bluuebunny/crossref_metadata_2025 huggingface dataset:
Limited phylogeographic structure in the flightless ground beetle, Calathus ruficollis, in southern California
Authors: Chatzimanolis Stylianos , Caterino Michael S.
Published: February 2009

The California Floristic Province is home to more than 8000 species of beetles, yet their geographical patterns of supra‐ and infraspecific diversity remain largely unexplored. In this paper, we investigate the phylogeography and population demographics of a flightless ground beetle, Calathus ruficollis (Coleoptera: Carabidae), in southern California. We sampled 136 specimens from 25 localities divided into 10 populations using a fragment of the mitochondrial cytochrome oxidase I gene. We tested several hypotheses, including the association of geography with particular clades and populations, the degree of differentiation among regions, and the expansion of populations. Parsimony and Bayesian phylogenetic analyses along with nested clade analysis and amova indicate a deep split between the southern Sierra Nevada population and populations south and west. This split corresponds closely to the split between subspecies C. ruficollis ignicollis (southern Sierra Nevada) and C. ruficollis ruficollis. Populations otherwise exhibit limited geographical structure, though Fst values indicate some local differentiation. Mismatch distributions and Fu's Fs indicate range expansion of several populations, suggesting that some structure may have been obscured by recent exchange. The population of C. ruficollis on Santa Cruz Island, which might have been expected to be isolated, shares several haplotypes with mainland populations, appearing to represent multiple colonizations.
Can more K‐selected species be better invaders? A case study of fruit flies in La Réunion
Authors: Duyck Pierre‐François , David Patrice , Quilici Serge
Published: February 2009

Invasive species are often said to be r‐selected. However, invaders must sometimes compete with related resident species. In this case invaders should present combinations of life‐history traits that give them higher competitive ability than residents, even at the expense of lower colonization ability. We test this prediction by comparing life‐history traits among four fruit fly species, one endemic and three successive invaders, in La Réunion Island. Recent invaders tend to produce fewer, but larger, juveniles, delay the onset but increase the duration of reproduction, survive longer, and senesce more slowly than earlier ones. These traits are associated with higher ranks in a competitive hierarchy established in a previous study. However, the endemic species, now nearly extinct in the island, is inferior to the other three with respect to both competition and colonization traits, violating the trade‐off assumption. Our results overall suggest that the key traits for invasion in this system were those that favoured competition rather than colonization.
Sandy beaches at the brink
Authors: Schlacher Thomas A. , Dugan Jenifer , Schoeman Dave S. , Lastra Mariano , Jones Alan , Scapini Felicita , McLachlan Anton , Defeo Omar
Published: February 2009

Sandy beaches line most of the world's oceans and are highly valued by society: more people use sandy beaches than any other type of shore. While the economic and social values of beaches are generally regarded as paramount, sandy shores also have special ecological features and contain a distinctive biodiversity that is generally not recognized. These unique ecosystems are facing escalating anthropogenic pressures, chiefly from rapacious coastal development, direct human uses — mainly associated with recreation — and rising sea levels. Beaches are increasingly becoming trapped in a ‘coastal squeeze’ between burgeoning human populations from the land and the effects of global climate change from the sea. Society's interventions (e.g. shoreline armouring, beach nourishment) to combat changes in beach environments, such as erosion and shoreline retreat, can result in severe ecological impacts and loss of biodiversity at local scales, but are predicted also to have cumulative large‐scale consequences worldwide. Because of the scale of this problem, the continued existence of beaches as functional ecosystems is likely to depend on direct conservation efforts. Conservation, in turn, will have to increasingly draw on a consolidated body of ecological theory for these ecosystems. Although this body of theory has yet to be fully developed, we identify here a number of critical research directions that are required to progress coastal management and conservation of sandy beach ecosystems.
Spatial scale and evolutionary history determine the degree of taxonomic homogenization across island bird assemblages
Authors: Cassey Phillip , Lockwood Julie L. , Blackburn Tim M. , Olden Julian D.
Published: February 2009

It is widely documented that human activities have elevated the extirpation of natural populations as well as the successful introduction to new areas of non‐native species. These dual processes of introduction and extirpation can change the similarity of communities, but the direction and magnitude these changes take are likely to depend on the manner in which introductions and extirpations occur, the spatial scale at which the changes are measured, and the initial similarity of the communities before the human‐induced drivers occurred. Here, we explore patterns of extirpation and introduction and their influence on the similarity of global oceanic island bird assemblages from four different Oceans (Atlantic, Caribbean, Indian, Pacific). We show that different historical patterns of introduction and extirpation have produced varying trends in compositional similarity both between islands within archipelagos and between islands across different archipelagos within the same ocean. Patterns of bird assemblage convergence (i.e. taxonomic homogenization) or divergence (i.e. taxonomic differentiation) among islands depended on the scale of examination, the evolutionary associations among species of the region, and the cultural history of human colonization. These factors are all likely to be leading to a series of multiple interacting processes that are shaping the complex compositional changes observed among global island bird faunas over time.
Squamate richness in the Brazilian Cerrado and its environmental–climatic associations
Authors: Costa Gabriel C. , Nogueira Cristiano , Machado Ricardo B. , Colli Guarino R.
Published: February 2009

