Umberto Kubota

Hung out to dry: choice of priority ecoregions for conserving threatened neotropical anurans depends on life-history traits.

Background In the Neotropics, nearly 35% of amphibian species are threatened by habitat loss, habitat fragmentation, and habitat split; anuran species with different developmental modes respond to habitat disturbance in different ways. This entails broad-scale strategies for conserving biodiversity and advocates for the identification of high conservation-value regions that are significant in a global or continental context and that could underpin more detailed conservation assessments towards such areas. Methodology/Principal Findings We identified key ecoregion sets for anuran conservation using an algorithm that favors complementarity (beta-diversity) among ecoregions. Using the WWFs Wildfinder database, which encompasses 700 threatened anuran species in 119 Neotropical ecoregions, we separated species into those with aquatic larvae (AL) or terrestrial development (TD), as this life-history trait affects their response to habitat disturbance. The conservation target of 100% of species representation was attained with a set of 66 ecoregions. Among these, 30 were classified as priority both for species with AL and TD, 26 were priority exclusively for species with AL, and 10 for species with TD only. Priority ecoregions for both developmental modes are concentrated in the Andes and in Mesoamerica. Ecoregions important for conserving species with AL are widely distributed across the Neotropics. When anuran life histories were ignored, species with AL were always underrepresented in priority sets. Conclusions/Significance The inclusion of anuran developmental modes in prioritization analyses resulted in more comprehensive coverage of priority ecoregions–especially those essential for species that require an aquatic habitat for their reproduction–when compared to usual analyses that do not consider this life-history trait. This is the first appraisal of the most important regions for conservation of threatened Neotropical anurans. It is also a first endeavor including anuran life-history traits in priority area-selection for conservation, with a clear gain in comprehensiveness of the selection process.

Integrating economic costs and biological traits into global conservation priorities for carnivores

Background Prioritization schemes usually highlight species-rich areas, where many species are at imminent risk of extinction. To be ecologically relevant these schemes should also include species biological traits into area-setting methods. Furthermore, in a world of limited funds for conservation, conservation action is constrained by land acquisition costs. Hence, including economic costs into conservation priorities can substantially improve their conservation cost-effectiveness. Methodology/Principal Findings We examined four global conservation scenarios for carnivores based on the joint mapping of economic costs and species biological traits. These scenarios identify the most cost-effective priority sets of ecoregions, indicating best investment opportunities for safeguarding every carnivore species, and also establish priority sets that can maximize species representation in areas harboring highly vulnerable species. We compared these results with a scenario that minimizes the total number of ecoregions required for conserving all species, irrespective of other factors. We found that cost-effective conservation investments should focus on 41 ecoregions highlighted in the scenario that consider simultaneously both ecoregion vulnerability and economic costs of land acquisition. Ecoregions included in priority sets under these criteria should yield best returns of investments since they harbor species with high extinction risk and have lower mean land cost. Conclusions/Significance Our study highlights ecoregions of particular importance for the conservation of the worlds carnivores defining global conservation priorities in analyses that encompass socioeconomic and life-history factors. We consider the identification of a comprehensive priority-set of areas as a first step towards an in-situ biodiversity maintenance strategy.

Flower-heads, herbivores, and their parasitoids: food web structure along a fertility gradient

Abstract.  1. The ways in which a soil fertility gradient affects three trophic level food webs defined by plants of the family Asteraceae, flower‐head herbivores, and their parasitoids was investigated. It was tested how the fertility gradient alters: (i) the abundance and richness of plants, herbivores, and their parasitoids, (ii) the herbivore–plant ratio, and (iii) the connectance of the plant–herbivore community matrix.

Key Neotropical ecoregions for conservation of terrestrial vertebrates

Conservation planning analyses show a striking progression from endeavors targeted at single species or at individual sites, to the systematic assessment of entire taxa at large scales. These, in turn, inform wide-reaching conservation policies and financial investments. The latter are epitomized by global-scale prioritization frameworks, such as the Biodiversity Hotspots. We examine the entire Neotropical region to identify sets of areas of high conservation priority according to terrestrial vertebrate distribution patterns. We identified a set of 49 ecoregions in which 90, 82 and 83%, respectively of total, endemic and threatened vertebrates are represented. A core subset of 11 ecoregions captured 55, 27 and 38% of these groups. The Neotropics hold the largest remaining wilderness areas in the world, and encompass most of the tropical ecosystems still offering significant options for successful broad-scale conservation action. Our analysis helps to elucidate where conservation is likely to yield best returns at the ecoregion scale.

