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The diversification of angiosperms has largely been attributed to adaptive radiation of their pollination and mating systems, which are relevant drivers of the macroevolution processes. The fig (Ficus, Moraceae) and fig wasp (Agaonidae, Hymenoptera) interaction is an example of obligate mutualism. Passive and active pollination modes have been associated with morphological traits in both partners. However, more information is required to assess the relationship between floral traits and pollination modes, particularly in Neotropical Ficus species. This study evaluates the morphological traits of figs and fig wasps regarding pollination modes in species belonging to Neotropical Ficus sections (three species each of Americanae and Pharmacosycea). Pollination mode was identified by floral morphology, anther/ovule ratio, and specialized structures fig wasps use for pollen transport (pollen pocket and coxal combs). Fig species in sect. Americanae are actively pollinated because pistillate flowers form a synstigma, present anther/ovule ratios <0.11, and their pollinator Pegoscapus fig wasps have pollen pockets and coxal combs. In contrast, species in sect. Pharmacosycea have free pistillate flowers, with anther/ovule ratios >0.27; they are pollinated by Tetrapus wasps, which lack specialized structures to carry pollen. Each species of Ficus was associated with a single morphospecies of fig wasp. The results support previous contributions that consider reciprocal morphological traits between fig species and their pollinating wasps as evidence of a close co-evolutionary history., (© 2024 The Author(s). Plant Biology published by John Wiley & Sons Ltd on behalf of German Society for Plant Sciences, Royal Botanical Society of the Netherlands.)

We examined the variation in liana community composition and structure across geopedological land units to test the hypothesis that environmental heterogeneity is a driving force in liana community assembly. The study site was the Los Tuxtlas Tropical Biology Station, SE Mexico, a reserve that encompasses 640 ha of tropical rainforest. We sampled all lianas with basal diameter ≥1 cm in three 0.5-ha plots established in each of five land units (totaling 15 plots and 7.5 ha). We censused 6055 individuals and 110 species. Overall, the most speciose families were also the most abundant ones. Density and basal area of some dominant liana species differed among land units, and a permutational multivariate analysis of variance (PERMANOVA) and a non-metric multidimensional scaling ordination (NMDS) revealed differences in the presence, density, and basal area of liana species across the landscape. Liana composition and structure were highly heterogeneous among land units, suggesting that variations in soil water availability and relief are key drivers of liana community spatial differentiation. By showing that soil and topography play an important role at the landscape scale, we underscore the ecological relevance of environmental heterogeneity for liana community assembly. In the future, as our ability to assess the local environmental complexity increases, we will gain a better understanding of the liana community assembly process and their heterogeneous distribution in tropical forests., Competing Interests: The authors declare no conflicts of interest., (© 2024 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)

Genetic diversity is a key component of evolution, and unraveling factors that promote genetic differentiation in space and time is a central question in evolutionary biology. One of the most diverse and ecologically important tree genera in tropical forests worldwide is Ficus (Moraceae). It has been suggested that, given the great dispersal capacity of pollinating fig wasps (Chalcidoidea; Agaonidae), the spatial genetic structure, particularly in monoecious fig species, should be weak. However, no studies have addressed the factors that determine the genetic structure of Ficus species in regions of high geological, geographic, and climatic complexity, such as the Mexican Transition Zone. Using nuclear single nucleotide polymorphisms (5311 SNPs) derived from low-coverage whole genomes and 17 populations, we analyzed the population genomics of Ficus pringlei to characterize neutral and adaptive genetic variation and structure and its association with geographic barriers such as the Trans-Mexican Volcanic Belt, environmental heterogeneity, and wind connectivity. From genomic data of 71 individuals, high genetic diversity, and the identification of three genomic lineages were recorded (North, South, and Churumuco). The results suggest that genetic variation is primarily determined by climatic heterogeneity. Ficus pringlei populations from the north and south of the Trans-Mexican Volcanic Belt also exhibited minimal genetic differentiation ( F ST  = 0.021), indicating that this mountain range may not act as an insurmountable barrier to gene flow. Wind connectivity is also highlighted in structuring putative adaptive genetic variation, underscoring the intricate complexity of the various factors influencing genetic variation in the species. This study provides information on the possible mechanisms underlying the genetic variation of endemic species of the tropical dry forest of Western Mexico, such as F . pringlei ., Competing Interests: All authors claim no conflict of interest., (© 2024 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)

