Plant communities as a tool for setting priorities in biodiversity conservation: a novel approach to Iberian aquatic vegetation

Although conservation efforts are traditionally based on species red lists or similar documents, recent initiatives are starting to shift this scope to include other biodiversity structures and biological classifications. Plant communities have been indicated as being among the most promising categories for setting conservation priorities but their importance and potential is still underestimated. In this study we develop a conservation priority list based on aquatic plant communities of the Iberian Peninsula. Four criteria were used to perform a cumulative point-scoring ranking: regional responsibility, local rarity, wealth of its endangered flora, and habitat vulnerability. Our ranking constitutes the first comprehensive classification of aquatic vegetation in relation to its conservation priorities in Southern Europe. It reveals that amphibious communities are the most important vegetation target for conservation in Iberia related to oligotrophic environments with a bioclimatic Atlantic distribution. Plant communities characteristic of eutrophic waters or widely distributed were found to be cause for less concern when setting conservation priorities. Our results bring to light various discrepancies and gaps in current conservation laws affecting the Iberian Peninsula. Our study highlights the potential of plant communities in biodiversity conservation as they provide valuable information of habitat singularity, and supports that neither the sole use of species nor large scale approaches unaware of regional singularities are appropriate in setting conservation priorities.     

Persistence at distributional edges: Columbia spotted frog habitat in the arid Great Basin,USA

A common challenge in the conservation of broadly distributed, yet imperiled species is understanding which factors facilitate persistence at distributional edges, locations where populations are often vulnerable to extirpation due to changes in climate, land use, or distributions of other species. For Columbia spotted frogs (Rana luteiventris) in the Great Basin (USA), a genetically distinct population segment of conservation concern, we approached this problem by examining (1) landscape‐scale habitat availability and distribution, (2) water body‐scale habitat associations, and (3) resource management‐identified threats to persistence. We found that areas with perennial aquatic habitat and suitable climate are extremely limited in the southern portion of the species’ range. Within these suitable areas, native and non‐native predators (trout and American bullfrogs [Lithobates catesbeianus]) are widespread and may further limit habitat availability in upper‐ and lower‐elevation areas, respectively. At the water body scale, spotted frog occupancy was associated with deeper sites containing abundant emergent vegetation and nontrout fish species. Streams with American beaver (Castor canadensis) frequently had these structural characteristics and were significantly more likely to be occupied than ponds, lakes, streams without beaver, or streams with inactive beaver ponds, highlighting the importance of active manipulation of stream environments by beaver. Native and non‐native trout reduced the likelihood of spotted frog occupancy, especially where emergent vegetation cover was sparse. Intensive livestock grazing, low aquatic connectivity, and ephemeral hydroperiods were also negatively associated with spotted frog occupancy. We conclude that persistence of this species at the arid end of its range has been largely facilitated by habitat stability (i.e., permanent hydroperiod), connectivity, predator‐free refugia, and a commensalistic interaction with an ecosystem engineer. Beaver‐induced changes to habitat quality, stability, and connectivity may increase spotted frog population resistance and resilience to seasonal drought, grazing, non‐native predators, and climate change, factors which threaten local or regional persistence.     

Does prescribed burning result in biotic homogenization of coastal heathlands?

Biotic homogenization due to replacement of native biodiversity by widespread generalist species has been demonstrated in a number of ecosystems and taxonomic groups worldwide, causing growing conservation concern. Human disturbance is a key driver of biotic homogenization, suggesting potential conservation challenges in seminatural ecosystems, where anthropogenic disturbances such as grazing and burning are necessary for maintaining ecological dynamics and functioning. We test whether prescribed burning results in biotic homogenization in the coastal heathlands of north‐western Europe, a seminatural landscape where extensive grazing and burning has constituted the traditional land‐use practice over the past 6000 years. We compare the beta‐diversity before and after fire at three ecological scales: within local vegetation patches, between wet and dry heathland patches within landscapes, and along a 470 km bioclimatic gradient. Within local patches, we found no evidence of homogenization after fire; species richness increased, and the species that entered the burnt Calluna stands were not widespread specialists but native grasses and herbs characteristic of the heathland system. At the landscapes scale, we saw a weak homogenization as wet and dry heathland patches become more compositionally similar after fire. This was because of a decrease in habitat‐specific species unique to either wet or dry habitats and postfire colonization by a set of heathland specialists that established in both habitat types. Along the bioclimatic gradient, species that increased after fire generally had more specific environmental requirements and narrower geographical distributions than the prefire flora, resulting in a biotic ‘heterogenisation’ after fire. Our study demonstrates that human disturbance does not necessarily cause biotic homogenization, but that continuation of traditional land‐use practices can instead be crucial for the maintenance of the diversity and ecological function of a seminatural ecosystem. The species that established after prescribed burning were heathland specialists with relatively narrow geographical ranges.     

