Different regions of the tropics vary in overall tree species diversity, with the tropical Americas exhibiting strikingly higher regional tree species richness than Africa and Southeast Asia. We investigated whether these differences also occur at the local scale and whether the environmental conditions associated with tree species richness are consistent across tropical regions despite highly dissimilar species pools. A spatial random forest model was trained by using a network of 429 1-hectare plots across the tropics, together with 24 environmental variables, to predict plot-level tree α diversity. A combination of climatic, soil and topographical variables explained ∼86% of the variation in richness. Despite differences in regional species pools and the potentially disruptive effects of different geological, climatic and evolutionary histories, the relationship between environmental variables and local-scale tree species richness is closely similar across different continents. Our findings imply a pervasive role of niche-based mechanisms in structuring local tree species richness, regardless of the regional species assemblages. This pantropical convergence in the richness-environment relationship poses a challenge for ecology to explain.

Aims: Calamus castaneus is a non-climbing rattan plant widely distributed in tropical rainforests. The sharp spines of rattan palm harbour endophytic fungi, which may produce extracellular enzymes that contribute to various functions without harming the host plant. This study was aimed to evaluate the ability of fungal endophytes isolated from the C. castaneus spines to produce extracellular enzymes, including protease, pectinase, amylase, lipase and cellulase. Methodology and results: Thirty-four (34) endophytic fungal isolates were tested for their ability to produce extracellular enzymes using the agar plate method. Enzyme activity was measured using the enzyme index (EI) by measuring the halo (clear zone) on the agar medium. The EI value indicates the strength of the enzyme produced by the endophytes. Results demonstrated that all thirty-four fungal endophytes could produce at least one extracellular enzyme. Xylaria cubensis BR90 showed the highest protease activity of 5.73 EI. Muyocopron laterale (SM60) showed the highest pectinase activity of 2.74 EI. For lipase and cellulase activities, Cyphellophora guyanensis (BR71) produced Conclusion, significance and impact of study: Endophytic fungi from spines of C. castaneus were able to produce cellulase, pectinase, lipase, protease and amylase. The extracellular enzymes degraded different substrates, suggesting different types of interaction of the fungal endophytes with the host plant.

All vascular plants contain communities of endophyte fungi within their foliar tissues. These fungi can act as plant bodyguards and disrupt the efficacy of weed biological control agents, yet studies of invasive plant biology hardly ever consider the background endophyte communities. Here, we investigated the factors that affect the structure of cultivable endophyte communities in the highly invasive weed Impatiens glandulifera. We found that community composition varies according to location, but that seasonal accumulation patterns of endophytes are similar between sites. Biotic factors influencing endophytes include arbuscular mycorrhizal fungi, insect herbivores and plant pathogens. Endophyte species richness per plant was consistently low compared with other herbaceous plants and communities appear to be a random sub-set of the available species pool, with the plant acting as a strong filter of species. This information should enable community structure to be modelled and manipulated, making biological control of this weed more effective.

Aim: We test the hypothesis that wind dispersal is more common among emergent tree species given that being tall increases the likelihood of effective seed dispersal. Location: Americas, Africa and the Asia-Pacific. Time period: 1970-2020. Major taxa studied: Gymnosperms and Angiosperms. Methods: We used a dataset consisting of tree inventories from 2821 plots across three biogeographic regions (Americas, Africa and Asia- Pacific), including dry and wet forests, to determine the maximum height and dispersal strategy of 5314 tree species. A web search was used to determine whether species were wind-dispersed. We compared differences in tree species maximum height between biogeographic regions and examined the relationship between species maximum height and wind dispersal using logistic regression. We also tested whether emergent tree species, that is species with at least one individual taller than the 95% height percentile in one or more plots, were disproportionally wind dispersed in dry and wet forests within each biogeographic region. Results: Our dataset provides maximum height values for 5314 tree species, of which more than half (2914) had no record of this trait in existing global databases. We found that, on average, tree species in the Americas have lower maximum heights compared to those in Africa and the Asia Pacific. The probability of wind dispersal increased significantly with tree species maximum height and was significantly higher among emergent than non-emergent tree species in both dry and wet forests in all three biogeographic regions. Main conclusion: Wind dispersal is more prevalent in tall, emergent tree species than in non-emergent species and may thus be an important factor in the evolution of tree species maximum height. By providing the most comprehensive dataset so far of tree species maximum height and wind dispersal strategies, this study paves the way for advancing our understanding of the eco-evolutionary drivers of tree size.