Protected areas are of paramount relevance to conserving wildlife and ecosystem contributions to people. Yet, their conservation success is increasingly threatened by human activities including habitat loss, climate change, pollution, and species overexploitation. Thus, understanding the underlying and proximate drivers of anthropogenic threats is urgently needed to improve protected areas' effectiveness, especially in the biodiversity-rich tropics. We addressed this issue by analyzing expert-provided data on long-term biodiversity change (last three decades) over 14 biosphere reserves from the Mesoamerican Biodiversity Hotspot. Using multivariate analyses and structural equation modeling, we tested the influence of major socioeconomic drivers (demographic, economic, and political factors), spatial indicators of human activities (agriculture expansion and road extension), and forest landscape modifications (forest loss and isolation) as drivers of biodiversity change. We uncovered a significant proliferation of disturbance-tolerant guilds and the loss or decline of disturbance-sensitive guilds within reserves causing a "winner and loser" species replacement over time. Guild change was directly related to forest spatial changes promoted by the expansion of agriculture and roads within reserves. High human population density and low nonfarming occupation were identified as the main underlying drivers of biodiversity change. Our findings suggest that to mitigate anthropogenic threats to biodiversity within biosphere reserves, fostering human population well-being via sustainable, nonfarming livelihood opportunities around reserves is imperative., Competing Interests: Competing interests statement:The authors declare no competing interest.

Mexico is a major center of evolutionary radiation for the genus Quercus, with oak species occurring across different habitat types and showing a wide variation in morphology and growth form. Despite representing about 20% of Mexican species, scrub oaks have received little attention and even basic aspects of their taxonomy and geographic distribution remain unresolved. In this study, we analyzed the morphological and climatic niche differentiation of scrub oak populations forming a complex constituted by six named species, Quercus cordifolia, Quercus frutex, Quercus intricata, Quercus microphylla, Quercus repanda, Quercus striatula and a distinct morphotype of Q. striatula identified during field and herbarium work (hereafter named Q. striatula II). Samples were obtained from 35 sites covering the geographic distribution of the complex in northern and central Mexico. Morphological differentiation was analyzed through geometric morphometrics of leaf shape and quantification of trichome traits. Our results indicated the presence of two main morphological groups with geographic concordance. The first was formed by Q. frutex, Q. microphylla, Q. repanda and Q. striatula, distributed in the Trans-Mexican Volcanic Belt, the Sierra Madre Occidental and a little portion of the south of the Mexican Altiplano (MA). The second group consists of Q. cordifola, Q. intricata and Q. striatula II, found in the Sierra Madre Oriental and the MA. Therefore, our evidence supports the distinctness of the Q. striatula II morphotype, indicating the need for a taxonomic revision. Within the two groups, morphological differentiation among taxa varied from very clear to low or inexistent (i.e. Q. microphylla-Q. striatula and Q. cordifolia-Q. striatula II) but niche comparisons revealed significant niche differentiation in all pairwise comparisons, highlighting the relevance of integrative approaches for the taxonomic resolution of complicated groups such as the one studied here., (© 2023. The Author(s).)