Sex‐dependent habitat selection in a high‐density Little Bustard Tetrax tetrax population in southern France,and the implications for conservation

Conservation measures often rely on habitat management, so knowledge about a species’ habitat use is a prerequisite for effective conservation planning. The Little Bustard Tetrax tetrax, a medium‐sized bird native to the Palaearctic steppes and today found in extensively farmed habitats, is a threatened species. Its population experienced a 94% decline in farmland habitats in France between 1982 and 1996, and populations all over Europe have suffered equally sharp declines. Due to this steep negative trend, this species has been the subject of a number of habitat selection studies in order to develop relevant conservation measures based on its habitat requirements. In this study, we investigated the habitat selection of a range of habitat types by both sexes and at two nested spatial scales: plot scale and landscape scale. In addition, we analysed intra‐specific social interactions by incorporating conspecific density in the statistical models of habitat use. The study was conducted on a very high‐density population, perhaps the highest ever recorded for this species at around 50 Bustards per 100 ha of suitable habitat. Our methodology combined two field approaches (point counts and quadrat counts). The findings showed rather limited sexual dimorphism in terms of habitat selection at a local scale, with only vegetation height differing between sexes at a micro‐habitat scale, no selection at landscape scale, and a prevailing role of social factors at both scales. The implications for future conservation strategies in relation to population density and landscape composition are discussed.     

Mammal indicator species for protected areas and managed forests in a landscape conservation area of northern India

There is a realization that managed forests and other natural areas in the landscape matrix can and must make significant contributions to biodiversity conservation. Often, however, there are no consistent baseline vegetation or wildlife data for assessing the status of biodiversity elements across protected and managed areas for conservation planning, nor is there a rapid and efficient means to acquire those data. We used a unified vegetation classification and simple animal sampling design to describe the patterns of abundance of selected mammals as indicator, or characteristic, species in different vegetation types and protected areas vs. managed forest units in the Terai Conservation Area (TCA) in northern Uttar Pradesh state, India. We quantified the relative abundance of 15 mammals of conservation concern from dung counts in vegetation sampling plots within 122 sample patches in 13 vegetation types and 4 management units. Assemblages of species differed both among vegetation types and among management units. Species assemblages in the two protected areas differed strongly from those in two managed forests. Grasslands in protected areas were the most species diverse among vegetation types and had several indicator species. Protected forests were dominated by chital (Axis axis) and nilgai (Boselaphus tragocamelus) in a second species group. A third species group in open grasslands and savannas in managed forests was characterized by cattle (Bos taurus) and Indian hare (Lepus nigricollis). Protected areas clearly are the core conservation area of the TCA for their relatively high habitat value and species diversity, and their protected status minimizes human disturbance. Impacts of human use are high in managed forests, indicating their compromised value for biodiversity conservation. Our simple assessment methodology gives managers a simple way to assess the status of important mammals across landscape conservation units.     

Three fishes in one: cryptic species in an Amazonian floodplain forest specialist

Accurately describing biodiversity in tropical regions such as Amazonia is difficult because of insufficient morphological inventories and the lack of studies on the distribution of genetic diversity. Aquatic organisms from Amazonian flooded forests are generally expected to move laterally along the forests during the annual inundation cycle, a behaviour that should promote admixture of populations and reduce within‐drainage speciation. We used an unprecedented fine‐scale sampling effort and multiple DNA markers to quantify region‐wide population differentiation in an Amazonian floodplain forest specialist, the black‐wing hatchet fish Carnegiella marthae ( Myers, 1927 ). Our study revealed three previously unsuspected and ancient cryptic species of black‐wing hatchet fish in the Rio Negro floodplain (RNF), in central Amazonia. Two species produce occasional first‐generation hybrids. The third and rarer species, although found in extreme sympatry with another species, appears to be reproductively isolated, and also differs in external morphology and dentition. Our findings have important implications for guiding conservation management because C. marthae is harvested commercially in the RNF ornamental fishery. They also suggest that the diversity of Amazonian ichthyofauna is vastly underestimated, including that found in landscapes lacking contemporary barriers to account for population divergence and speciation. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102 , 391–403.     

