The biogeography of sodium in Neotropical figs (Moraceae)

© 2016 The Association for Tropical Biology and Conservation Sodium is essential for animals but not for most plants. Terrestrial sodium comes largely from marine aerosols, so inland ecosystems should have greater potential for sodium limitation than coastal ecosystems. We report a significant decrease of sodium in fruits of four Neotropical Ficus species with distance from presumed marine source

Comparison of three collection techniques for capture of Coleoptera, with an emphasis on saproxylic species, in Great Smoky Mountains National Park, USA

Collection methods and/or habitats sampled influence how many and which species are captured during entomological surveys. Here we compare Coleoptera catches among three survey activities, each using a single collection method, at the same study sites in Great Smoky Mountains National Park, USA. Activities included: short-term flight intercept trapping (FITs); sifting/Berlese funneling of leaf litter and extremely decayed downed coarse woody debris; and using emergence chambers containing coarse woody debris of various decay classes. In total, 2472 adult beetle specimens, representing 217 lowest identifiable taxa within 164 genera and 42 families, were collected during the FIT survey. Each survey activity yielded more than 2000 specimens, and a combined total of 413 species was collected. A combination of all surveys yielded the highest species richness when normalized for number of specimens indicating that variation of habitat and/or collection method significantly increases species richness. Of single surveys the FIT survey had the highest absolute species richness (217) and the highest richness when normalized for number of specimens. Species overlap among survey activities was low (Sorensen’s quotient of similarity was 0.20–0.27), which showed that each was about equally dissimilar from all others. Overlap of catch between FITs and emergence chambers was too low to justify substitution of emergence surveys with the FIT survey protocol used when attempting to collect saproxylic Coleoptera

Coloration in the polymorphic frog Oophaga pumilio associates with level of aggressiveness in intraspecific and interspecific behavioral interactions

© 2015, Springer-Verlag Berlin Heidelberg. Intraspecific morphological variation may correspond to behavioral variation that helps determine the nature of species interactions. Color variation among populations of variably toxic organisms has been shown to associate with alternative anti-predator behaviors. However, the effects of these alternative behavioral tendencies on the outcomes of interspecific interactions other than predator–prey remain largely unexplored. We investigated how coloration and body size variation in Oophaga pumilio, one of the most phenotypically diverse amphibians known, associated with territorial aggressiveness and how this association influenced the outcome of agonistic male–male interactions with conspecifics and heterospecifics of two sympatric species (Andinobates claudiae and Phyllobates lugubris). Irrespective of body size, resident frogs from more conspicuous, red-colored O. pumilio populations responded to same-morph conspecifics and P. lugubris more quickly and exhibited more aggressive behaviors and more energetically expensive behaviors than resident frogs from green populations under these same treatments. Furthermore, red-colored resident frogs dominated most of the interactions in which they were involved, whereas green residents dominated only a few of the interactions, despite their status as residents. Because conspecific and heterospecific intruders did not behave more aggressively toward red resident frogs, aggressiveness of red residents does not appear to be a response to higher aggression being directed toward them. These results suggest that coloration in O. pumilio is a good indicator of aggressiveness that associates with the outcome of intraspecific and some interspecific behavioral male–male interactions, providing support for a positive association among anti-predator traits, agonistic behavior, and dominance in both intraspecific and interspecific, intraguild interactions

Supplemental irrigation increases seedling performance and diversity in a tropical forest

Diversity is positively correlated with water availability at global, continental and regional scales. With the objective of better understanding the mechanisms that drive these relationships, we investigated the degree to which variation in water availability affects the performance (recruitment, growth and survival) of juvenile trees. Precipitation was supplemented throughout two dry seasons in a seasonal moist forest in south-eastern Peru. Supplementing precipitation by 160 mm mo1, we increased soil moisture by 17%. To generate seedling communities of known species composition, we sowed 3840 seeds of 12 species. We monitored the fates of the 554 seedlings recruited from the sown seeds, as well as 1856 older non-sown seedlings (10 cm height \u3c 50 cm), and 2353 saplings (\u3e 1 m tall). Watering significantly enhanced young seedling growth and survival, increasing stem density and diversity. Watering diminished the recruitment of species associated with upland forests, but increased the survival of both upland- and lowland-associated species. Though supplemental watering increased the growth of older seedlings, their density and diversity were unaffected. Sapling performance was insensitive to watering. We infer that variation in dry-season water availability may affect seedling community structure by differentially affecting recruitment and increasing overall survival. These results suggest that differential seedling recruitment and survival may contribute to the observed relationships between water availability, habitat associations and patterns of tree species richness. Copyright © 2009 Cambridge University Press

Variation in small sapling density, understory cover, and resource availability in four neotropical forests