The syconium is the urn-shaped inflorescence shared by all species of the genus Ficus. The orifice at the apex of the syconium is called the ostiole, and it is covered by interlocking bracts. The ostiolar bracts can have different arrangements, which only allow the entry of mutualist wasps and promote reproductive isolation among Ficus species. Here, we analyze the ostiolar structures that could play a role as selective filter and therefore impact the fig-fig wasp mutualism in the neotropical Ficus sections Americanae and Pharmacosycea. Samples of syconia with pistillate flowers during the receptive phase of seven species of Ficus were examined using light and scanning electron microscopy. Tests for histolocalization of substances were employed to detect secretory activity throughout the ostiolar tissues. Our results indicated that the ostiole has two components: ostiolar bracts and the periostiolar zone. Interspecies variation in ostiolar bract arrangement in both sections studied was broader than previously reported. We report for the first time for Ficus: (i) two types of ostiolar osmophores (mesophyll and diffuse), that could be a source of volatile compounds for attracting fig wasps; (ii) colleters in the axil of ostiolar bracts, which probably lubricate and facilitate the entry of pollinating wasps into the syconial cavity; (iii) secretory trichomes around the ostiolar bracts, and (iv) syconium basal bracts (F. isophlebia) covering the ostiole, which are the first physical barrier that the fig wasps must overcome to access receptive pistillate flowers. We describe the zones that compose the ostiole, which support the hypothesis that the ostiole is a selective filter in the interactions of fig trees with Agaonidae fig wasps. We also suggest that ostiolar osmophores, colleters, the periostiolar zone, and the arrangements of the ostiolar bracts may be informative with respect to Ficus systematics., (© 2022. The Author(s) under exclusive licence to The Botanical Society of Japan.)

Regionalization through the analysis of species groups offers important advantages in conservation biology, compared to the single taxon approach in areas of high species richness. We use a systematic framework for biogeographic regionalization at a regional scale based on species turnover and environmental drivers (climate variables and soil properties) mainly of herbaceous plant species richness. To identify phytogeographic regions in the Balsas Depression (BD), we use Asteraceae species, a family widely distributed in Seasonally Dry Tropical Forest (SDTF) and the most diverse of the vascular plants in Mexico. Occurrence records of 571 species were used to apply a quantitative analysis based on the species turnover, the rate of changes in their composition between sites (β-Simpson index) and the analysis of the identified environmental drivers. Also, the environmental predictors that influence species richness in the SDTF were determined with a redundancy analysis. We identified and named two phytogeographic districts within the SDTF of the BD (Upper Balsas and Lower Balsas). According to the multi-response permutation procedure, floristic composition of the two districts differs significantly, and the richness of exclusive species in Upper Balsas was higher (292 species) than in the Lower Balsas (32 species). The proportion of Mg and Ca in the soil and the precipitation of the driest three-month period were the environmental factors with greatest positive influence on species richness. The division of geographic districts subordinated to the province level, based on diverse families such as Asteraceae, proved to be appropriate to set up strategies for the conservation of the regional flora, since at this scale, variation in species richness is more evident. Our findings are consistent with a growing body of biogeographic literature that indicates that the identification of smaller biotic districts is more efficient for the conservation of biodiversity, particularly of endemic or rare plants, whose distribution responds more to microhabitats variation., Competing Interests: The authors have declared that no competing interests exist.

The benefits provided by tropical rainforests are unevenly distributed throughout the landscape and are shaped by abiotic and biotic components that influence the spatial distribution and functional traits of the species involved. We tested whether environmental stratification of the rainforest in biophysical Landscape Units (LU), defined by topography and soil, is related to the spatial distribution of diversity, abundance and productivity (standing biomass) of tree assemblages that provide potential forest products (PFP). Considering that different PFP are associated with specific plant traits, we also tested whether a phylogenetic signal exists among the species that comprise specific use categories. Non-metric multidimensional scaling ordinations and permutational analysis of variance were based on the frequency, abundance and productivity of 129 species, the PFP of which were classified as fodder, food, fuelwood, medicinal, melliferous, ornamental, plywood and timber in 15 plots of 0.5 ha each. We constructed a phylogenetic tree of the studied species and analyzed the phylogenetic signal strength (D-statistic) among them. The spatial distribution of diversity and abundance of useful species changes among the LU. Specific PFP can be provided in contrasting habitat conditions, but generally not by the same species. The PFP categories that presented a phylogenetic signal were associated with wood characteristics (fuelwood and plywood) and the palatability of the leaves and reproductive structures (fodder). The Moraceae family was significantly related to fodder and plywood, whereas Meliaceae, Myrtaceae and Sapotaceae were mostly used for fuelwood. The medicinal species presented convergent traits distributed throughout the phylogeny. However, since our study included a broad variety of plant structures, it is possible that phylogenetic dispersion can change if we consider the specific uses within each category. Our findings show that the assemblages of PFP suppliers can be clustered through biophysical units based on soil and topography, and specific categories of PFP are often supplied by phylogenetically related species. This knowledge is fundamental in order to incorporate the high diversity of tree species and their potential uses into productive reforestation and agroforestry programs., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

