A meta-analysis of fauna and flora species richness and abundance in plantations and pasture lands

We conducted a systematic global review of differences between timber plantations and pasture lands in terms of animal and plant species richness and abundance, and assessed the results using meta-analysis techniques. Our principal aim was to test the hypothesis that plantations contain higher species richness or abundance than pasture. Of the 1967 studies of potential relevance, 66 provided biological monitoring information and 36 met the requirements for meta-analyses. Sufficient data were available for meta-analyses to be conducted comparing the species richness and abundance of plantations and pasture lands for five taxonomic groups: plants, invertebrates, reptiles/amphibians, mammals, and birds. Within each taxon there was considerable variation in the difference between species richness and abundance between plantations and pasture lands. Birds and reptile/amphibians exhibited significantly higher species richness, and mammals exhibited significantly higher abundance, in plantations than in pasture lands which lacked remnant vegetation. Reptile/amphibian species richness was significantly higher in plantations in general. No significant differences in species richness were found for mammals, plants, or invertebrates, and no significant differences in abundance were found for birds, reptiles/amphibians, invertebrates, or plants. It is only within the presence of taxonomic caveats (i.e. reptiles/amphibians), or specific landscape features (i.e. absence of remnant vegetation within pasture), that it can be concluded that plantations support higher species richness or abundance than pasture land. We emphasize that caution is warranted when making general statements about the inherent biodiversity value of diverse and broadly-defined land-uses.     

Herpetofauna diversity and microenvironment correlates across a pasture-edge-interior ecotone in tropical rainforest fragments in the Los Tuxtlas Biosphere Reserve of Veracruz, Mexico

We evaluated the relationship between amphibian and reptile diversity and microhabitat dynamics along pasture-edge-interior ecotones in a tropical rainforest in Veracruz, Mexico. To evaluate the main correlation patterns among microhabitat variables and species composition and richness, 14 ecotones were each divided into three habitats (pasture, forest edge and forest interior) with three transects per habitat, and sampled four times between June 2003 and May 2004 using equal day and night efforts. We measured 12 environmental variables describing the microclimate, vegetation structure, topography and distance to forest edge and streams.After sampling 126 transects (672 man-hours effort) we recorded 1256 amphibians belonging to 21 species (pasture: 12, edge: 14, and interior: 13 species), and 623 reptiles belonging to 33 species (pasture: 11, edge: 25, and interior: 22 species). There was a difference in species composition between pasture and both forest edge and interior habitats. A high correlation between distance to forest edge and temperature, understorey density, canopy cover, leaf litter cover, and leaf litter depth was found. There was also a strong relationship between the composition of amphibian and reptile ensembles and the measured environmental variables. The most important variables related to amphibian and reptile ensembles were canopy cover, understorey density, leaf litter cover and temperature.Based on amphibian and reptile affinity for the habitats along the ecotone, species were classified into five ensembles (generalist, pasture, forest, forest edge and forest interior species). We detected six species that could indicate good habitat quality of forest interior and their disappearance may be an indication of habitat degradation within a fragment, or that a fragment is not large enough to exclude edge effects. Different responses to spatial and environmental gradients and different degrees of tolerance to microclimatic changes indicated that each ensemble requires a different conservation strategy. We propose to maintain in the Los Tuxtlas Biosphere Reserve the forest remnants in the lowlands that have gentler slopes and a deep cover of leaf litter, a dense understorey, and high relative humidity and low temperature, to buffer the effects of edge related environmental changes and the invasion of species from the matrix.     

The efficacy of small-scale conservation efforts, as assessed on Australian golf courses