Diversidade e ocorrência de Asteraceae em cerrados de São Paulo

De abril a maio de 2000 a 2002 oito localidades com remanescentes de cerrados sensu stricto no estado de Sao Paulo foram amostradas para o levantamento das especies de asteraceas, uma das familias mais representativas da flora herbaceo-arbustiva nestas formacoes. Foram feitas 23 amostragens e cada area de estudo foi amostrada em media uma vez por ano durante o pico de floracao das plantas. Ao todo foram obtidas 399 amostras, nas quais foram reconhecidas 89 morfoespecies (74 foram identificadas como especies conhecidas). Quarenta por cento das especies foram registradas uma unica vez (unicatas), indicando um grande numero de especies raras. Apenas 10% das especies que ocorreram em mais de uma amostra foram obtidas de uma mesma area (sobreposicao espacial) ou de um mesmo ano de estudo (sobreposicao temporal). A riqueza de especies em cada area foi estimada por meio de transecoes e depois comparada a riqueza total observada em cada area de estudo, sendo esta na maioria das vezes mais alta que a estimada com base nas transecoes. A lista de especies obtida para os cerrados amostrados foi comparada a outras 24 listas publicadas para cerrados no Brasil. Embora a maioria das especies mais comuns tenha coincidido, oito especies (11% das especies identificadas) nao constam das listas publicadas. Concluimos que as areas de cerrado sensu stricto estudadas no estado de Sao Paulo encontram-se isoladas, com uma grande parte da flora herbaceo-arbustiva composta por varias especies raras e exclusivas. Diante deste quadro, sugerimos que a manutencao da biodiversidade de Asteraceae depende da conservacao de todo o conjunto de remanescentes de cerrado do estado de Sao Paulo.

Assemblages of endophagous insects on Asteraceae in São Paulo Cerrados

A survey of the endophagous insects fauna associated to Asteraceae capitula was carried out from 2000 to 2002 in eight cerrado sensu stricto sites located in the Brazilian state of Sdo Paulo. Sixty-four endophagous species of Diptera and Lepidoptera were recorded from 49 asteracean host plants. Approximately half of the species were obtained from a single locality, with a large proportion emerging from a single sample (unicates). Thirty percent of the species were singletons (i.e. only one individual was recorded). The large proportion of rare species suggests a high species turnover among localities. Lepidopteran species were recorded on more host species than dipterans, confirming their more polyphagous food habit, also observed in other Brazilian biomes and in Europe. We conclude that the studied cerrado localities, all within São Paulo State, are isolated with its invertebrate fauna composed of many rare and exclusive species. We suggest that the maintenance of Asteraceae biodiversity and their endophagous insects depend on the conservation of all cerrado remnants in the state.

Invasive grasses and native Asteraceae in the Brazilian Cerrado

Anthropogenic disturbances frequently modify natural disturbance regimes and foster the invasion and spread of nonindigenous species. However, there is some dispute about whether disturbance events or invasive plants themselves are the major factors promoting the local extinction of native plant species. Here, we used a set of savanna remnants comprising a gradient of invasive grass cover to evaluate whether the species richness of Asteraceae, a major component of the Brazilian Cerrado, is affected by invasive grass cover, or alternatively, whether variation in richness can be directly ascribed to disturbance-related variables. Furthermore, we evaluate whether habitat-specialist Asteraceae differ from habitat generalist species in their responses to grass invasion. Abundance and species richness showed unimodal variation along the invasive grass gradient for both total Asteraceae and habitat-generalists. The cerrado-specialist species, however, showed no clear variation from low-to-intermediate levels of grass cover, but declined monotonically from intermediate-to-higher levels. Through a structural equation model, we found that only invasive grass cover had significant effects on both abundance and species density of Asteraceae. The effect of invasive grass cover was especially high on the cerrado-specialist species, whose proportion declined consistently with increasing invasive dominance. Our results support the prediction that invasive grasses reduce the floristic uniqueness of pristine vegetation physiognomies.