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Trade-offs are crucial for species divergence and reproductive isolation. Trade-offs between investment in growth versus defense against herbivores are implicated in tropical forest diversity. Empirically exploring the role of growth-defense trade-offs in closely related species' reproductive isolation can clarify the eco-evolutionary dynamics through which growth-defense trade-offs contribute to diversity. Costus villosissimus and C. allenii are recently diverged, interfertile, and partially sympatric neotropical understory plant species primarily isolated by divergent habitat adaptation. This divergent adaptation involves differences in growth rate, which may constrain investment in defense. Here, we investigate growth-defense trade-offs and how they relate to the divergent habitat adaptation that isolates these species. We characterize leaf toughness and chemistry, evaluate the feeding preferences of primary beetle herbivores in controlled trials and field-based experiments, and investigate natural herbivory patterns. We find clear trade-offs between growth and defense: slower-growing C. allenii has tougher leaves and higher defensive chemical concentrations than faster-growing C. villosissimus. Costus villosissimus has rapid growth-based drought avoidance, enabling growth in drier habitats with few specialist herbivores. Therefore, growth-defense trade-offs mediate synergistic biotic and abiotic selection, causing the divergent habitat adaptation that prevents most interspecific mating between C. villosissimus and C. allenii. Our findings advance understanding of ecological speciation by highlighting the interplay of biotic and abiotic selection that dictates the outcome of trade-offs.

Functional traits, which shift as a plant develops from seed to adult and may be phylogenetically conserved, are widely acknowledged to be associated with exotic species invasion. However, existing studies comparing functional traits between native and invasive species often focus on a single ontogenetic stage, yielding mixed results. It remains unclear whether the functional trait differences and their relationship with invasiveness (e.g. range size) of exotic species remain consistent across ontogenetic stages. In this study, we experimentally compared 18 traits across the seed, early growth and adult stages of 127 native and exotic species from 19 families. These species are common and often co‐occur in the subtropical region of China. We also explored the linkage between these traits, alongside their phylogenetic relatedness with native species and exotic species' range size in China. Our results show that only seed mass differed between native and exotic species. Moreover, the compositions of traits across all stages and the entire lifespan were primarily influenced by phylogenetic relatedness rather than geographic origin. Further, the range size of exotic species in China positively correlated with their mean phylogenetic distance to native species, with no association with individual functional traits or functional distinctiveness. Synthesis. Our results emphasize the importance of comparing functional traits across ontogenetic stages between native and exotic species to improve our understanding of the role of functional traits in shaping plant invasion. Our findings also underscore the pivotal role of phylogenetic relatedness in shaping plant functional traits and the distribution of exotic species in their new ranges. [ABSTRACT FROM AUTHOR]

Summary Hybridization is increasingly recognized as an important evolutionary process across the tree of life. In many clades, phylogenomic approaches have permitted unparalleled insight into the extent and frequency of hybridization. However, we continue to lack a deep understanding of the factors that limit and shape patterns of hybridization, especially in evolutionary radiations. In this study, we characterized patterns of introgression across Costus (Costaceae), a young evolutionary radiation of tropical understory plants that maintain widespread interfertility despite exhibiting strong prezygotic reproductive isolation. We analyzed a phylogenomic dataset of 756 genes from 54 Costus species using multiple complementary approaches – D‐statistics, gene‐tree‐based tests, and phylogenetic network analyses – to detect and characterize introgression events throughout the evolutionary history of the radiation. Our results identified a moderate number of introgression events, including a particularly ancient, well‐supported event spanning one of the deepest divergences in the clade. Most introgression events occurred between taxa or ancestral lineages that shared the same pollination syndrome (bee‐pollinated or hummingbird‐pollinated). These findings suggest that prezygotic barriers, including pollinator specialization, have been key to the balance between introgression and reproductive isolation in Costus. [ABSTRACT FROM AUTHOR]

Terrestrial vegetation emits substantial amounts of highly reactive isoprene, significantly impacting atmospheric chemistry and climate change. Both atmospheric carbon dioxide (CO2) concentration and temperature can influence plant isoprene emissions; however, whether these factors have a synergistic effect remains unclear, particularly for tropical/subtropical plants. In this study, we conducted in-situ controlled experiments on Eucalyptus urophylla, a representative tropical/subtropical species, to investigate the seasonal variation in the response of isoprene emissions to CO2 concentrations (ISOP-CO2 response) and to identify potential controlling factors. The results showed that high CO2exerts a nearly linear inhibitory effect on isoprene emissions, as indicated by the slope of the ISOP-CO2 response curve. This inhibitory effect exhibited evident seasonal changes, with stronger suppression during cooler seasons and weaker suppression during warmer seasons. This finding contrasts with the default ISOP-CO2 response in the MEGAN model, which ignored seasonal variation. Further analysis showed a significant correlation between the slope of the ISOP-CO2 response curve and growth temperature from the past 10 days, indicating that these metrics are effective indicators for predicting seasonal changes. Our findings reveal a synergistic mechanism between temperature and CO2 concentration effects on isoprene emissions. By coupling the effects of growth temperature with the ISOP-CO2 response, this mechanism can be integrated into models to provide more accurate predictions of future isoprene emissions, reducing prediction biases, especially during cooler seasons. [ABSTRACT FROM AUTHOR]

The article "Exploring biodiversity of Uruguayan vascular plants through DNA barcoding" published in Frontiers in Genetics on October 15, 2024, discusses the use of DNA barcoding to study the biodiversity of Uruguayan vascular plants. The study aims to address the decline in biodiversity in Uruguay by establishing a DNA barcode national network. By analyzing 171 sequences from four loci for 50 vascular plant species, the researchers identified suitable markers for plant DNA barcoding and contributed to the Uruguayan Barcode of Life Initiative. The study highlights the importance of creating a comprehensive public database for species identification and biodiversity research. [Extracted from the article]

Anisomeles malabarica, the commonly called "Malabar catmint" is a wild tropical plant belonging to the family Lamiaceae. Traditionally this plant is used as mosquito repellent, snakebite antidote and to treat fever and gastrointestinal discomfort by the people of South India. It is an important endemic plant used in the indigenous medicine systems of India such as Ayurveda, Siddha, and Unani in various formulations. The rich phytochemistry of A. malabarica includes cembrane terpenes, flavonoids, alkaloids, steroids, flavones, glycosides, and other bioactive compounds contributing for its medicinal potential. Extracts and metabolites of A. malabarica shows wide range of significant pharmacological effects in combating cancer cells through apoptosis, inhibiting viral agents (HPV and SARS-CoV-2), immune regulation, and DNA protection. The phytocompounds of A. malabarica were also reported for anti-malarial, anti-rheumatic, anti-inflammatory, anti-epileptic, anti-diabetic, anti-parasitic activity, and hepatoprotective properties. This systematic review summarizes the therapeutic properties with botanical characteristics, ethnobotany, and phytochemistry of A. malabarica. It also documents the ingrained traditional use of A. malabarica in religious custom in southern states of India. Therefore further exploration of this promising medicinal herb for its metabolites and ethnobotanical records would possibly support the development of modern medicine systems and provides insights for future research. [ABSTRACT FROM AUTHOR]