Habitat remnants on urban green-space areas (i.e. parks, gardens and golf courses) sometimes provide refuge to urban-avoiding wildlife, leading some to suggest these areas may play a role in wildlife conservation if they are appropriately designed and managed. The high densities observed on some green-space areas may however be attributed to external influences. Localised efforts to enhance the habitat value of urban green-space areas may therefore have little more than a cosmetic effect. This study investigated environmental factors influencing bird, reptile, mammal and amphibian diversity on Australian golf courses to assess the efficacy of small-scale conservation efforts. Abundance and species richness did not simply reflect local habitat qualities but were instead, partly determined by the nature of the surrounding landscape (i.e. the area of adjacent built land, native vegetation and the number of connecting streams). Vertebrate abundance and species richness were however, also associated with on-site habitat characteristics, increasing with the area of native vegetation (all vertebrates), foliage height diversity and native grass cover (birds), tree density, native grass cover and the number of hollows (mammals), woody debris, patch width and canopy cover (reptiles), waterbody heterogeneity and aquatic vegetation complexity (frogs). Localised conservation efforts on small land types can benefit urban-avoiding wildlife. Urban green-space areas can provide refuge to urban-avoiding vertebrates provided combined efforts are made at patch (management), local (design) and landscape (planning) scales.     

Amphibian distribution in a traditionally managed rural landscape of Eastern Europe: Probing the effect of landscape composition

A massive decline of biodiversity is caused by land-use changes. Efforts must therefore be made to better understand the factors that govern organismal distribution, especially for countries where traditional management is about to be intensified such as in Romania. We here document the spatial distribution of amphibians from a Romanian rural landscape where land-use is still largely traditional. We related the occurrence of nine amphibian species and species richness to measures of composition and configuration of the landscape surrounding 54 ponds at three spatial scales: circular areas of 400, 600 and 800 m radii. Busy roads most severely impacted single species and amphibian richness whereas landscape composition measures, such as cover of urban areas, agricultural areas, pastures, forests and wetlands were of little importance. We suggest that the relative unimportance of landscape compositional measures on amphibians is a consequence of the traditional management of these landscapes that keep the environmental conditions favorable for most species.     

Land Use and Basin Characteristics Determine the Composition and Abundance of the Microzooplankton

The influence of watershed land use on microzooplankton was examined. Six rivers and a shallow lake located in rural (agriculture, livestock) and urban areas were sampled during 4 weeks at low water, low temperatures and 3 weeks at high water, high temperatures. The major aim of this study was to analyze the composition, richness and abundance of the microzooplankton in relation to land use, taking into account nutrient concentration, biological oxygen demand (BOD₅), conductivity, pH, transparency, dissolved oxygen, and chlorophyll-a. Redundancy analysis was used to assess microzooplankton response to environmental gradients. The composition and abundance can be considered good indicators of the land used and characteristic of the basin (broad range of conductivity water). The species composition show a gradient along the conductivity, pH and chlorophyll-a. Brachionus spp. were associated with saline waters on rural area and Keratella spp. (except Keratella tropica) were associated with urban water bodies. The microzooplankton abundance diminished by a factor of ten from the rivers in livestock?Cagriculture-dominated watersheds to those located in strictly urban areas. Urban rivers had low abundances of chlorophyll-a and microzooplankton despite the high concentration of nutrients. However, the effect of urbanization (mesotrophic/mesosaprobious state and lead presence) cannot be analyzed alone due to the potential effect of a filter-feeding invasive mollusk that colonizes the hard surfaces of harbor buildings and bridge pillars.     

Human land use and patterns of parasitism in tropical amphibian hosts

Landscape alterations by humans can change patterns of parasite transmission. Depending on the type alteration and the life histories of parasites and hosts, parasitism may increase or decrease. To investigate whether parasitism in tropical amphibians was associated with land use change, I studied three species of amphibians, Rana vaillanti, Eleutherodactylus fitzingeri, and Smilisca puma from the Province of Heredia, Costa Rica, in the Atlantic lowlands. Frogs were collected and examined for parasites during the rainy seasons of 2001-2003 from sites in forest or clear-cut cattle pastures. The abundances of five species of parasites and parasite species richness of R. vaillanti were significantly higher in pasture habitat. A single parasite species shared by E. fitzingeri and S. puma showed a trend of increased abundance in pasture habitats. Overall, the abundances of six parasite species (three trematodes, an intestinal nematode, an encysted nematode, and a filarial nematode) were higher in pastures, while two species (trematodes) were higher in forest. This study suggests that land use activities in tropical regions affects the abundance and richness of amphibian parasites. Converting forest to pasture may impact the abundance of amphibian parasites because subsequent water quality changes (e.g. eutrophication, higher pH) often enhance habitat and resources for intermediate hosts (e.g. snails, mosquitoes) involved in parasite life cycles. Aquatic amphibians (e.g. R. vaillanti) may be particularly prone to experiencing increases in parasitism in agricultural habitats due to the positive relationship between many aquatic intermediate hosts and water quality changes associated with agricultural land use.     