Sustainable urban ecosystems require healthy green spaces that provide ecological services to meet social and environmental needs. This study evaluates the proportion of green areas in the urban campus and assesses the effects of pavement on the health of Samanea saman. The MAPIR Normalised Difference Vegetation Index (NDVI) camera mounted on a drone captured a proportion of green areas of approximately 27.80%, which is roughly a quarter of the total study sites. However, the significance of green areas depends on the health of the trees. Therefore, the pavement effects on the health status of trees in green areas were studied using Visual Tree Assessment (VTA) and aerial image analysis using the MAPIR (NDVI) camera on a drone. Although both methods evaluate health status, the final outputs differed. VTA produced categorical outputs, which assigned trees into health categories based on a visual assessment of factors. In contrast, NDVI produced linear outputs, which provided a numerical value to demonstrate tree health. Both methods indicate that trees in non-paved areas are healthier, particularly for the excellent trees identified by the VTA, which suggests that pavement negatively impacts tree health. However, the effects of paved and non-paved areas on tree health status analysis using the aerial image are not significant (p>0.05), which may be due to the low quality and accuracy of the images. The study provides insights into the importance of green areas and tree health in creating sustainable urban ecosystems.

Trees structure the Earth's most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1-6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth's 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world's most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.

ABSTRACTProtected areas (PA) have been considered as biodiversity conservation hub across the globe. The conventional “top-down” management approach has been failed to ensure resource sustainability in many PA. Therefore, co-management was introduced to secure the PA of Bangladesh and started with legal framework in 2008 (IPAC Project) until 2018 (CREL Project). Thus, land-use and biodiversity change analysis from a decade before and after 2008 has generated comparison of previous and after scenario of co-management. Hence for evaluating effects of co-management on temporal biodiversity and land-use change in Bangladesh, two PA, Chunati Wildlife Sanctuary (CWS) under IUCN Protected Area Category IV and Lawachara National Park (LNP) under IUCN Protected Area Category II, were selected. Community structure of both vascular plants and avifauna species was used to determine current biodiversity variations with habitat influence. Land-use change analysis revealed deforestation and settlements expansion in CWS but decrease in LNP. Trend analysis forecasted good future of LNP in terms of forest cover till 2038. Biodiversity analysis revealed that CWS is slightly more diverse and even than LNP. Comparative analysis recognized prominent loss of biodiversity before co-management period. Therefore, co-management system can be employed in the rest of reserve-forest areas of Bangladesh for conservation betterment.

Impatiens glandulifera or Himalayan balsam is one of the most invasive weeds across Europe and can seriously reduce native plant diversity. It often forms continuous monocultures along river banks, but the mechanisms of this arrested succession are largely unknown. Here, we investigated the effect of arbuscular mycorrhizal (AM) fungi on balsam competitive ability with two native plant species, Plantago lanceolata and Holcus lanatus. We also studied how competition with Impatiens affects colonisation by foliar endophytes and mycorrhizas of two other co-occurring native species, Urtica dioica and Cirsium arvense. Mycorrhizal colonisation reduced balsam growth when the plants were grown singly, but appeared to have little effect when balsam experienced intra- or interspecific competition. Competition with balsam together with the addition of mycorrhizas had no effect on P. lanceolata biomass, suggesting that the fungi were beneficial to the latter, enabling it to compete effectively with balsam. However, this was not so with H. lanatus. Meanwhile, competition with Impatiens reduced endophyte numbers and mycorrhizal colonisation in U. dioica and C. arvense, leading to enhanced susceptibility of these plants to insect attack. Himalayan balsam is known to degrade soil fungal populations and can also reduce foliar beneficial fungi in neighbouring plants. This allows the plant to compete effectively with itself and other native species, thereby leading to the continuous monocultures.

Himalayan balsam ( Impatiens glandulifera ) is one of the most invasive weeds across Europe. The rust fungus, Puccinia komarovii var. glanduliferae has been introduced as a biological control agent, but success has been patchy. Here, we investigated whether mycorrhizal and endophytic fungi can affect rust efficacy and plant growth. Over three experiments, we found that AM fungi and the rust alone or together consistently reduced plant growth, but this depended on the identity of species in the AM inoculum. Meanwhile, AM fungi increased infection frequency of the endophyte Colletotrichum acutatum . Rust inoculation had no detrimental effects on mycorrhizal colonisation or C. acutatum infection, but the latter two fungi reduced rust sporulation. However, plant size was reduced when all three fungal types were present, suggesting that a combined fungal inoculum offers a promising approach for the control of this weed.