In tropical dry forests, although seed germination and seedling establishment are in general limited by the seasonal availability of water, high interspecific variability, nonetheless, exists in terms of seedling traits and germination dynamics. Differences among species in seed germination and seedling traits may be related to other plant life-history traits, such that assessing these relationships may increase our understanding of factors influencing plant establishment, which would affect the regeneration pathways of tropical dry forest communities. In this study, taking into consideration the effect species' phylogeny, we evaluated the relationships of seed germination metrics (percentage, lag time, and rate of germination) and seedling types (i.e. cotyledons functional morphology), with plant life-history traits (growth form, seed mass, dispersal syndrome and dispersal phenology) for 110 species in a Neotropical dry forest in Mexico. A total of 92% of the species studied disperse their seeds during the dry season, mainly at the beginning of this season (66%), a strategy mostly associated with autochorous herbs. Seed germination was more frequent in species that dispersed seeds at the end of the dry season. Germination percentage was not related to any of the traits studied. However, germination lag time and rate were negatively related to seed mass, a trait that in turn depended on growth form and dispersal syndrome. The dominant seedling type in the community was phanerocotylar epigeal with foliaceous cotyledons (56%), which was mostly associated with small seed mass and herbaceous growth form. Our results provide evidence that several plant life-history traits explain an important part of the variation in seed germination and seedling characteristics observed among species. Therefore, these plant life-history traits may be useful for grouping species in terms of their establishment strategies and roles on the regeneration of tropical dry communities., Competing Interests: The authors have declared that no competing interests exist.

In tropical dry forests, a high interspecific variation in the strategies of fruiting phenology has been documented. Therefore, phenological responses may be mediated by influence of environmental variables, functional plant attributes or phylogenetic inertia. During 2 years, we recorded the fruiting phenology of 151 species belonging to 5 different growth forms of a Neotropical dry forest in Mexico. We evaluated the relationships between fruiting phenology, abiotic factors (precipitation, temperature, day-length) and functional attributes (growth form, dispersal syndrome, size and time for fruit development) using phylogenetic least squares models (PGLS). More species had ripe fruits during the dry season (92%) than during rainy months and dispersed their seeds by autochory and endozoochory. We found that fruit development time was positively correlated with fruit size and together the morphological fruit traits (size and dispersal syndrome) showed an important relationship with the growth form, but with a strong phylogenetic signal. Environmental seasonality had a strong influence on fruit ripening time, without a relevant association to the phylogeny of plant species. However, the phenological response to the environment (rainfall and day-length) at the community level was mediated by growth form. In woody species, we documented a high interspecific fruiting variation linked with the different dispersal syndromes. In herbaceous species, fruiting phenology is a trait restricted by the duration of their life cycle by rainfall seasonality, which in turn might have selected some traits (e.g., dry fruit, presence of spines, explosive dehiscence) for maximizing seed dispersal during the dry season.

