Climate and atmospheric changes are impacting forest function and structure worldwide, but their effects on tropical forest diversity are unclear. Nowhere is the scientific challenge greater than in the Andes and the Amazon, which together include the world’s most diverse forests. Here, using 406 permanent plots spanning four decades of intact lowland and montane forest dynamics, we test for long-term change in species richness and assess the influence of climate and other variables. We show that, at a continental scale, species richness appears stable, but this masks substantial regional variation. Species richness increased in Northern Andean and Western Amazon plots, yet declined in the Central Andes, Guyana Shield and Central-Eastern Amazon. Overall, warmer, drier and more seasonal forests lost species, while those at higher elevations, in less fragmented areas and with faster rates of tree turnover experienced increases. Region-specific drivers, particularly precipitation seasonality and demographic factors, modulated these trends. The results highlight the diverse ways in which Amazon–Andes forests are changing and underscore the critical need to preserve large-scale ecosystem integrity to maintain local tree diversity. By doing so, Northern Andean forests in particular could serve as an important refuge for species increasingly displaced by climate change. This study examines long-term changes in species richness across tropical forests in the Andes and Amazon. Hotter, drier and more seasonal forests in the eastern and southern Amazon are losing species, while Northern Andean forests are accumulating species, acting as a refuge for climate-displaced species.
Intact tropical peatlands are globally important carbon stores, yet their hydrology remains poorly understood due to limited accessibility and sparse field measurements. In this study, we evaluate the potential of L-band Synthetic Aperture Radar (SAR) backscatter to monitor above-ground water level variation across diverse lowland peatland ecosystems in Colombia and Peru. Using vegetation structure metrics from GEDI with ancillary remote sensing data, we assess the sensitivity of L-band HH (L-HH) backscatter to water level changes. We observed significant linear correlations between water level and L-HH backscatter in white-sand ecosystems, palm swamp peatlands (open and forested) and seasonally flooded forests. Pole forest peatland water levels showed no correlation with L-HH backscatter. To predict these regressions, we developed ecosystem-specific multiple linear regression models using L-band HV backscatter, NDVI, and GEDI metrics, achieving strong predictive performance (R2 = 0.8-0.94). We further tested the temporal robustness of these relationships by predicting water levels across different years. Our results demonstrate the potential of combining L-band SAR with vegetation metrics derived from spaceborne data for regional monitoring of peatland hydrology. This provides a methodological pathway for integrating tropical peatland dynamics into carbon cycle models.
Galling arthropods are endophagous herbivorous that induce in plants the development of structures named galls. The abundance and richness of these organisms are influenced by many conditions, like the vegetation structure and seasonality. In the Brazilian Cerrado, the knowledge about the gall-inductors is still emerging, as well as the conditions that affect their community structure. Thus, this work aimed perform an inventory of galling arthropods in areas of cerrado sensu stricto in the Serra do Cabral State Park (Minas Gerais, Brazil), besides evaluate the effect of the vegetation structure and seasonality on the galling community. The host plant and gall sampling was performed in 20 plots (each 100 m2), including all woody plants alive, during September and November 2019, representing the dry and rainy seasons, respectively. Statistical analyses were carried out through GLM's, using data of vegetation structure and seasonality as explanatory variables. As results, we obtained 50 gall morphotypes corresponding to 20 botanical families, with Fabaceae presenting the greater gall richness (18 morphotypes). The galling arthropods were indeterminate in mostly, and among the identified, Cecidomyiidae (Diptera) was the richest group, responsible for 15 morphotypes. The shape of gall shape more frequent was lenticular (48%). We recovered the effect of the vegetation structure as significant on the galling arthropods richness, besides a higher diversity during the dry season. These results can be assigned to the correlation between the plant and galling diversities, and the endophagous biology of the immatures along the dry season, usually emerging only to reproduce in the rainy season. This work evidences the influence of the vegetation structure and seasonality on the community of galling arthropods in an area of Cerrado.
Myrciaria dubia (camu-camu) is a shrubby fruit tree native to the continental Amazon whose fruits have been intensively harvested from wild stands, potentially reducing effective population sizes. We quantified genetic diversity and population structure across seven wild Peruvian Amazon populations and delineated river-basin genetic units to guide provenance-aware germplasm conservation and breeding. We genotyped 254 individuals from the Napo, Ucayali, Nanay, Tahuayo, Putumayo, Tigre, and Curaray basins using six polymorphic microsatellite loci. Overall, 48 alleles were detected. Observed heterozygosity (0.149–0.483) was generally lower than expected heterozygosity (0.220–0.531), and population-level inbreeding coefficients (FIS = − 0.038–0.560) indicated significant heterozygote deficits in Napo, Curaray, and Tahuayo. The Putumayo population harbored nine private alleles, representing a unique genetic reservoir. Pairwise differentiation was substantial (FST = 0.093–0.660; Nei’s distance = 0.068–1.734), with the strongest divergence between Tigre and Ucayali. Neighbor-joining, Bayesian assignment, and Discriminant Analysis of Principal Components (DAPC) initially supported three major genetic units and highlighted Putumayo as genetically isolated; additionally, hierarchical STRUCTURE analyses resolved eight clusters, and DAPC distinguished seven population-specific groups. Analysis of molecular variance attributed 56.5
In this study parameters, correlations, and expected direct (DGg%) e indiretos (IGg%) genetic gains from mass selection and selection among progenies were estimated for growth, crown architecture, and reproductive traits in 105 open-pollinated Inga edulis progenies, 18 months old, established at three sites in the Peruvian Amazon, aiming at the simultaneous selection of multiple traits. Significant differences were detected among progenies for most traits within sites and joint sites. The estimation of narrow-sense heritabilities, mean-progeny heritability, and additive within progeny heritability showed that the traits are under genetic control and can be improved by mass selection or selection among progenies. The genotype-environment interaction was low for all traits, showing that selection can be carried out in only one of the site. The estimated genetic parameters were generally higher at site 1, indicating this site as more suitable for selection. The estimated genetic parameters were higher for diameter at breast height (D) in the joint site analysis, suggesting this trait as more suitable for direct selection. Genetic correlations were significantly greater than zero between D and the traits height, crown diameter, and fruit length, demonstrating that simultaneous genetic improvement of multiple traits is possible through direct selection for D. The greatest direct (DGg%) e indirect (IGg%) genetic gains were obtained through among and within progeny selection. The results show that crown architecture and reproductive traits can respond well to indirect selection based on direct selection for D.
