Habitat Suitability, Population Structure and Conservation Status of Pinanga arinasae (Arecaceae), an Endemic Palm in Bali Island, Indonesia

The conservation of species should be based on knowledge of habitat requirements, population structure and conservation status. This knowledge is quite important to design conservation areas for species and to promote long-term persistence. In this study, we investigated habitat suitability, population size structure and conservation status of Pinanga arinasae in Bali. Plots with palms and adjacent areas with no palms were sampled to characterize key habitat variables. Habitat suitability was modeled using Artificial Neural Network (ANN) and Random Forest (RF) methods. The population size structure was characterized by counting and measuring the height and reproductive status of the individuals found in plots. Furthermore, we assessed the extinction risk of the species using the IUCN Red List Criteria. The ANN variables that best explained occurrence were litter depth, elevation, canopy openness and slope. The RF variables that best explained the data were elevation, litter depth, slope, and aspect. Both ANN and RF are robust models that can be used to predict the occurrence of P. arinasae. The population size structure included many seedlings, but juvenile and mature individuals were found in relatively small numbers. Based on the findings, we proposed Endangered B1+B2ab(i,ii,iii,v); D as the conservation status of P. arinasae.

Herpetofauna assemblage in two watershed areas of Kumoan Himalaya, Uttarakhand, India

We surveyed herpetofauna along the poorly-explored region of two watersheds of Kumoan Himalaya, Dabka and Khulgarh. Adaptive cluster method was used to collect forest floor reptiles, and stream transect was used for stream reptiles and amphibians. In total, 18 species of reptiles were recorded in two watersheds, with 15 and nine species recorded in Dabka and Khulgarh, respectively. Forest floor density of reptiles was 87.5/ha in Dabka and 77.7/ha in Khulgarh. In terms of species, Asymblepharus ladacensis and Lygosoma punctatus density were highest in Dabka and Khulgarh, respectively. Eight species of amphibians were recorded in Dabka with a density of 9.4/ha and four species in Khulgarh with density of 5.2/ha. In both watersheds, density of Euphlyctis cyanophlyctis was highest. Reptilian and amphibian diversity of Dabka was 1.52 and 1.23, respectively, and in Khulgarh 0.43 and 0.23, respectively. In both watersheds reptile density, diversity and richness decreased with increasing elevation. Reptile density showed a weak correlation with microhabitat features such as litter cover, litter depth, and soil moisture in both watersheds. Amphibian density was positively correlated with soil moisture, litter cover, and litter depth. Comparison showed that Dabka is richer and more diverse than Khulgarh, presumably because of the undisturbed habitat, broad and slow stream, and deeper forest litter of the former.

Estimating Fuel Loads and Structural Characteristics of Shrub Communities by Using Terrestrial Laser Scanning

Forest fuel loads and structural characteristics strongly affect fire behavior, regulating the rate of spread, fireline intensity, and flame length. Accurate fuel characterization, including disaggregation of the fuel load by size classes, is therefore essential to obtain reliable predictions from fire behavior simulators and to support decision-making in fuel management and fire hazard prediction. A total of 55 sample plots of four of the main non-tree covered shrub communities in NW Spain were non-destructively sampled to estimate litter depth and shrub cover and height for species. Fuel loads were estimated from species-specific equations. Moreover, a single terrestrial laser scanning (TLS) scan was collected in each sample plot and features related to the vertical and horizontal distribution of the cloud points were calculated. Two alternative approaches for estimating size-disaggregated fuel loads and live/dead fractions from TLS data were compared: (i) a two-steps indirect estimation approach (IE) based on fitting three equations to estimate shrub height and cover and litter depth from TLS data and then use those estimates as inputs of the existing species-specific fuel load equations by size fractions based on these three variables; and (ii) a direct estimation approach (DE), consisting of fitting seven equations, one for each fuel fraction, to relate the fuel load estimates to TLS data. Overall, the direct approach produced more balanced goodness-of-fit statistics for the seven fractions considered jointly, suggesting that it performed better than the indirect approach, with equations explaining more than 80% of the observed variability for all species and fractions, except the litter loads.