Patch and landscape characteristics associated with the distribution of woodland amphibians in an agricultural fragmented landscape: an information-theoretic approach

In the Midwestern United States, agricultural landscapes with scattered patches of fragmented forest are common. To investigate the relationship between amphibian distributions and wetland, woodlot, and landscape characteristics, we studied the pond-breeding amphibians within a 15,450-ha plot in rural north-central Ohio. We surveyed 25 woodlots and one area of continuous riparian forest for amphibians, and each surveyed woodland contained at least one temporary wetland. We used Akaike's Information Criterion (AIC) to evaluate the effectiveness of 13 a priori models in predicting total amphibian species richness, anuran richness, caudate richness, and the presence of individual species in woodlots. We identified 13 species of amphibians within the study plot, and every woodlot contained at least one amphibian species. The most important variable in predicting total amphibian and anuran species richness was hydroperiod. For caudates, woodlot edge-to-area ratio, hydroperiod, pH, and ammonia were important characteristics in predicting species richness. Woodlots within agricultural landscapes are important refuges for amphibians.     

Recovery of amphibian species richness and composition in a chronosequence of secondary forests,northeastern Costa Rica

In some tropical regions, following the abandonment of agriculture and pastures, secondary forests can recover plant species richness and forest structure (e.g. canopy cover, biomass); however, the importance of these secondary forests for fauna is not clear. Secondary forests can benefit fauna by providing suitable habitats, connecting forests fragments, and increasing gene flow. Previous studies of forest regeneration have showed different levels of amphibian recovery. In Puerto Rico, 1–5 years old secondary forests achieved similar amphibian species richness and composition in comparison with old-growth forests, while in Brazil secondary forests from 14 to 19 years of recovery only recovered 60% of the species of old-growth forests. We evaluated amphibian recovery in secondary forests in northeastern Costa Rica, by assessing amphibian recovery in 12 secondary forests that vary in age of recovery and in three old-growth forests using visual and acoustic surveys. Our sites varied in terms of their landscape (e.g. amount of surrounding forest) and forest characteristics (e.g. forest age, aboveground biomass, basal area, number of tree species, number of stems, leaf-litter depth), but there was no relationship between these characteristics and amphibian species richness or species composition. We found that amphibians are recovering rapidly in secondary forests in Costa Rica, and even young forests (10–16 years) had similar species richness and composition in comparison with old-growth forests. These forests are providing suitable microhabitats conditions for amphibians. In addition, this study highlights the importance of landscape characteristics. The abundance of amphibian species sources (e.g. forest patches) and connections between forests appear to be helping the species colonize these sites. Worldwide, the area of secondary forests is increasing, and our results show that these habitats are suitable for a diversity of amphibian species, suggesting that these forests can help reduce amphibian population and species decline.     

Urban Influences on Stream Chemistry and Biology in the Big Brushy Creek Watershed, South Carolina

Naturally high total dissolved solids and upstream agricultural runoff often mask the influence of urban land cover on stream chemistry and biology. We examined the influence of headwater urbanization on the water chemistry, microbiology, and fish communities of the Big Brushy Creek watershed, a 96 km² drainage basin in the piedmont of South Carolina, USA. Concentrations of most major anions and cations (especially nitrate, sulfate, chloride, sodium, potassium, and calcium) were highest in the urban headwaters and decreased downstream. Generally, the highest concentrations of suspended coliform bacteria occurred in the urban headwaters. In contrast, stream habitat quality and the abundance, species richness, and species diversity of fishes did not differ significantly between urban and rural sites. Discharge of wastewater treatment plant effluent at one rural location caused an increase in concentrations of many solutes and possibly the abundance of benthic algae. We hypothesize that atmospheric dry deposition and domestic animal wastes are important sources of stream solutes and of coliform bacteria, respectively, in the urban headwaters. The lack of significant differences in fish abundance and diversity between urban and rural sites may indicate that urban development in the Big Brushy Creek watershed has not yet degraded habitat conditions greatly for stream fishes. Alternatively, agriculture or other land uses may have degraded stream habitat quality throughout the watershed prior to urbanization.     