We investigate patterns of species richness of squamates (lizards, snakes, and amphisbaenians) in the Brazilian Cerrado, identifying areas of particularly high richness, and testing predictions of large‐scale richness hypotheses by analysing the relationship between species richness and environmental climatic variables. We used point localities from museum collections to produce maps of the predicted distributions for 237 Cerrado squamate species, using niche‐modelling techniques. We superimposed distributions of all species on a composite map, depicting richness across the ecosystem. Then, we performed a multiple regression analysis using eigenvector‐based spatial filtering (Principal Coordinate of Neighbour Matrices) to assess environmental–climatic variables that are best predictors of species richness. We found that the environmental–climatic and spatial filters multiple regression model explained 78% of the variation in Cerrado squamate richness (r2 = 0.78; F = 32.66; P < 0.01). Best predictors of species richness were: annual precipitation, precipitation seasonality, altitude, net primary productivity, and precipitation during the driest quarter. A model selection approach revealed that several mechanisms related to the different diversity hypothesis might work together to explain richness variation in the Cerrado. Areas of higher species richness in Cerrado were located mainly in the south‐west, north, extreme east, and scattered areas in the north‐west portions of the biome. Partitioning of energy among species, habitat differentiation, and tolerance to variable environments may be the primary ecological factors determining variation in squamate richness across the Cerrado. High richness areas in northern Cerrado, predicted by our models, are still poorly sampled, and biological surveys are warranted in that region. The south‐western region of the Cerrado exhibits high species richness and is also undergoing high levels of deforestation. Therefore, maintenance of existing reserves, establishment of ecological corridors among reserves, and creation of new reserves are urgently needed to ensure conservation of species in these areas.
Introduction history and invasion success in exotic vines introduced to Australia
Authors: Harris Carla J. , Murray Brad R. , Hose Grant C. , Hamilton Mark A.
Published: February 2009

The ecological damage caused by invasive vines poses a considerable threat to many natural ecosystems. However, very little data are available for this potentially environmentally destructive functional group in Australia. In order to address this paucity of information, we assembled the first inventory of exotic vines that have become established in natural ecosystems across Australia. The influence that introduction history attributes, variables that relate to the introduction of a species to a new area, may have on the occurrence and distribution of exotic vines was also determined. We asked whether the continent of origin, reason for introduction, and residence time related to the prevalence and distribution of exotic vines across Australia. A total of 179 exotic climbing plant species from 40 different families were found to have become established across continental Australia. However, five families accounted for over 50% of these species. Most exotic vines originated from South America, and were introduced for ornamental purposes. The length of time in which an exotic vine had been present in its new range was significantly related to its distribution, with a positive relationship found between residence time and area of occupancy across the continent. No other introduction history attribute was significantly related to the area of occupancy, or distribution, of a species. This suggests that while the trends found among introduction history attributes are important in explaining the prevalence of exotic vines in Australia, only residence time is currently a useful predictor of their future success.
Priority sites for conservation of land snails in Gabon: testing the umbrella species concept
Authors: Fontaine Benoît , Gargominy Olivier , Neubert Eike
Published: February 2009

In order to assess the potential for molluscan conservation of a protected area considered representative of regional megafauna, we sampled molluscs inside and outside Lopé National Park in Gabon. In the northern part of Lopé National Park, 116 stations were surveyed and 71 species collected. Outside the park, 37 stations yielded 96 species, including 71 in Lastoursville, a small limestone area where molluscs are significantly more abundant than in other collecting sites. Lastoursville is among the richest sites known for molluscs in Africa. Overlap between sampling areas was limited, with 20.0% of the species found only in Lopé National Park, and 40.8% of the species found only outside. This suggests that Lopé National Park does not protect the whole molluscan diversity of central Gabon. Given the high levels of allopatric diversity of tropical land snails, conservation strategies cannot be the same for snails and for wide‐ranging vertebrates. Protecting small areas with a high abundance and diversity of molluscs would be less expensive and as efficient for molluscan conservation as protecting large tracts of rainforest. Despite limited general knowledge of central African molluscs, robust estimates of site‐specific diversity can be produced. Limestone areas harbour a remarkable biodiversity: sites such as Lastoursville would be ideal candidates for small protected areas dedicated to the conservation of land snails, and would complement the role of large protected areas.
Prediction and validation of the potential global distribution of a problematic alien invasive species — the American bullfrog
Authors: Ficetola Gentile Francesco , Thuiller Wilfried , Miaud Claude
Published: February 2009