Contrasting effects of mosaic structure on alpha and beta diversity of bird assemblages in a human‐modified landscape

Habitat loss and fragmentation are key processes causing biodiversity loss in human‐modified landscapes. Knowledge of these processes has largely been derived from measuring biodiversity at the scale of ‘within‐habitat’ fragments with the surrounding landscape considered as matrix. Yet, the loss of variation in species assemblages ‘among’ habitat fragments (landscape‐scale) may be as important a driver of biodiversity loss as the loss of diversity ‘within’ habitat fragments (local‐scale). We tested the hypothesis that heterogeneity in vegetation cover is important for maintaining alpha and beta diversity in human‐modified landscapes. We surveyed bird assemblages in eighty 300‐m‐long transects nested within twenty 1‐km² vegetation ‘mosaics’, with mosaics assigned to four categories defined by the cover extent and configuration of native eucalypt forest and exotic pine plantation. We examined bird assemblages at two spatial scales: 1) within and among transects, and 2) within and among mosaics. Alpha diversity was the mean species diversity within‐transects or within‐mosaics and beta diversity quantified the effective number of compositionally distinct transects or mosaics. We found that within‐transect alpha diversity was highest in vegetation mosaics defined by continuous eucalypt forest, lowest in mosaics of continuous pine plantation, and at intermediate levels in mosaics containing eucalypt patches in a pine matrix. We found that eucalypt mosaics had lower beta diversity than other mosaic types when ignoring relative abundances, but had similar or higher beta diversity when weighting with species abundances. Mosaics containing both pine and eucalypt forest differed in their bird compositional variation among transects, despite sharing a similar suite of species. This configuration effect at the mosaic scale reflected differences in vegetation composition among transects. Maintaining heterogeneity in vegetation cover could help to maintain variation among bird assemblages across landscapes, thus partially offsetting local‐scale diversity losses due to fragmentation. Critical to this is the retention of remnant native vegetation.     

Restricted-Range Fishes and the Conservation of Brazilian Freshwaters

Background

Freshwaters are the most threatened ecosystems on earth. Although recent assessments provide data on global priority regions for freshwater conservation, local scale priorities remain unknown. Refining the scale of global biodiversity assessments (both at terrestrial and freshwater realms) and translating these into conservation priorities on the ground remains a major challenge to biodiversity science, and depends directly on species occurrence data of high taxonomic and geographic resolution. Brazil harbors the richest freshwater ichthyofauna in the world, but knowledge on endemic areas and conservation in Brazilian rivers is still scarce.

Methodology/Principal Findings

Using data on environmental threats and revised species distribution data we detect and delineate 540 small watershed areas harboring 819 restricted-range fishes in Brazil. Many of these areas are already highly threatened, as 159 (29%) watersheds have lost more than 70% of their original vegetation cover, and only 141 (26%) show significant overlap with formally protected areas or indigenous lands. We detected 220 (40%) critical watersheds overlapping hydroelectric dams or showing both poor formal protection and widespread habitat loss; these sites harbor 344 endemic fish species that may face extinction if no conservation action is in place in the near future.

Conclusions/Significance

We provide the first analysis of site-scale conservation priorities in the richest freshwater ecosystems of the globe. Our results corroborate the hypothesis that freshwater biodiversity has been neglected in former conservation assessments. The study provides a simple and straightforward method for detecting freshwater priority areas based on endemism and threat, and represents a starting point for integrating freshwater and terrestrial conservation in representative and biogeographically consistent site-scale conservation strategies, that may be scaled-up following naturally linked drainage systems. Proper management (e. g. forestry code enforcement, landscape planning) and conservation (e. g. formal protection) of the 540 watersheds detected herein will be decisive in avoiding species extinction in the richest aquatic ecosystems on the planet.     