Plant–hummingbird interactions are considered a classic example of coevolution, a process in which mutually dependent species influence each other's evolution. Plants depend on hummingbirds for pollination, whereas hummingbirds rely on nectar for food. As a step towards understanding coevolution, this review focuses on the macroevolutionary consequences of plant–hummingbird interactions, a relatively underexplored area in the current literature. We synthesize prior studies, illustrating the origins and dynamics of hummingbird pollination across different angiosperm clades previously pollinated by insects (mostly bees), bats, and passerine birds. In some cases, the crown age of hummingbirds pre‐dates the plants they pollinate. In other cases, plant groups transitioned to hummingbird pollination early in the establishment of this bird group in the Americas, with the build‐up of both diversities coinciding temporally, and hence suggesting co‐diversification. Determining what triggers shifts to and away from hummingbird pollination remains a major open challenge. The impact of hummingbirds on plant diversification is complex, with many tropical plant lineages experiencing increased diversification after acquiring flowers that attract hummingbirds, and others experiencing no change or even a decrease in diversification rates. This mixed evidence suggests that other extrinsic or intrinsic factors, such as local climate and isolation, are important covariables driving the diversification of plants adapted to hummingbird pollination. To guide future studies, we discuss the mechanisms and contexts under which hummingbirds, as a clade and as individual species (e.g. traits, foraging behaviour, degree of specialization), could influence plant evolution. We conclude by commenting on how macroevolutionary signals of the mutualism could relate to coevolution, highlighting the unbalanced focus on the plant side of the interaction, and advocating for the use of species‐level interaction data in macroevolutionary studies. [ABSTRACT FROM AUTHOR]

The morphological characters of Southeast Asia's indigenous Peperomia species are very similar, especially in their flower structures. The flowers are simple, hermaphrodite and lack a perianth. Therefore, many species are hard to distinguish using morphological characters alone. Here, we apply chemometric data for species identification and classification, gathered using multiwavelength detection combined with the colour scale High-Performance Thin-Layer Chromatography (HPTLC) fingerprinting procedure and chemical compounds determined by Gas Chromatography–Mass Spectrometry (GC-MS). Fourteen taxa were investigated using hexane, ethyl acetate and ethanol solvent extractions. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used with the colour scale fingerprints to classify the Peperomia species. The PCA and HCA using the chromatogram profile from hexane divided the taxa into six groups compared to the profile from ethyl acetate and ethanol, which each detected seven groups. The chromatogram from the combined dataset of all three solvents can differentiate all the species. The GC-MS data detected a total of 40 compounds from the hexane extract, and these differed among Peperomia species. This approach based on HPTLC fingerprinting and GC-MS analysis can therefore be used as a tool for authentication and identification studies of Peperomia species. [ABSTRACT FROM AUTHOR]

Invasive plants disrupt ecosystems by influencing species interactions, aiding co-invader integration, and worsening competition for native plants. Successful forest invasive species management relies on grasping these interaction patterns at the community level. This study aims to assess the community attributes of invasive plants in tropical forests of Northeast India, examining their dominance in various habitats, elucidating their influence at the community level and some species-specific effects on associated co-invaders and non-invasive groups. The present investigation recorded 101 invasive plant species mostly of neotropical origin, comprising of grasses, sedges, forbs, shrubs, trees, and vines. The findings revealed both positive and negative effects of invasive species richness and their percentage at community level and throughout different habitats. However, the presence of dominant invasive species caused a substantial decrease in species diversity of plant community in the study area, depicting a significant negative association with the non-invasive group and a notable positive association with the co-invasive group. These findings offer valuable insights by specifying the community-level impacts of exotic invaders on the natural plant population which will be very helpful in devising effective management plans to counter biotic invasion in the biodiversity rich tropical forested landscapes. [ABSTRACT FROM AUTHOR]

Aquilaria (Thymelaeaceae), a tropical and subtropical plant, is one of the main genera that can produce agarwood. Aquilaria sinensis and Aquilaria yunnanensis are native Chinese tree species, and A. sinensis is China's main agarwood source. Agarwood is a nontimber forest product with high economic and medicinal value. First‐grade agarwood is sold as much as $100 000 per kilogram. There has been little research on the saprobic fungi associated with Aquilaria, with only 11 records having been reported. In the present study, 10 terrestrial saprobic fungi associated with A. sinensis and A. yunnanensis were collected in China. Based on morphological and phylogenetic studies, these 10 collections are introduced herein as one new genus (Aquilariomyces), nine new species – Aquilariomyces aquilariae, Corynespora aquilariae, Melomastia maomingensis, Nigrograna aquilariae, Parathyridariella aquilariae, Peroneutypa maomingensis, Phaeoseptum aquilariae, Pseudothyridariella aquilariae, and Triangularia aquilariae, and one known species (Camarographium clematidis). Descriptions, illustrations of morphological characteristics, photo plates, phylogenetic trees, and the results of a pairwise homoplasy index test (PHI) test results are provided. [ABSTRACT FROM AUTHOR]

Using population genomics and molecular biological methods, a recent study reveals the molecular mechanisms of vivipary in mangroves, a term designating all woody plants of the tropical intertidal zones. [ABSTRACT FROM AUTHOR]

Extreme heat events are becoming increasingly common, and the short‐term acclimation of photosynthesis will have a large impact on plant performance. Trees in lowland tropical forests, which are hypothesized to have limited abilities to tolerate rising temperatures, may need to rely on short‐term acclimation of their more plastic traits, like photosynthetic thermal tolerance, to persist in the face of increasingly variable climates. Here, we investigated seasonal acclimation of thermal tolerances in plant species of the moist Amazon. Specifically, we measured the photosynthetic thermal tolerances of six common woody Amazonian species at the beginning and at the end of the dry season to determine the species' abilities to acclimate to intra‐annual changes to climate. In addition, we used the natural thermal gradient present at our research site to test the acclimation of individual plants to maximum air temperatures not currently observed elsewhere in the moist lowland Amazon (up to ~43°C). Between seasons, there were significant overall increases in the thermal tolerances of three species (i.e. higher thermal tolerances in the hotter dry season), suggesting that leaf megathermy is prominent in these species. Also, three species acclimated their thermal tolerances to microsite‐level differences in seasonal temperature maxima, suggesting closer fidelity between leaf and air temperatures (i.e. limited homeothermy) for these species. Our results show that some woody species from the moist Amazon can acclimate their thermal tolerances over short time‐scales, although acclimation is likely insufficient to overcome thermal stress during extreme temperature events. Some species may therefore be more sensitive to heatwaves than others, which could impact survival and composition of tropical lowland forests into the future. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Psidium guajava: is a tropical tree that is widely used in traditional medicine, especially for treating diarrhea. While P. guajava has been the subject of numerous reviews, none have specifically examined its ethnobotany, pharmacology, and phytochemistry in relation to its antidiarrheal activity. This review aims to summarize the evidence of effectiveness and safety of P. guajava in the treatment of diarrhea. Literature searches were conducted through Web of Science, PubMed, and ScienceDirect by using keywords "Psidium guajava" and "diarrhea" in October 2022. A total of 189 studies were included in this review. P. guajava is widely used in traditional medicine in 44 countries. Decoction and oral were the most represented method of preparation and administration, respectively, while leaves represented the most frequently cited part of the plant. Around 27 antidiarrheal or antibacterial compounds have been isolated and identified, including benzophenone glycosides, terpenes, polysaccharides, phenols, and flavonoids. This article presents ethnobotanical and pharmacological evidence for the efficacy of P. guajava leaves in the treatment of diarrhea and provides reference information for further investigation of this plant. However, despite the large number of publications on the topic, there are still some questions to answer: are quercetin and its glycosides the only ones to act as antidiarrheal agents? What is the mechanism of action of P. guajava antidiarrheal compounds? are the use of guava leaves safe in all types of populations including children, and at what dosage? To answer these questions, more complete phytochemical studies and systematic clinical trials are needed. [ABSTRACT FROM AUTHOR]