Predicting the probability of successful establishment and invasion of alien species at global scale, by matching climatic and land use data, is a priority for the risk assessment. Both large‐ and local‐scale factors contribute to the outcome of invasions, and should be integrated to improve the predictions. At global scale, we used climatic and land use layers to evaluate the habitat suitability for the American bullfrogRana catesbeiana, a major invasive species that is among the causes of amphibian decline. Environmental models were built by using Maxent, a machine learning method. Then, we integrated global data with information on richness of native communities and hunting pressure collected at the local scale. Global‐scale data allowed us to delineate the areas with the highest suitability for this species. Predicted suitability was significantly related to the invasiveness observed for bullfrog populations historically introduced in Europe, but did not explain a large portion of variability in invasion success. The integration of data at the global and local scales greatly improved the performance of models, and explained > 57% of the variance in introduction success: bullfrogs were more invasive in areas with high suitability and low hunting pressure over frogs. Our study identified the climatic factors entailing the risk of invasion by bullfrogs, and stresses the importance of the integration of biotic and abiotic data collected at different spatial scales, to evaluate the areas where monitoring and management efforts need to be focused.
Invasive plants and their ecological strategies: prediction and explanation of woody plant invasion in New England
Authors: Herron Patrick M. , Martine Christopher T. , Latimer Andrew M. , Leicht‐Young Stacey A.
Published: February 2009

Effective management of introduced species requires the early identification of species that pose a significant threat of becoming invasive. To better understand the invasive ecology of species in New England, USA, we compiled a character data set with which to compare non‐native species that are known invaders to non‐native species that are not currently known to be invasive. In contrast to previous biological trait‐based models, we employed a Bayesian hierarchical analysis to identify sets of plant traits associated with invasiveness for each of three growth forms (vines, shrubs, and trees). The resulting models identify a suite of ‘invasive traits’ highlighting the ecology associated with invasiveness for each of three growth forms. The most effective predictors of invasiveness that emerged from our model were ‘invasive elsewhere’, ‘fast growth rate’, ‘native latitudinal range’, and ‘growth form’. The contrast among growth forms was pronounced. For example, ‘wind dispersal’ was positively correlated with invasiveness in trees, but negatively correlated in shrubs and vines. The predictive model was able to correctly classify invasive plants 67% of the time (22/33), and non‐invasive plants 95% of the time (204/215). A number of potential future invasive species in New England that deserve management consideration were identified.
Plant families as predictors of plant biodiversity in Mexico
Authors: Villaseñor José Luis , Maeda Pedro , Rosell Julieta A. , Ortiz Enrique
Published: February 2009

Three speciose plant families (Asteraceae, Fabaceae s.l., and Poaceae) are evaluated for their appropriateness as predictors of overall regional patterns of plant diversity in Mexico. These families fulfil criteria for usefulness as indicators advocated by several authors, such as adequate taxonomic knowledge, wide geographical distribution, and occurrence in different plant communities. Known richness was determined from a database including 17,903 species from floristic inventories, review of taxonomic literature, and the study of herbarium specimens. Mexico was divided into 253 cells, each 1° latitude by 1° longitude; for each cell, total plant diversity and number of species in each predictor's family were determined. In addition, each species was categorized by ‘preferred’ vegetation type (temperate forest, dry tropical forest, humid tropical forest, xerophytic scrubland). Both multiple and simple regression models show that the three families are good predictors of total vascular floristic richness. Fabaceae s.l. has the highest semipartial correlations for all multiple models except with the xerophytic scrubland data set, for which it shares the highest values with Poaceae. Univariate models also predict satisfactorily the vascular floristic richness, especially when Fabaceae s.l. is used as the predictor, and the effect of vegetation type is included. Our results indicate that these three families can be used as potential predictors for total vascular plant species richness in Mexico although Fabaceae s.l. is the best predictor.
La Niña's signature: synchronous decline of the mammal community in a ‘protected’ area in India
Authors: Waite T. A. , Campbell L. G. , Chhangani A. K. , Robbins P.
Published: February 2009

