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Riparian zones are one of the most productive ecosystems in the world, but are at risk due to agricultural expansion and climate change. To maximize return on conservation investment in mixed-use landscapes, it is important to identify the minimum intact riparian forest buffer sizes to conserve riparian ecosystem services. The minimum riparian forest buffer width necessary to maintain tropical river water quality remains unclear, and there is little analysis of effective riparian buffer lengths. Also, in studies on the effect of land use on river water quality globally, there is little standardization in the area where land use is analyzed. Here, these challenges were addressed in the Osa Peninsula in southwestern Costa Rica. Water quality parameters and social variables were sampled at 194 locations across the region. For each sample, land use was calculated in nine different riparian buffer sizes and at the sampling location. Riparian forest cover had a positive effect on water quality parameters, while agricultural cover had a negative effect. The longer the length of the buffer considered, the greater the relative support for influencing water quality (1000 m > 500 m > 100 m). All buffer widths yielded similar support within each length class. These results indicate that length of riparian forest buffers, not width, drives their ability to conserve water quality. While wide and long riparian forests are ideal to maximize the protection of river water quality and other ecosystem services, in landscapes where that is impractical, the 15-m-wide riparian forest buffers that are supported by Costa Rican legislation could improve water quality, providing that they are at least 500 m long. The results also indicate the importance of methodological standardization in studies that monitor land use effects on water quality. The authors propose that studies in similar regions analyze land use in riparian zones 15-m-wide by 1000 m upstream. Conserving and restoring narrow, long riparian forest buffers could provide a rapid, economical management approach to balance agricultural production and water quality protection.

Approximately 20% of the Brazilian Amazon has now been deforested, and the Amazon is currently experiencing the highest rates of deforestation in a decade, leading to large-scale land-use changes. Roads have consistently been implicated as drivers of ongoing Amazon deforestation and may act as corridors to facilitate species invasions. Long-term data, however, are necessary to determine how ecological succession alters avian communities following deforestation and whether established roads lead to a constant influx of new species.We used data across nearly 40 years from a large-scale deforestation experiment in the central Amazon to examine the avian colonization process in a spatial and temporal framework, considering the role that roads may play in facilitating colonization.Since 1979, 139 species that are not part of the original forest avifauna have been recorded, including more secondary forest species than expected based on the regional species pool. Among the 35 species considered to have colonized and become established, a disproportionate number were secondary forest birds (63%), almost all of which first appeared during the 1980s. These new residents comprise about 13% of the current community of permanent residents.Widespread generalists associated with secondary forest colonized quickly following deforestation, with few new species added after the first decade, despite a stable road connection. Few species associated with riverine forest or specialized habitats colonized, despite road connection to their preferred source habitat. Colonizing species remained restricted to anthropogenic habitats and did not infiltrate old-growth forests nor displace forest birds.Deforestation and expansion of road networks into terra firme rainforest will continue to create degraded anthropogenic habitat. Even so, the initial pulse of colonization by nonprimary forest bird species was not the beginning of a protracted series of invasions in this study, and the process appears to be reversible by forest succession.

In order to test the hypothesis that elevation may be an important factor accounting for the distribution of myxomycetes in tropical forests, this project was designed and conducted in Costa Rica. Two lower elevational belts were selected for this work due to their floristic and structural resemblance. Using the moist chamber technique, 40 different sites located in four different transects in two different macroclimatic regions were surveyed using three substrates during the rainy and the dry periods of 2014 and 2015. The results showed a lack of differences in diversity-based estimators according to elevation using different approaches and taxonomic differences were found across transects, collecting periods and substrates but not in relation with elevation either. Our results suggest that when increased spatial sampling resolution is implemented and floristic elements are common, elevation may not be as important of a factor in shaping the distribution of myxomycetes in tropical forests as commonly believed.

There is a huge lack of information regarding the natural history of subterranean species, particularly focusing on aspects of the behavioral ecology of Brazilian cave fauna. In the present work, we aimed to describe and evaluate the behavioral repertoire of Xangoniscus itacarambiensis (Isopoda, Styloniscidae) through observations in the field and laboratory and also by means of complementary experiments. Overall, we recorded 25 spontaneous behaviors. Besides describing the physical habitat, we recorded some intraspecific interactions, agonistic and territorial behaviors, as well as the amphibian habit. There was a direct relationship between the size of travertine dams where they live (measurements of length and width) and the mean number of individuals, although there was no significant correlation with the pool depth. Behaviors observed in the laboratory differed qualitatively and quantitatively from those observed in the field, with individuals more active in the latter. This scenario alerts about the significant behavioral alteration of such isopods when removed from their natural habitat, what must be considered in future behavioral studies including troglobites given their natural sensitivity to environmental changes.

