Search

Southern U.S. forests are essential for carbon storage and timber production but are increasingly impacted by natural disturbances, highlighting the need to understand their dynamics and recovery. Canopy cover is a key indicator of forest health and resilience. Advances in remote sensing, such as NASA's GEDI spaceborne LiDAR, enable more precise mapping of canopy cover. Although GEDI provides accurate data, its limited spatial coverage restricts large-scale assessments. To address this, we combined GEDI with Synthetic Aperture Radar (SAR), and optical imagery (Sentinel-1 GRD and Landsat–Sentinel Harmonized (HLS)) data to create a comprehensive canopy cover map for Florida. Using a random forest algorithm, our model achieved an R2 of 0.69, RMSD of 0.17, and MD of 0.001, based on out-of-bag samples for internal validation. Geographic coordinates and the red spectral channel emerged as the most influential predictors. External validation with airborne laser scanning (ALS) data across three sites yielded an R2 of 0.70, RMSD of 0.29, and MD of −0.22, confirming the model's accuracy and robustness in unseen areas. Statewide analysis showed lower canopy cover in southern versus northern Florida, with wetland forests exhibiting higher cover than upland sites. This study demonstrates the potential of integrating multiple remote sensing datasets to produce accurate vegetation maps, supporting forest management and sustainability efforts in Florida. [ABSTRACT FROM AUTHOR]

Copyright of Functional Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ciência Florestal (01039954) is the property of Ciencia Florestal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study assessed the impact of altitude, precipitation, and soil conditions on species richness (SR), phylogenetic diversity (PD), and functional diversity (FD) standardized effect sizes in subtropical Brazilian Atlantic Forest tree communities. We considered specific trait information (FDs) for FD, reflecting recent adaptive evolution, contrasting with deeper phylogenetic constraints in FD. Three functional traits (leaf area‐LA, wood density‐WD, and seed mass‐SM) were examined for their response to these gradients. Generalized least squares models with environmental variables as predictors and diversity metrics as response variables were used, and a fourth‐corner correlation test explored trait‐environmental relationships. SR decreased with altitude, while PD increased, indicating niche convergence at higher altitudes. Leaf area and seed mass diversity also decreased with altitude. For LA, both FD and FDs were significant, reflecting filtering processes influenced by phylogenetic inheritance and recent trait evolution. For SM, only the specific trait structure responded to altitude. LA and SM showed significant trait‐environmental relationships, with smaller‐leaved and lighter‐seeded species dominant at higher altitudes. Soil gradients affect diversity. Fertile soils have a wider range of LA, indicating coexistence of species with different nutrient acquisition strategies. WD variation is lower for FDs. SM diversity has different relationships with soil fertility for FDs and FD, suggesting phylogeny influences trait variation. Soil pH influences WD and LA under acidic soils, with deeper phylogenetic constraints (FD). Environmental factors impact tree communities, with evidence of trait variation constraints driven by conditions and resources. Subtropical Atlantic forests' tree assemblies are mainly influenced by altitude, pH, and soil fertility, selecting fewer species and narrower trait spectra under specific conditions (e.g., higher altitudes, pH). Functional diversity patterns reflect both phylogenetic and recent evolution constraints, with varying strength across traits and conditions. These findings highlight the intricate processes shaping long‐lived species assembly across diverse environments in the Southern Brazilian Atlantic Forest. [ABSTRACT FROM AUTHOR]

The study aimed to evaluate the degree of conservation, analyse the structural and floristic similarity of the woody and herbaceous layers of two ecotone forest communities and evaluate the indicator species of a Mixed Ombrophilous Forest (MOF) and Dense Ombrophilous Forest (DOF). We outlined 30 sampling units of 100 m2 in each area (West and East), where we measured three woody and one herbaceous layers. Each species was classified into ecological groups, phytogeographic distribution and conservation status. We selected other 13 studies performed on similar ecosystems to carry out cluster and indicator species analyses. We registered 213 species, arranged into 63 families. The richest families were Myrtaceae, Lauraceae and Fabaceae. In the woody layers Araucaria angustifolia, Allophylus edulis and Cupania vernalis highlighted in West area, while Casearia sylvestris, Cyathea phalerata and Ilex paraguariensis highlighted in East area. Ctenitis paranaensis predominates in herbaceous layer of both areas. Our cluster analysis has formed two groups (MOF; DOF), including both study areas in MOF group. The study areas are in a maturation process. Serra da Baitaca State Park presents high conservationist importance. We list indicator species of montane MOF and DOF forests in the Paraná State, which can be used for monitoring alterations in vegetation caused by environmental changes. [ABSTRACT FROM AUTHOR]