Mounting evidence indicates large‐scale climatic phenomena such as El Niño Southern Oscillation (ENSO) can overwhelm endogenous factors that govern the population dynamics of wild species. We add to this evidence by documenting an ENSO‐related decline of large mammals in the Kumbhalgarh Wildlife Sanctuary, in Rajasthan, India. This event coincided with the drought of 2000, following two consecutive monsoon failures. Time series of biennial counts (1991–2005) shared a common feature: all 13 species declined in abundance from 1999 to 2001, with 11 species experiencing an apparent decline exceeding 25%. An ENSO index explained much of the variability in population size, apparently reflecting mass mortality and/or recruitment failure caused by the major 1998–2000 La Niña event, followed by a rapid rebound. ENSO apparently overwhelmed endogenous factors and synchronized the dynamics of the mammalian community. Our findings may prove to be symptomatic of geographically broad impacts of large‐scale climate on the dynamics of terrestrial vertebrate communities, even in protected areas. Our findings reinforce the growing recognition that we should not overlook global‐scale causal agents of ecological change.
Modelling ecological niches from low numbers of occurrences: assessment of the conservation status of poorly known viverrids (Mammalia, Carnivora) across two continents
Authors: Papeş M. , Gaubert P.
Published: February 2009

The conservation of poorly known species is difficult because of incomplete knowledge on their biology and distribution. We studied the contribution of two ecological niche modelling tools, the Genetic Algorithm for Rule‐set Prediction (GARP) and maximum entropy (Maxent), in assessing potential ranges and distributional connectivity among 12 of the least known African and Asian viverrids. The level of agreement between GARP and Maxent predictions was low when < 15 occurrences were available, probably indicating a minimum number below that necessary to obtain models with good predictive power. Unexpectedly, our results suggested that Maxent extrapolated more than GARP in the context of small sample sizes. Predictions were overlapped with current land use and location of protected areas to estimate the conservation status of each species. Our analyses yielded range predictions generally contradicting with extents of occurrence established by the IUCN. We evidenced a high level of disturbance within predicted distributions in West and East Africa, Sumatra, and South‐East Asia, and identified within West African degraded lowlands four relatively preserved areas that might be of prime importance for the conservation of rainforest taxa. Knowing whether these species of viverrids may survive in degraded or alternative habitats is of crucial importance for further conservation planning. The level of coverage of species suitable ranges by existing and proposed IUCN reserves was low, and we recommend that the total surface of protected areas be substantially increased on both continents.
Bryophyte diversity and distribution along an altitudinal gradient on a lava flow in La Réunion
Authors: Ah‐Peng Claudine , Chuah‐Petiot Min , Descamps‐Julien Blandine , Bardat Jacques , Stamenoff Pierre , Strasberg Dominique
Published: February 2009

Non‐vascular plant distribution patterns were examined in three microhabitats along an altitudinal gradient on a recent lava flow of the Piton de la Fournaise volcano (La Réunion, Mascarene archipelago). The uniform nature of the lava flow provides an excellent system to study the relationship between altitude and species diversity and distribution, and at the same time avoiding confusing multiple effects of substrate and vegetation heterogeneity. Non‐vascular plants were surveyed with quadrats within an altitudinal range from 250 m to 850 m a.s.l. Fine‐scale variations in bryophyte communities between three ecological microhabitats (the ground and on the rachises of two fern species) were investigated. Three specific questions were addressed: (1) What is the species diversity of bryophyte communities on a 19‐year‐old lava flow? (2) How does altitude influence the diversity and distribution of bryophytes on a lava flow? (3) Does microhabitat variation control bryophyte diversity? In our study, bryophyte diversity increased with altitude. Unexpectedly, species richness was very high; 70 species of bryophytes were recorded including nine new records for the island. Diversity was also controlled by ecological microhabitats. Bryophyte species were structured into six categories according to altitude and microhabitat preferences. Results suggested that the high diversity of these cryptic organisms on this lava flow is fostered in part by their host substrate and their adaptative strategies on new substrates. On a broader scale, it was concluded that lava flows as primary mineral environments are important to conserve, as they support a high diversity of pioneer organisms that constitute the early stages of the development of La Réunion's remnant lowland rainforest.
Dynamics of fish in Australian desert springs: role of large‐mammal disturbance
Authors: Kodric‐Brown Astrid , Wilcox Chris , Bragg Jason G. , Brown James H.
Published: February 2009

Human activities affect even the most remote and best preserved places on Earth. One of those places is Dalhousie Springs, Witjira National Park, in the arid centre of Australia. In 2003 we resurveyed the fish communities in springs to document changes since an earlier survey in 1991. Over the 12 years there were 18 population extirpations and only two colonizations, so total occurrences of five native species in 30 springs decreased from 83 to 67 populations. One species, the endemic Dalhousie goby, Chlamydogobius gloveri, accounted for 12 of the 18 population extirpations. Each fish species tended to persist in springs larger than some threshold size. Extirpations were related to spring size, with smaller springs more readily loosing populations, and to major habitat changes, which included large increases in the tropical reed Phragmites and concomitant decreases in open water, disturbed habitats, and dissolved oxygen. Extirpations of fish populations can be attributed primarily to habitat changes associated with reduced disturbance and herbivory as a result of the removal of feral livestock. These changes highlight the keystone impacts of large mammals on habitats and biotas of desert springs, and should be considered in management practices and policy decisions.
Inferring species decline from collection records: roller dung beetles in Italy (Coleoptera, Scarabaeidae)
Authors: Carpaneto Giuseppe Maria , Mazziotta Adriano , Valerio Laura
Published: February 2009