This study explores the role of floral volatile organic compounds (FVOCs) in insect behavior, focusing on Aquilaria sinensis (AS), a valuable tropical plant threatened by Heortia vitessoides Moore. Despite H. vitessoides' attraction to AS and non-host plants like Elaeocarpus decipiens (ED) and Dalbergia odorifera (DO), little is known about their chemical interactions. FVOCs from these plants were analyzed at 9:00 and 18:00 using GC×GC-QTOF-MS and HS-SPME. The results showed that ED exhibiting the highest concentration (92.340 ng/mg), followed by DO (75.167 ng/mg) and AS (64.450 ng/mg). Through GC-EAD and EAG, a total of 11 FVOC compounds with electrophysiological activates were identified. These compounds, except linalool, showed dose-dependent responses. Y-Tube bioassays confirmed phenylethyl alcohol or the mixture of EAD-active compounds produced positive chemotactic responses in both males and females. FVOCs have the potential to be used as a natural and sustainable alternative to chemical insecticides in pest control. [ABSTRACT FROM AUTHOR]

Turkey berry, also known as Solanum torvum Swartz, is native to Africa, Asia and South America. This tropical plant of the family Solanaceae has versatile uses in both food and medicine in tropical and subtropical countries. It has been employed in traditional medicine all over the world. Chemical composition of this fruit, its pharmacological properties as ascertained through scientific investigations and its clinical applications are discussed. S. torvum contains numerous important metabolites such as saponins steroids and flavonoids, which function as antioxidants, antifungal, antidiabetic, anticancer, antiulcer, antianxiety and immunomodulators. Various notable roles in ethnomedicinal uses and approaches as a traditional medicinal herb. These have been found in large amounts and have various functions, including antioxidant properties against cardiovascular diseases and immune-modulating activities. Notably leaves extracts, fruits etc. have beneficial therapeutic traits. For a long time now, "Solanum torvum" has been used to treat numerous conditions such as fever, wounds, etc. Research backs up these traditional uses by pointing out the plant's blood pressure management, kidney protection nature, and immune-boosting capabilities. The review summarizes the importance of ethnobotany, its chemical composition, and the scientifically proven pharmacological activities of S. torvum. [ABSTRACT FROM AUTHOR]

Fruit and seed morphometry was studied across 1070 plant species belonging to 140 families from 27 contrasting plant communities. The main objectives were to identify allometric relationships and describe the frequency distributions of the weights and sizes of fruits and seeds across plant species, regardless of any qualitative attribute or community type. The frequency distributions of 12 morphometric variables were then determined. Pearson correlations were used to describe associations between quantitative attributes and estimate the slopes of the lines (allometric coefficients) obtained. In general, small fruits and seeds (<1 cm) prevailed in the sample examined. The frequency distributions of the weight and size parameters of the fruits and seeds were bell‐shaped, with the exception of the number of seeds per fruit, which was skewed to the right. The highest allometric coefficients were found between the dry weights and sizes of the fruits and seeds, suggesting that these traits are mutually supporting. The cost of seed packaging per fruit, or the pericarp/seed ratio, tended to decrease with increasing investment in progeny, and the number of seeds per fruit decreased with an increase in seed weight. The significant associations between the fruit shape indexes and the morphometric attributes show that the shape of fruits is related to their size and weight. The highest allometric coefficients were found between the dry weights and sizes of the fruits and seeds. Fruit and seed size can predict their biomass and vice versa. There is a close relationship between fruit biomass values and their components (seeds and pericarp). Most species invest more biomass in pericarp (protection and dispersal) compared with the investment in progeny (seed per fruit). The sample examined could be influenced taxonomically along with selective pressures that favour the reproductive economy of the species and suggest that morphometric traits have evolved in coordination. [ABSTRACT FROM AUTHOR]

Indoor greening is becoming popular because it provides many benefits for people. However, plant selection for indoor greening is limited to shade-tolerant tropical plants internationally, and little research has been performed to expand the use of native herb plant species. The aim of this research was to study growth characteristics of Japanese native herbs under common light intensity regimes in office buildings. Eight species of Japanese native herbs (Acorus gramineus, Cameilla sinensis, Farfugium japonicum, Gynostemma pentaphyllum, Perilla frutescens var. crispa f. viridis, Petasites japonicus, Sasa veitchii, and Saxifraga stolonifera) were examined in an open growth chamber with light-emitting diode light tape under three light intensities [photosynthetic photon flux densities of 3 µmol⋅m-2⋅s-1 (250 lx), 6 µmol⋅m-2⋅s-1 (500 lx), and 12 µmol⋅m-2⋅s-1 (750 lx)] from 8 AM to 10 PM every day from Jun 2021 to Oct 2021 in an office. Farfugium japonicum and Saxifraga stolonifera were as shade-tolerant as typical tropical plants and grew well under all light intensities. Sasa veitchii performed well under high and medium light intensity. The other plant species require supplemental lightning to achieve sufficient growth indoors. [ABSTRACT FROM AUTHOR]

Fire-adaptive traits in plants of tropical and subtropical grassy ecosystems have been the subject of considerable global research, but only recently studied in pyrogenic Florida subtropical grasslands. Plant growth forms, belowground organs, and post-fire recovery strategies were studied for 198 grassland specialists in peninsular Florida. Community types (dry-mesic, mesic, wet-mesic, and wet) were sampled with 1m2 plots along the edaphic-hydrologic gradient and the association between these variables and fire-related plant traits was tested using fourth-corner analysis. Caulescent herbs (43), cespitose graminoids (27), and rosette herbs (31) are the most common growth forms among species sampled. Plants with epigeogenous and hypogeogenous rhizomes dominate the sample plots, including matrix graminoids, shrub geoxyles, and an acaulescent rhizomatous fire-resilient palm (Serenoa repens). Most species (163; 82%) exhibit resprouting, including 30 facultative resprouters and 133 obligate resprouters. All woody rhizomatous species are obligate resprouters, and 35 ephemeral herbaceous species are obligate reseeders. Community type was a better predictor of species abundances than hydrology, however, hydrology was significantly associated with species traits measured, particularly rhizome texture, with woody rhizomes prevalent in all but the wet sites. Belowground organs (xylopodia, geoxylic suffructices) and growth form were associated with frequent fire and phylogeny, suggesting fire regime as a driver of community phylogenetic diversity. Persistence, rapid resilience and co-occurrence of geoxyles align Florida subtropical grasslands with other global geoxyle grasslands. The old-growth, pyrogenic grassy ecosystems of peninsular Florida are the center of geoxyle diversification on the southeastern US coastal plain. [ABSTRACT FROM AUTHOR]