Stochastic and deterministic processes differently affect the community structure of edaphic mites (Acari: Mesostigmata) in the southern Brazilian Atlantic Forest

Most mesostigmatid mites (Arachnida: Parasitiformes) are soil-dwelling predators, feeding predominantly on detritivorous and fungivorous invertebrates. Little is known about the role of environmental and spatial parameters in driving the structure of their local communities. The aim of this study is to assess the relative importance of environmental/spatial parameters in different scales and microhabitats on the community structure of edaphic mesostigmatid mites in the southern Brazilian Atlantic Forest. Soil and litter samples were collected in 20 sites (six subsamples per microhabitat per site; N = 240 samples) distant from each other over ranges varying from 100 m to seven km. Geographic distances between sampling sites and spatial eigenfunctions were used as proxies of stochastic processes to assess the influence of spatial parameters on mite community structure. Environmental parameters included soil grain size, moisture and organic matter, vegetation structure, litter depth and percentage of leaves, branches, and thin roots in plant litter. We collected 1135 Mesostigmata individuals from 77 species/morphospecies. Mite composition strongly differed between soil and litter microhabitats. Mite communities geographically closer were more similar to each other in terms of Mesostigmata composition than expected if there is no spatial structure. Litter depth, soil organic matter and soil moisture significantly contributed to edaphic mite community structure. Deterministic processes predominated in explaining the composition of the litter fauna, while the composition of the soil fauna was more sensitive to stochastic processes. Our results provide evidence that the composition of Mesostigmata communities not only differ between microhabitats, but they are differently structured by environmental and spatial parameters depending on the scale. This provides new insight into the processes affecting of mite diversity within soil ecosystem at fine and broad scales, and highlights the importance of the spatial proximity and microhabitat in driving the composition of mite communities.

Wildfire and Prescribed Fire Effects on Forest Floor Properties and Erosion Potential in the Central Appalachian Region, USA

Short- and long-term impacts of wildland fires on forest floor properties and erosion potential were examined at three locations in the Central Appalachian region, U.S.A. In 2018, two wildfires were investigated within six months of burning on the George Washington–Jefferson National Forest (GWJNF) in Bland County, Virginia and the Monongahela National Forest (MNF) in Grant County, West Virginia. An additional wildfire was studied eight years post-fire on the Fishburn Forest (FF) in Montgomery County, Virginia. A 2018 prescribed fire was also studied within six months of burning on the MNF in Pendleton County, West Virginia. Litter and duff consumption were examined to evaluate fire severity and char heights were measured to better understand fire intensity. The Universal Soil Loss Equation for forestlands (USLE-Forest) was utilized to estimate potential erosion values. For the 2018 comparisons, litter depth was least as a result of the wildfires on both the MNF and GWJNF (p < 0.001). Wildfire burned duff depths in 2018 did not differ from unburned duff depths on either the MNF or GWJNF. Eight years after the FF wildfire, post-fire litter depth was less than that of an adjacent non-burned forest (p = 0.29) and duff depth was greater than that of an adjacent non-burned forest (p = 0.76). Mean GWJNF wildfire char heights were greatest of all disturbance regimes at 10.0 m, indicating high fire intensity, followed by the MNF wildfire and then the MNF prescribed fire. USLE-Forest potential erosion estimates were greatest on the MNF wildfire at 21.6 Mg soil ha−1 year−1 due to slope steepness. The next largest USLE-Forest value was 6.9 Mg soil ha−1 year−1 on the GWJNF wildfire. Both the prescribed fire and the 2010 wildfire USLE-Forest values were approximately 0.00 Mg soil ha−1 year−1. Implications for potential long-term soil erosion resulting from similar wildfires in Central Appalachian forests appeared to be minimal given the 2010 wildfire results.

VERTICAL SEGREGATION IN PRISTIMANTIS SPECIES FROM A BAMBOO FOREST IN SOUTHEAST OF AMAZONIA, BRAZIL

In this work, the vertical stratification in Pristimantis species was studied in a remanescent forest dominated by bamboo in the southwest region of the Amazon. The field work was carried out between December 2012 and May 2013. The differences in height of the perch were analyzed interspecifically, and intraspecific in relation to the structure of the vegetation. A total of four species were recorded, Pristimantis fenestratus being the most abundant and occurring in all sampling units. There was significant interspecific difference in perch height, as well as between adults and juveniles. For P. fenestratus, there was no differentiation of segregation between sampling units. The structure of the vegetation did not explain the preference of heights; however, leaf litter depth influenced its vertical stratification. More data and occurrences are needed in all sampling units to infer better explanations.