The decline of roller dung beetles (Coleoptera, Scarabaeidae) in Italy, at national and regional level, was described using a database of both literature and unpublished data, since the late of 19th century. The probability of finding roller species was assessed for each decade of the 20th century in order to detect changes in their distribution and status. An analysis of decline was performed using a complementary approach of different extinction indexes, according to IUCN criteria. During the 20th century, both the absolute number of records and the UTM cells where roller beetles were found increased clearly as a consequence of the escalation of entomological surveys. Nevertheless, comparing R species (rollers) with all the scarab dung beetles from the first to the last quarter of the 20th century, the relative frequency of roller records decreased by 31%, while the relative number of occupied UTM cells dropped by 23%. Six roller species showed a significant decline in Italy from the first to the second part of the 20th century, and nine in the last 30years. Other two species disappeared from the majority of the northern regions. Finally, the values of all the extinction indexes were strongly correlated and detected a high risk of extinction in Italy for six species. A gradual change in land use during the last three decades, consisting of a reduced extension of grasslands in favour of either intensive agriculture or reforestation after abandonment of livestock raising, was likely the main factor inducing decline and local extinction of roller species.
Correlates of extinction proneness in tropical angiosperms
Authors: Sodhi Navjot S. , Koh Lian Pin , Peh Kelvin S.‐H. , Tan Hugh T. W. , Chazdon Robin L. , Corlett Richard T. , Lee Tien Ming , Colwell Robert K. , Brook Barry W. , Sekercioglu Cagan H. , Bradshaw Corey J. A.
Published: February 2009

Rapid losses and degradation of natural habitats in the tropics are driving catastrophic declines and extinctions of native biotas, including angiosperms. Determining the ecological and life‐history correlates of extinction proneness in tropical plant species may help reveal the mechanisms underlying their responses to habitat disturbance, and assist in the pre‐emptive identification of species at risk from extinction. We determined the predictors of extinction proneness in 1884 locally extinct (n = 454) and extant (n = 1430) terrestrial angiosperms (belonging to 43 orders, 133 families, and 689 genera) in the tropical island nation of Singapore (699.4 km2), which has lost 99.6% of its primary lowland evergreen rainforest since 1819. A wide variety of traits such as geographical distribution, pollination system, sexual system, habit, habitat, height, fruit/seed dispersal mechanism, and capacity for vegetative re‐sprouting were used in the analysis. Despite controlling for phylogeny (as approximated by family level classification), we found that only a small percentage of the variation in the extinction probability could be explained by these factors. Epiphytic, monoecious, and hermaphroditic species and those restricted to inland forests have higher probabilities of extinction. Species dependent on mammal pollinators also probably have higher extinction probabilities. More comparative studies that use species traits to identify extinction‐prone plant species are needed to guide the enormous, but essential task of identifying species most in need of conservation action.
Do cities export biodiversity? Traffic as dispersal vector across urban–rural gradients
Authors: von der Lippe Moritz , Kowarik Ingo
Published: February 2009

Urban areas are among the land use types with the highes richness in plant species. A main feature of urban floras is the high proportion of non‐native species with often divergent distribution patterns along urban–rural gradients. Urban impacts on plant species richness are usually associated with increasing human activity along rural‐to‐urban gradients. As an important stimulus of urban plant diversity, human‐mediated seed dispersal may drive the process of increasing the similarity between urban and rural floras by moving species across urban–rural gradients. We used long motorway tunnels as sampling sites for propagules that are released by vehicles to test for the impact of traffic on seed dispersal along an urban–rural gradient. Opposite lanes of the tunnels are separated by solid walls, allowing us to differentiate seed deposition associated with traffic into vs. out of the city. Both the magnitude of seed deposition and the species richness in seed samples from two motorway tunnels were higher in lanes leading out of the city, indicating an ‘export’ of urban biodiversity by traffic. As proportions of seeds of non‐native species were also higher in the outbound lanes, traffic may foster invasion processes starting from cities to the surrounding landscapes. Indicator species analysis revealed that only a few species were confined to samples from lanes leading into the city, while mostly species of urban habitats were significantly associated with samples from the outbound lanes. The findings demonstrate that dispersal by traffic reflects different seed sources that are associated with different traffic directions, and traffic may thus exchange propagules along the urban–rural gradient.
Ecological and historical factors affecting distribution pattern and richness of endemic plant species: the case of the Maritime and Ligurian Alps hotspot
Authors: Casazza Gabriele , Zappa Elena , Mariotti Mauro G. , Médail Frédéric , Minuto Luigi
Published: February 2009

The aim of this study was to test a method to locate all the foci, centres, and areas of endemism in a biodiversity hotspot in order to understand the influence of ecological and historical factors on the distribution pattern and to identify priority areas for future conservation projects. The study area was the Maritime and Ligurian Alps hotspot.

