Simultaneous acoustic monitoring uncovers evidence of biodiversity loss and overlooked temporal variation in a threatened Amazonian bird community

Birds are frequently used as indicator taxon in ecology, but traditional surveys are prone to error and largely inadequate in the dense, speciose tropical forests where they are most needed. Passive acoustic monitoring (PAM) has the potential to address many of these pitfalls, providing unique advantages for both long-term monitoring and rapid biodiversity assessment. Here, we evaluate the effectiveness of PAM for characterizing spatiotemporal variation in avian species richness, diversity, vocal activity, and community composition in the Amazon basin global biodiversity hotspot. We employed an array of ten autonomous recording units (ARUs) spanning edge, degraded, and interior forest at a reserve on the deforestation frontier of Madre de Dios, Peru, a region featuring some of the richest, most complex avian assemblages on Earth. Recordings from 21 dawn-hours across three days at seven sites were manually annotated by a single observer. ARUs and manual annotation performed well as an inventory method, especially for midstory and understory species. Sites in edge and degraded habitats featured significantly lower avian species richness, Shannon diversity, and vocal activity levels than in the forest interior, patterns that replicate the findings of prior high-effort avian censuses in the region. We observed significant temporal variation between days; at all featured sites, vocal activity was highest on January 20th and lowest on January 31st. We demonstrated that novel annotation-generated metrics can work as effective proxies for abundance data and per-capita song rate, correlating with diversity indices and efficiently characterizing habitats at a level of detail unobtainable with human observers. Generalist species were significantly overrepresented in the soundscapes of interior forest, relative to their contributed share of species richness, and interior specialists were underrepresented, suggesting that the entire 191ha site is degraded. The between-days temporal variation that we documented, almost certainly overlooked without simultaneous monitoring, may obfuscate or distort the results of traditional surveys. Synthesis & Applications. We propose that PAM should become a cornerstone of biodiversity research. The standardization advantages demonstrated in this study, permanent storage, multi-taxa applications, and potential of automated identification make bioacoustics an ideal methodological avenue for guiding management and policy under rapid global change.

Amphibians and reptiles of the Atlantic Forest in Recôncavo Baiano, east Brazil: Cruz das Almas municipality

A list of amphibian and reptile species that occur in open and forested areas of the Atlantic Forest in the municipality of Cruz das Almas, in the Recôncavo Baiano, eastern Brazil is presented. Field sampling occurred between January 2015 to March 2019, totalling 117 samples distributed in three areas: Parque Florestal Mata de Cazuzinha, Mata da Cascalheira, and Riacho do Machado. A total of 1,848 individuals of 69 species (31 anurans, 14 lizards, 19 snakes, two amphisbaenians, and three testudines) was recorded. Additionally, one individual of Ophiodes striatus was found in Mata da Cascalheira after the end of sampling, totalling 15 lizard species and 70 herpetofaunal species. The prevalence of open-area species and the presence of Phyllopezus lutzae, Diploglossus lessonae, and Dryadosaura nordestina in interior forest patches are discussed. Additionally, a new record of the invasive terrapin Trachemys dorbigni in the State of Bahia is reported.

Influence of beech forests fragmentation of Stilsky Hillside on their microclimatic parameters

Estimation of changes in the microclimatic parameters of beech forests of the Stilsky Hillside, by measuring the water-temperature indicators of the soil regime and bryoindication, were performed. Fragmentation of forest causes significant changes in microclimatic parameters in bondary habitats areas, which leads to both biodiversity loss and a decrease of the unchanged forest areas. In fragmented beech forests, the influence of the edge effect on the water-temperature regime of soils is observed within a distance of 20-40 meters, but the eco-floristic structure of nemoral moss vegetation is stabilized only at a distance from 160 m. Thus, bryobiontes are a shown to be a sensitive marker of the microclimatic regime changes in a fragmented ecosystem. In the studied beeches Metzgeria furcata, Radula complanata, Anomodon attenuatus, A. viticulosus, Cirriphyllum crassinervium are indicators of the "interior forest". The determined amplitude of the edge effect indicates the fragmentation as a crucial factor on the small areas of forest and its role in the loss of climate-sensitive groups of biota, primarily mosses.