Giant Araucaria trees in Brazilian Atlantic forests today are rare but remain critically important for structuring these ecosystems, providing unique and rare habitat elements that can serve as points of reference for their management. Old‐growth Araucaria trees, with their complex crowns and big trunk cavities, supply more important ecological services than smaller trees with simple crowns. Forest ecology managers lack information on the old‐growth structures of Brazilian Araucaria forest, their ecological importance and their potential societal values and uses. In this study, we investigated old‐growth attributes of Araucaria angustifolia and relate their wide structural variability to ecological management goals. In this study, we used currently available data on the last large old Araucaria trees, as well as our own new records, from large trees of 1.6–3.2 m diameter in the Araucaria forests in southern Brazil. In order to quantify the structural attributes of these remnant trees, their main trunks, any reiterated canopy trunks and trunk cavities were measured for diameters, heights and volumes. These old‐growth trees had an average height of 38.4 m, and total tree volumes ranged from 21.5 to 106.6 m3. The biggest reiterated trunk was 1.1 m in diameter and 17 m long, which is larger than most adult Araucaria trees. Number of cavities and number of reiterated trunks were all significantly related to the diameters of these large remnant Araucaria trees; both features are absent in Araucaria <50 cm in diameter. The maximum diameter and average length of reiterated trunks were correlated with the number and size of trunk cavities. Commercial wood values and uses are limited for all trees with main trunk diameters exceeding 1.5 m due to large internal cavities—however, these rare, relictual old‐growth structures are of high ecological value for the local fauna and flora. [ABSTRACT FROM AUTHOR]

Copyright of Ciência Florestal (01039954) is the property of Ciencia Florestal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Rodriguésia is the property of Revista Rodriguesia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The understanding of the succession process is a fundamental condition in defining strategies for the conservation and sustainable use of forest ecosystems. Therefore, we aimed at testing which ecological factors affect short-term successional changes in the upper-montane forests of the "Planalto Sul Catarinense" Region, Brazil. We evaluated the influence of propagules source, soil seed bank, edaphic and topographic variables, nucleating elements and natural regeneration floristic-structural composition on demographic rates of tree-shrub regenerating component in three disturbed open vegetation areas at São Joaquim National Park. We inventoried the regenerative component in 2014, 2015 and 2016, within one 20x100 m transect in each area. Afterwards, demographic rates were determined for each period. The influence of explicative variables on demographic rates of the regenerating component was tested through the Generalized Least Square (GLS) model. We found an increment in both individuals and richness over time. When analyzing the influence of the explanatory variables on the speed of the successional process, we observed that only the floristic-structural composition of the natural regeneration was determinant. We conclude that the speed of the represented succession is, to a large extent, a feature related to the phase of the successional trajectory in which the vegetation is found. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Agricultural Sciences / Revista Brasileira de Ciências Agrárias is the property of Universidade Federal Rural de Pernambuco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aim: Predictions of plant traits over space and time are increasingly used to improve our understanding of plant community responses to global environmental change. A necessary step forward is to assess the reliability of global trait predictions. In this study, we predict community mean plant traits at the global scale and present a systematic evaluation of their reliability in terms of the accuracy of the models, ecological realism and various sources of uncertainty. Location: Global. Time period: Present. Major taxa studied: Vascular plants. Methods: We predicted global distributions of community mean specific leaf area, leaf nitrogen concentration, plant height and wood density with an ensemble modelling approach based on georeferenced, locally measured trait data representative of the plant community. We assessed the predictive performance of the models, the plausibility of predicted trait combinations, the influence of data quality, and the uncertainty across geographical space attributed to spatial extrapolation and diverging model predictions. Results: Ensemble predictions of community mean plant height, specific leaf area and wood density resulted in ecologically plausible trait–environment relationships and trait–trait combinations. Leaf nitrogen concentration, however, could not be predicted reliably. The ensemble approach was better at predicting community trait means than any of the individual modelling techniques, which varied greatly in predictive performance and led to divergent predictions, mostly in African deserts and the Arctic, where predictions were also extrapolated. High data quality (i.e., including intraspecific variability and a representative species sample) increased model performance by 28%. Main conclusions: Plant community traits can be predicted reliably at the global scale when using an ensemble approach and high‐quality data for traits that mostly respond to large‐scale environmental factors. We recommend applying ensemble forecasting to account for model uncertainty, using representative trait data, and more routinely assessing the reliability of trait predictions. [ABSTRACT FROM AUTHOR]