Analyses were performed on the presence/absence matrix of 36 vascular plant taxa endemic to the study area. For each operational geographical unit, the number of endemic taxa present was counted. Additionally, the weighted endemism value was calculated. Areas of endemism were distinguished using cluster analysis and parsimony analysis of endemicity. The influence of ecological characteristics and historical factors was evaluated using Multi‐Response Permutation Procedure and the Nonparametric Multiplicative Regression. The Indicator Species Analysis (INDVAL) method was used to identify the species characterizing the areas of endemism. Our results show the importance and location of four main areas of endemism within the Maritime and Ligurian Alps and explain the distribution pattern of endemic plants. These areas are easily interpreted by historical and ecological factors, and INDVAL indicates which taxa took part in the history of each endemism area.
Geographical range size of tropical plants influences their response to anthropogenic activities
Authors: Lozada Tannya , de Koning G. H. J. , Kessler Michael , Klein Alexandra‐Maria , Tscharntke Teja
Published: February 2009

Biodiversity patterns may be influenced by the species geographical range sizes, but this is rarely shown. We used a highly replicated and large‐scale study in coastal Ecuador to determine for the first time the importance of latitudinal range size of plant species in their response to land‐use activities. We examined herbaceous plant communities of five land‐use types with decreasing anthropogenic disturbance (from the most intervened rice and pasture to the less intervened managed agroforest, abandoned agroforest, and forest) in a low and a high impact human‐dominated landscape. All species were classified in four latitudinal range size quartiles, from the 25% species with the narrowest to the 25% with the widest range size. We found notable differences between patterns of total species richness and those of individual range size quartiles. Whereas total species richness was higher in more intervened land‐use types, percentages of narrow‐ranged species were significantly higher in less intervened land‐use types. In contrast, percentages of wide‐ranging species were higher in more intervened land‐use types. Hence, responses of plant species to human activities were influenced by traits that determine their range sizes. An analysis of floristic similarity between land‐use types revealed that narrow‐ranged species were mainly preserved in forest fragments, but the other land‐use types supported many unique narrow‐ranged species and therefore made an important contribution to their preservation at the landscape level. Conservation efforts should combine protection of natural habitats with strategies to maintain a diversity of low‐intensity land‐use types, looking for win‐win solutions or trade‐offs between biodiversity conservation and human welfare in human‐dominated landscapes.
Elephant management: why can't we throw out the babies with the artificial bathwater?
Authors: Chamaillé‐Jammes Simon , Valeix Marion , Fritz Hervé
Published: February 2009

Elephant management is highly controversial and any elephant‐related study is quickly seen as a pro or con for one of the usual elephant management practices (laissez‐faire, culling, contraception or metapopulation management). Managing water sources has also been suggested as one option, even though no experimental data exist. In a recent issue of Diversity and Distributions, Smit et al. (2007) rejected this management tool as an efficient method to control elephant distribution and dynamics in Kruger National Park, South Africa. However, we believe that (1) Smit et al.'s conclusion is poorly supported by the available data, and (2) that this non‐intrusive management tool has the potential for being one of the few practices able to reconcile managers, scientists, and the public opinion in the never‐ending ‘elephant problem’. For these reasons, we believe that the strong conclusions of Smit et al. should be moderated.
Climatic seasonality, resource bottlenecks, and abundance of rainforest birds: implications for global climate change
Authors: Williams Stephen E. , Middleton Jeffery
Published: February 2009

We demonstrate that within‐year climatic variability, particularly rainfall seasonality, is the most significant variable explaining spatial patterns of bird abundance in Australian tropical rainforest. The likely mechanism causing this pattern is a resource bottleneck (insects, nectar, and fruit) during the dry season that limits the population size of many species. The patterns support both the diversity–climatic–stability hypothesis and the species–energy hypothesis but clearly show that seasonality in energy availability may be a more significant factor than annual totals or means. An index of dry season severity is proposed that quantifies the combined effect of the degree of dryness and the duration of the dry season. We suggest that the predicted increases in seasonality due to global climate change could produce significant declines in bird abundance, further exacerbating the impacts of decreased range size, increased fragmentation, and decreased population size likely to occur as a result of increasing temperature. We suggest that increasing climatic seasonality due to global climate change has the potential to have significant negative impacts on tropical biodiversity.
Life history and population size variability in a relict plant. Different routes towards long‐term persistence
Authors: García María B.
Published: February 2009