Knowledge about the biogeographic affinities of the world's tropical forests helps to better understand regional differences in forest structure, diversity, composition, and dynamics. Such understanding will enable anticipation of region-specific responses to global environmental change. Modern phylogenies, in combination with broad coverage of species inventory data, now allow for global biogeographic analyses that take species evolutionary distance into account. Here we present a classification of the world's tropical forests based on their phylogenetic similarity. We identify five principal floristic regions and their floristic relationships: ( i ) Indo-Pacific, ( ii ) Subtropical, ( iii ) African, ( iv ) American, and ( v ) Dry forests. Our results do not support the traditional neo- versus paleotropical forest division but instead separate the combined American and African forests from their Indo-Pacific counterparts. We also find indications for the existence of a global dry forest region, with representatives in America, Africa, Madagascar, and India. Additionally, a northern-hemisphere Subtropical forest region was identified with representatives in Asia and America, providing support for a link between Asian and American northern-hemisphere forests., Competing Interests: Conflict of interest statement: V.A.-R., K.B.-G., B.B., F.Q.B., N.F., M.K., W.F.L., S. G. Letcher, C.B.S., D.S., T. Stevart, and S. Wiser have coauthored papers with Jens-Christian Svenning in the past 48 months. A.M.L. and Jens-Christian Svenning are both affiliated with Aarhus University., (Copyright © 2018 the Author(s). Published by PNAS.)

Premise of the Study: Analyses of the influence of temporal variation in abiotic factors on flowering phenology of tropical dry forest species have not considered the possible response of species with different growth forms and pollination syndromes, while controlling for phylogenetic relationships among species. Here, we investigated the relationship between flowering phenology, abiotic factors, and plant functional attributes, while controlling for phylogenetic relationship among species, in a dry forest community in Mexico., Methods: We characterized flowering phenology (time and duration) and pollination syndromes of 55 tree species, 49 herbs, 24 shrubs, 15 lianas, and 11 vines. We tested the influence of pollination syndrome, growth form, and abiotic factors on flowering phenology using phylogenetic generalized least squares., Key Results: We found a relationship between flowering duration and time. Growth form was related to flowering time, and the pollination syndrome had a more significant relationship with flowering duration. Flowering time variation in the community was explained mainly by abiotic variables, without an important phylogenetic effect. Flowering time in lianas and trees was negatively and positively correlated with daylength, respectively., Conclusions: Functional attributes, environmental cues, and phylogeny interact with each other to shape the diversity of flowering patterns. Phenological differentiation among species groups revealed multiples strategies associated with growth form and pollination syndromes that can be important for understanding species coexistence in this highly diverse plant community., (© 2017 Botanical Society of America.)

Rainforests are undergoing severe deforestation and fragmentation worldwide. A huge amount of small forest patches are being created, but their value in conserving biodiversity and forest structure is still controversial. Here, we demonstrate that in a species-rich and moderately-managed Mexican tropical landscape small rainforest patches (<100 ha) can be highly valuable for the conservation of tree diversity and forest structure. These patches showed diverse communities of native plants, including endangered species, and a new record for the country. Although the number of logged trees increased in smaller patches, patch size was a poor indicator of basal area, stem density, number of species, genera and families, and community evenness. Cumulative species-area curves indicated that all patches had a similar contribution to the regional species diversity. This idea also was supported by the fact that patches strongly differed in floristic composition (high β-diversity), independently of patch size. Thus, in agreement with the land-sharing approach, our findings support that small forest patches in moderately-managed landscapes should be included in conservation initiatives to maintain landscape heterogeneity, species diversity, and ecosystem services.

The repeated use of sleeping sites by frugivorous vertebrates promotes the deposition and aggregation of copious amounts of seeds in these sites. This spatially contagious pattern of seed deposition has key implications for seed dispersal, particularly because such patterns can persist through recruitment. Assessing the seed rain patterns in sleeping sites thus represents a fundamental step in understanding the spatial structure and regeneration of plant assemblages. We evaluated the seed rain produced by spider monkeys (Ateles geoffroyi) in latrines located beneath 60 sleeping trees in two continuous forest sites (CFS) and three forest fragments (FF) in the Lacandona rainforest, Mexico. We tested for differences among latrines, among sites, and between forest conditions in the abundance, diversity (α-, β- and, γ-components) and evenness of seed assemblages. We recorded 45,919 seeds ≥ 5 mm (in length) from 68 species. The abundance of seeds was 1.7 times higher in FF than in CFS, particularly because of the dominance of a few plant species. As a consequence, community evenness tended to be lower within FF. β-diversity of common and dominant species was two times greater among FF than between CFS. Although mean α-diversity per latrine did not differ among sites, the greater β-diversity among latrines in CFS increased γ-diversity in these sites, particularly when considering common and dominant species. Our results support the hypothesis that fruit scarcity in FF can 'force' spider monkeys to deplete the available fruit patches more intensively than in CFS. This feeding strategy can limit the effectiveness of spider monkeys as seed dispersers in FF, because (i) it can limit the number of seed dispersers visiting such fruit patches; (ii) it increases seed dispersal limitation; and (iii) it can contribute to the floristic homogenization (i.e., reduced β-diversity among latrines) in fragmented landscapes.