Modern biology builds upon the historic exploration of the natural world. Recognizing the origin of a species\' name is one path to honor the historic exploration and description of the natural world and the indigenous peoples that lived closely with organisms prior to their description. While digitization of historic papers catalogued in databases such as the Biodiversity Heritage Library (BHL) allows for searching of the first use and origin of names, the rapid pace of taxonomic publishing can occlude a thorough search for etymologies. The etymological origin of the genus name Ameiva is one such case; while unattributed in multiple recent works, it is of Tupí language origin. The first description was in the Historiae Rerum Naturalium Brasiliae by George Marcgrave (1648). Ameiva was the name used by Marcgrave\'s Amerindian hosts in 17th century Dutch Brazil, where local people spoke the now extinct language Tupí. The Tupí origin was not lost, however, until as recently as the 2000s. Herein, the pre- and post-Linnaean use of the name Ameiva is traced and when the name is attributed to the Tupí language and to Marcgrave through time it is noted. The opportunity to discover and/or recover etymological origins, especially names from extinct and indigenous languages, provides insight into the early Western sciences. Careful study of etymology by naturalists is consistent with the idea that science is an evolving process with many predecessors to appreciate.

Arid biomes are particularly prominent in the Neotropics providing some of its most emblematic landscapes and a substantial part of its species diversity. To understand some of the evolutionary processes underlying the speciation of lineages in the Mexican Deserts, the diversification of Fouquieria is investigated, which includes eleven species, all endemic to the warm deserts and dry subtropical regions of North America. Using a phylogeny from plastid DNA sequences with samples of individuals from populations of all the species recognized in Fouquieria, we estimate divergence times, test for temporal diversification heterogeneity, test for geographical structure, and conduct ancestral area reconstruction. Fouquieria is an ancient lineage that diverged from Polemoniaceae ca. 75.54 Ma. A Mio-Pliocene diversification of Fouquieria with vicariance, associated with Neogene orogenesis underlying the early development of regional deserts is strongly supported. Test for temporal diversification heterogeneity indicates that during its evolutionary history, Fouquieria had a drastic diversification rate shift at ca.12.72 Ma, agreeing with hypotheses that some of the lineages in North American deserts diversified as early as the late Miocene to Pliocene, and not during the Pleistocene. Long-term diversification dynamics analyses suggest that extinction also played a significant role in Fouquieria\'s evolution, with a very high rate at the onset of the process. From the late Miocene onwards, Fouquieria underwent substantial diversification change, involving high speciation decreasing to the present and negligible extinction, which is congruent with its scant fossil record during this period. Geographic phylogenetic structure and the pattern of most sister species inhabiting different desert nucleus support that isolation by distance could be the main driver of speciation.

Lack of resolution on species boundaries and distribution can hamper inferences in many fields of biology, notably biogeography and conservation biology. This is particularly true in megadiverse and under-surveyed regions such as Amazonia, where species richness remains vastly underestimated. Integrative approaches using a combination of phenotypic and molecular evidence have proved extremely successful in reducing knowledge gaps in species boundaries, especially in animal groups displaying high levels of cryptic diversity like amphibians. Here we combine molecular data (mitochondrial 16S rRNA and nuclear TYR, POMC, and RAG1) from 522 specimens of Anomaloglossus, a frog genus endemic to the Guiana Shield, including 16 of the 26 nominal species, with morphometrics, bioacoustics, tadpole development mode, and habitat use to evaluate species delineation in two lowlands species groups. Molecular data reveal the existence of 18 major mtDNA lineages among which only six correspond to described species. Combined with other lines of evidence, we confirm the existence of at least 12 Anomaloglossus species in the Guiana Shield lowlands. Anomaloglossus appears to be the only amphibian genus to have largely diversified within the eastern part of the Guiana Shield. Our results also reveal strikingly different phenotypic evolution among lineages. Within the A. degranvillei group, one subclade displays acoustic and morphological conservatism, while the second subclade displays less molecular divergence but clear phenotypic divergence. In the A. stepheni species group, a complex evolutionary diversification in tadpole development is observed, notably with two closely related lineages each displaying exotrophic and endotrophic tadpoles.