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The Cerrado has a wide diversity of fauna and flora, and the knowledge of its horizontal structure, in different time intervals allows the prediction of its structural and floristic characteristics. The aim of this study was to evaluate the changes in structure and composition of tree community in three fragments of Cerrado with low anthropization, in an interval of 11 years at Minas Gerais state. Rectangular plots of fixed size were sampled, measuring stem diameter and height of all living arboreal individuals with diameter at 1.30 meters above ground (DBH) ≥ 5 cm. The tree vegetation dynamics study of the areas was performed, as well as the floristic analysis and the diametric structure. Considering all fragments and years of measurement, the recruitment of trees surpassed its mortality. The basal area varied between 3.67 and 13.07 m².ha-1. The studied areas, considering all fragments and years of measurement, showed a Shannon diversity index (H') from 3.43 to 3.87 nat.ind-1 and Pielou equitability index (J') ranged an interval between 0.77 and 0.82. The similarity calculated by the Jaccard index (J), when performed per plot considering the three fragments, showed a value of 0.2653. Also, related to the development and growth of the study areas, it can be inferred that all fragments and their respective years of measurement had a J-inverse pattern. In conclusion, it can be inferred that the three fragments maintained a representative growth in number of individuals and basal area.

As global change shifts the species composition of forests, we need to understand which species characteristics affect soil organic matter (SOM) cycling to predict future soil carbon (C) storage. Recently, whether a tree species forms a symbiosis with arbuscular (AM) versus ectomycorrhizal (EcM) fungi has been suggested as a strong predictor of soil C storage, but there is wide variability within EcM systems. In this study, we investigated how mycorrhizal associations and the species composition of canopy trees and mycorrhizal fungi related to the proportion of soil C and nitrogen (N) in mineral associations and soil C:N across four sites representing distinct climates and tree communities in the eastern US broadleaf forest biome. In two of our sites, we found the expected relationship of declining mineral-associated C and N and increasing soil C:N ratios as the basal area of EcM-associating trees increased. However, across all sites these soil properties strongly correlated with canopy tree and fungal species composition. Sites where the expected pattern with EcM basal area was observed were (1) dominated by trees with lower quality litter in the Pinaceae and Fagaceae families and (2) dominated by EcM fungi with medium-distance exploration type hyphae, melanized tissues, and the potential to produce peroxidases. This observational study demonstrates that differences in SOM between AM and EcM systems are dependent on the taxa of trees and EcM fungi involved. Important information is lost when the rich mycorrhizal symbiosis is reduced to two categories.

We compiled a data set for all tree species collected to date in lowland Amazonian Ecuador in order to determine the number of tree species in the region. This data set has been extensively verified by taxonomists and is the most comprehensive attempt to evaluate the tree diversity in one of the richest species regions of the Amazon. We used four main sources of data: mounted specimens deposited in Ecuadorian herbaria only, specimen records of a large‐scale 1‐hectare‐plot network (60 plots in total), data from the Missouri Botanical Garden Tropicos® database (MO), and literature sources. The list of 2,296 tree species names we provide in this data set is based on 47,486 herbarium records deposited in the following herbaria: Alfredo Paredes Herbarium (QAP), Catholic University Herbarium (QCA), Herbario Nacional del Ecuador (QCNE), Missouri Botanical Garden (MO), and records from an extensive sampling of 29,768 individuals with diameter at breast height (dbh) ≥10 cm recorded in our plot network. We also provide data for the relative abundance of species, geographic coordinates of specimens deposited in major herbaria around the world, whether the species is native or endemic, current hypothesis of geographic distribution, representative collections, and IUCN threat category for every species recorded to date in Amazonian Ecuador. These data are described in Metadata S1 and can be used for macroecological, evolutionary, or taxonomic studies. There are no copyright restrictions; data are freely available for noncommercial scientific use (CC BY 3.0). Please see Metadata S1 (Class III, Section B.1: Proprietary restrictions) for additional information on usage.

Mangrove forests are known for their exceptional carbon storage capacity, but the influence of environmental factors on this service remains understudied. This study examines how environmental conditions shape tree community composition and carbon storage in Mallorquin Swamp, an urban mangrove ecosystem in Barranquilla, Colombia. We assessed tree composition, vegetation structure, soil pH, and salinity across 18 circular plots in areas of Low, Medium, and High salinity. Above ground biomass (AGB) and carbon stock were estimated using allometric equations and wood density databases. Our findings revealed significant salinity differences among sampling areas, especially during the dry season, while soil pH showed minimal variation. Avicennia germinans was dominant in Low salinity areas, Laguncularia racemosa in Medium salinity areas, and Rhizophora mangle in High salinity areas. Trees in Low salinity zones were notably taller and larger, contributing to significantly higher carbon stock (4098.6 Mg C) compared to Medium (104.6 Mg C) and High (1761 Mg C) salinity areas. These results underscore the importance of local environmental factors, particularly salinity, in shaping mangrove structure and carbon dynamics. Identifying such patterns is vital for guiding conservation efforts and carbon policies, particularly in urban and climate-sensitive areas, where focused management can strengthen mangrove resilience and carbon storage.