Fast evolutionary response of house mice to anthropogenic disturbance on a Sub‐Antarctic island

Invasions and anthropogenic disturbances challenge species with rapid environmental changes. Understanding how organisms respond to these changes is of major concern for the future of biodiversity. The house mouse on a Sub‐Antarctic island (Guillou Island, Kerguelen Archipelago) had to face such challenges twice: first when invading the island two centuries ago; and nowadays when coping with an in‐depth remodeling of its habitat due to a cohort of anthropogenic changes. Morphometric and biomechanical results show that the initial invasion triggered the evolution of a jaw shape adapted to the local food resources. Contemporary changes are also associated to changes in jaw morphology, but are not directly functionally relevant. Here, a complex response integrating feeding behaviour, investment in feeding structure, and degree of mineralization, may provide the mice with a better tool to benefit of wider resources utilization and/or better cope with intra‐specific competition in a changing habitat. These Sub‐Antarctic mice exemplify that success of invasive species rely on the capacity of facing rapidly varying environments through integrated, multi‐faceted responses involving behaviour to morphology through life‐history traits. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 114 , 513–526.     

Partitioning the diversity of riverine fish: the roles of habitat types and non-native species

1. Quantifying how biological diversity is distributed in the landscape is one of the central themes of conservation ecology. For this purpose, landscape classifications are being intensively used in conservation planning and biodiversity management, although there is still little information about their efficacy. 2. I used data from 158 running water sites in Hungary to examine the contribution of six a priori established habitat types to regional level diversity of fish assemblages. Three community measures [species richness, diversity (Shannon, Simpson indices), assemblage composition] were examined at two assemblage levels (entire assemblage, the native assemblage). The relative role of non‐native species was quantified to examine their contribution to patterns in diversity in this strongly human influenced landscape. 3. Additive diversity partitioning revealed the primary importance of beta diversity (i.e. among‐site factors) to patterns in species richness. Landscape‐scale patterns in species richness were best explained by between‐habitat type (beta₂: 41.2%), followed by within‐habitat type (beta₁: 37.7%) and finally within‐site (alpha: 21.1%) diversity. Diversity indices showed patterns different from species richness, indicating the importance of relative abundance distributions on the results. Exclusion of non‐natives from the analysis gave similar results to the entire‐assemblage level analysis. 4. Canonical analysis of principal coordinates, complemented with indicator species analysis justified the separation of fish assemblages among the habitat types, although classification error was high. Multivariate dispersion, a measure of compositional beta diversity, showed significant differences among the habitat types. Contrary to species diversity (i.e. richness, diversity indices), patterns in compositional diversity were strongly influenced by the exclusion of non‐natives from the analyses. 5. This study is the first to quantify how running water habitat types contribute to fish diversity at the landscape scale and how non‐native species influence this pattern. These results on riverine fish assemblages support the hypothesis that environmental variability (i.e. the diversity of habitat types) is an indication of biodiversity and can be used in large‐scale conservation designs. The study emphasises the joint application of additive diversity partitioning and multivariate statistics when exploring the contribution of landscape components to the overall biodiversity of the landscape mosaic.     

Influence of fine‐scale habitat requirements and riparian degradation on the distribution of the purple‐crowned fairy‐wren (Malurus coronatus coronatus) in northern Australia

Species distributions are influenced by variation in environmental conditions across many scales. Knowledge of fine‐scale habitat requirements is important for predicting species occurrence and identifying suitable habitat for target species. Here we investigate the perplexing distribution of a riparian habitat specialist, the western subspecies of the purple‐crowned fairy‐wren (Malurus coronatus coronatus), in relation to fine‐scale habitat associations and patterns of riparian degradation. Surveys of vegetation attributes, river structure and disturbance indicators that are likely to be causal determinants of the species occurrence were undertaken at 635 sites across 14 catchments. Generalized Linear Mixed Modelling demonstrated that the probability of purple‐crowned fairy‐wren occurrence increased with Pandanus aquaticus crown cover, shrub density and height of emergent trees, while riparian structure and signs of cattle were indirect predictors of occurrence. As our study area predominantly contained Pandanus type habitat, we failed to identify river grass as an important component of habitat. Predictions from a cross‐validated model of purple‐crowned fairy‐wren occurrence suggested distribution is constrained by three factors: (i) low quality of local habitat within catchments where the species occurs; (ii) broad‐scale reduction in habitat quality that has resulted in extinction of the species from parts of its range; and (iii) unmeasured variables that limit the exploitation of suitable habitat. The reliance of the species on dense shrubby understorey suggests conservation efforts should aim to maintain the complexity of understorey structure by managing fire and grazing intensity. Efforts to halt the continuing decline of riparian condition and maintain connectivity between areas of quality habitat will help to ensure persistence of riparian habitat specialists in northern Australia.     