Taro is a tropical plant and an underutilized root crop that has a good source of carbohydrate. Taro tuber contains 70%–80% of starch on dry basis. This review highlights the extraction of taro starch, latest advancements in the modification such as physical, chemical and enzymatic modification of taro starch. Furthermore, after modification of taro starch, molecular weight and amylopectin branch chain length distribution, granular shape, percentage crystallinity, swelling and solubilization, pasting and thermal properties and in vitro digestibility of taro starch were significantly affected. Additionally, researchers have explored novel methods to modify the physicochemical characteristics of taro starch, enhancing its functionality as a thickening, gelling, and stabilizing agent in various food formulations. However, fabrication of nanoparticles from taro starch was also studies. Various health benefits of taro starch have been reported in this study. One significant health benefit of taro starch is its potential to improve blood sugar management. Furthermore, the versatility of taro starch in food applications has expanded, ranging from traditional staples to modern convenience foods. Its gluten‐free nature makes it an attractive option for individuals with gluten sensitivity or celiac disease. Taro starch is increasingly incorporated into bakery products, snacks, noodles, and as a thickening agent in soups and sauces. The unique sensory attributes and nutritional profile of taro starch contribute to the development of novel, health‐conscious food products that cater to evolving consumer preferences. [ABSTRACT FROM AUTHOR]

Invasive alien plants (IAPs) pose a significant threat to island biodiversity and severely impact ecosystems. Understanding the species–area relationship and environmental determinants of growth forms for IAP species on subtropical islands is crucial for establishing an IAP's early warning mechanism, enhancing island ecological management, and protecting the ecosystems of Fujian and other subtropical islands. The study identified significant species–area relationships for IAPs and different life-form plants (trees, shrubs, and herbs), with slopes of 0.27, 0.16, 0.15, and 0.24, respectively. The small island effect does not apply to all species. Isolation has little effect on species richness, and the IAPs on Fujian islands do not conform to the isolation effect in island biogeography. Landscape factors are the main determinants of IAPs and different life-form species richness, with area, shape index, and perimeter–area ratio being the three primary landscape factors. These environmental factors are closely related to habitat heterogeneity. Besides landscape factors, different life forms respond differently to environmental factors. Climate drives the species richness distribution of shrubs and herbs, while trees are mainly influenced by human activities. Overall, landscape, human disturbance, and climate jointly drive the distribution of IAPs, with landscape factors being the most significant. [ABSTRACT FROM AUTHOR]

AbstractLitsea costalis is a well-known medicinal plant in tropical and subtropical areas. Four significant flavonoids were extracted and characterized from the plant leaf extract. One component was discovered for the first time in flavonoid chemistry, flavan-4-ol, (3′, 4′-methylenedioxy-5,7-dimethoxy chroman-4-ol). Three flavonoids were discovered for the first time in this plant. The detected products are (+)-pinostrobin, (+)-onysilin, and (+)-pinocembrin. The fourth component was characterized for the first time in this plant and introduced in flavonoid chemistry. The extracted component antioxidant activity against DPPH indicated an IC50 value of around 30 µg/mL. [ABSTRACT FROM AUTHOR]

Passiflora spp. or passion fruit is a tropical plant that is often used as a food source. The large morphological variations of Passiflora cause difficulties in identifying the species. The objectives of the study are to identify the specific morphological and anatomical characters of Passiflora spp. in Yogyakarta and to determine their phenetic relationship for identification. A total of 15 samples of Passiflora were taken by purposive sampling technique from Bantul, Sleman, Kulon Progo, and Yogyakarta City, and then carried through the morphological and anatomical characterization. The morphological characters observed stems, leaves, and flowers, while the anatomical characters observed leaves. The results show that the observed samples are identified as four species, P. foetida, P. vitifolia, P. edulis, and P. quadrangularis. The P. edulis species consists of two forms, P. edulis f. flavicarpa and P. edulis f. edulis. The variation of morphological character lie in young stem shape, leaf shape, the texture of stem and leaf surface, bract shape and color, sepal and petal color, and the presence of a purple corona ring. While the variation of anatomical characters lie in the pattern of the vascular bundles, the shape of the upper and lower sides of the leaf veins, the shape and size of the palisade cells, as well as the type and density of stomata. Based on the phenetic analysis on the 0.8 phenon line, four main clusters were formed, P. foetida, P. vitifolia, P. edulis, and P. quadrangularis. [ABSTRACT FROM AUTHOR]

Baccaurea is a group of fruit-bearing potential wild tropical plants. West Sumatra is one of the Indonesian provinces with a sizable forest area. However, the high deforestation rate threatens the germplasm, especially Baccaurea wild plants, before well exploring their potential. The study aimed to analyze the sequence characters and phylogenetics of Baccaurea species found in West Sumatra using ITS molecular markers. DNA extraction relied on the Kit protocol using ITS molecular markers. The study employed the MEGA X application for sequence analysis and kinship relationships. Results of the analysis based on sequence characters of Baccaurea’s six species showed lengths ranging from 696 to 749 bp, the percentage composition of G + C bases (63.8%) and A + T bases (36.2%), the range of genetic distance (1%–5%), the number of conservative characters (549 bp), the number of informative characters (69 bp), and the point mutation in the nucleotide sequence (369 and 489). Meanwhile, the phylogenetic analysis using the ML method grouped the six species of Baccaurea to form a monophyletic clade with a bootstrap value of 100%-99%-100%. The results revealed for the first time the inclusion of ITS sequences of six Baccaurea species indigenous to West Sumatra in the NCBI database, which can benefit future investigations in identifying Baccaurea species and as a valuable reference for plant breeding in Baccaurea wild fruit plants’ development and conservation. [ABSTRACT FROM AUTHOR]

Garcinia pedunculata, a tropical plant found abundantly in the north-east region of India, has been used by many traditional healers for various gastrointestinal ailments. Studies are being carried out for the proper pharmacological identification of the compounds as well as the mode of action for the treatment of various diseases. In this study, phytochemistry of the fruit was evaluated, followed by a quantitative analysis of the total phenolic and flavonoid content of the methanolic crude extract as well as different fractions (n-hexane, chloroform, ethyl acetate, and n-butanol). The fraction with the most potent flavonoid and phenolic content was evaluated for its anti-inflammatory activity using both in vitro and in vivo assays. The chloroform fraction of G. pedunculata fruit extract was found to have a substantial amount of phenols and flavonoids. This fraction inhibited the denaturation of BSA and significantly stabilized human RBC membrane compared to the standard drug Diclofenac sodium. The fraction also significantly reduced the formaldehyde-induced paw edema in mice and normalized the blood parameters. This study provides evidence that G. pedunculata fruit extract plays a critical role in anti-inflammatory activity, indicating that it can be a potential candidate for further investigation in the treatment of inflammation-related diseases. [ABSTRACT FROM AUTHOR]

Karst areas in Indonesia are arid landscapes with water-use limitations because of dissolved carbonates. Long-term water scarcity stunts plant growth and often kills them. For tropical karst forestry-greening, the three best legume and three best non-legume species from a previous trial comprising 20 species were compared. Since October 2011, seedlings of the top three non-legume, species Aleurites mollucana, Sterculia foetida, and Alstonia scholaris, and three legume species, Acacia auriculiformis, Cassea seamea, and Acacia mangium, have been grown for four months. In January 2012, field trials were established at two dry karst locations, i.e., Pracimantoro, Central Java, and Bunder, Gunung Kidul Yogyakarta. A randomized block design was used to raise 1.764 seedlings at the two sites with 7x7 plots, 3x3 spacing between trees, and three blocks. After 10 months, legumes and non-legumes differed greatly in all growth parameters. These disparities lasted up to 30 months, when trees should have adapted to their new surroundings. After seven years of planting, legume trees raised the soil's organic matter concentration from low to medium, making it more fertile, similar to soil from intensive agricultural regions. Thus, early or mixed legume plantings on tropical karst sites may aid in better re-greening than the establishment of non-legumes. [ABSTRACT FROM AUTHOR]

