Understanding why species composition and diversity varies spatially and with environmental variation is a long-standing theme in macroecological research. Numerous hypotheses have been generated to explain species and phylogenetic diversity gradients. Much less attention has been invested in explaining patterns of beta diversity. Biomes boundaries are thought to represent major shifts in abiotic variables accompanied by vegetation patterns and composition as a consequence of long-term interactions between the environment and the diversification and sorting of species. Using North American plant distribution data, phylogenetic information and three functional traits (SLA, seed mass, and plant height), we explicitly tested whether beta diversity is associated with biome boundaries and the extent to which two components of beta diversity-turnover and nestedness-for three dimensions of biodiversity (taxonomic, phylogenetic, and functional)-are associated with contrasting environments and linked to different patterns of historical climatic stability. We found that dimensions of vascular plant beta diversity are strongly coupled and vary considerably across North America, with turnover more influential in biomes with higher species richness and greater environmental stability and nestedness more influential in species-poor biomes characterized by high environmental variability. These results can be interpreted to indicate that in harsher climates with less stability explain beta diversity, while in warmer, wetter more stable climates, patterns of endemism associated with speciation processes, as well as local environmental sorting processes, contribute to beta diversity. Similar to prior studies, we conclude that patterns of similarity among communities and biomes reflects biogeographic legacies of how vascular plant diversity arose and was shaped by historical and ecological processes.

Aim Explaining species richness gradients in space and time requires understanding the evolutionary processes that ultimately alter the number of species.Here we examine species richness differences between primary habitats (forest versus open) for Furnariides birds, a Neotropical endemic bird clade, to test three major historical hypothesesdiversification rate, out of the tropics and tropical niche conservatismand assess the role of evolutionary processes in driving the Furnariides species richness gradient.Location Neotropics. MethodsWe used phylogenetic and spatial data to tests the historical hypotheses. First, we used GeoSSE and Bayesian Analysis of Macroevolutionary Mixture models to evaluate differential diversification and dispersal rates between habitats. Second, we quantify the root distance of each species and examined the phylogenetic structure of the richness gradient and the correlation between total species richness and the richness of early-diverged and recently originated species.Results Furnariides species richness is higher in forest than in open habitats. However, we found higher speciation, extinction, and dispersal rates in open when compared to forest habitats, resulting in a higher diversification rate in open habitats and higher dispersal rate out of open habitats than into them. The phylogenetic structure of the richness gradient showed strong spatial pattern, with early diverged species richness peaking in forest habitats and driving the overall Furnariides gradient.Main conclusions The Furnariides species richness gradient results from the joint effect of differential rates of macroevolutionary processes. Our findings highlight dispersal and extinction as dominant forces driving richness differences between habitats, through the addition and extirpation of species from open to forest habitats. Differences in species richness between habitats support niche conservatism of forest habitat preferences of Furnariides species. We suggest that open habitats are effective evolutionary arenas and a key to the maintenance of bird diversity in forest habitats over evolutionary time.

Abstract.-Descriptions of intra-and interspecific variation in migratory patterns of closely related species are rare yet valuable because they can help assess how differences in ecology and life-history strategies drive the evolution of migration. We report data on timing and location of migration routes and wintering areas, and on migratory speed and phenology,

To the Editor -Wyborn and Evans 1 argue that global priority maps for conservation have questionable utility and may crowd out local and more contextual research. While we agree with the authors' central argument that effective and equitable conservation must be rooted at local scales, the assertion that "conservation needs to break free from global priority mapping" presents a false dichotomy. We should not think in terms of a binary choice of methods (local or global), but rather recognize that information across scales will have the most relevance and power in the future. Wyborn and Evans challenge the creators of global maps to identify their theory of change. Here, we outline six major areas of contribution relevant for priority setting and other conservation-related decisions.(1) Broader context for local decisions.Making effective local policy relies on anticipating economic, political or environmental change operating at larger scales and understanding how it affects local social or biophysical conditions. Global maps reveal the importance of distant connections (also known as telecoupling) in driving change in nature and its contributions to people 2 . Similarly, species extinction risk is governed by how rare a species is, and a purely local focus cannot fully reveal the regional, continental and global landscape of extinction risks 3 . Analyses of linkages across scales from local to regional to global are essential for a full understanding of the impacts of policies or actions. Ignoring linkages across scales results in missed opportunities and unintended consequences. correspondence approach against another, we must seek better ways of integrating a wide diversity of perspectives across scales to address the challenges ahead.