Analysis of the structure, diversity, and demographic dynamics of tree assemblages in tropical forests is especially important in order to evaluate local and regional successional trajectories.We conducted a long‐term study to investigate how the structure, species richness, and diversity of secondary tropical forests change over time. Trees (DBH ≥ 5 cm) in the Atlantic Forest of southern Brazil were sampled twice during a 10‐year period (2007 and 2017) in six stands (1 ha each) that varied in age from their last disturbance (25, 60, 75, 90, and more than 100 years). We compared forest structure (abundance and basal area), species richness, alpha diversity, demographic rates (mortality, recruitment, and loss or gain in basal area), species composition, spatial beta diversity, and temporal beta diversity (based on turnover and nestedness indices) among stand ages and study years.Demographic rates recorded in a 10‐year interval indicate a rapid and dynamic process of species substitution and structural changes. Structural recovery occurred faster than beta diversity and species composition recovery. The successional gradient showed a pattern of species trade‐off over time, with less spatial dissimilarity and faster demographic rates in younger stands. As stands grow older, they show larger spatial turnover of species than younger stands, making them more stochastic in relation to species composition. Stands appear to split chronologically to some extent, but not across a straightforward linear axis, reflecting stochastic changes, providing evidence for the formation of a nonequilibrium community.Policy implications. These results reiterate the complexity and variability in forest succession and serve as a reference for the evaluation and monitoring of local management and conservation actions and for defining regional strategies that consider the diversity of local successional trajectories to evaluate the effectiveness of restoration measures in secondary forests of the Atlantic Forest biome. [ABSTRACT FROM AUTHOR]

Across tropical and subtropical forests and savannas, variation in temperature, precipitation, and edaphic preferences is related to functional characteristics turnover across space. Here we use a unique dataset of 133 woody community sites (127 ha sample and 1351 species included) covering six forest and savanna vegetation types, to reexamine structural and functional patterns and their environmental drivers. Furthermore, we evaluated whether vegetation types (identified by floristic and environmental characteristics) consistently exhibited structural and functional distinctions. We also assessed the importance of vegetation type identity by quantifying the additional contribution of vegetation type in explaining vegetation patterns when compared to environmental models that include temperature, climate, soil and fire. Our variables included fundamental structural characteristics such as number of trees, basal area and average diameter, alongside functional attributes such as aboveground carbon stock, wood density and representativity of multi-stemmed trees. We also include the innovative approach to representativeness of species with compound leaves, which is a proxy for ecological patterns. We found that vegetation types have consistent differentiation for most structural and functional variables, so that vegetation types exist as distinct units beyond floristic differentiation. In addition, environmental variables play an important role in vegetation patterns, but associated with differences between vegetation types for most variables. Overall, vegetation types attributes serve as important drivers of most vegetation variables, contributing up to 30% to the explanation of variable patterns. Our work is the first to explore structural and functional variations among Brazilian tropical and subtropical vegetation types in a broad scale, reviewing ecological patterns previously defined by specific work or carried out using other approaches. Furthermore, our work contributing to the ecological patterns of Brazilian vegetation, in addition to producing reference values that can be used in conservation projects. • Vegetation types are discrete units regarding functional and structural variables. • Vegetation type contributes to the explanation of structural and functional attributes along the environmental gradients. • Climatic and soil variables drive both structural and functional attributes. • Compound-leaf variables are a powerful proxy for functional information. [ABSTRACT FROM AUTHOR]

Copyright of Bosque (03048799) is the property of Facultad de Ciencias Forestales, Universidad Austral de Chile and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The study of tree community dynamics may help improve our understanding of forest ecosystem function. Here, we aimed to investigate the influences of climate, soils, landscape, forest structure, and chronic anthropogenic disturbances on tree community demography in the fragments of Araucaria Forest in Southern Brazil. Nine forest fragments were inventoried between 2008 and 2012, and were inventoried again from three to six years later. For the tree community in each forest remnant, we calculated mortality, recruitment, basal area loss- and gain, net changes, and turnover rates. For each study area, we also measured altitude, climate, soil type, fragment patch metrics, cattle presence, and tree component structure. We used Principal Component Analyses (PCA) to order the multivariate data (Tree community dynamics: demographic rates; Climate: altitude + climate; Patch metric: area + core + shape + Cai). The relationships between the patterns of the dynamics and the explanatory variables were subjected to regression tree analyses and t tests. We found that the Araucaria Forest dynamics mainly varied in terms of tree mortality and basal area loss rates. In general, mortality and basal area loss rates were smaller within larger fragments, which had a greater proportion of interior areas. Therefore, we concluded that anthropogenic fragmentation is a key driver of tree community dynamics in the Araucaria Forest of Southern Brazil. Based on our results, we would recommend (i) the protection of small and large tracts of forest fragments; and (ii) incentives to promote the silviculture of the most relevant timber species, the light demanding Araucaria angustifolia , in the deforested lands of the region. [ABSTRACT FROM AUTHOR]