Unlike majority of generalist predators of soft-body phytophagous insects, the giant ladybeetle predator, Anisolemnia dilatata (Fabricius), is a specialist predator of woolly aphids of bamboo plants in parts of tropical Asia. This predator has a long development time and reproductive duration. This study investigated through a field-cum-laboratory approach how a predator optimizes its reproductive and generational timing in bamboo habitats with patchy resources of woolly aphids. Results revealed that the giant ladybeetle females produced 69.20% of total eggs in the high prey density phase (mean ± SEM: 52.52 ± 9.65 aphids/leaf), comprising an average of 11 weeks out of the prey population cycle of 38 weeks. However, gravid females initiated egg-laying at a minimum average prey density of 16.35 aphids/leaf. Females chose narrow and thin parts of bamboo plants for depositing egg batches at a minimum distance of 21.05 cm and a maximum of 46.95 cm from the nearest aphid colony. Such behaviour is unique in aphidophagous predators directed at avoiding egg predation from actively growing conspecific or heterospecific larvae that continue to feed aphids after cessation of egg-laying in the declining phase of the population when prey resources become scarce. [ABSTRACT FROM AUTHOR]

Hybridization has significant evolutionary consequences across the Tree of Life. The process of hybridization has played a major role in plant evolution and has contributed to species richness and trait variation. Since morphological traits are partially a product of their environment, there may be a link between hybridization and ecology. Plant hybrid species richness is noted to be higher in harsh environments, and we explore this hypothesis with a keystone tropical plant lineage, palms (Arecaceae). Leveraging a recent literature review of naturally occurring palm hybrids, we developed a method to calculate hybrid frequency, and then tested if there is phylogenetic signal of hybrids using a phylogeny of all palms. Further, we used phylogenetic comparative methods to examine the interaction between hybrid frequency and presence in dry environments, on islands, and the species richness of genera. Phylogenetic generalized least squares models had stronger support than models of random association, indicating phylogenetic signal for the presence of hybrids in dry and island environments. However, all p‐values were >.05 and therefore the correlation was poor between hybridization and the trait frequencies examined. Presence in particular environments are not strongly correlated to hybrid frequency, but phylogenetic signal suggests a role in its distribution in different habitats. Hybridization in palms is not evenly distributed across subfamilies, tribes, subtribes yet plays an important role in palm diversity, nonetheless. Increasing our understanding hybridization in this economically and culturally important plant family is essential, particularly since rates are projected to increase with climate change, reconfiguring the dynamics and distribution of biodiversity. [ABSTRACT FROM AUTHOR]

• Synergistic effect on tyrosinase inhibition activity of Cassia fistula flower extract and Gynura procumbens leaf extract. • Antagonism of this combinarion occureed at lower concentration (Fa < 0.5). • The quantitative result of the synergistic effect were obtained using CompuSyn software. The antioxidants and tyrosinase inhibitors found in plants are promising agents in skincare products. Cassia fistula and Gynura procumbens are tropical plants found in many Southeast Asian countries. This study evaluated the antioxidant and tyrosinase inhibitory activities of ethanol extracts prepared from Cassia fistula flowers and Gynura procumbens leaves. The antioxidant activity of Cassia fistula flower and Gynura procumbens leaf extracts were investigated via the stable free radical 2,2-diphenyl-1-picrylhydrazyl method. The tyrosinase inhibitor effects of extracts and its combination against tyrosinase were examined with L-DOPA as substrate. The synergistic effect of Cassia fistula flower and Gynura procumbens leaf extracts combination was demonstrated by using the combination index method based on the median-effect principle that allows quantitative determination of its combination, where CI < 1, =1, and >1 indicates synergism, additive effect and antagonism, respectively. The CompuSyn software was used for determining synergism and antagonism at all concentrations or effects levels simulated automatically. The antioxidant activity of Cassia fistula flower extract was 2.7-fold higher than Gynura procumbens leaf extract, but the tyrosinase inhibitor activity was lower. The combination of Cassia fistula extract and Gynura procumbens extract in ratio 7:1.2 demonstrated synergistic effects when the inhibition was greater than 50 % with the CI ranged 0.90 to 0.49 for the fractional inhibition of Fa = 0.50–0.95. In conclusion, this combination demonstrated a synergistic effect and may be used further in cosmetic formulation. [ABSTRACT FROM AUTHOR]

The flowers of Peperomia (Piperaceae) are simple, minute, and unique structures within the angiosperms consisting of a rounded bract, two stamens and an ovary, but generally lack taxonomic value at species level. Because of this, morphological characters of vegetative parts have been mainly used for species level taxonomy. There is a need to supplement these vegetative characters with anatomical characters. We selected 17 native Thai species representatives of South East Asian Peperomia to investigate the utility of vegetative anatomical characters for species delimitation, taxon identification, and classification. Stem, petiole, and leaf anatomical characters were studied using standard microscopic techniques. The anatomical characters demonstrated high diversity and supported species identification. Unweighted Pair Group Method with Arithmetic Mean (UPGMA) culstering, Principal Coordinates analysis (PCoA), and Principal Component Anaysis (PCA) were used to investigate patterns in the multivariate anatomical data and identify groupings of value to species classification. Four broad groupings were retrieved and some subgroupings identified. The most important characters that differentiated the species in the multivariate analysis included stem shape (roundness and ridges), petiole indumentum and trichome type, vascular bundle pattern and number, stem pith cavity, mucilage canals, and stem cortex sclerenchyma. These data were further used to prepare anatomical descriptions at generic and species levels and to provide a key to species. [ABSTRACT FROM AUTHOR]

The European Commission requested the EFSA Panel on Plant Health to conduct a pest categorisation of Ceroplastes rubens Maskell (Hemiptera: Coccidae), following the commodity risk assessments of Acer palmatum plants grafted on A. davidii and Pinus parviflora bonsai plants grafted on P. thunbergii from China, in which C. rubens was identified as a pest of possible concern to the European Union (EU). The pest, which is commonly known as the pink, red or ruby wax scale, originates in Africa and is highly polyphagous attacking plants from more than 193 genera in 84 families. It has been present in Germany since 2010 in a single tropical glasshouse. It is known to attack primarily tropical and subtropical plants, but also other host plants commonly found in the EU, such as Malus sylvestris, Prunus spp., Pyrus spp. and ornamentals. It is considered an important pest of Citrus spp. The pink wax scale reproduces mainly parthenogenetically, and it has one or two generations per year. Fecundity ranges from 5 to 1178 eggs. Crawlers settle usually on young twigs and later stages are sessile. All life stages of C. rubens egest honeydew on which sooty mould grows. Host availability and climate suitability suggest that parts of the EU would be suitable for establishment. Plants for planting and cut branches provide the main pathways for entry. Crawlers could spread over short distances naturally through wind, animals, humans or machinery. C. rubens could be dispersed more rapidly and over long distances via infested plants for planting for trade. The introduction of C. rubens into the EU could lead to outbreaks causing damage to orchards, amenity ornamental trees and shrubs. Phytosanitary measures are available to inhibit the entry and spread of this species. C. rubens satisfies the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest. [ABSTRACT FROM AUTHOR]

