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QUESTION: Functional differences among climber species may reflect different strategies to cope with the environment created by the set of trees and shrubs used to reach the canopy. Moreover, climber diversity may be promoted and maintained by associations with subordinate woody species. Considering that functional differences among climbers may reflect this relationship, we aimed to identify trait differences among climbers, and the traits related to the association between climbers and woody species. LOCATION: Restinga de Jurubatiba National Park, a tropical sandy coastal plant community in southeast Brazil. METHODS: Relative abundances of climbers and shrubs/trees were surveyed, and climber species were described by a set of traits related to dispersal, establishment and persistence. Principal coordinate analysis was used to identify trait differences among climbers. Further, we performed principal components analysis in a community‐weighted mean trait values matrix (CWM) and compared the major pattern of variation with the abundance of dominant and subordinate woody species, and with environmental variables. RESULTS: The analyses revealed functional traits behind the association between climbers and subordinate woody species. These species are mostly characterized by the presence of latex and dry fruits, anemochorous dispersal and stem twining climbing strategy. They were associated with the subordinate shrub Erythroxylum subsessile. Tendril climbers were more generalist and were also characterized by zoochoric dispersal and the presence of endosperm. CONCLUSIONS: The associative behaviour between climbers and the subordinate shrub E. subsessile is explained by a specific set of traits present in species of the same plant family, Apocynaceae. While stem twiners were positively associated with the specialist nurse E. subsessile, tendril climbers were associated with the dominant nurses. These results offer clues to understand the presence of specialist and generalist groups of climber species in tropical plant communities, as well as community assembly through facilitation driven by subordinate species.

The initiation of a new plant community in a restoration area hinges on the performance of seedlings post-planting. This study aimed to evaluate the impact of species functional traits—specific leaf area (SLA), wood density (WD), seed dry mass (SDM), and potential height (H)—on the seedling performance 25 months after planting, comparing two planting designs (rows and clusters) and the influence of fertilization addition in clusters. The restoration area is a riparian tropical forest located on the coastal plain at Caraguatatuba municipality, São Paulo, Brazil. We monitored 3017 tree seedlings and estimated their survivorship and relative growth rate (RGR) using the diameter, height, and canopy area of the surviving seedlings and the stem biomass for the cluster RGR estimation. Using linear mixed models, we analyzed how the planting designs and the functional traits affect species survival and their RGR. We underscored the significance of slow-growth traits (low SLA, and high SDM and WD) in enhancing species survival, whereas, maximizing species growth entails prioritizing seedlings with greater potential height. Cluster survival and growth improved with a greater abundance of species with low values of SDM (i.e., fast-growth species) and communities with low functional divergence (high similarity). Fertilized clusters improved the RGR of large-seeded species. Accounting for functional traits in restoration is advantageous for enhancing seedling performance at the species level, which is an important consideration for restoration practitioners. To optimize applied nucleation, clusters should target functional diversity at this community level and include competitive species to improve productivity.

Natural regeneration provides multiple benefits to nature and human societies, and can play a major role in global and national restoration targets. However, these benefits are context specific and impacted by both biophysical and socioeconomic heterogeneity across landscapes. Here, we investigate the benefits of natural regeneration for climate change mitigation, sediment retention and biodiversity conservation in a spatially explicit way at very high resolution for a region within the global biodiversity hotspot of the Atlantic Forest. We classified current land-use cover in the region and simulated a natural regeneration scenario in abandoned pasturelands, areas where potential conflicts with agricultural production would be minimized and where some early stage regeneration is already occurring. We then modeled changes in biophysical functions for climate change mitigation and sediment retention, and performed an economic valuation of both ecosystem services. We also modeled how land-use changes affect habitat availability for species. We found that natural regeneration can provide significant ecological and social benefits. Economic values of climate change mitigation and sediment retention alone could completely compensate for the opportunity costs of agricultural production over 20 yr. Habitat availability is improved for three species with different dispersal abilities, although by different magnitudes. Improving the understanding of how costs and benefits of natural regeneration are distributed can be useful to design incentive structures that bring farmers’ decision making more in line with societal benefits. This alignment is crucial for natural regeneration to fulfill its potential as a large-scale solution for pressing local and global environmental challenges.

Climate change and ecosystem degradation have achieved unprecedented levels nowadays. In this context, assessing restoration projects to recover native vegetation and ecosystem services is fundamental to understanding the success of these initiatives. This study evaluated the effects of different restoration techniques on the basal area, diversity, and composition of regenerating and planted species in a restoration area in the Atlantic Forest, Southeast Brazil. The experiment consisted of three treatments: row planting (ROW, 2 × 2 m spacing); nucleation (NUC, 13 individuals/nucleus, 5 × 5 m spacing); and control with passive restoration (PAS). The active restoration techniques had different planting densities at project implementation (NUC: 5.200 seedlings ha-1; ROW: 2.177 seedlings ha-1). A floristic survey was carried out within 8 sampling units (15 × 15 m) per treatment 10 years after implementation of the project, including all planted and regenerating individuals with a diameter at ground level > 2.5 cm. The abundance, basal area, and species richness of the planted and regenerated communities were estimated. The active restoration techniques (ROW and NUC) resulted in higher values of basal area, abundance and species richness compared to passive restoration (PAS). A higher abundance of natural regeneration was observed in ROW than in NUC. Additionally, the rarefaction curves suggested a trend toward higher diversity indices in ROW. Regarding the successional trajectory, greater variation in species composition was observed in ROW after 10 years of planting. The species composition was similar in ROW and NUC and differed from the composition in PAS. The species identified as indicator species in each treatment were Annona glabra L. in ROW, Trema micranthum (L.) Blume in NUC, and Vernonanthura polyanthes(Sprengel) Vega & Dematteis in PAS. Our study revealed that active restoration techniques, such as seedling planting in rows and nuclei, were more effective in restoring ecological indicators than passive restoration. These results emphasize the importance of restoration techniques in enhancing plant community diversity and structure in the Brazilian Atlantic Forest.