A central goal of comparative plant ecology is to understand how functional traits vary among species and to what extent this variation has adaptive value. Here we evaluate relationships between four functional traits (seed volume, specific leaf area, wood density, and adult stature) and two demographic attributes (diameter growth and tree mortality) for large trees of 240 tree species from five Neotropical forests. We evaluate how these key functional traits are related to survival and growth and whether similar relationships between traits and demography hold across different tropical forests. There was a tendency for a trade-off between growth and survival across rain forest tree species. Wood density, seed volume, and adult stature were significant predictors of growth and/or mortality. Both growth and mortality rates declined with an increase in wood density. This is consistent with greater construction costs and greater resistance to stem damage for denser wood. Growth and mortality rates also declined as seed volume increased. This is consistent with an adaptive syndrome in which species tolerant of low resource availability (in this case shade-tolerant species) have large seeds to establish successfully and low inherent growth and mortality rates. Growth increased and mortality decreased with an increase in adult stature, because taller species have a greater access to light and longer life spans. Specific leaf area was, surprisingly, only modestly informative for the performance of large trees and had ambiguous relationships with growth and survival. Single traits accounted for 9-55% of the interspecific variation in growth and mortality rates at individual sites. Significant correlations with demographic rates tended to be similar across forests and for phylogenetically independent contrasts as well as for cross-species analyses that treated each species as an independent observation. In combination, the morphological traits explained 41% of the variation in growth rate and 54% of the variation in mortality rate, with wood density being the best predictor of growth and mortality. Relationships between functional traits and demographic rates were statistically similar across a wide range of Neotropical forests. The consistency of these results strongly suggests that tropical rain forest species face similar trade-offs in different sites and converge on similar sets of solutions.

Seedling morphology of 210 species (173 trees and 37 lianas) was studied from a community perspective to identify major patterns of seedling functional types in a Mexican rain forest. Five types of seedlings were distinguished: cryptocotylar with reserve storage or absorption cotyledons (epigeal [CER] and hypogeal [CHR]), phanerocotylar epigeal, either with photosynthetic cotyledons (PEF) or with reserve storage or absorption cotyledons (PER), and phanerocotylar hypogeal with reserve cotyledons (PHR). The most common seedling type was PEF (49.5%), followed by CHR (31.4%), PER (9.5%), PHR (7.2%), and CER (2.4%). Excepting the CER type, seedling type frequencies did not differ between trees and lianas. The PEF seedlings had the lightest seeds, whereas CHR seedlings had the heaviest ones. Pioneer trees showed lighter seeds than persistent trees or lianas in species with PEF but not in species with PER. Pioneer trees (38 species) showed three seedling types and the most common was PEF (82%). Persistent trees (135 species) showed the five seedling types but PEF (43%) and CHR (37%) were the most frequent. Seedling type frequencies differed among dispersal syndrome groups. The animal dispersal syndrome was significantly more frequent in species with CHR. Our results show an evolutionary convergence of seedling types at the community level worldwide and the existence of a phylogenetic inertia in the evolution of initial seedling morphology. A comparison among eight tropical communities indicated on average that PEF is the most frequent type and CER the least common, although the relative frequency of each seedling type differs among communities, particularly between Neotropical and Paleotropical sites.