Phosphorus (P) is a key element for energy transfer, and biosynthesis of nucleic acids and cell membranes. The objective of this study was to investigate and quantify P utilization by different grain—maize (Zea mays L.) and soybean (Glycine max L.)—and forage-cover crop brachiaria (Brachiaria ruziziensis) plant species in a low fertility highly weathered Oxisol. Two rates of P (25 and 50 mg kg−1) were applied by water-soluble P fertilizer (triple superphosphate) to each of 12 crop cycles, together with a control (no P added). Measurements included plant biomass production and P uptake for each cycle, and analysis of soil P fractions (including labile and non-labile) and enzymes activities (acid phosphatase and β-glucosidase) were done at the beginning of the experiment and after 3, 6, and 12 cycles. Total biomass production and P uptake/removal were significantly higher for brachiaria than maize and soybean, which was reflected in the P use efficiency (PUE), being higher for brachiaria (57%), compared with maize (26%) and soybean (21%). The higher PUE by brachiaria was partly attributed to higher levels of acid phosphatase and β-glucosidase activities which indicated enhanced biological activity and P cycling under brachiaria. Data from the control treatment clearly demonstrated that all three plant species mobilized stable/occluded fractions of P throughout the experiment, however, brachiaria could produce more using less P. The findings of this study indicated the inclusion of brachiaria in crop rotations as a forage or cover crop/green manure may enhance overall P use efficiency. [ABSTRACT FROM AUTHOR]

The increasing frequency and intensity of heat waves caused significant damages to urban woody species, and the different leaf structures between evergreen and deciduous species may be closely related to leaf heat tolerance. However, whether the different leaf structural traits of evergreen and deciduous plants contribute to their different responses under heat waves is still unclear.During the record‐breaking and long‐lasting 2022 summer heat waves in China, we investigated the relationships between leaf thermal indices and leaf structural traits of 36 urban woody species in four cities along the Yangtze River.We found that all the four thermal indices were significantly but weakly related with leaf damage status. The critical temperature that causes the initial 15% damage to photosystem II (Tcrit) may serve as a sensitive measure of heat tolerance. Evergreen species suffered less leaf damage during the heat waves and exhibited higher leaf heat tolerance, thicker leaves than deciduous species. Tcrit was significantly correlated with leaf mass per area, leaf thickness and thickness of spongy tissue.Synthesis. Urban woody species with higher Tcrit, leaf mass per area and leaf thickness tend to be more tolerant to heat stress. This study provides insights for predicting leaf heat tolerance of urban woody plants in subtropical China and their physiological and ecological responses to severe heat waves. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Plant invasions threaten the biodiversity of islands, causing serious impacts on their ecosystems. To investigate the distribution patterns of invasive alien plants on subtropical islands, the environmental determinants of species richness, and the growth forms of invasive alien plants, this study analyzed the composition and origin of invasive alien plants on 77 islands in Fujian. The similarity in the distribution of invasive alien plants between islands was assessed using the UPGMA. Moreover, feature selection, best-subset regression, and variance decomposition were performed using 19 environmental variables characterizing climate, anthropogenic disturbance, and landscape/geography, as well as the species richness and growth forms of invasive alien plants. Through the analysis, the main environmental factors affecting the species richness and growth forms of invasive alien plants on the Fujian islands were identified. The results showed 142 species of invasive alien plants in 38 families and 102 genera on 77 islands in Fujian. Annual herbs constituted the most representative growth form of invasive alien plants and tropical America was the main origin of invasive alien plants. The distribution of invasive alien plants across the 77 islands in Fujian showed a high degree of similarity, suggesting a nested pattern in their distribution. The proportions of building and farmland area (BFA), island area (A), and maximum elevation (ME) were the main driving factors of species richness and growth forms for invasive alien plants. In particular, BFA played a key role in driving plant invasion. The results of this study can help establish an early warning mechanism for invasive alien plants and better implement island ecological management, which are important for the protection of subtropical island ecosystems. [ABSTRACT FROM AUTHOR]

n the Neotropics, the focus of apomictic studies predominantly centres on trees within the Brazilian savanna, characterized, mostly as sporophytic and facultative, associated with polyploidy and polyembryony. To enhance our understanding of the mechanisms governing apomixis and sexual reproduction in tropical herbaceous plants, we clarify the relationship between apomixis, chromosome counts, and polyembryony in the epiphytic orchid Zygopetalum mackayi , which forms a polyploid complex within rocky outcrops in both the Brazilian savanna and the Atlantic forest. To define embryo origins and describe megasporogenesis and megagametogenesis, we performed manual self-pollinations in first-day flowers of cultivated plants, considering all three cytotypes (2 x , 3 x , 4 x) of this species. Flowers and fruits at different stages were collected to describe the development and morphology of ovules and seeds considering sexual and apomictic processes. As self-pollination treatments resulted in high fruit abortion in diploids, we also examined pollen tube development in aborted flowers and fruits to search for putative anomalies. Megasporogenesis and megagametogenesis occur regularly in all cytotypes. Apomixis is facultative and sporophytic, and associated with polyploid cytotypes, while diploid individuals exclusively engage in sexual reproduction. Polyembryony is caused mainly by the production of adventitious embryos from nucellar cells of triploids and tetraploids, but also by the development of multiple archesporia in all cytotypes. Like other apomictic angiosperms within the Brazilian savanna, our findings demonstrate that apomixis in Z. mackayi relies on pollinators for seed production. We also consider the ecological implications of these apomictic patterns in Z. mackayi within the context of habitat loss and its dependence on pollinators. [ABSTRACT FROM AUTHOR]

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Exotic plant invasions threaten biodiversity and are costly to farmers. Land use is a major pathway promoting the spread of exotic plant species; however, little is known about the processes underlying the success of exotic plants in tropical agricultural landscapes. Focussing on the heterogeneous smallholder landscapes of north‐eastern Madagascar, we studied exotic plants of understorey communities across a land‐use intensity gradient from unburned lands (old‐growth forests, forest fragments and forest‐derived vanilla agroforests) to burned ones (fallow‐derived vanilla agroforests, woody fallows and herbaceous fallows).We quantified the absolute species richness, abundance and cover of exotic plants across land‐use types and their proportional contribution to community richness, abundance and cover as indicators of exotic plant invasion. We tested for the effects of land‐use parameters, namely land‐use history, canopy closure and landscape‐level forest cover, on exotic plants. Additionally, we tested whether the phylogenetic relatedness between exotic and native species in the same plot affected invasion success, testing Darwin's naturalisation and pre‐adaptation hypotheses.All indicators of exotic plant invasion were lowest in old‐growth forests and forest fragments and highest in fallow‐derived vanilla agroforests, woody fallows and herbaceous fallows. Absolute and proportional exotic richness were negatively affected by canopy closure, and landscapes with high forest cover had lower proportions of exotic plant richness. High phylogenetic relatedness between exotics and natives was associated with lower proportional richness but higher proportions of exotics in abundance and cover. However, individual exotic species showed contrasting responses to land‐use parameters and relatedness to natives.Synthesis and applications: Our results indicate that maintaining unburned lands, land‐use types with dense canopies and landscapes with high forest cover prevents the spread of exotic plants within the agricultural landscapes of north‐eastern Madagascar. Supporting Darwin's pre‐adaptation hypothesis, exotic plants that are phylogenetically closely related to native plants are more likely to become successful invaders in terms of abundance and cover. Nevertheless, individual species show different responses to land‐use changes and phylogenetic relatedness. Therefore, land‐use decisions and management choices can be tailored to limit the spread of exotic species and to preserve native plants in this global biodiversity hotspot. [ABSTRACT FROM AUTHOR]