Amphibian ecology and conservation in the urbanising world: A review

Urbanisation currently threatens over one-third of the world’s known amphibian species. The main threats of urbanisation to amphibian populations are habitat loss, habitat fragmentation and isolation, and degradation of habitat quality. A complex array of interacting biotic and abiotic factors impact amphibians in urban and urbanising landscapes. These can lead to a decrease in species richness and the abundance of individual species towards the centre of cities and towns. The ability of amphibians to disperse can be significantly reduced in urban and suburban landscapes. However, different species exhibit markedly different responses to urbanisation. Amphibian species that are habitat generalists or have relatively low dispersal requirements appear to be better able to survive in urban and suburban landscapes. There is insufficient information on the ecology of amphibians in urban and suburban areas, particularly in the tropics and sub-tropics, despite worldwide declines reported over past decades. Future research of amphibians in urban and suburban landscapes would greatly benefit by using long-term studies at sites along urban-rural gradients, conducted at both local and landscape scales. Research needs to be directed to the developing world in the tropics and sub-tropics, which has the highest rates of urbanisation. Research into amphibian ecology and conservation in the urbanising world would be improved through experimental approaches to determine the proximate causes of species’ responses to human modification of the landscape. Maintaining viable populations of amphibians in urban and suburban landscapes will require conservation strategies that consider key urbanisation processes (i.e. habitat availability and habitat quality) and the key responses and adaptations to urbanisation (i.e. species availability and species response). Conservation strategies for amphibians in urban and suburban landscapes need to include actions to prevent further loss and degradation of both terrestrial and aquatic habitat, and to reconnect the landscape to facilitate dispersal and long-term regional persistence of amphibian populations and communities.     

Regrowth and revegetation in temperate Australia presents a conservation challenge for reptile fauna in agricultural landscapes

Secondary vegetation, associated with changes in land use, presents a conservation issue in the preservation of biological diversity in agricultural landscapes. We examine the interactive effect of eucalypt regrowth and rock habitat on reptile species richness and assemblage structure in fragmented agricultural landscapes in south-eastern Australia. Zoogeographic and geomorphic factors influenced species richness and community composition. Saxicolous and arboreal species were less abundant in grassy woodland regrowth, whereas Bassian and fossorial species responded positively to forest regrowth (and tree plantings). Regrowth with rock habitat had higher reptile richness, and more old growth-associated taxa, than regrowth without rock habitat. Thus, the presence of saxicolous habitat can reduce the time required for regrowth to attain a climax community structure and elements of old growth fauna. However, in the absence of vegetation management, secondary vegetation can reduce habitat suitability for a broad range of reptiles. In agricultural landscapes historically supporting savannah-like vegetation, habitat manipulation may be necessary to maintain reptile diversity. Furthermore, tree plantings in temperate agricultural landscapes should aim to restore historical vegetation composition and structure, thereby reflecting the habitat requirements of extant species and facilitating evolutionary processes. In grassy woodland ecosystems, this may involve heterogeneous plantings which emulate natural levels of canopy cover and solar penetration. Maintaining biodiversity in agricultural landscapes will therefore involve managing trade-offs to preserve areas of dense regeneration for regrowth-dependant fauna, while at the same time, creating open-canopy environments to enhance habitat for ectothermic organisms.     

