Abundance of the Resplendent Quetzal Pharomachrus mocinno (Trogoniformes, Trogonidae) in the tourist sector of a cloud forest reserve

The Resplendent Quetzal (Pharomachrus mocinno) exhibits characteristics that are common to species prone to extinction, such as occurring at low densities, presenting strict ecological requirements, and inhabiting locations with high rates of degradation. The lack of data on the abundance of threatened species makes it difficult to make management decisions and does not allow to know trends over time, which is essential for conservation in their distribution areas. The abundance and density of the Resplendent Quetzal was estimated from audio/visual detections analyzed with distance sampling techniques. Data was collected in the public use sector of La Tigra National Park, a reserve of virgin and secondary growth cloud forest in Honduras, Central America. A population N = 136 was found with a density of 40 quetzals per km2. There are no systematic studies on the population size and density of the species for this site since 1979, in which a population of 145 quetzals was reported. The estimation of the Resplendent Quetzal population for the total area of the park is a main research priority, which will make it possible to evaluate the viability of the species and the establishment of a new baseline for conservation policies and environmental education efforts in the area of influence.

A morphological, anatomical and palynological study of Aethionema lepidioides (Brassicaceae) - an endangered species endemic to Turkey

Aethionema lepidioides Hub.-Mor. is an endangered endemic species in Turkey with a very narrow natural distribution area. The present study aims to reveal the structural features of this species. For this purpose, its unknown morphological features – such as leaf, petal, sepal dimensions and shapes, filament and anther lengths, as well as seed dimensions, shape, colour and micromorphology – have been studied for the first time. To reveal the pollen characteristics of Ae. lepidioides, light microscope and SEM studies were conducted. Additionally, in the present study the anatomical features of Ae. lepidioides were also studied for the first time. The Ae. lepidioides leaves were found to be linear-oblanceolate, with an entire margin and a subacute to obtuse apex. The seeds were found to be dark brown and oval-shaped, with reticulated surface ornamentation. Anatomical studies found roots in the secondary growth stage, with xylem-filled pith. The stem was in the primary growth stage, featuring a multi-layer cortex under its outermost single-layered epidermis, a pronounced endodermis and a central cylinder beneath. The leaves were thick, amphistomatic and covered with a prominent wax layer. Their mesophyll was equifacial, and their stoma type was anisocytic. A stomatal index of 26 was found for the upper epidermis, while a corresponding index of 28.4 was found for the lower epidermis. The pollens were monad, radially symmetrical and isopolar. The pollen type was colpate, and the pollen shape was found to be prolate-spheroidal with a P/E ratio of 1.08.

Transformation of Selected Fusarium Toxins and Their Masked Forms during Malting of Various Cultivars of Wheat

This study investigated the impact of malting of six wheat cultivars inoculated with Fusarium culmorum on the dynamics of content changes of selected Fusarium toxins. The grains of all the tested cultivars showed a high content of deoxynivalenol (DON), zearalenone (ZEN), and their derivatives, whereas nivalenol (NIV) and its glucoside were found only in the Legenda cultivar. Our experiments confirmed that the malting process of wheat grain enables the secondary growth of Fusarium, and mycotoxin biosynthesis. The levels of toxins in malt were few-fold higher than those in grain; an especially high increase was noted in the case of ZEN and its sulfate as the optimal temperature and pH conditions for the biosynthesis of these toxins by the pathogen are similar to those used in the grain malting process. This is the first paper reporting that during the malting process, biosynthesis of ZEN sulfate occurs, instead of glycosylation, which is a typical modification of mycotoxins by plant detoxication enzymes.

Carbon storage estimation in a secondary tropical forest at CIEE Sustainability Center, Monteverde, Costa Rica

Secondary growth tropical rainforests have the potential to sequester large amounts of atmospheric carbon dioxide and as such are an important carbon sink. To evaluate a local forest, a Carbon Neutrality Program was initiated at the Council on International Educational Exchange, San Luis Campus, Monteverde, Costa Rica. The study was conducted on 50 hectares of forest classified as Premontane Wet Forest. The forest, part of the Arenal-Monteverde Protected Zone, is estimated to be aproximately 50 years old and is in the upper regions of the San Luis valley at 1100 m elevation. Assessment of the carbon stock in trees was carried out in two permanent, 1 hectare plots, 100 m by 100 m, Camino Real and Zapote. The plots were divided into 25 subplots, 20 m by 20 m totaling 400 m2 per subplot. Ten subplots in each area were studied which represented 1.6% the total surface area of the forest. All of the trees were measured within the subplots that had a diameter at breast height ≥ 10 cm and the height of 10% of the trees measured. The estimated total CO2 sequestered by the campus forest was 18,210 ton (in 2019).

Growth of Palm Trees and Woods in the Urban Environment

Trees in the urban environment provide several ecosystem benefits to the population, such as decreasing temperature, increasing humidity, shading, improving air quality, as well as physical and mental well-being. These can be enhanced through the knowledge of the growth of the trees in function of the characteristics of the place where they are inserted. Thus, the objective was to estimate the growth in diameter, height and volume of forest species in the urban environment, in Viçosa, Minas Gerais, Brazil. For this, woody individuals and palm trees present in the urban afforestation of the headquarters campus of the Federal University of Viçosa were selected based on age and had their diameter, breast height and height measured. Allometric equations specific to the study site were used to estimate their volume, and through the relationship with age, the average annual increment was obtained. Woody individuals showed a growth rate in volume of 0,0279 ± 0,0274 m³ year-1 and palm trees, 0,0139 ± 0,0119 m³ year-1. The differences in the average annual increase in volume found between woody individuals and palm trees may be due to morphological differences that affect the secondary growth of individuals. The growth rate of trees in the urban environment is higher when compared to those in forest fragments and experimental plantings. The decrease in growth rates with increasing age was expected due to the relationship between them being of the non-linear type, following a sigmoidal model.

Colloidal Synthesis of MoSe2/WSe2 Heterostructure Nanoflowers via Two-Step Growth

The ability to control the active edge sites of transition metal dichalcogenides (TMDs) is crucial for modulating their chemical activity for various electrochemical applications, including hydrogen evolution reactions. In this study, we demonstrate a colloidal synthetic method to prepare core-shell-like heterostructures composed of MoSe2 and WSe2 via a two-step sequential growth. By overgrowing WSe2 on the surface of preexisting MoSe2 nanosheet edges, MoSe2-core/WSe2-shell heterostructures were successfully obtained. Systematic comparisons of the secondary growth time and sequential order of growth suggest that the low synthetic temperature conditions allow the stable overgrowth of shells rich in WSe2 on top of the core of MoSe2 with low Gibbs formation energy. The electrochemical analysis confirms that the catalytic activity correlates to the core-shell composition variation. Our results propose a new strategy to control the edge site activity of TMD materials prepared by colloidal synthesis, which is applicable to diverse electrochemical applications.