Trends in studies of edge influence on vegetation at human-created and natural forest edges across time and space

Forest edges, or boundaries between adjacent ecosystems, play important ecological roles. Both anthropogenic and natural forest edges affect vegetation while contributing to landscape heterogeneity. The recent proliferation of studies on vegetation at edges suggests that a comprehensive review of global edge studies is timely. We reviewed the literature on forest edges to identify trends in edge studies over time, to determine types and localities of studied edges, and to compare findings on edge influence. We found 446 studies conducted in 55 different countries that considered edge influence on vegetation structure and/or composition. Research on vegetation at anthropogenic edges has increased and expanded geographically, but studies are still scarce in some areas and at natural forest edges. Forest edges were generally characterized by greater species diversity and non-native species abundance than interior forest. Distance of edge influence on vegetation extended furthest at tropical anthropogenic forest edges compared to other edge types and locations. Edge influence on responses caused by indirect effects of edges generally extended further into the forest than on responses related to forest structure. Our findings indicate that vegetation characteristics differ between edge and forest types and should be considered in the sustainable management of heterogeneous forested landscapes.

The effects of a national highway on the Endangered golden-brown mouse lemur Microcebus ravelobensis in Ankarafantsika National Park, Madagascar

Although roads are often assumed to be barriers to the dispersal of arboreal species, there has been little empirical testing of this assumption. If arboreal animals are unable to cross roads, population subdivision may occur, or resources may become inaccessible. We tested the hypothesis that Route Nationale 4 (RN4), a paved highway, was a barrier to movement and dispersal of the Endangered golden-brown mouse lemur Microcebus ravelobensis in Ankarafantsika National Park, in north-west Madagascar. During June–August 2015 we conducted a capture–mark–recapture study at three sites: two adjacent to RN4 and one within intact forest without a potential barrier. During 2,294 trap nights we captured 120 golden-brown mouse lemurs 1,032 times. In roadside habitats we captured significantly more males than females, whereas the opposite was the case in interior forest habitat. We detected eighteen crossings of highway transects by nine individuals; however, all potential dispersal events involved males. In roadside habitat, movement was significantly inhibited in both males and females. We present some of the first data on the effects of roads on movement patterns in arboreal Malagasy mammals, showing species- and sex-biased effects of roads as dispersal barriers. Our findings indicate that roads may not be complete barriers to dispersal in lemurs. We recommend that conservation managers and scientists examine explicitly the effects of roads and natural arboreal bridges in Madagascar in future studies.

Regional and Local Genetic Variation in Japanese Stiltgrass (Microstegium vimineum)

Nonnative M. vimineum has been expanding rapidly in the eastern United States, where it can negatively affect plant communities. Locally, the species is assumed to spread from roadsides into nearby forests, where it can form dense populations after disturbances, especially in light gaps. Using microsatellite markers, we quantified patterns of genetic variation and structure among populations at nine sites in West Virginia. We then examined patterns of local dispersal within each population, focusing on subpopulations along the roadside, those coalescing nearby along the forest edge, and subpopulations in the interior forest. We found that levels of genetic variation of M. vimineum were relatively low overall across populations but with genetic structure present among populations (Fst = 0.60). Within populations, subpopulations along the roadside were genetically variable, containing 4 to 22 unique, multilocus genotypes. Many of these genotypes were also identified in the adjacent forest, consistent with local, diffusive spread from the roadway. However, several genotypes in the interior forest were unique to the population, indicating that dispersal from other sites may also occur. Overall, it appears that genetic diversity and structure in M. vimineum reflects a variety of processes, including localized dispersal and long-distance migration.