Effects of nonnative fish and habitat characteristics on lentic herpetofauna in Yosemite National Park, USA

Nonnative fishes have been introduced into naturally fishless mountain lakes worldwide, often with negative consequences for native fauna. In this study, I used data collected during a census of native herpetofauna, nonnative trout, and habitat characteristics at all lentic water bodies in Yosemite National Park (n=2655) to quantify the effect of trout introductions and habitat on the distribution of four amphibian species and two reptile species. Impacts of trout on amphibians and reptiles were characterized using generalized additive models that included as predictor variables fish presence/absence, amphibian presence/absence (only in models for the two reptile species), elevation, water depth, littoral zone and shoreline substrate composition, relative survey date, and location. All species showed significant associations with habitat characteristics, and elevation and water depth appeared particularly important in influencing distributions. In addition, distributions of the mountain yellow-legged frog (Rana muscosa) and Pacific treefrog (Hyla regilla) were strongly negatively associated with the presence of nonnative trout while those of the Yosemite toad (Bufo canorus) and Sierra newt (Taricha torosa sierrae) were unrelated to trout presence. The distribution of the mountain garter snake (Thamnophis elegans elegans) was strongly negatively associated with the presence of nonnative trout and positively associated with the presence of native amphibians. Regression results for the Sierra garter snake (Thamnophis couchi couchi) were similar except that the direct effect of nonnative trout was considerably weaker. Together, these results indicate that trout introductions have resulted in considerable alteration of Yosemite's herpetofauna. Long-term studies will be necessary to determine whether removal of nonnative trout populations, where possible, would allow these impacts to be partially reversed.     

Forecasting faunal and floral homogenization associated with human population geography in North America

Human population and urbanization is unprecedented in its rate of growth and geographic scope. With the help of humans, exotic species have piggybacked their way to distant lands, which in combination with the loss of endemic native species, has led to the convergence of biological communities toward common and ubiquitous forms. However, the extent to which this “biotic homogenization” varies along gradients of human population size and urbanization remains mostly unexplored, especially at broad spatial scales. The present paper combines a recent conceptual model of homogenization with estimates of species invasions and extinctions to provide the first estimates of homogenization for five major taxonomic groups - land birds, freshwater fish, terrestrial mammals, plants, and freshwater reptiles and amphibians - at the continental-scale of North America (exclusive of Mexico). On average, the greatest levels of biotic homogenization were predicted for plants (22%) and fishes (14%), followed by reptiles/amphibians (12%), mammals (9%) and birds (8%). Substantial spatial variation in predictions of community similarity exists and emphasize that the outcome of species invasions and extinctions may not only increase community similarity, but may also decrease it (i.e., differentiation). Homogenization is predicted to be greatest for fish in southwestern and northeastern US, highest in eastern North America for plants, greatest for birds and mammals along the west coast of North America, and peak in southern US for reptiles and amphibians. We show that predicted change in community similarity for all taxonomic groups is positively related to human population size and urbanization, thus providing the first quantitative linkage between human population geography and homogenization for a number of major taxonomic groups at the continental-scale of North America. Our study helps identify regional hotspots of biotic homogenization across North America, thus setting the stage for future studies where more directed investigations of biotic homogenization along urban gradients can be conducted.     

Conservation assessment and prioritization of areas in Northeast India: Priorities for amphibians and reptiles

This study combines niche modeling and systematic area prioritization using distribution data for 131 species of amphibians and reptiles from Northeast India and Burma, with two objectives: (i) to evaluate the performance of the current conservation area network in Northeast India with respect to the representation of amphibians and reptiles, and (ii) to identify potential areas for expanding the current conservation area network. In a two-step protocol, maximum entropy niche modeling was used to project species’ potential geographic occurrences, and the resulting probabilistic distribution data were used to prioritize areas with algorithms that maximize the representation of all species in minimal total area. The results provided a critical assessment of conservation priorities in this data-deficient region, and indicate the utility of combining niche modeling with systematic area prioritization in such situations. Many areas that had been overlooked in previous assessments were identified. Although the existing protected areas were found to be inadequate for representation of amphibian and reptile diversity, the prioritization results show that by targeting a minimal representation of 5% of the current total area suitable for each species, the gaps can be filled with a relatively modest (0.41%) increase in the current total area covered by the network. Extended analyses were also performed to assess the effects of putatively rare species on reserve selection, which showed that the inclusion of these taxa can change the prioritization solutions significantly. The prioritization results also highlight areas of Northeast India that warrant attention from future surveys.     