The dried leaf powder of malunggay (Moringa oleifera) contains an excellent nutritional value, and this tropical plant is widely available in the Philippines. On the other hand, squash (Cucurbita moschata) is an incredibly beneficial food with high amounts of vitamins. The nutrients from Malunggay and squash can help prevent deficiencies in children. The main focus of the research was to determine the acceptability of the different formulations of M. oleifera and C. moschata cookies. The study determined the most preferred cookie formulation based on sensory evaluation using descriptive testing of the product's appearance, aroma, taste, sweetness, texture, and acceptability rating of the formulations. The respondents were 20 food experts and 40 non-experts. The Analysis of Variance was used to examine the statistical significance of mean differences among the distinct groups. Subsequently, Tukey's Honest Significant Difference (HSD) test was employed to ascertain the significance of differences between pairs of group means, providing a more nuanced understanding of the variations observed within these groups. Results showed that among the three cookie formulations, F3 got the highest mean score of the different attributes, namely appearance (x = 4.45; x = 4.6) aroma (x = 4.9; x = 4.7), taste (x = 4.95; x = 4.93), sweetness (x = 4.9; x =4.75), and texture (x = 4.8; x = 4.68), as perceived by the expert and non-expert, respectively. This implies that respondents prefer cookie formulation F3 over the two other formulations. [ABSTRACT FROM AUTHOR]

The dynamic changes in membrane phospholipids affect membrane biophysical properties and cell signaling, thereby influencing numerous biological processes. Nonspecific phospholipase C (NPC) enzymes hydrolyze common phospholipids to release diacylglycerol (DAG), which is converted to phosphatidic acid (PA) and other lipids. In this study, 2 Arabidopsis (Arabidopsis thaliana) tandemly arrayed genes, NPC3 and NPC4, were identified as critical factors modulating auxin-controlled plant growth and tropic responses. Moreover, NPC3 and NPC4 were shown to interact with the auxin efflux transporter PIN-FORMED2 (PIN2). The loss of NPC3 and NPC4 enhanced the endocytosis and vacuolar degradation of PIN2, which disrupted auxin gradients and slowed gravitropic and halotropic responses. Furthermore, auxin-triggered activation of NPC3 and NPC4 is required for the asymmetric PA distribution that controls PIN2 trafficking dynamics and auxin-dependent tropic responses. Collectively, our study reveals an NPC-derived PA signaling pathway in Arabidopsis auxin fluxes that is essential for fine-tuning the balance between root growth and environmental responses. Nonspecific phospholipases NPC3 and NPC4 interact with the transporter PIN-FORMED2 and regulate auxin transport and signaling. [ABSTRACT FROM AUTHOR]

Premise: Theories of plant–herbivore interactions hold that seedlings are more vulnerable to herbivory in warmer and more stable climates at lower elevations. Hypotheses of plant apparency, resource concentration, and resource availability have been proposed to explain variability in leaf herbivory. However, seasonal differences in the effects of these hypotheses on leaf herbivory on seedlings remain unclear. Methods: We evaluated the three herbivory hypotheses by comparing the percentage and frequency of leaf herbivory in understory broadleaf seedlings in a subtropical forest in May (spring) and October (autumn) along an elevational gradient (290–1370 m a.s.l.). In total, we measured 2890 leaves across 696 seedlings belonging to 95 species and used beta regressions to test the effects of plant apparency (e.g., leaf area, seedling height), resource concentration (e.g., plant species diversity), and resource availability (e.g., canopy openness, soil available N and P) on leaf herbivory. Results: Seedlings exhibited unimodal patterns of leaf herbivory along elevation, with drivers of leaf herbivory varying by the month. Variation in the frequency of leaf herbivory was best explained by the resource concentration hypothesis (e.g., plant species diversity) in both months, and herbivory was lower on seedlings in sites with higher plant diversity. Plant apparency hypothesis (e.g., leaf area, seedling height) was weakly supported only in spring, and the evidence for resource availability hypothesis (e.g., canopy openness, soil nutrients) was mixed. Conclusions: This study supports the resource concentration hypothesis and reveals the importance of seasonal difference on understanding leaf herbivory patterns and the drivers of plant diversity in subtropical forests. [ABSTRACT FROM AUTHOR]

Oil palm (Elaeis guineensis) is considered as the world's leading edible oil producing plant and in tropical countries well established as a perennial plantation crop. Oil palm has spread over 10,000 hectares in the wet zone of the Island. Immature phase of oil palm plantation up to 5 years, there is sufficient space available inside the cultivation. Land productivity in immature plantations could be sustainably increased with some selected intercrops. A field experiment is being conducted at Thalgaswella Estate (6° 24′ 60″ °N, 80° 27′ 44″ °E. 48 m above sea level, WL2a) in Galle district to investigate the suitability of different intercrops during the immature phase. Banana, ginger, and turmeric were selected as intercrops. The experiment was designed with Randomized Complete Block Design (RCBD) with four treatments, including three replicates. Growth parameters of intercrops and maincrop were taken at 2 months intervals. Yield of intercrops were taken accordingly. In addition to this, the chlorophyll content of leaves was also measured in both intercrops and main crop. Soil chemical parameters were measured annually. There was a significant difference in the height of banana plants and the leaf width of Turmeric grown under oil palm during the first year of this experiment. Intercropped turmeric, ginger, and banana have given yields 4875, 4500, and 7550 kg/ha, respectively. During immature phase of the oil palm hardly any income to the grower, hence intercropping will give a very good chance to gain an income before the first harvest of oil palm being done. Percentage yields of intercrops were shown in banana, turmeric, and ginger as 60.64%, 32.8%, and 61.22% respectively against the monocrop and findings will help to make sustainable use of lands in oil palm plantations. [ABSTRACT FROM AUTHOR]

