appropriate non-breeding home range with sufficient foraging resources. This can affect demographic processes such as over-winter survival, migration mortality and subsequent breeding success. In the Sahel region of Africa, where millions of migratory songbirds attempt to survive the winter, some species of insectivorous warblers occupy both wetland and dry-scrubland habitats, whereas other species are wetland or dry-scrubland specialists. In this study we examine evidence for strategic regulation of body reserves and competition-driven habitat selection, by comparing invertebrate prey activity-density, warbler body size and extent of fat and pectoral muscle deposits, in each habitat type during the non-breeding season. Invertebrate activity-density was substantially higher in wetland habitats than in dry-scrubland. Eurasian reed warblers Acrocephalus scirpaceus occupying wetland habitats maintained lower body reserves than conspecifics occupying dry-scrub habitats, consistent with buffering of reserves against starvation in food-poor habitat. A similar, but smaller, difference in body reserves between wet and dry habitat was found among subalpine warblers Sylvia cantillans but not in chiffchaffs Phylloscopus collybita inhabiting dry-scrub and scrub fringing wetlands. Body reserves were relatively low among habitat specialist species; resident African reed warbler A. baeticatus and migratory sedge warbler A. schoenobaenus exclusively occupying wetland habitats, and Western olivaceous warblers Iduna opaca exclusively occupying dry habitats. These results suggest that specialists in preferred habitats and generalists occupying prey-rich habitats can reduce body reserves, whereas generalists occupying prey-poor habitats carry an increased level of body reserves as a strategic buffer against starvation.     

Local and geographical distributions for a tropical tree genus,Scaphium (Sterculiaceae) in the Far East

Tropical rain forests have an amazingly large number of closely related, sympatric species. How the sympatric species coexist is central to understanding the maintenance of high biodiversity in tropical rain forests. We compared local and geographical distributions among trees in Scaphium (Sterculiaceae), a tropical canopy tree genus. Scaphium is endemic to the Far Eastern tropics and comprises six species. Scaphium scaphigerum is distributed in drier regions than the other species' geographical distribution ranges. Scaphium longiflorum is distributed swamp forests, whereas the others were distributed in lowland and hill tropical rain forests on undulating land. Scaphium borneense, S. longipetiolatum, and S. macropodum co-occurred in a 52-ha plot in Lambir, Sarawak and clearly showed an allopathic pattern of distribution related to elevation in it. In the plot, the elevational difference was correlated with soil variation. Consequently, the difference in edaphic condition promoted the habitat segregation of the species. Thus these five Scaphium species have divergent habitats at various spatial scales and coexist because they reduce direct competition by habitat niche differentiation. Although the non-equilibrium hypothesis for the coexistence of Scaphium species cannot be rejected categorically due to the lack of enough information about S. linearicarpum, the equilibrium force may play the predominant role which permits their coexistence.     

Living on the edge: The use of fruit-feeding butterflies to evaluate edge effect on subtropical assemblages

This study evaluated how the edge effect influences the structuration of fruit-feeding butterfly assemblages in swamp forest fragments of the subtropical Atlantic Forest, Southern Brazil. Sampling was carried out twice in 10 fragments using baited traps placed in sampling units both at the forest edge and 50 m within the forest interior, with the habitats being defined by a set of environmental variables. Richness and abundance were higher for edge habitats with an effect of temperature depending on humidity and luminosity. The subfamily/tribe composition of fruit-feeding butterflies was segregated between edge and interior and was predicted by wind speed and the interaction between humidity and luminosity. Fifty meters within the forest interior is not sufficient to cause homogenization of butterfly composition between the edge and interior of swamp forest fragments, indicating distinct assemblages in each habitat. The interior harboured forest-loving butterfly groups while the edge harboured generalist sun-loving and common butterflies associated with disturbed areas, suggesting resistance to the effects of habitat fragmentation. We highlight the importance of using fruit-feeding butterfly groups, instead of species, to evaluate edge effects. We also suggest that a heterogeneous matrix with native habitats and distinct semi-natural land-use systems be maintained to manage subtropical areas by increasing connectivity within the landscape. Considering the impacts that the Atlantic Forest suffers, increased knowledge of modifications caused at small and regional scales is crucial for the maintenance of ecological processes and represents a tool for conservation planning and environmental agendas.     

Factors influencing the distribution of leopard in a semiarid landscape of Western India

Previously, factors governing distribution of leopard (Panthera pardus fusca) in forest habitats of the Indian subcontinent were unknown. The present study assessed the influence of different ecogeographic variables determining the distribution of leopards in and around Sariska Tiger Reserve through MaxEnt habitat suitability model based on camera trapping method. Camera trapping was used to collect presence/absence information in the study area from December 2008 to June 2010. Information of 11 macrohabitat characteristics and variables (habitat types, prey species, Normalized Difference Vegetation Index (NDVI), elevation, livestock, village, water source, etc.) were collected along with leopard presence data. The probability of presence of leopards increased with decreasing distance to water and increasing encounter rate of peafowl (Pavo cristatus), chital (Axis axis), sambar (Rusa unicolor), and wild pig (Sus scrofa). It was found that the probability of presence of leopards increased with increasing area of Zizyphus mixed forest patches and NDVI. Results of this study showed that the probability of presence of leopards was higher in habitat types with intermediate cover, high wild prey base, and water sources. They also indicated that leopards are not always ‘generalists’ showing some degree of specialization, at least in their choice of habitat, and this information is useful for conserving leopard in human-dominated landscapes.