ABSTRACT Palms are among the most abundant trees in the Amazon and a key element in the structure and function of the forest. However, impacts of plant-herbivore interactions on this functionally important group, particularly under environmental disturbance, remain poorly understood. Here, we report, for the first time, an intense predation event of the palm Euterpe precatoria Mart., by capuchin monkeys (Sapajus apella). The event was likely driven by an ENSO drought-driven food scarcity and resulted in 70% mortality of palm individuals from a population in Central Amazonia. While arborescent palms may often appear resilient to short-term drought due to access to shallow water tables or internal water storage, shifts in plant-herbivore interactions during these disturbances could weaken this resilience and potentially impact palm populations in tropical forests.
Abstract Amazonian rainforests exhibit marked variation in seasonal flooding, water availability, climate, and light conditions, providing an important setting for understanding intraspecific functional adjustments. In this context, Evodianthus funifer (Poit.) Lindm., a species widely distributed across Amazonian rainforests, offers an excellent opportunity to investigate the role of intraspecific variation of functional traits in the persistence of species along environmental gradients. We hypothesized that E. funifer would exhibit intraspecific variation in leaf and stem traits, reflecting different ecological strategies across light and water gradients. We measured: leaf thickness (LT), stem specific density (SSD), leaf area (LA), specific leaf area (SLA), leaf dry matter content (LDMC), leaf density (LD), petiole length (PL), and plant height (H). Significant intraspecific variation associated with the contrasting forest types was detected in LA, LD, LT, PL, and SLA. Individuals in upland forests exhibited greater LT, a trait associated with enhanced water conservation, increased drought resistance, and reduced transpirational water loss under high irradiance. In turn, higher LA, LD, and PL values were recorded in white-water floodplain forests, reflecting strategies that increase photosynthetic surface area, reduce self-shading, and facilitate leaf positioning above seasonal flood levels. These trait trade-offs illustrate the capacity of E. funifer to adjust along environmental gradients. The classic acquisitive-conservative pattern did not apply to intraspecific variation among individuals of the studied species. Knowledge on these adjustments is essential for predicting plant responses to climate change and informing conservation strategies in Amazonian forests.
ABSTRACT Climate change is restructuring ecological dynamics worldwide, with particularly severe impacts in tropical regions, especially forested areas. The Amazon ecosystem is currently undergoing rapid deforestation. The owl family, Strigidae, is especially sensitive to habitat disturbance and may have strong population declines due to environmental change. In this study, the potential effects of climate change were investigated with the recently recognized Xingu Screech-owl (Megascops stangiaeDantas, Weckstein, Bates, Oliveira, Catanach & Aleixo 2021) by applying species distribution models (SDMs) to predict how climatically suitable habitat will change over time. The M. stangiae is likely to be negatively impacted because of the loss of climatically suitable areas, because it is dependent on preserved forests. The owls’ distribution was modeled using occurrence records and bioclimatic variables under the current emissions scenario, as well as two future projections: optimistic and pessimistic. We found that both scenarios predicted a loss of more than half of the area suitable for the owl. Although M. stangiae is currently classified as least concern (LC) by the International Union for Conservation of Nature Red List (IUCN), our findings indicate that the species may soon require being classified as critically endangered (CR). These results underscore the urgent need to understand the ecological consequences of climate change for Amazonian endemic species and to implement targeted conservation strategies.
Abstract Vanilla is the most economically important genus of Orchidaceae due to the aromatic potential of some species, and comprises approximately 120 taxa. Lipid and phenolic compounds play key roles in flavor, aroma, antioxidant activity, and potential health benefits. This study compared the lipid and phenolic composition of leaves from two Amazonian Vanilla species, one of which is better documented, using chromatographic and infrared analyses integrated with in situ histochemical localization. Histochemical tests detected proteins, total phenolics, polysaccharides, mucilages, tannins, lipids, starch, alkaloids, and lignin in both species. Chromatographic analyses revealed 81 substances, of which 46 were identified: 31 common to both species, five exclusive to V. labellopapillata, and 10 exclusive to V. pompona. Infrared spectra showed high similarity between hexane extracts. This pioneering study, particularly for V. labellopapillata, demonstrates comparable metabolic and histochemical profiles, highlighting its potential for sustainable use and contributing to the valorization of Brazilian biodiversity.
ABSTRACT We report the first record of Latheticomyia peruana Marques & Rafael, 2016 in Colombia, based on three males collected using a Malaise trap in a dense secondary forest in a mountainous ecosystem in the locality of Vereda El Jardín del Bosque, municipality of Florencia-Caquetá, at an altitude of 1139 m.a.s.l. This finding constitutes the first record of the genus Latheticomyia in Colombia and considerably extends the known distribution of L. peruana -- previously known only from its type locality in Quincemil, Cusco, Peru -- by approximately 1745 km northward to the Colombian Andean-Amazon region. In addition, we report intraspecific variation in colour, size and reproductive structures among the specimens in Peru and Colombia.