Coastal urbanization and the integrity of estuarine waterbird communities: Threshold responses and the importance of scale

Estuarine ecosystems are becoming increasingly altered by the concentration of human populations near the coastline, however a robust indicator of this change is lacking. We developed an index of waterbird community integrity (IWCI) and tested its sensitivity to anthropogenic activities within 28 watersheds and associated subestuaries of Chesapeake Bay, USA. The IWCI was used as a tool to gain insight into how human land use affects estuarine ecosystem integrity. Based on Akaike’s information criteria (AIC), a single variable model including percent developed land in estuarine watersheds was thirteen (2002) and twenty-six (2003) times more likely than models including percent agriculture and forest cover to fit the IWCI data. Consequently, we examined how suburban, urban, and total development shaped IWCI scores at three spatial scales: (1) watershed; (2) inverse-distance-weighted (IDW) watershed (land cover near the coastline weighted proportionally greater than that farther away); (3) local (land cover within 500 m of the coastline). Suburban, urban, and total development were all significant predictors of IWCI scores. Relationships were stronger at the IDW and local scales than at the whole watershed scale. Nonparametric changepoint analysis revealed a >80% probability of a threshold in IWCI scores when as little as 3.7% (2002) and 3.5% (2003) of the IDW land cover within the watershed was urban. Our results indicate that, of the landscape stressors we examined, development near estuarine coastlines is the primary stressor to estuarine waterbird community integrity, and that estuarine ecosystem integrity may be impaired by even extremely low levels of coastal urbanization.     

Lizards and landscapes: integrating field surveys and interviews to assess the impact of human disturbance on lizard assemblages and selected reptiles in a savanna in South Africa

Habitat degradation through over-grazing and wood collection is especially prevalent in developing countries such as South Africa. As human populations expand and the demand for land increases, the traditional idiom of setting aside protected areas for conservation is insufficient and assessment and protection of diversity outside these areas is needed. We assessed the impact of land use on lizard assemblages in communal rangelands in South Africa by comparing abundance, species richness and species diversity between degraded communal lands with a protected area. We first quantified vegetation differences between the study areas and found marked differences. Communal lands had significantly fewer large trees and less ground cover. Contrary to prediction, we found no evidence that any species of lizard was negatively affected by habitat disturbance. Some species were more common in communal lands, and species richness and diversity were also higher using certain sampling techniques. Terrestrial diversity was likely enhanced due to the preference of many terrestrial lizards for open, sparsely grassed areas. We discuss other reasons for increased diversity such as the intermediate disturbance hypothesis and/or reduced numbers of predators and competitors. We also conducted surveys of households and traditional healers to investigate the relationship between human uses of reptiles and abundance. The predominant users of reptiles were traditional healers. The most commonly used species were not encountered in our field surveys, and respondents indicated that they appeared to be declining. Our results emphasise the importance of integrating local knowledge into biodiversity assessment and conservation planning. Although we did not identify a negative impact of disturbance on lizard communities, community structure was different and this likely influenced ecosystem integrity and function in some way.     

Landscape and patch-level factors influence bird communities in an urbanized tropical island

As human population continues to increase and intensification of human land use escalates, it is important to address the role of urban forest patches in supporting bird communities. We related bird species richness and community assemblage to landscape- and patch- level factors in 40 forest patches in the densely populated metropolitan area of San Juan, Puerto Rico. In total, 54 bird species were observed including 26 resident, 10 endemic, 12 migratory, and 6 introduced species. Patch size, level of urbanization in the surrounding matrix, and vertical heterogeneity of forest patches were the most important variables in explaining species richness. Patch size had the highest predictive power in explaining species richness for all groups except migrants, which were best predicted by patch-level factors (vegetation heterogeneity). The degree of matrix urbanization was correlated negatively with endemic species richness, but positively with introduced species. Endemic species were particularly sensitive to landscape factors (patch size, matrix urbanization, and canopy texture). Introduced species richness was not dependent on any patch-level factors. Eight species were relatively unaffected by urbanization, whereas two species were only found in large forest patches, and two species were sensitive to urban development. Seven species demonstrated a preference for small patches. Recommendations for land managers and conservation agencies to maintain a high bird species richness and diversity include: (1) preserve both large and small forest patches, (2) limit urban development near forest patches, (3) manage forest patch structure to maintain vertical heterogeneity, and (4) maintain forest patches with different vegetation types.     