A central tenet of conservation biology is that population size affects the persistence of populations. However, many narrow endemic species combine small population ranges and sizes with long persistence, thereby challenging this tenet. I examined the performance of three different‐sized populations of Petrocoptis pseudoviscosa (Caryophyllaceae), a palaeoendemic rupicolous herb distributed along a small valley in the Spanish Pyrenees. Reproductive and demographic parameters were recorded over 6 years, and deterministic and stochastic matrix models were constructed to explore population dynamics and extinction risk. Populations differed greatly in structure, fecundity, recruitment, survival rate, and life span. Strong differentiation in life‐history parameters and their temporal variability resulted in differential population vulnerability under current conditions and simulated global changes such as habitat fragmentation or higher climatic fluctuations. This study provides insights into the capacity of narrow endemics to survive both at extreme environmental conditions and at small population sizes. When dealing with species conservation, the population size–extinction risk relationship may be too simplistic for ancient, ecologically restricted organisms, and some knowledge of life history may be most important to assess their future.
Response to De Silva et al. (2007): Endemic freshwater finfish of Asia: distribution and conservation status
Authors: Darwall William R. T. , Pollock Caroline M. , Smith Kevin G. , Vié Jean‐Christophe
Published: February 2009

De Silva et al. (2007) present an overview of the distribution and conservation status of the endemic freshwater fish of Asia. Within that review they use data from the IUCN Red List of Threatened Species™ (2006) to conduct an analysis of the conservation status of those endemic fish species. Their analysis is incorrect and provides a very misleading impression of the level of threat to Asian freshwater fish and to freshwater fish at the global scale. The errors stem from a misinterpretation of the data presented on the IUCN Red List. The sources of errors are discussed below and the opportunity is taken to clarify what the information on the IUCN Red List represents.
Land‐cover and land‐use change and its contribution to the large‐scale organization of Puerto Rico's bird assemblages
Authors: Acevedo Miguel A. , Restrepo Carla
Published: February 2009

Global biodiversity is changing rapidly driven by human alteration of habitat, and nowhere this is more dramatic than in insular habitats. Yet land‐cover change is a complex phenomenon that not only involves habitat destruction but also forest recovery over different time scales. Therefore, we might expect species to respond in diverse ways with likely consequences for the reorganization of regional assemblages. These changes, however, may be different in tropical islands because of their low species richness, generalist habits and high proportion of endemics. Here, we focus on the island of Puerto Rico and ask how island‐wide changes in land cover and land use has influenced the large‐scale organization of bird assemblages. To address this question, we combined in a Geographical Information System (GIS) the first 6 years (1997–2002) of the Puerto Rican Breeding Bird Survey (PR‐BBS) with land‐cover and land‐use data extracted from a published digital map derived from the classification of Landsat images. A Non‐metric Multidimensional Scaling (NMS) ordination based on the composition and abundance of birds, and percentage land‐use types showed that land use followed by climate could explain most of the variation observed among routes in terms of species composition and abundance. Moreover, endemic and exotic species were widely distributed throughout the island, but the proportion of endemic species is higher in closed forests while exotic species are more abundant in open habitats. However, historical accounts from the early 1900s indicate that endemic species were distributed across the entire island. Today, most of the land cover transformation in Puerto Rico occurs in the lowlands which may explain the high abundance of endemic species in cloud forests and the high abundance of exotic species in open habitats in the lowlands.
Garden bird feeding predicts the structure of urban avian assemblages
Authors: Fuller Richard A. , Warren Philip H. , Armsworth Paul R. , Barbosa Olga , Gaston Kevin J.
Published: February 2009

Households across the developed world cumulatively spend many millions of dollars annually on feeding garden birds. While beneficial effects on avian assemblages are frequently claimed, the relationships between levels of garden bird feeding and local avian populations are unknown. Using data from a large UK city, we show that both avian species richness and abundance vary across different socioeconomic neighbourhood types. We examined whether patterns in bird feeding could explain this variation. The density of bird feeding stations across the urban environment was strongly positively related to avian abundance, after controlling for differences in habitat availability. This effect was almost exclusively driven by the abundance of those species known to utilize garden feeding stations frequently. In contrast, the density of feeding stations had no effect on avian species richness. We also examined variation in the proportion of households in different communities that provide food for birds, a factor that is not correlated with feeder density. The prevalence of bird feeding across different neighbourhoods declined as socioeconomic deprivation increased, and increased with avian species richness and abundance. Our results suggest that the provision of supplementary food for birds by multiple landowners across a city can impact the status of urban bird populations. The potential for harnessing these actions for conservation needs to be explored.
Integration of palaeontological, historical, and geographical data on the extinction of koa‐finches
Authors: James Helen F. , Price Jonathan P.
Published: February 2009