Timber management directly influences the population dynamics of tree species, like Copaifera spp. (copaíba), which provide oil-resin with ecological and economic importance. The aim of this study was to evaluate the structure and population dynamics of Copaifera in unmanaged and managed stands by reduced-impact logging (RIL) in eastern Amazon in Pará state, Brazil. Based on a stem map of the study area, 40 Copaifera trees were randomly selected, where an equal number of trees were selected in managed and unmanaged stands. A transect of 10 Χ100 m was centered at each tree (50 m each side) to assess Copaifera regeneration. Transects were subdivided into ten plots, of which six were systematically chosen to assess the height, diameter and number of Copaifera seedlings and saplings. The field assessment occurred in 2011 and 2013. To estimate the amount of sunlight transmitted to the forest floor, we computed canopy cover from airborne LiDAR data. According to the results, the abundance of Copaifera seedlings/saplings was higher in managed than unmanaged stands. About 5% of Copaifera regeneration was found between 45–50 m from the Copaifera tree while ~73% of regeneration was concentrated within a 10 m radius of the Copaifera tree. We verified that the diameter distribution of Copaifera regeneration was not a negative exponential distribution, as is typical of most tree species in natural forest. Rather, the Copaifera regeneration had a spatially aggregated distribution. In this short-term analysis, the impact of timber management is not negatively affecting the population structure or dynamics of Copaifera regeneration. [ABSTRACT FROM AUTHOR]

Plant functional traits have been recognized as important factors related to the ecological strategies of species in forest ecosystems. We examined the relationships between functional traits and both tree species performance and environmental conditions in a subtropical forest in Brazil. Over four years (2008-2012), we investigated how demographic rates were related to functional traits (wood density, leaf area and tree height) of 20 species sampled within 50 plots of 10 × 20 m, which had previously evaluated as to environmental conditions. Non-metric multidimensional scaling was used to order the species by their functional traits. The demographic rates were fit a posteriori to the ordination, with significant rates (p < 0.05) plotted as vectors. The relationships between environmental conditions and the community-weighted means (CWMs) of trait values were verified using redundancy analysis. CWM wood density was positively correlated with soil pH. CWM leaf area and CWM maximum tree height were both negatively correlated with altitude and positively correlated with soil magnesium (Mg) content. The taller species with lower wood density, which occupied the forest canopy, had a greater diameter increment and lower recruitment than did the shortest species with higher wood density. The shorter species with higher wood density, which occupied the understory, had greater recruitment and a greater increase in abundance than did the taller/lower-wood-density species. Our study (i) revealed changes in the forest related to the light environment, with an increase in the relative participation of shade-tolerant species with higher wood densities, and (ii) detected small-scale spatial variation in community traits as a response to variations in soil chemical properties and topography. [ABSTRACT FROM AUTHOR]

• Subtropical forests have a great capacity to store above-ground biomass and carbon. • Biomass is driven by large-sized trees and temperature annual range. • Temperature annual range imposes an environmental restriction for biomass storage. • The effect of large trees highlight the needs of conservation of old-growth remnants. Subtropical forests certainly contribute to terrestrial global carbon storage, but we have limited understanding about the relative amounts and of the drivers of above-ground biomass (AGB) variation in their region. Here we assess the spatial distribution and drivers of AGB in 119 sites across the South American subtropical forests. We applied a structural equation modelling approach to test the causal relationships between AGB and environmental (climate and soil), structural (proportion of large-sized trees) and community (functional and species diversity and composition) variables. The AGB on subtropical forests is on average 246 Mg ha−1. Biomass stocks were driven directly by temperature annual range and the proportion of large-sized trees, whilst soil texture, community mean leaf nitrogen content and functional diversity had no predictive power. Temperature annual range had a negative effect on AGB, indicating that communities under strong thermal amplitude across the year tend to accumulate less AGB. The positive effect of large-sized trees indicates that mature forests are playing a key role in the long-term persistence of carbon storage, as these large trees account for 64% of total biomass stored in these forests. Our study reinforces the importance of structurally complex subtropical forest remnants for maximising carbon storage, especially facing future climatic changes predicted for the region. [ABSTRACT FROM AUTHOR]