Forest restoration and tree-planting projects initiated as a response to climate change and biodiversity loss are increasingly important around the globe. Small-scale and community-based tree nurseries have been promoted as a potential route to meeting some local or regional supply-side bottlenecks. A study in the UK used a mixed methods approach to assess the potential contribution of community tree nurseries (CTNs) to tree material supply. Semi-structured interviews (SSIs) were undertaken with 16 CTNs across the UK to generate a sector-wide characterisation of CTNs. A UK-wide online survey assessed the total number of CTNs, production methods and volumes, biosecurity practices and benefits of community involvement. Another 13 CTNs receiving support to establish and extend their operations took part in SSIs assessing their development. The results indicate that there are four broad types of CTN (Organisation- and project-based, Community-based, Enterprise and Network CTNs). A significant number of CTNs in Britain are new and establishing. The sustainability of CTNs relies in large part on grant support rather than income from tree sales. Production is almost exclusively native broadleaves and local provenances. There are policy implications concerning: i. the suitability of species being produced to future climatic and market conditions and ii. the tension around financial viability, grant dependence and CTN sustainability for those CTNs focused on social and environmental benefits rather than income generation. Identifying gaps in the provision of trees by commercial nurseries, e.g., uncommon or recalcitrant species, could be a feasible financial strategy. It is likely that financial support and skills development are likely to be required as social innovation in the community-supported tree nursery sector establishes and develops. Judging the success and impact of some types of CTNs in terms of production and finance measures may be unfair, as other social and environmental benefits may be as important and valuable. It is clear that more evaluative research is needed to quantify and better understand these kinds of outcomes and the added value they accrue.

1. Islands formed upstream of mega hydroelectric dams are excellent experimental landscapes to assess the impacts of habitat fragmentation on biodiversity. We examined the effects of plot-, patch- and landscape-scale variables on the patterns of floristic diversity across 34 forest islands that had experienced 26 years of isolation since the creation of the 4437 km2 Balbina Hydroelectric Reservoir of central Brazilian Amazonia. In addition, three undisturbed continuous forest sites in neighbouring mainland areas were also sampled across a comparable elevational gradient. 2. We identified all live trees ≥10 cm DBH at species level within a total of 87 quarter-hectare forest plots and conducted a comprehensive compilation of functional attributes of each tree species. We then examined species-area relationships (SARs) and the additional effects of patch and landscape-scale metrics on patterns of tree assemblage heterogeneity, both in terms of taxonomic and functional diversity. 3. Despite a clearly positive SAR, edge-mediated forest disturbance was the single most important driver of species composition and abundance within islands. Our results suggest that non-random floristic transitions within island plots followed a predictable pattern, with different life-history traits either penalizing or rewarding local persistence of different functional groups. Distance to edges mediated the probability of tree mortality induced by windfalls and episodic surface fires, clearly resulting in faster species turnover and unidirectional changes in guild structure within small islands where light-wooded fast-growing pioneers largely replaced heavy-wooded species of the old-growth flora. 4. Synthesis. Following a simultaneous 26-year post-isolation history, we disentangle the effects of habitat loss and insularization on tree assemblages within a large set of Amazonian 'true' forest islands, of variable sizes, sharing a uniform open-water matrix. Area effects are expressed via a response to edge effects, with trees in smaller islands being more vulnerable to edge-related surface fires and wind-throws. Additionally, forest edge effects can be a powerful driver of non-random floristic transitions across islands within the Balbina archipelago via a process of rapid pioneer proliferation, drastically affecting both the taxonomic and functional composition of insular tree communities. Finally, our results indicate that detrimental effects of forest fragmentation induced by hydroelectric dams are considerably stronger than those of forest patches embedded within a terrestrial vegetation matrix.

Abstract As global change shifts the species composition of forests, we need to understand which species characteristics affect soil organic matter (SOM) cycling to predict future soil carbon (C) storage. Recently, whether a tree species forms a symbiosis with arbuscular (AM) versus ectomycorrhizal (EcM) fungi has been suggested as a strong predictor of soil C storage, but there is wide variability within EcM systems. In this study, we investigated how mycorrhizal associations and the species composition of canopy trees and mycorrhizal fungi related to the proportion of soil C and nitrogen (N) in mineral associations and soil C:N across four sites representing distinct climates and tree communities in the eastern US broadleaf forest biome. In two of our sites, we found the expected relationship of declining mineral‐associated C and N and increasing soil C:N ratios as the basal area of EcM‐associating trees increased. However, across all sites these soil properties strongly correlated with canopy tree and fungal species composition. Sites where the expected pattern with EcM basal area was observed were (1) dominated by trees with lower quality litter in the Pinaceae and Fagaceae families and (2) dominated by EcM fungi with medium‐distance exploration type hyphae, melanized tissues, and the potential to produce peroxidases. This observational study demonstrates that differences in SOM between AM and EcM systems are dependent on the taxa of trees and EcM fungi involved. Important information is lost when the rich mycorrhizal symbiosis is reduced to two categories.