The phenological events of rattan were seldomly studied due to its nature of survival by climbing on other trees (i.e., liana). However, some rattans are non-climbing and found to produce fruits throughout the year. Therefore, it aimed to record Calamus castaneus duration of flowering and fruiting over a year and identify which environmental variables affect the duration. This study was conducted for 12 months in three forest reserves, namely Bukit Mertajam Forest Eco-Park (BMFEP), Teluk Bahang Forest Reserve (TBFR), and Segari Melintang Forest Reserve (SMFR). Five study plots (10 m × 10 m each) were established, and overall, 53 C. castaneus individual palm in the plots were monitored. Findings have revealed that female inflorescences bloomed shorter than males. Also, C. castaneus fruits take about three to four months to get matured. The canonical correspondence analysis (CCA) highly regulated the event by microclimate and locality. Thus, the flowering and fruiting duration may not directly be affected by a very specific environmental factor.

AIMS:In this study, we sought to determine the pathogenic ability of endophytic fungi recovered from the spines of Calamus castaneus, a common rattan palm growing in the forests of Peninsula Malaysia.METHODS AND RESULTS:Ten endophytic fungal isolates were selected for pathogenicity tests: Colletotrichum boninense, Colletotrichum fructicola, Colletotrichum cliviae, Diaporthe hongkongensis, Diaporthe arengae, Diaporthe cf. nobilis, Neopestalotiopsis saprophytica, Neopestalotiopsis formicarum, Fusarium solani and Fusarium oxysporum. These endophytes were tested against leaves of bertam (Eugeissona sp.), oil palm (Elaeis guineensis) and mango (Mangiferae indica) and the fruits of chilli (Capsicum annum), tomato (Solanum lycopersicum) and banana (Musa acuminata). The fungal isolates showed infectivity against bertam, oil palm and mango leaves with degrees of virulence ranging from low to moderate, whereas infectivity against chilli, tomato and banana ranged from low to very high.CONCLUSIONS:Fungal endophytes isolated from the spines of C. castaneus are pathogenic to different crop plants with differing degrees of virulence or aggressiveness.SIGNIFICANCE AND IMPACT OF THE STUDY:Spines of C. castaneus can harbour fungal pathogens of a number of different crops as endophytes. The ability of the fungal endophytes to colonize and infect different crops demonstrate their importance towards agricultural crops. There is a possibility the endophytes behave as latent pathogen. When conditions become favourable, the fungal endophytes transform to pathogenic form and potentially infect other plants.

Calamus castaneus is a common rattan palm species in the tropical forests of Peninsular Malaysia and is noticeable by the yellow-based spines that cover the stems. This study aimed to determine the prevalence of fungal endophytes within C. castaneus spines and whether they inhibit the growth of fungal pathogens. Twenty-one genera with 40 species of fungal endophytes were isolated and identified from rattan palm spines. Based on molecular identification, the most common isolates recovered from the spines were Colletotrichum (n = 19) and Diaporthe spp. (n = 18), followed by Phyllosticta spp., Xylaria sp., Trichoderma spp., Helminthosporium spp., Penicillium spp., Fusarium spp., Neopestalotiopsis spp., Arthrinium sp., Cyphellophora sp., Cladosporium spp., Curvularia sp., Bionectria sp., and Acremonium spp. Non-sporulating fungi were also identified, namely Nemania primolutea, Pidoplitchkoviella terricola, Muyocopron laterale, Acrocalymma fici, Acrocalymma medicaginis, and Endomelanconiopsis endophytica. The isolation of these endophytes showed that the spines harbor endophytic fungi. Most of the fungal endophytes inhibited the growth of several plant pathogenic fungi, with 68% of the interactions resulting in mutual inhibition, producing a clear inhibition zone of <2 mm. Our findings demonstrate the potential of the fungal endophytes from C. castaneus spines as biocontrol agents.

Rattan is one of the most valuable non-wood forest products and in recent years is threatened by extensive harvests as well as land clearing. Meanwhile, the role of edaphic and climatic factors affecting rattan population diversity and composition in Malaysia remains almost unexplored. With an aim to associate edaphic and climatic properties with rattan diversity and composition, a total of 20 study sites were explored in Peninsular Malaysia. Three transect belt lines were established measuring 100 m × 20 m in each study site. Temengor Park recorded significantly highest rattan species diversity (H′ = 2.74) however, Royal Belum State Park recorded highest number of rattan species richness with 21 species. This study revealed that rattan species richness and abundance were significantly affected by high disturbance rate, light intensities and relative humidity. In terms of soil physico-chemical properties, the variables which greatly influencing rattan abundance and distribution were soil moisture content, soil pH, soil bulk density, concentration of potassium (K) and calcium (Ca). These findings reflect the variation of forest types and ecological conditions across various locations in Peninsular Malaysia, which covers lowland and highland areas, coastal forests as well as undisturbed and protected forests. Most rattans do well in forested habitats nearby watersides and regions with equally distributed precipitation. Thus, protection of low land rainforest should be given higher priority for the sustainable management of rattan diversity.