Even though many forest plants spend all or a significant portion of their lives in the forest understoty, few studies have compared understory composition, structure, and resource availability among forests. We used standardized transect-based methods to compare small sapling densities (10-50 cm tall), understory vegetation cover, canopy openness, and nutrient availability in non-gap portions of four lowland Neotropical forests: La Selva, Costa Rica (LS), Barro Colorado Island, Panama (BCI), Cocha Cashu, Peru (CC), and north of Manaus, Brazil (KM41). Sites differed significantly in all variables except canopy openness. LS had high palm and non-fern herb cover and low density of small saplings (0.7-1.6/m2) compared to other sites. CC had high fern cover, whereas BCI had low cover in all categories of understory vegetation (palms, ferns, and non-fern herbaceous plants). BCI, CC, and KM41 had similar small sapling densities, ranging from 4.8-7.5/m 2. Within each forest, cation (Ca, Mg, K, and Na) availability was usually higher on more fertile soil orders (Inceptisols, Alfisols, and Entisols) than on more weathered soil types (Ultisols and Oxisols). Extractable P was highest at LS and CC and lowest on BCI (no data for KM41). Spatial autocorrelation was present for some variables in some transects to distances beyond our detection ability (\u3e25 m). Understory palm cover was negatively correlated with small sapling density at fine (1 m2 quadrat) and coarse spatial scales (among forests), although across forests the effect of palms was due entirely to the difference between LS and the other three forests. These results provide cross-site support for the hypothesis that understory cover by palms decreases the density of small saplings that comprise the advance regeneration of the forest

Comparison of the Coleoptera communities in leaf litter and rotten wood in Great Smoky Mountains National Park, USA

The community within extremely decayed downed coarse woody debris, here referred to as decay class V (CWD5), has never been systematically sampled. The presumption has been that rotten wood is eventually overrun by surrounding soil and litter inhabitants. Leaf litter and CWD5 were sampled for Coleoptera with a sifting/ Berlese technique at three primary and three secondary forest sites in Great Smoky Mountains National Park, Tennessee, USA, during fall 2006 and spring 2007. A total of 4261 adult beetle specimens, representing 216 lowest identifiable taxa within 159 genera and 28 families, were collected. Sixty-six species (31%) were represented by single individuals. Many more specimens (3471) and species (170) were collected from leaf litter than from CWD5 (790 and 111, respectively) but species accumulation curves showed that species richness was not significantly different between the two habitats. Eight species were significantly associated with CWD5, and 40 species were significantly associated with leaf litter. Species richness was significantly higher in secondary forest than primary forest, but more species were significantly associated with primary than secondary forest. Species richness was significantly higher in spring than fall. Notes on the biology and photographs of the 59 species represented by 10 or more specimens are given to provide an atlas of common eastern U.S. beetle species found in these habitats. Overall CWD5 is a distinct but overlooked habitat that may harbor numerous undescribed species or species considered rare

Comparison of Coleoptera emergent from various decay classes of downed coarse woody debris in Great Smoky Mountains National Park, USA

Coleoptera species composition and succession in downed woody debris habitats are poorly known in eastern North America. A photoeclector emergence chamber was used to concentrate Coleoptera that emerged from various decay classes of fine and coarse woody debris (FWD and CWD, respectively) collected in primary and secondary forest sites in Great Smoky Mountains National Park, Tennessee, USA. A total of 5673 adult beetle specimens, representing 305 lowest identifiable taxa within 227 genera and 51 families, was collected. One hundred fifteen species (38%) were represented by single individuals. Many more specimens and species were collected from CWD (4129 and 247, respectively) than from FWD (1544 and 162, respectively), but species richness accumulation curves were not significantly different. Many more specimens but an equal number of species were collected from primary forest (3347 and 207, respectively) than from secondary forest (2326 and 207, respectively). Species accumulation curves indicated higher richness in secondary forests. Based on a subset of 71 species represented by 10 or more specimens, 27 species were associated with fresh fine woody debris, 11 species with weathered fine woody debris, four with coarse woody debris decay class I, 14 with coarse woody debris decay class II, and eight with coarse woody debris decay class III–IV. Sixteen species were associated with secondary forests, whereas 28 species were associated with primary forests. Coarse woody debris decay class II taken in primary forests had highest absolute species richness with 156 species. In coarse woody debris species overlap decreased with increased difference in decay indicating faunal succession. Published works related to the study of the ecology of downed woody material are briefly summarized. Recommendations on developing a database of legacy trees for future researchers are given. Notes on the biology and photographs of the 71 species represented by 10 or more specimens are given to provide an atlas of eastern U.S. beetle species most commonly encountered in these habitats

Collpas: Activity hotspots for frugivorous bats (Phyllostomidae) in the Peruvian Amazon

In the SE Peruvian Amazon, large numbers of frugivorous bats regularly visit natural forest clearings known locally as collpas (which are also referred to as clay licks or mineral licks). Bats arrive at collpas to drink water that has accumulated in depressions created by larger geophagous mammals that consume exposed soil. Although collpa visitation is common, little is known about its causes and its ecological implications for the bat community. We compared patterns of use of collpas and non-collpa forest sites by bats in SE Peru. We mist netted bats at collpas and non-collpa sites during the dry season and compared abundance, species richness, species composition, sex ratio, and reproductive condition. More species were captured at collpas than at non-collpa sites, and collpas were visited almost exclusively by frugivores. Overall, bat-capture frequency and combined frugivorous bat-capture frequency were higher at collpas than at non-collpa sites, although some species of frugivorous bats were captured more frequently at non-collpa sites than at collpas (e.g., Carollia spp.). Irrespective of capture site, more female bats were pregnant or lactating than not, but there was a distinct female sex bias in bats that visited collpas: 70 percent of bats captured at collpas were female, whereas 44 percent of bats captured away from collpas were female. These patterns suggest that collpas may provide important resources for frugivorous bats in SE Peru, just as they are thought to provide important resources to the vertebrates that consume collpa soils. Accordingly, collpas are important conservation targets in the region. © 2008 The Author(s)