Abstract Riparian ecotones host sharp hydrological-edaphic gradients that can restructure tree communities. We tested how soil hydromorphy and related attributes shape floristic composition in a 7.6-ha ecotone on the eastern boundary of Iguaçu National Park (Paraná, Brazil). We surveyed trees (DBH ≥ 15 cm) in 20 contiguous 10 × 10 m plots, evenly split between hydromorphic and non-hydromorphic soils, and measured groundwater level and surface-soil properties (0-20 cm). Multivariate analyses (PCA, CCA, PERMANOVA) revealed a clear compositional split between environments (PERMANOVA: F = 6.03, p = 0.0002). Soil structure was summarized by two principal components explaining 71.9% of variance; hydromorphic plots were associated with higher aluminum saturation, organic matter, total organic carbon and shallower water tables, whereas non-hydromorphic plots showed higher base status (Ca2+, Mg2+, SB, V) and pH. CCA indicated groundwater depth and aluminum saturation as the main drivers of floristic turnover, with indicator taxa segregating by environment (Vitex megapotamica, Mimosa bimucronata in hydromorphic sites and Ilex paraguariensis, Matayba elaeagnoides in non-hydromorphic sites). Altogether, soil hydromorphy, coupled to aluminum saturation, emerges as a proximal filter structuring tree communities across this subtropical riparian ecotone. These results provide a mechanistic basis for conservation and restoration, including species selection aligned with groundwater regime and soil chemistry. Resumo Ecótonos ripários apresentam gradientes edáficos e hidrológicos acentuados que reestruturam comunidades arbóreas. Avaliamos como a hidromorfia do solo e atributos associados influenciam a composição florística em um ecótono de 7,6 ha na borda leste do Parque Nacional do Iguaçu (Paraná, Brasil). Foram amostrados indivíduos arbóreos (CAP ≥ 15 cm) em 20 parcelas de 10 × 10 m, igualmente distribuídas em solos hidromórficos e não hidromórficos, com medições do nível do lençol freático e análises de solo superficial (0-20 cm). As análises multivariadas (PCA, CCA, PERMANOVA) evidenciaram separação clara entre ambientes (PERMANOVA: F = 6,03; p = 0,0002). Dois componentes principais explicaram 71,9% da variância: parcelas hidromórficas apresentaram maior saturação por alumínio, matéria orgânica, carbono orgânico total e lençol freático mais raso, enquanto as não hidromórficas tiveram maior soma de bases, saturação por bases e pH. A CCA destacou a profundidade do lençol freático e a saturação por alumínio como principais filtros da composição florística, com espécies indicadoras segregando-se por ambiente (Vitex megapotamica, Mimosa bimucronata em solos hidromórficos e Ilex paraguariensis, Matayba elaeagnoides em não hidromórficos). Concluimos que a hidromorfia do solo, aliada à saturação por alumínio, constitui filtro proximal que estrutura as comunidades arbóreas neste ecótono subtropical, oferecendo subsídios para conservação e restauração em função do regime hídrico e da química do solo.

Arthropods exhibit high diversity, wide ecological range, broad distribution, and are found in various environments and microhabitats. In the Cerrado biome, many arthropods interact with specific plants, which function as their habitat and foraging grounds. The shrub-tree species Ouratea hexasperma is common in the Cerrado and displays considerable variation in individual canopy size. A direct positive relationship linking area and richness is a widely studied topic in Ecology, with such relationship also being observed in island-like environments. Considering each canopy as an island-like community, in this study, we analyzed the relationship between arthropod richness (measured as family richness) and tree canopy size. We collected and identified 17 arthropod families from nine orders on O. hexasperma trees, with Insecta being the most abundant taxon, followed by Arachnida and Myriapoda. However, Arachnida presented the highest number of families (seven). Our results show a positive correlation between canopy size and arthropod richness, indicating that larger canopies support richer arthropod communities. Thus, our findings support the species-area relationships on small geographic scales.

Since the publication of the unified neutral theory in 2001, there has been much discussion of the theory, pro and con. The hypothesis of ecological equivalence is the fundamental yet controversial idea behind neutral theory. Assuming trophically similar species are demographically alike (symmetric) on a per capita basis is only an approximation, but it is equivalent to asking: How many of the patterns of ecological communities are the result of species similarities, rather than of species differences? The strategy behind neutral theory is to see how far one can get with the simplification of assuming ecological equivalence before introducing more complexity. In another paper, I review the empirical evidence that led me to hypothesize ecological equivalence among many of the tree species in the species-rich tropical forest on Barro Colorado Island (BCI). In this paper, I develop a simple model for the evolution of ecological equivalence or niche convergence, using as an example evolution of the suite of life history traits characteristic of shade tolerant tropical tree species. Although the model is simple, the conclusions from it seem likely to be robust. I conclude that ecological equivalence for resource use are likely to evolve easily and often, especially in species-rich communities that are dispersal and recruitment limited. In the case of the BCI forest, tree species are strongly dispersal- and recruitment-limited, not only because of restricted seed dispersal, but also because of low recruitment success due to heavy losses of the seedling stages to predators and pathogens and other abiotic stresses such as drought. These factors and the high species richness of the community strongly reduce the potential for competitive exclusion of functionally equivalent or nearly equivalent species.