Mitigating Particulate Matter Generation in a Commercial Cage-Free Hen House

Compared to conventional cage production systems, cage-free (CF) hen housing offers hens more space and opportunities to exercise their natural behaviors (e.g., perching, dust bathing, and foraging). However, CF housing poses a number of inherent environmental challenges, among which are high levels of particulate matter (PM) and ammonia (NH3). Spraying water on CF hen house litter (e.g., 125 mL m-2 per cm of litter depth) has been shown to mitigate generation of PM by 60% to 70% in our previous lab-scale tests. The objectives of this study were to verify the lab-scale findings of PM reduction in a commercial CF hen house in central Iowa and to evaluate the indoor air quality (e.g., PM and NH3 concentrations) and litter moisture content as affected by water spray. The commercial CF house had a nominal capacity of 50,000 laying hens and measured 154 m × 21.3 m × 3.0 m (L × W × H). A water sprinkling system was installed in half of the hen house in the length direction (treatment section), while the other half of the hen house served as the control. For each of the three trials conducted during the winter of 2017-2018, spray dosage (125 mL H2O m-2 per cm of litter depth) was set according to the initial litter depth before spraying. Results show that PM concentration was reduced by 37% to 51% in the treatment section of the CF hen house. The lower reduction efficiency in the field experiment than in the lab-scale tests was partially attributed to the fact that water spray in the commercial hen house was applied only to the open litter area, and not the litter area under the aviary system, due to limited space. Adjusting the spray dosage according to litter depth is necessary for maintaining an appreciable reduction efficiency. Litter moisture content in the treatment section was 9% to 14% higher than in the control section (15.6% vs. 14% in trial 1, 14.6% vs. 12.2% in trial 2, and 17.7% vs. 14.9% in trial 3), but NH3 concentrations in the treatment and control sections were similar during the field experiment. Keywords: Air quality, Alternative hen housing, Dust, Litter moisture content.

Feral-horse impacts on corroboree frog habitat in the Australian Alps

Context Introduced herbivores can have a substantial impact on native plants and animals, particularly in ecosystems that do not share a recent evolutionary history with similar herbivore species. The feral horse, Equus caballus, has a widespread but patchy distribution in Australia, with large populations present in national parks in the Australian Alps. There are few peer-reviewed studies of the impacts of feral horses on ecosystems in this region. However, impacts could be substantial, particularly in wetland and riparian environments that are focal points for horse activity and sensitive to trampling and physical disturbance. Aims In the present study, we used replicated horse exclosures to investigate the effects of feral horses on breeding habitat of the critically endangered northern corroboree frog, Pseudophryne pengilleyi, in the Australian Alps. Methods Pseudophryne pengilleyi constructs nests and lays eggs in dense litter surrounding small, seasonally flooded wetland pools. In 2010, we sampled the litter depth adjacent to pools at eight long-term P. pengilleyi monitoring sites. In 2011, horse exclosures were established at each of the eight sites, such that less than half of the wetland area was inside the exclosure. In 2015, we measured litter depth surrounding pools inside and outside the exclosures, as well as at three additional sites where feral horses were absent. Key results We found that the pool-edge litter was 1.9 times deeper in areas without horses (inside horse-exclosure plots and horse-free sites) than in areas accessible to horses (unfenced areas in horse-occupied sites). Conclusions Our study has presented experimental evidence that horse grazing and trampling reduce breeding-habitat quality for P. pengilleyi, which could result in reduced reproduction success. Implications Ensuring the persistence of high-quality habitat is crucial for the conservation of P. pengilleyi, particularly given the severity of the decline of this species associated with chytrid fungus. Our results have provided direct evidence of a negative feral-horse impact on the habitat of a threatened animal species in the Australian Alps.