Scale‐dependent occupancy patterns in reptiles across topographically different landscapes

Understanding what factors influence species occupancy in human‐modified landscapes is a central theme in ecology. We examined scale‐dependent habitat relationships and site occupancy in reptiles across three topographically different study areas in south‐eastern Australia. We collected presence–absence data on reptiles from 443 sites associated with three long‐term biodiversity monitoring programs, on four to seven occasions, between 2001 and 2013. We characterised sites by the following four variable domains: 1) field design, 2) topography, 3) local‐scale vegetation attributes and 4) landscape‐scale vegetation cover. We constructed occupancy models for 14 species and used an information‐theoretic approach to compare multiple alternative hypotheses to explain occupancy within and between study areas. We modelled detection probability and used the model with the lowest AIC in subsequent analyses. We then modelled occupancy probability against all subsets of the variable groups (field design, topography, local‐ and landscape‐scale vegetation), as well as a model that held occupancy constant (null model). We found that local‐scale vegetation attributes were important for explaining site occupancy in 12/19 possible models, although, in several cases model fit was improved by the addition of topographic variables or native vegetation cover in the surrounding landscape. Occupancy models for widespread species were broadly congruent across study areas. We demonstrate that topographic variables are important for explaining reptile occupancy in hilly landscapes, and local‐ and landscape‐scale variables are important for explaining reptile occupancy in flat or gently undulating landscapes. Management actions that improve habitat complexity at a site‐level, and encompass entire topographic gradients, will have greater benefit to woodland reptiles than simply increasing vegetation cover in the surrounding landscape.     

The conservation of arboreal marsupials in the Albury‐Wodonga region of south‐eastern Australia

Urban expansion is a major cause of land use change and presents a significant threat to biodiversity worldwide. Agricultural land is often acquired by local councils and developers to expand urban growth boundaries and establish new housing estates. However, many agricultural landscapes support high biodiversity values, especially farmlands that feature mosaics of native vegetation and keystone habitat such as hollow‐bearing trees. In south‐eastern Australia, many arboreal marsupials including the threatened Squirrel Glider (Petaurus norfolcensis) have populations within peri‐urban zones of expanding rural cities. A key challenge to planners, developers and conservation organisations is the need to maintain habitat for locally rare and threatened species as land undergoes changes in management. Critical to the sustainable development of peri‐urban landscapes is a thorough understanding of the distribution, habitat requirements and resources available to maintain and improve habitat for species dependent on limited resources such as tree cavities. In this management report, we present background information on an integrated research programme designed to evaluate potential impacts of urban development on fauna in the Albury Local Government Area, NSW. We mapped hollow‐bearing trees, erected nest boxes and monitored arboreal marsupials. Information presented in this report provides a blueprint for monitoring arboreal marsupials, including threatened species in other developing regions, and will assist the Albury‐Wodonga local governments in future planning of sustainable living environments.     

Objectives versus realities: Spatial,temporal, financial and social deficiencies in Australia’s public revegetation investment model

Past and continuing fragmentation and modification of ecosystems, as well as other threatening processes, cause ongoing biodiversity losses and species extinctions in Australia. At the same time as biodiversity declines, government funding for conservation and restoration is diminishing, leading to reduced action and greater reliance on private investment and community groups. In order to maintain and restore biodiverse ecosystems and the essential services they provide, both conservation of existing vegetation and habitat reconstruction are required. In this paper, we summarise the available data on planting area and cost from the Australian Government’s 20 Million Trees programme (2014–2020), the largest recent national‐scale revegetation incentives programme in Australia. We find that the current spatial scale of effort and investment in habitat reconstruction is insufficient to match the scale required to meet national conservation objectives. Furthermore, the funding rate ($/ha) and contracting arrangements are inadequate for the establishment of high‐quality self‐sustaining vegetation needed for the recovery of Australia’s threatened species and ecological communities. We estimate that the minimum amount of funding required for habitat reconstruction is at least five times higher than is provided for current national flagship programmes such as 20 Million Trees. We provide recommendations, designed to assist future habitat reconstruction programmes achieve their long‐term biodiversity objectives.     