Abstract.-Little is known about the timing of migration, migration routes, and migratory connectivity of most of the >230 species of birds that breed at south temperate latitudes of South America and then migrate toward the tropics to overwinter. We used light-level geolocators to track the migration of 3 male and 3 female Fork-tailed Flycatchers (Tyrannus savana) captured on their breeding territories in Argentina. All birds initiated fall migration between late January and late February, and migrated 45 to 66 km day -1 in a northwesterly direction through central South America to either one or two wintering areas. Five individuals first spent several weeks (in April and May) in western Amazonia (mainly Peru, northwestern Brazil, and southern Colombia) before moving east to spend the rest of the non-breeding season in central Venezuela and northern Brazil. One individual occupied primarily one wintering area in eastern Colombia, northwestern Brazil, and southwestern Venezuela. Fall migration took approximately 7-12 weeks to complete and covered a distance of 2,888-4,105 km. We did not analyze spring migration data because of broad overlap with the austral spring equinox. These results are the first data on wintering locations, migration timing, and routes of individual migrant passerine birds that breed in South America. Given the general lack of similar data for practically all migratory birds that breed in South America, geolocator technology has the potential to revolutionize our understanding of how birds migrate-and the threats they face-on South America's rapidly changing landscape. La migración a Larga Distancia de Aves en América del Sur Revelado por GeolocalizadoresResumen.-Poco se sabe sobre la fenología de la migración, las rutas de migración, y la conectividad migratoria de la mayoría de los >230 especies de aves que se reproducen en latitudes templadas del sur de Sur América, y que luego migran hacia los trópicos para invernar. Utilizamos geolocalizadores para estudiar la migración de tres machos y tres hembras de Tyrannus savana capturados en sus territorios de cría en Argentina. Todas las aves iniciaron la migración de otoño entre finales de enero y finales de febrero, y migraron de 45 a 66 km dia -1 hacia el noroeste por el centro de América del Sur, hasta una o dos áreas de invernada. Cinco individuos primero pasaron varias semanas (en abril y mayo) en la Amazonia occidental (principalmente Perú, noroeste de Brasil, y sur de Colombia), antes de moverse hacia el este para pasar el resto de la temporada no reproductiva en el centro de Venezuela y el norte de Brasil. Un individuo estuvo principalmente en un área de invernada en el este de Colombia, noroeste de Brasil, y el suroeste de Venezuela. La migración de otoño duró aproximadamente 7-12 semanas, y cubrió una distancia de 2888-4105 km. No analizamos los datos de la migración de primavera a causa de una amplia superposición con el equinoccio de la primavera austral. Estos resultados representan los primeros datos sobre los lugares de invernad...

Charles Darwin posited two alternative hypotheses to explain the success of nonnative species based on their relatedness to natives: nonnative species that are closely related to native species could experience (1) higher invasion success because of an increased probability of habitat suitability (conferred by trait similarity) or (2) lower invasion success due to biotic interference, such as competition and limiting similarity. The paradox raised by the opposing predictions of these two hypotheses has been termed "Darwin's naturalization conundrum" (DNC). Using plant communities measured repeatedly across an experimental fire gradient in an oak savanna (Minnesota, USA) over 31 yr, we evaluated the DNC by incorporating taxonomic, functional, and phylogenetic information. We used a "focal-species" approach, in which the taxonomic, functional, and phylogenetic structure of species co-occurring with a given nonnative (focal) species in local communities was quantified. We found three main results: first, nonnative species tended to co-occur most with closely related natives, except at the extreme ends of the fire gradient (i.e., in communities with no fire and those subjected to high fire frequencies); second, with increasing fire frequency, nonnative species were functionally more similar to native species in recipient communities; third, functional similarity between co-occurring nonnatives and natives was stable over time, but their phylogenetic similarity was not, suggesting that dynamic external forces (e.g., climate variability) influenced the phylogenetic relatedness of nonnatives to natives. Our results provide insights for understanding invasion dynamics across environmental gradients and highlight the importance of evaluating different dimensions of biodiversity in order to draw stronger inferences regarding species co-occurrence at different spatial and temporal scales.

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Interpolated climate surfaces have been widely used to predict species distributions and develop environmental niche models. However, the spatial coverage and density of meteorological sites used to develop these surfaces vary among countries and regions, such that the most biodiverse regions often have the most sparsely sampled climatic data. We explore the potential of satellite remote sensing (S-RS) products—which have consistently high spatial and temporal resolution and nearly global coverage—to quantify species-environment relationships that predict species distributions. We propose several new environmental metrics that take advantage of high temporal resolution in S-RS data and compare these approaches to classic climate-only approaches using the live oaks (Quercus section Virentes) as a case study. We show that models perform similarly but for some species, particularly in understudied regions, show less precision in predicting spatial distribution. These results provide evidence supporting efforts to enhance environmental niche models and species distribution models (ENMs/SDMs) with S-RS data and, when combined with other approaches for species detection, will likely enhance our ability to monitor biodiversity globally.