Identifying the root causes of extinction or endangerment requires long chronological records that begin before a population started to decline and extend until its extinction or functional extinction. We present a case study of the koa‐finches, genus Rhodacanthis, an extinct group of Hawaiian honeycreepers that was specialized to feed on green pods and seeds of the koa tree or other leguminous plants. Six island populations of koa‐finches are known; four in the Holocene fossil record and two that survived until the 1890s. We document the palaeoecological context of the fossils and identify constraints on the age span of the specimen record for each population using stratigraphic contexts, associated radiometric determinations, and museum specimen data. We estimate the potential geographical range of koa‐finches at the time of human arrival using two methods: assessment of their historical and palaeo‐habitats, and geographical information system mapping of the pre‐human distribution of the koa plant (Acacia koa) and its sister species, the koai‘a plant (Acacia koaia). After integrating the foregoing data with chronological records and distributional maps of the potential forcing agents of extinction, we conclude that at least two extinctions of island populations were due to ecological change in the lowlands in the prehistorical and perhaps the early historical periods. In the same time frame, the koa‐finch populations on Hawai‘i Island became rare and restricted to upland refugia, making them vulnerable to the upland forest harvesting and degradation that was accelerating in the 1890s. Neither climatic variation nor mosquito‐vectored diseases are likely to have caused the observed extinctions. This study illustrates an approach that can be applied to many other extinct and endangered island species to better understand the causes of high extinction rates in the human era.
Concordance among stream assemblages and spatial autocorrelation along a fragmented gradient
Authors: Grenouillet Gaël , Brosse Sébastien , Tudesque Loïc , Lek Sovan , Baraillé Yasmina , Loot Géraldine
Published: February 2009

Patterns of spatial autocorrelation of biota and distributional similarity (concordance) between assemblages of different organism groups have important implications in both theoretical ecology and biodiversity conservation. Here we report environmental gradients and spatial distribution patterns of taxonomic composition among stream fish, benthic macroinvertebrate, and diatom assemblages along a fragmented stream in south‐western France. We quantified spatial patterns of lotic assemblage structure along this stream, and we tested for concordance in distribution patterns among the three taxonomic groups. Our results showed that both environmental characteristics and stream assemblages were spatially autocorrelated. For stream fish and diatom assemblages, these patterns reflected assemblage changes along the longitudinal stream gradient, whereas environmental variables and benthic macroinvertebrates exhibited a more patchy spatial pattern. Cross‐taxa concordance was significant between stream fish and diatoms, and between stream fish and benthic macroinvertebrates. The assemblage concordance between stream fish and diatoms could be attributed to similar responses along the longitudinal gradient, whereas those between stream fish and benthic macroinvertebrates may result from biotic interactions. Based on potential dispersal capacities of taxa, our results validated the hypotheses that weakly dispersing taxa exhibit greater concordance than highly dispersing ones and that dispersal capacities affect how taxonomic groups respond to their local environment. Both diatoms and highly dispersing stream fish were affected by stream fragmentation (i.e. the number of dams between sites), while the effect of fragmentation was not significant for invertebrates that fly well in their adult stage, thus emphasizing the importance of the way of dispersal. These results suggest that addressing the effects of dispersal capacity on stream assemblage patterns is crucial to identifying mechanisms behind patterns and to better understanding the determinants of stream biodiversity.
The performance ofPolylepis australistrees along their entire altitudinal range: implications of climate change for their conservation
Authors: Marcora Paula , Hensen Isabell , Renison Daniel , Seltmann Peggy , Wesche Karsten
Published: February 2009

Altitudinal gradients are expected to heavily influence the general performance of mountain tree species. For this study we evaluated vitality, radial growth and reproductive efficiency inPolylepis australis(Rosaceae) throughout its complete altitudinal range in central Argentina. We selected seven forest fragments ranging from 900 to 2700 m a.s.l. In the field, we subjectively assigned vitality and seed productivity indexes to 12P. australistrees per fragment. In addition, we cored and assessed for radial growth 10–18 trees per altitudinal level. In the laboratory, we individually weighed seeds from four or five trees from each altitudinal level and divided into two seed mass classes (light and heavy). We then tested for germination and monitored their seedlings for survival. Seedlings of three trees per altitudinal level were harvested after 40 days and assessed for dry mass. Seedlings of one to two trees per altitudinal level were monitored for survival until both leaves and roots had died. Our main results showed two types of responses to altitude: a unimodal relationship with an optimum at intermediate altitudes of around 1800 m a.s.l. for tree vitality, radial growth, seed productivity and seed mass; and an increase with altitude for in‐vitro seed germination and seedling survival. A rise in temperature due to climate change could restrictP. australisto the upper most altitudes, where conservation of these forests will be a priority.