Spatially explicit models of seasonal habitat for greater sage‐grouse at broad spatial scales: Informing areas for management in Nevada and northeastern California

Defining boundaries of species' habitat across broad spatial scales is often necessary for management decisions, and yet challenging for species that demonstrate differential variation in seasonal habitat use. Spatially explicit indices that incorporate temporal shifts in selection can help overcome such challenges, especially for species of high conservation concern. Greater sage‐grouse Centrocercus urophasianus (hereafter, sage‐grouse), a sagebrush obligate species inhabiting the American West, represents an important case study because sage‐grouse exhibit seasonal habitat patterns, populations are declining in most portions of their range and are central to contemporary national land use policies. Here, we modeled spatiotemporal selection patterns for telemetered sage‐grouse across multiple study sites (1,084 sage‐grouse; 30,690 locations) in the Great Basin. We developed broad‐scale spatially explicit habitat indices that elucidated space use patterns (spring, summer/fall, and winter) and accounted for regional climatic variation using previously published hydrographic boundaries. We then evaluated differences in selection/avoidance of each habitat characteristic between seasons and hydrographic regions. Most notably, sage‐grouse consistently selected areas dominated by sagebrush with few or no conifers but varied in type of sagebrush selected by season and region. Spatiotemporal variation was most apparent based on availability of water resources and herbaceous cover, where sage‐grouse strongly selected upland natural springs in xeric regions but selected larger wet meadows in mesic regions. Additionally, during the breeding period in spring, herbaceous cover was selected strongly in the mesic regions. Lastly, we expanded upon an existing joint–index framework by combining seasonal habitat indices with a probabilistic index of sage‐grouse abundance and space use to produce habitat maps useful for sage‐grouse management. These products can serve as conservation planning tools that help predict expected benefits of restoration activities, while highlighting areas most critical to sustaining sage‐grouse populations. Our joint–index framework can be applied to other species that exhibit seasonal shifts in habitat requirements to help better guide conservation actions.     

Habitat Selection by the Spur-thighed Tortoise Testudo graeca in a Multisuccessional Landscape: Implications for Habitat Management

As a result of human activities, natural Mediterranean landscapes (including agro-ecosystems) are characterised by a mosaic-like structure with habitat-patches at different successional stages. These systems have high biodiversity levels and are home to a large number of species protected by European laws whose habitats should be adequately managed. In the present work, we study habitat use from an applied point of view in the spur-thighed tortoise Testudo graeca, an endangered reptile present in semi-arid Mediterranean agro-ecosystems. Results show that, at a landscape scale, the species selects simplified vegetation structures and includes in its home range re-colonisation shrubland and small non-irrigated fields. Within the home range, habitat selection patterns vary and areas with higher vegetation cover and complexity are selected. Detected patterns are discussed in terms of the ecological requirements of the species and with a hierarchical view of resources and conditions. The implications of our findings for habitat management aimed at the conservation of the species are also discussed.     

Ecological and biodiversity gradients across alpine dry grassland habitats: implications for an endangered species

Dry grasslands are of great interest for nature conservation in Europe, because they have a central role in the conservation of numerous rare and endangered species. In this study carried out in the Brenta mountain group (Italian alps), we investigated the effect of environmental factors mainly controlled by topography, on the biodiversity trends across different dry grassland habitats where the threatened alpine stenoendemic Erysimum aurantiacum grows. Plant community data and ecological factors were analysed by means of a multi‐habitat CCA approach and by analysis of biodiversity gradients in 7 natural and semi‐natural habitats. We found that species turnover and biodiversity patterns vary as a function of multi‐factorial ecological gradients. For the single habitats, elevation gradient was the main factor explaining compositional variation, followed by inclination and proportion of exposed rock surface. Despite its endangered status, E. aurantiacum showed a relatively high degree of ecological plasticity across these semiarid grassland habitats that probably allows it to survive in different environments, including in some cases those impacted by human activities. This prompts for habitat‐ more than species‐level conservation actions. According to their characteristics and threats, habitat‐specific management practices are recommended for long term conservation of plant species communities in the different ecological niches.     