Diversity of small land mammals in a subtropical Atlantic forest in the western region of the state of Santa Catarina, southern Brazil

Small land mammals possess features that significantly influence the dynamics of ecosystems and participate in various levels of the food web. In the Brazilian Atlantic Forest the richness of these animals is high, which makes them even more ecologically and numerically relevant in this environment. In this context, we investigated the species composition of small mammals in an unexplored area of southern Brazil, and compared the species composition of this area with other Atlantic Forest regions in order to understand how this community is related to others. The study area was located in an interior Atlantic forest formation, at a transition region between deciduous and Araucaria forests. Small mammals were captured at five collection points using pitfall traps. We compared the species composition found in our studied area with the composition of other 11 studies in different regions by a cluster analysis, and we investigated the presence of spatial autocorrelation between communities with a Mantel test. We recorded 779 individuals from 21 species of small rodents (15 species) and marsupials (six species) during the 13 months of the collection period. This richness was high compared to other studies conducted in the Atlantic Forest formations near to coastline and in interior forest formations. This may be a result of the conditions provided by this transition area (deciduous and Araucaria forests), where could be found elements of the both forests formations, which probably allows the establishment of small mammal species from both forest types. Despite differences in sampling effort of the studies, our results suggest that the interior forest formations may harbor a number of species comparable to the formations near the coast. The species composition of this area was similar to those found in other interior forest formations with the same phytophysiognomy characteristics and at nearby regions, and it was less similar to the distant formations located in southeastern and northeastern Brazil and nearby to the coastline. This can be a result of both the spatial autocorrelation (i.e. more nearby communities tend to have more similar species composition) and the differences of forest characteristics among regions.

Avian responses to experimental harvest in southern boreal mixedwood shoreline forests: implications for riparian buffer management

Conventional management of shoreline forest in harvested boreal landscapes involves retention of treed buffer strips to provide habitat for wildlife species and protect aquatic habitats from deleterious effects of harvesting. With shoreline forests being considered for harvest in several jurisdictions, it is important to determine the potential impacts of this disturbance on birds. In this study, responses of riparian- and upland-nesting birds to three levels of harvest (0%–50%, 50%–75%, and 75%–100% within 100 m of the water) in shoreline forests around boreal wetlands were assessed 1 year before and each year for 4 years after harvest relative to unharvested reference sites. Upland-nesting species showed variable responses to harvest, with greatest declines in abundance of interior forest nesting species (e.g., Ovenbird, Seiurus aurocapillus L.) with the highest levels of harvest. Shrub-nesting and generalist species increased in abundance in harvest treatments relative to reference sites. Riparian birds showed little response to harvest, suggesting that shoreline forest harvest has little effect on their abundance up to 4 years after harvest. Retention of small buffers may not be an effective management strategy for conservation of birds occupying shoreline forests, particularly interior forest nesting species. We suggest that alternatives to conventional buffer management be explored.

Assessing rainforest restoration: the value of buffer strips for the recovery of rainforest remnants in Australia?s Wet Tropics

Throughout the tropics, forest remnants are under increasing pressure from habitat fragmentation and edge effects. To improve the conservation value of forest remnants, restoration plantings are used to accelerate and redirect ecological succession. Unfortunately, many restoration projects undergo little to no evaluation in achieving project goals. Here we evaluate the success of one common restoration technique, ?buffer strip planting,? at the Malanda Scrub in North Queensland, Australia. Buffer strips are used to reduce the impacts associated with edge effects and improve overall forest quality. To evaluate the success of the Malanda project, we compared the microclimate, understorey community structure and functional trait-state diversity (functional diversity) for a range of plant functional traits along the original forest edge, a reference forest edge, and the interior forest of the Malanda reserve. We found the buffer strip restored the original forest edge to interior forest conditions for the majority of measured features. Edge effects were not found more than 5 m from any measured edge, and edge effects penetrated to even shorter distances along the buffer strip edge. The buffer strip appeared to have a similar microclimate (here represented by soil temperature) and physical structure; however, it did not (after 14 years) closely resemble the interior forest floristically nor did it have the same functional diversity for measured traits. Results suggest that the buffer strip was successful in reducing edge effects but not in restoring the forest to original conditions within 14 years.