Seed germination is a physiological process strongly influenced by environmental factors, particularly temperature, which regulates both germination speed and percentage. Dormancy, however, can hinder seedling emergence even under apparently favorable environmental conditions. This study evaluated the germination and vigor of Banisteriopsis campestris (A. Juss.) Little seeds under different temperatures (15, 20, 25, 30, and 35 °C) and dormancy-breaking methods (mechanical scarification with sandpaper, wing cutting, immersion in hot water for 1 minute at 70, 80, and 90 °C, and imbibition at 20°C and 30 °C for 24 hours). The experiment was conducted between September and December 2017. Scarification accelerated initial imbibition, whereas intact seeds absorbed water more slowly. Germination was highest at 25 °C, which also resulted in the highest germination speed index (GSI). Extreme temperatures (15°C and 35 °C) significantly reduced both parameters. Among dormancy-breaking treatments, immersion in water at 70 °C for 1 minute yielded the highest germination percentage. GSI was higher in scarified seeds and in those imbibed at 20°C and 30 °C for 24 hours. Seed quality assessment showed a high proportion of empty seeds, with no significant differences among treatments, and higher mortality following sandpaper scarification. The highest residual dormancy was observed in seeds immersed in water at 90 °C.
Context: Managed tropical forests play a crucial role in climate regulation and in maintaining carbon stocks; however, integrated assessments that treat biomass and carbon as environmental assets remain limited. Originality/Contribution: This study integrates IPCC methodological approaches with the System of Environmental-Economic Accounting (SEEA) Central Framework to organize biomass and carbon stocks and flows as forest environmental assets under sustainable management. Objective: To evaluate the intertemporal dynamics of forest volume, biomass, and carbon stocks in a managed Amazonian forest. Methodology: Trees with a DBH ≥ 20 cm were analyzed in Annual Production Unit 4 of the Tapajós National Forest, from 2009 to 2022. Stem volume was converted into biomass, carbon, and CO₂ equivalents using conversion factors consistent with IPCC guidelines and regional references. Stock changes were estimated using the Gain–Loss and Stock-Difference methods, and exploratory multivariate analyses were performed to assess the structural and temporal coherence of forest variables. Results: Gross increment reached 87.38 m³ ha⁻¹, while total reductions amounted to 88.47 m³ ha⁻¹, i.e., forest volume was stable over the study period. After conversions, stability of biomass and carbon stocks was also observed, with minimal net emissions. Multivariate analysis revealed a temporal trajectory characterized by post-harvest structural reorganization followed by biomass accumulation within the monitored forest component. Conclusions: The results indicate that biomass and carbon stocks remained approximately stable in the monitored area throughout the study period. Environmental-economic accounting provided a consistent framework for organizing biomass and carbon stocks and flows, supporting the assessment of stock changes in managed Amazonian forests.
Powdery mildew is a fungal disease that poses a significant threat to global Eucalyptus cultivation; yet the species-level identity of causal agents often remains unresolved due to the limitations of morphological diagnosis. Here, the first estimates of powdery mildew incidence in Eucalyptus clonal mini gardens in Uruguay is provided, and the first approach of species identification within this system is presented. Surveys across three industrial nurseries revealed an overall powdery mildew incidence exceeding 70%, with noteworthy temporal variation and differences among clones. Molecular analyses, using DNA-based identification tools targeting the ITS and LSU rDNA regions, confirmed the presence of Podosphaera pannosa, previously identified in Eucalyptus grandis infections based only on morphological characteristics. Furthermore, this study reports, for the first time, P. aphanis, P. cfr. ruborum and an undescribed Podosphaera species infecting Eucalyptus dunnii in Uruguay. The results highlight the strong influence of host genotype on disease dynamics, with some clones exhibiting consistently lower susceptibility. These findings highlight the importance of integrating genetic resistance, cultural measures, and targeted fungicide applications into management strategies, as well as the critical need for active phytosanitary monitoring to track pathogen spread and inform control efforts. This work lays the foundation for future epidemiological studies and breeding programs aimed at mitigating the impact of powdery mildew on Uruguay’s commercially vital Eucalyptus forestry sector.
ABSTRACT The tropical forests in the Peruvian High Amazon are strategic ecosystems for biodiversity conservation; however, their structural complexity and successional patterns remain understudied, limiting the development of effective management plans. This study characterizes the floristic composition, Importance Value Index (IVI), diametric structure, and sociological position of the National Agrarian University of the Amazon Reserved Forest (BRUNAS). The study provides a quantitative diagnostic of the forest’s structural integrity to facilitate conservation strategies in high-altitude Amazonian remnants. Two permanent sampling plots (1.0 ha each) were established, recording all individuals with a diameter at breast height (DBH) ≥ 10 cm. Horizontal structure was determined through IVI, while vertical organization was assessed using sociological position analysis. The results revealed high taxonomic diversity, with a total richness of 113 and 114 species per plot. Senefeldera inclinata (IVI = 16.4%) and Parkia panurensis (IVI = 10.2%) emerged as the most dominant species. The diameter distribution followed an inverted "J" curve, with 85.5% of individuals concentrated in the lower DBH classes (10-20 cm), indicating vigorous natural regeneration. Vertical stratification showed a well-defined hierarchy where S. inclinata dominates the lower strata, whereas P. panurensis occupies the middle and upper layers. In conclusion, the BRUNAS forest exhibits a balanced structure and high resilience, typical of primary forest remnants. These findings demonstrate that stem diameter distribution and vertical organization analysis is essential to ensure the long-term conservation of these high-Amazonian ecosystems.
Forest road transport in Brazil faces challenges related to vehicle diversity and varying road conditions, with different proportions of roads having asphalt surfacing. In this context, the appropriate choice of vehicle type is decisive for operational performance and logistics costs. This study aimed to evaluate the operational performance of two B double vehicle models in forest road transport under different road surface conditions with asphalt surfacing. This research was based on telemetry data provided by a logistics company in the state of Paran & aacute;. Two types of Freight Vehicle Combinations (FVCs) were analyzed: heavy bogie (with hub reduction) and light bogie (without hub reduction), across four scenarios of roads with asphalt surfacing: C1 (up to 25%), C2 (25-50%), C3 (50-75%), and C4 (>75%). The evaluated variables included traveled distance, travel time, average speed, net load transported, and fuel consumption, from which indicators of operational efficiency, energy yield, and productive capacity were determined. Statistical analyses included univariate and multivariate tests (MANOVA and discriminant analysis). The results indicated significant differences between vehicle types and asphalt surfacing scenarios. The heavy bogie showed lower fuel consumption (8-12% less) and higher energy yield on routes with a lower proportion of asphalt surfacing, while the light bogie showed better performance on roads with a higher proportion of asphalt surfacing, with shorter travel time and higher average speed. The multivariate analysis confirmed that the proportion of asphalt surfacing is the main factor influencing average speed and energy efficiency. It is concluded that B double vehicles with heavy bogies are more suitable for routes with low asphalt surfacing, while those with light bogies are more appropriate for predominantly asphalt surfaced highways.