Morphological variation in the Cape Dwarf Chameleon (Bradypodion pumilum) as a consequence of spatially explicit habitat structure differences

An organism's phenotype is to some extent influenced by costs and benefits in terms of natural and sexual selection. The intensity of natural selection can in part be driven by habitat structure, which may result in varying levels of crypsis and/or selection on traits related to maximizing performance in that habitat. This may be countered by sexual selection, which can lead to sexual dimorphism in body size and/or the expression of conspicuous ornamentation relating to maximizing reproductive success. The intensity of these forces can also be different between the sexes, resulting in complex patterns of phenotypic variation. With this in mind, we examined morphological variation within the Cape Dwarf Chameleon, Bradypodion pumilum. The species inhabits two geographically disjunct habitat types and, in the present study, we demonstrate that chameleons from the two habitats show morphological differences. Large, conspicuous individuals inhabit closed vegetation, whereas small, drab individuals inhabit open vegetation. However, when morphological traits are size‐adjusted, the open vegetation morph displays many traits that are larger for its body size than the closed vegetation morph, especially for characters related to locomotion (limbs) and bite force (head width). Sexual dimorphism is also present, although the degree and number of dimorphic characters was very different between the two morphs, with size‐adjusted male‐biased dimorphism much more pronounced in the closed morph. Overall, our findings suggest that natural selection in open habitats limits both body size and conspicuous characters, although sexual selection in closed habitats favours the development of ornamentation related to display. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102 , 878–888.     

Vegetation structure and ground cover attributes describe the occurrence of a newly discovered carnivorous marsupial on the Tweed Shield Volcano caldera,the endangered black‐tailed dusky antechinus (Antechinus arktos)

The black‐tailed dusky antechinus (Antechinus arktos) is a recently discovered, endangered, carnivorous marsupial mammal endemic to the Tweed Shield Volcano caldera, straddling the border between Queensland and New South Wales in eastern Australia. The species' preference for cool, high‐altitude habitats makes it particularly vulnerable to a shifting climate as these habitats recede. Aside from basic breeding and dietary patterns, the species' ecology is largely unknown. Understanding fine‐scale habitat attributes preferred by this endangered mammal is critical to employ successful conservation management. Here, we assess vegetation attributes of known habitats over three sites at Springbrook and Border Ranges National Parks, including detailed structure data and broad floristic assessment. Floristic compositional assessment of the high‐altitude cloud rainforest indicated broad similarities. However, only 22% of plant species were shared between all sites indicating a high level of local endemism. This suggests a diverse assemblage of vegetation across A. arktos habitats. Habitat characteristics were related to capture records of A. arktos to determine potential fine‐scale structural habitat requirements. Percentage of rock cover and leaf litter were the strongest predictors of A. arktos captures across survey sites, suggesting a need for foraging substrate and cover. Habitat characteristics described here will inform predictive species distribution models of this federally endangered species and are applicable to other mammal conservation programs.     

The nest predator community of grassland birds responds to agroecosystem habitat at multiple scales

Nest predation is the leading cause of reproductive failure for grassland birds of conservation concern. Understanding variation in nest predation rates is complicated by the diverse assemblage of species known to prey on nests. As part of a long‐term study of grassland bird ecology, we monitored populations of predators known to prey on grassland bird nests. We used information theoretic approach to examine the predator community's association with habitat at multiple scales, including local vegetation structure of grassland patches, spatial attributes of grassland patches (size and shape), and landscape composition surrounding grassland patches (land cover within 400 and 1600 m). Our results confirmed that nest predators respond to habitat at multiple scales and different predator species respond to habitat in different ways. The most informative habitat models we selected included variability in local vegetation (CV in the density of forbs), local patch (area and edge‐to‐interior ratio), and landscape within a 1600 m buffer around grasslands (percent of land covered by human structures and development). As a separate question, we asked if models that incorporated information from multiple scales simultaneously might improve the ability to explain variation in the predator community. Multi‐ scale models were not consistently superior to models derived from variables focused at a single spatial scale. Our results suggest that minimizing human development on and surrounding conservation land and the management of the vegetation structure on grassland fragments both may benefit grassland birds by decreasing the risk of nest predation.