The Brazilian Atlantic Forest has undergone adverse land-use change due to deforestation for urbanization and agriculture. Numerous restoration initiatives have been taken to restore its ecosystem services. Deforested areas have been restored through active intervention or natural regeneration. Understanding the impact of those different reforestation approaches on soil quality should provide important scientific and practical conclusions on increasing forest cover in the Brazilian Atlantic Forest biome. However, studies evaluating active planting versus natural regeneration in terms of soil recovery are scarce. We evaluate soil dynamics under those two contrasting strategies at an early stage (<10 years). Reforestation was conducted simultaneously on degraded lands previously used for cattle grazing and compared to an abandoned pasture as a reference system. We examined soil physicochemical properties such as: pH, soil organic matter content, soil moisture, N, P, K, Ca, Mg, Na, Fe, Mn, Cu, Al, and soil texture. We also present the costs of both methods. We found significant differences in restored areas regarding pH, Na, Fe, Mn content, and the cost. Soil moisture was significantly higher in pasture. Our research can contribute to better decision-making about which restoration strategy to adopt to maximize restoration success regarding soil quality and ecosystem services in the tropics.

Sandy coastal plant communities in tropical regions have been historically under strong anthropic pressure. In Brazil, these systems shelter communities with highly plastic plant species. However, the potential of these systems to regenerate without human assistance after disturbances has hardly been examined. We determined the natural regeneration of a coastal sandy plain vegetation (restinga) in Brazil, 16 years after the end of sand removal. We inventoried 38 plots: 20 within a sand‐mined site and 18 in an adjacent undisturbed site. We expected lower diversity values in the sand‐mined site compared to the undisturbed site, but similar species composition between the two sites due to the spatial proximity of the two sites and the high plasticity of restinga species. Species were ranked using abundance and importance value index in both sites, and comparisons were performed using Rényi entropy profiles, rarefaction curves, principal component analysis, and redundancy analysis. Species composition and dominant species differed markedly between the two sites. Bromeliads and Clusia hilariana, well‐known nurse plants, dominated the undisturbed site but were almost absent in the regenerating site. Species richness did not differ between both sites, but diversity was higher in the undisturbed site. Within‐site composition differences in the mined area were associated with field characteristics. Interestingly, species classified as subordinate or rare in the undisturbed site became dominants in the regenerating site. These newer dominants in the sand‐mined site are not those known as nurse plants in other restingas, thus yielding strong implications for restoration. Passive restoration of sandy coastal plains degraded by sand mining may not rely on the positive effects of typical nurse plants due to their absence or very low abundances in mined areas, even 16 years after disturbance. Rare or subordinate species in the undisturbed site became abundant in the mined area, and we suggest that these species should be screened for their potential role as nurse plants.

Question: Does the creation of linear canopy openings in a lowland Atlantic tropical forest cause edge effects on understorey treelets, saplings and shrubs? Location: União Biological Reserve, Rio de Janeiro state, southeastern Brazil (22°25′30″S, 42°02′30″W). Methods: We sampled shrub, sapling and treelet communities at forest edges adjacent to two linear canopy openings (gas pipeline and power line) and in forest interiors far from any edge. Rarefaction curves were plotted to assess differences in species richness among treatments. Variation partitioning was used to assess main drivers of species composition and abundance. Partial Mantel correlations were calculated to verify edge effects controlling for effect of space on the abundance of Euterpe edulis palm and two ecological groups. For this purpose, species were classified either as disturbance-tolerant or disturbance-sensitive. Results: Edge effects of linear canopy openings affect understorey species composition, but not species richness. Disturbance-tolerant species were more abundant in edges than in forest interiors, while disturbance-sensitive species did not show differences among treatments. However, the late-successional palm Euterpe edulis, which is abundant in forest interiors, was significantly less common at edges. Response to edge effects was stronger among treelets than shrubs and saplings. Conclusions: The creation of infrastructure-related linear canopy openings caused edge effects that significantly affected understorey communities in the studied lowland Atlantic forest remnant. Such effects however were clearly distinct from those found at typical edges of tropical forest fragments.

Disentangling the mechanisms that shape community assembly across diversity gradients is a central matter in ecology. While many studies have explored community assembly through species average trait values, there is a growing understanding that intraspecific trait variation (ITV) can also play a critical role in species coexistence. Classic biodiversity theory hypothesizes that higher diversity at species-rich sites can arise from narrower niches relative to species-poor sites, which would be reflected in reduced ITV as species richness increases. To explore how ITV in woody plant communities changes with species richness, we compiled leaf trait data (leaf size and specific leaf area) in a total of 521 woody plant species from 21 forest communities that differed dramatically in species richness, ranging from boreal to tropical rainforests. At each forest, we assessed ITV as an estimate of species niche breadth and we quantified the degree of trait overlap among co-occurring species as a measure of species functional similarity. We found ITV was relatively invariant across the species richness gradient. In addition, we found that species functional similarity increased with diversity. Contrary to the expectation from classic biodiversity theory, our results rather suggest that neutral processes or equalizing mechanisms can be acting as potential drivers shaping community assembly in hyperdiverse forests.