Natural enemies play an important role in controlling plant population growth and vegetation dynamics. Tropical rainforests host the greatest diversity of herbivores, from large mammalian ungulates to microscopic pathogens, generating and maintaining plant diversity.By feeding on the same resources, large mammalian herbivores may interfere with plant consumption and leaf damage by important enemy guilds such as invertebrate herbivores and pathogens, triggering indirect trophic cascades. However, the impact of local extinctions of large herbivores on plant–enemy interactions is relatively unknown.We experimentally tested the effects of defaunation of large mammalian herbivores (e.g. peccaries, tapirs and brocket deer; hereafter, large herbivores) on the leaf damage of 3350 understorey plants in tropical rainforests of Brazil. We examined leaf damage in 10,050 leaves from 333 morphospecies by assigning the area consumed or damaged by five guilds of insect herbivores and leaf pathogens within 86 paired open‐closed plots and investigating the joint effects of defaunation and plant phylogenetic diversity.Plants released from large herbivores had 9% less leaf damage; this difference was due to the lower leaf pathogens incidence (29%) rather than insect herbivory. Evolutionary distinctness was positively correlated with leaf damage in a similar way in all treatments, suggesting additive effects of defaunation and phylogenetic diversity. Total and pathogenic leaf damage (but not insect damage) decreased with plant richness across treatments, and large herbivores exclusion resulted in increased plant species richness. This suggests that large herbivores exclusion leads to a dilution of total and pathogens' leaf damage by increasing plant species richness.Our results suggest that indirect effects of large herbivores decrease the dilution potential of plant communities against pathogens and rather reinforce their top‐down impact on vegetation, demonstrating a previously overlooked cascading effect of large herbivore extinction on forest ecosystems.Synthesis: The extinction of large mammalian herbivores can lead to a decrease in pathogen‐driven leaf damage, a previously unknown indirect effect in forest ecosystems, which might have consequences for plant fitness and ultimately for plant diversity. Large herbivores and plant pathogens might have synergistic effects in regulating the diversity of plant communities in some of the most diverse ecosystems on Earth. [ABSTRACT FROM AUTHOR]

Variation in plant dispersal capabilities strongly influences the assembly of island plant communities. Many tropical plants have seeds capable of long‐distance, often oceanic, dispersal; in some cases, these taxa speciate into island interior endemics with reduced dispersal capabilities, though whether this is a general pattern is debated. Flotation times are highly variable among plants with oceanic dispersal and between such plants and their inland congeners. Here, we experimentally compared salt‐water flotation in three woody plant genera in Palau, Micronesia, comparing broadly distributed and island endemic species within each genus. The widespread Calophyllum inophyllum (with oceanic and vertebrate dispersal), C. soulattri (vertebrate dispersal), and Terminalia catappa had substantially longer flotation than their inland endemic relatives C. pelewense and T. crassipes. This supports the "Loss of dispersal ability" hypothesis for Calophyllum though, for Terminalia, additional phylogenetic information is needed to determine T. crassipes' sister species. Seed flotation in the widespread, oceanic dispersed Pandanus tectorius did not significantly differ from that of the Palau endemics P. palawensis and P. aimiriikensis. Our results highlight that differences among taxa in dispersal modes, speciation modes, and their interactions may influence the assembly of island floras. [ABSTRACT FROM AUTHOR]

Abiotic resource limitation presents organisms with a dilemma about how to use resources when they become available. Characterizing how resource allocation affects investment in growth or defensive traits that affect organismal survival strategies allows us to understand the environmental contexts in which species interact. Our goal was to measure how macronutrient availability drives nitrogen and phosphorus allocation towards functional growth and defensive chemical traits of the Neotropical passion vine, Passiflora biflora.We investigated this question with a paired field study in La Selva, Costa Rica and a full factorial greenhouse experiment to determine whether the concentration of a key secondary chemical defence is driven by nitrogen availability. We correlated defensive chemical concentration with soil nitrogen availability in naturally occurring plants, measured the effects of nitrogen and phosphorus availability on growth and secondary chemical defence traits in the greenhouse and characterized the P. biflora leaf metabolome to assess how nutrient availability affected shifts in metabolism related to plant fitness.We found that nutrient allocation increased the magnitude of both growth and defence traits. Increased nitrogen availability resulted in higher concentrations of toxic leaf secondary chemicals, longer vines, greater biomass and more leaves with a superior ability to capture sunlight. In addition, plants from high nitrogen environments had metabolomes with significantly greater secondary metabolite richness and biochemical pathway diversity, as well as increases in the number of metabolites from several chemical classes related to basic cell function and defence. Nutrient availability had no significant effect on the richness and diversity of primary metabolites involved in basic cell functions. A direct comparison of the relative strength of quantitative growth and secondary defence traits indicated that P. biflora favours nutrient allocation to growth at low nitrogen levels but invests in both strategies more evenly as nitrogen availability increases.These findings lead us to predict that passion vines are better prepared to tolerate and resist herbivory when nutrients are plentiful and experience a trade‐off between growth and chemical defence against natural enemies when they are scarce. These findings are consistent with both the 'escape' and 'defend' syndromes that are often used to describe tropical plant survival strategies. This is one of the only studies to measure nutrient allocation in vines, a group comprising a significant percentage of global plant diversity. Moreover, this work demonstrated the power of leveraging untargeted metabolomics to characterize how nutrient addition affects plant growth and defence, highlighting its potential for understanding functional trait variation. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Root respiration is a critical physiological trait that significantly influences root system activity. Recent studies have associated root respiration with the economic functioning of roots; however, research on root respiration in tropical plants remains limited. This study examined the fine root respiration and the relationship between root respiration and root chemical and morphological traits in 16 tropical plant species, including both evergreen and deciduous species. Findings revealed that deciduous species exhibited higher root respiration compared to evergreen species. Root respiration positively correlated with root nitrogen concentration and specific root length and correlated negatively with root diameter and root tissue density across all species. The root respiration patterns in evergreen species aligned with those seen in all tree species, while deciduous species showed a distinct negative correlation with root tissue density and no significant correlations with other root traits. Principal component analysis revealed that the patterns of root variation in both evergreen and deciduous trees were multidimensional, with deciduous trees exhibiting acquisitive traits and evergreen trees displaying conservative traits. Random forest and multiple regression analysis showed that specific root length exerted the most significant influence on root respiration in both evergreen and deciduous trees. These findings are ecologically significant, enhancing our understanding of root respiration in tropical plants and its impact on ecosystem functions. They contribute valuable insights and support the conservation and management of tropical vegetation. [ABSTRACT FROM AUTHOR]

Drought has a significant impact on plant–insect interactions by altering plant survival, growth, leaf quality, and defense traits. Tropical plants are particularly vulnerable to water depression because of shallow root depth. In the context of climate change, drought events are expected to increase in frequency and intensity; however, their impact on tropical ecosystems remains poorly known. Insect herbivores represent the largest feeding guild of arthropods, and they devour four to five times more plant material than vertebrates do. Understanding how drought affects plant traits and leaf palatability in a keystone and ecologically diverse plant genus, such as Ficus (Moraceae), is crucial for predicting how climate change might alter tropical plant–insect interactions. We examined the impact of drought intensity and duration on the leaf nutritional quality, defensive traits, and herbivory damage by caterpillars in three tropical and one Mediterranean Ficus species in a greenhouse. We also conducted food choice trials with generalist caterpillars to evaluate the impact of drought on herbivores. Drought intensity and duration had no direct effect on leaf palatability across the Ficus species. However, drought indirectly affected leaf palatability via drought‐induced leaf traits in a species‐specific manner. Drought intensity and duration decreased leaf water content, resulting in decreased leaf palatability in F. benjamina and F. lyrata. Leaf defensive traits such as flavonoid concentration were affected by drought intensity and decreased leaf palatability in F. carica. Drought influenced the leaf traits of F. elastica, but none of them affected leaf palatability. Overall, this study establishes the link between drought and insect feeding on plants via leaf traits. The species‐specific responses to drought highlight the significance of climate‐related plant life histories in relation to climate change, underscoring the need for further investigations. [ABSTRACT FROM AUTHOR]