Effects of age and intensity of urbanization on farmland bird communities

Urban sprawl is now occurring worldwide and considered as a major large-scale perturbation on ecosystems. Consequently, urban territory is replacing other habitats such as agricultural areas. As farmland biotic communities are already reported to be declining, it seems necessary to assess the urbanization impact on them. We conducted a bird survey on 92 plots of 1 × 1 km chosen after stratification on the proportion of urban area and farmland habitat (either 0%, 25%, 50%, 75%), focusing on farmland habitat. Two aspects of urbanization were studied: its intensity and its age. We found that farmland bird species richness did not vary with increasing proportion of urbanized habitat. Non-farmland bird species richness increased from 0% to 25% classes and was constant for other classes. No effect of the urbanization age on farmland bird species richness was found, whereas a positive one was found on the non-farmland birds’ species richness. Abundance of the most specialized farmland birds decreases with urbanization intensity and age. We also found that, the more urbanized and the more recently urbanized the plots, the more similar bird communities. A strong difference in farmland bird’s communities’ compositions was found between 0% and 25% of urbanization, whereas no distinction was found between 50% and 75%. Altogether, our results suggest that to maintain for farmland birds, it is better to add new urban habitat in place where it already exist, rather than to spread it in small lots throughout the landscape.     

Detrimental effects of peat mining on amphibian abundance and species richness in bogs

Peat bogs of eastern North America are increasingly being mined for peat, which results in the extensive draining of these systems. First, I quantified the effects of peat mining on amphibian species richness and abundance in bog remnants adjacent to mining activity and unmined bogs. I then investigated amphibian occurrence patterns in bog remnants relative to the distance to the mined edge, after accounting for microhabitat and distance to landscape elements. The response of amphibians to peat mining varied across taxa. For instance, amphibian species richness, total amphibian captures (all spp. combined), as well as those of green frogs (Rana clamitans) were greater in unmined bogs than in bog remnants. Wood frogs (Rana sylvatica) were most abundant in unmined bogs in areas far from bog ponds, as well as in unmined bogs in areas near shrub patches. After accounting for microhabitat and landscape variables, American toads (Bufo americanus) in bog remnants were most abundant close to mined edges, whereas the other species did not respond to the proximity of mined edges. Peat mining negatively impacts amphibians occurring in bog remnants. The response of amphibians to peat mining is similar to the one of birds and plants, but differs with small mammals. Maintaining a complex mosaic of bog ponds, shrub and forest patches might help mitigate peat mining effects on amphibian patterns of abundance.     

Amphibian conservation: Are we on the right track?

Amphibian declines and extinctions are a worldwide concern. Conservation priorities for amphibians should target threatened taxa (taxonomic targets) and regions with high levels of species endemism (geographical targets). Does published research on amphibian conservation reflect the global taxonomic and geographic priorities? I surveyed six years (2000-2005) of 10 conservation and herpetological journals (Amphibia-Reptilia, Animal Conservation, Applied Herpetology, Biodiversity and Conservation, Biological Conservation, Conservation Biology, Copeia, Herpetologica, Journal of Herpetology and Oryx), and analyzed all articles on amphibians. Attention indexes were calculated for orders, threatened species and biogeographic realms. I also examined how well research from tropical developing nations (with high levels of richness and endemism) are represented in the international literature. Attention indexes results show that the most studied amphibian order is Caudata, whereas Gymnophiona is the least studied one. The same trend is observed for threatened species, with threatened Caudata species receiving proportionally more attention than threatened Anura and Gymnophiona. The biogeographic realms that receive most attention by amphibian conservationists are: Oceania, Nearctic and Palearctic. However, the Neotropical, Afrotropical and Indomalayan are the regions with higher species diversity. Forty-one countries contributed articles, but the majority of amphibian conservation research is conducted by North American and western European researchers. There is urgent need for capacity building in tropical developing nations. Amphibians are more threatened and are declining more rapidly than either birds or mammals. However, amphibian conservation is still misplacing its focus in lower-biodiversity regions and non-threatened species. If such trends are not changed, the consequences for the persistence of amphibians worldwide may be dire.