The aim of this study was to characterize the demographic structure and spatial pattern of Campomanesia xanthocarpa (Mart.) O. Berg, Myrcianthes gigantea (D. Legrand) D. Legrand and Myrciaria delicatula (DC.) O. Berg. Within one hectare of Ombrophilous Mixed Forest, all the three populations' individuals were counted and measured with regard to their height and diameter. From the collected data, the assessment of the demographic structure was realized after the individual's size classification. Spatial pattern was determined by applying the Standardized Morisita's Index. C. xanthocarpa and M. delicatula showed an inverted-J frequency distribution in the individuals size classes, which differed from M. gigantea that did not follow the same pattern. The spatial pattern of C. xanthocarpa and M. delicatula populations was found mainly to be aggregated; whereas, M. gigantea showed spatial randomness. The three Myrtaceae populations responded differently with regard to structure and spatial distribution in sites with the same environmental filters. [ABSTRACT FROM AUTHOR]

The aims of this study were to identify floristic assemblages for alluvial forests in the Atlantic Forest and Pampa regions in Brazil, assess the level of floristic similarity between assemblages, and determine environmental gradients and indicator species for these assemblages. Surveys carried out in alluvial forests in the Atlantic Forest and Pampa regions were selected, based on which a presence/absence matrix was built for tree species. A cluster analysis was performed to verify the existence of species assemblages. Floristic similarity was determined by means of the Sorensen Distance measure, from which a dendrogram was developed. The floristic matrix was ordinated by means of NMDS. A PCA was performed with climatic data from areas to determine environmental gradients. An assessment of indicator species was carried out afterwards. Two groups of areas not related to the separation of the regions became visible from the dendrogram and were corroborated by NMDS. Temperature, rainfall and altitude gradients were synthesized by the PCA. Gymnanthes klotzschiana and Andira fraxinifolia were the most relevant species, respectively, in the Paraná-Uruguay and Atlantic assemblages. Alluvial forests were gradually separated in two floristic assemblages associated with river basins and migration routes, while especially influenced by tropicality and altitude gradients.

Biological invasion is a major threat to global biodiversity and ecosystem services. We examined the functional traits similarity between a set of native and non-native invasive tree species from the Southern Brazilian subtropical mixed forest, part of an important global hotspot for biodiversity conservation. We hypothesized that invasive species occupy marginal niche spaces. We ordered the species using the Principal Component Analysis based on their wood density, leaf area, and specific leaf area. These are all important traits that summarize essential ecological strategies associated with resource acquisition and conservation. Functional overlaps between non-native and native species were analyzed through kernel density estimation of continuous traits data. While native and non-native invasive species were distributed along the same functional gradients, the position of non-native species in the functional space is species and traits specific. We concluded that within Brazilian subtropical mixed forests, the functional dissimilarity as a key factor in invasion success could not be generalized for all species and traits.

Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives., (© 2019 The Authors. Global Change Biology published by John Wiley & Sons Ltd.)

We aimed to investigate the taxonomic and functional variations of tree component of Araucaria Forest (AF) areas located along an altitudinal gradient (700, 900 and 1,600 m asl), in the southern region of Brazil. The functional traits determined were leaf area, specific leaf area, wood density, maximum potential height and dispersal syndromes and deciduousness. The data were analyzed through a functional and taxonomic dissimilarity dendrograms, community-weighted mean trait values, parametric and nonparametric tests, and Principal Component Analysis. The largest floristic-structural similarity was observed between the lower altitude areas (700 and 900 m asl), whose Bray-Curtis distance was 0.63. The area at 700 m asl was characterized by a predominance of deciduous and semi-deciduous species, with a high number of self- and wind-dispersed species, whereas the area at 1,600 m asl exhibited a predominance of animal-dispersed and evergreen species. It was also observed that there were significant variations for leaf traits, basic wood density and maximum potential height. Over all altitudinal gradient, the ordinations indicated that there was no evidence of functional differentiation among dispersal and deciduousness groups. In conclusion, the evaluated Araucaria Forest areas presented high floristic-functional variation of the tree component along the altitudinal gradient.