Background: The use of tree species’ functional traits is a promising approach in forest restoration. However, some traits may change during ontogeny. Questions: Does intraspecific variation in functional traits occur between sapling and adult stages? Do groups of species can be delimited based on functional traits regardless of their ontogenetic stage? Study sites and dates: Cloud forest restoration, Veracruz, Mexico, 2016. Methods: Saplings and adults of eight native tree species in different age plantations were measured for leaf area (LA), specific leaf area (SLA), stomatal density (SD), foliar nutrient content (C, N, P) and relative growth rate (RGR). Wood density (WD) was measured for adults. Data were analyzed using linear mixed models and principal component analysis (PCA). Results: Overall, SLA was higher in saplings than in adults. A few species showed intraspecific variation for LA (three species), SD (three) and foliar N content (one). Species with high WD (Quercus spp.) and intermediate WD (e.g. Liquidambar styraciflua) tended to have lower LA and SLA, and higher SD. Species with low WD (e.g. Heliocarpus donnellsmithii) had high SLA, RGR, and N content. PCA highlighted that saplings and adults of a same species were close to each other within the ordination space.  Conclusions: Intraspecific variation between saplings and adults was small for most traits (except SLA) in comparison to differences across species. Therefore species trait values (measured in individuals of any age) could be a useful tool to characterize groups of species during the forest restoration trajectory.

Neotropical seasonal dry forest (NSDF) is one of the most threatened ecosystems under global climate change (GCC) predictions, with likely species losses and uneven modification of diversity patterns all through its distribution. Nonetheless, few studies have evaluated the GCC impacts on the diversity patterns of NSDF plants. The lack of continental-scale approaches restricts our understanding of GCC consequences in the high beta-diverse NSDF. We showed some potential impacts of GCC on the distributions of over 1000 species of the NSDF, species richness patterns, and species composition of assemblages (beta diversity). We focus on five representative plant families that are abundant, dominant, and have a high endemism rate within the NSDF. These families were Cactaceae, Capparaceae, Fabaceae, Malvaceae, and Zygophyllacea. We reconstructed potential species distributions in the present and future scenarios (2040–2080) considering an intermediate Shared Socio-economic Pathway scenario and two dispersal ability assumptions on the taxa. We correlated climate-induced changes in the species distribution ranges with drought tolerance. We found that, even under a favorable dispersal scenario, species distribution and richness showed significant declines in the future across sites where temperatures are predicted to increase in the future. In Fabaceae, we observed a negative correlation between drought tolerance and changes in species distribution ranges in the future. Our results suggested biotic homogenization across the NSDF, but biotic heterogenization is the likely outcome at the continental scale under dispersal limitations. This information is critical for further planning of conservation actions as it can help to assess the current and future value of NSDF-protected areas and define new areas worth protecting.

Background and Aims: Droughts induced by climate change are expected to affect tropical cloud forests. As functional traits are useful indicators of plant species performance, this study aimed to determine the effect of light environment and drought on leaf area (LA), specific leaf area (SLA), chlorophyll content, leaf thickness and toughness, survival and relative growth rate (RGR) of seedlings in forest understory and gap. Methods: In a cloud forest from Veracruz, Mexico, rainout shelters to simulate drought in the forest understory and gap were used. Leaf area, SLA, chlorophyll content, leaf thickness and toughness, survival, and RGR in Eugenia capuli (shade-tolerant understory tree), Liquidambar styraciflua (intermediate shade-tolerant canopy tree), and Trema micranthum (pioneer tree that colonizes gaps) in understory-control and -drought, and gap-control and -drought were measured. Key results: Leaf area increased with drought in E. capuli in gaps and decreased in L. styraciflua in both light environments. Chlorophyll content was similar between water treatments for E. capuli and L. styraciflua in the understory. Leaf thickness and toughness differed with drought for E. capuli and L. styraciflua in the gap. Leaf traits of T. micranthum tended to change in understory and not in gap. Overall, the highest survival occurred in gap. Eugenia capuli displayed the highest and similar survival across treatments. Liquidambar styraciflua displayed higher survival in gap-drought, and T. micranthum in gap conditions. Eugenia capuli had the highest RGR in understory, whereas T. micranthum has the highest RGR in gap. Conclusions: Plant functional traits of E. capuli and L. styraciflua seedlings responded to moderate drought more in gap than in understory. The results suggest that functional traits of intermediate and shade-tolerant species may shift less under a moderate drought than those of a pioneer tree, as long as the forest light environment is maintained.