Aim Palms are an iconic, diverse and often abundant component of tropical ecosystems that provide many ecosystem services. Being monocots, tree palms are evolutionarily, morphologically and physiologically distinct from other trees, and these differences have important consequences for ecosystem services (e.g., carbon sequestration and storage) and in terms of responses to climate change. We quantified global patterns of tree palm relative abundance to help improve understanding of tropical forests and reduce uncertainty about these ecosystems under climate change. Location Tropical and subtropical moist forests. Time period Current. Major taxa studied Palms (Arecaceae). Methods We assembled a pantropical dataset of 2,548 forest plots (covering 1,191 ha) and quantified tree palm (i.e., >= 10 cm diameter at breast height) abundance relative to co-occurring non-palm trees. We compared the relative abundance of tree palms across biogeographical realms and tested for associations with palaeoclimate stability, current climate, edaphic conditions and metrics of forest structure. Results On average, the relative abundance of tree palms was more than five times larger between Neotropical locations and other biogeographical realms. Tree palms were absent in most locations outside the Neotropics but present in >80% of Neotropical locations. The relative abundance of tree palms was more strongly associated with local conditions (e.g., higher mean annual precipitation, lower soil fertility, shallower water table and lower plot mean wood density) than metrics of long-term climate stability. Life-form diversity also influenced the patterns; palm assemblages outside the Neotropics comprise many non-tree (e.g., climbing) palms. Finally, we show that tree palms can influence estimates of above-ground biomass, but the magnitude and direction of the effect require additional work. Conclusions Tree palms are not only quintessentially tropical, but they are also overwhelmingly Neotropical. Future work to understand the contributions of tree palms to biomass estimates and carbon cycling will be particularly crucial in Neotropical forests.

Rattan spines are most often regarded as an identification trait and perhaps as a physical protection structure. In this study, we study the spinescence traits from five different species rattan: Daemonorops lewisiana, Daemonorops geniculata, Calamus castaneus, Plectomia griffithii, and Korthalsia scortechinii. We tested length, width, angle, strength, spine density, cross-section surface, spine color, and leaf trichomes (only for D. lewisiana, C. castaneus and D. geniculata). We also tested whether the spines were capable of deterring small climbing mammals (for Plectomia griffithii and Calamus castaneus) by using a choice selection experiment. Due to a variety of spine traits, we could not categorize whether any species is more or less spinescent than the others. We suggest that spines have a much more significant role than merely as a physical defense and work together with other rattan characteristics. This is also evidenced by our choice selection experiment, in which the spines on a single stem donot deter small climbing mammals. However, this is a work in progress, and we have outlined several alternative methods to be used in future work.

In Malaysian forests, the population dynamics of rattan has not been fully documented. Hence, this study was aimed to investigate the population dynamics pattern of the Calamus castaneus, a non-climbing rattan. The association of growth and phenology cycle to environmental variables on the population dynamics were studied for one year. Three forest reserves were selected as the study sites: Segari Melintang Forest Reserve (SMFR) in Perak, Teluk Bahang Forest Reserve (TBFR), and Bukit Mertajam Forest Eco-Park (BMFEP) in Penang. The fieldwork was conducted from March 2017 until March 2018. With the plot size of 10 m x 10 m (100 m(2)), five plots were established in each study site. All the C castaneus individuals inside the plots were marked with numbered plastic tags. A total of 180 individuals were evaluated: TBFR (52 individuals), SMFR (86 individuals), and BMFEP (42 individuals). The findings have revealed that the C. castaneus abundancy is comparatively similar in all sites, as shown by the Kruskal-Wallis test with no significant difference (p> 0.05) between all life stages. The canonical correspondence analysis (CCA) for all sites has displayed that the rattan growth parameters are closely associated with the microclimate parameters and soil properties. Overall, SMFR showed the fastest growth increment and the largest population size of C. castaneus among all three sites.

The richness and diversity of woody plants are important indices for maintaining and conserving tropical forests. In this study, we evaluated the alpha diversity and richness indices of some ecologically important primary and old secondary forests in Penang, Malaysia. Plots of size 2000 m2 which were further divided into 5 subplots of size 20 x 20 m2 were established in each of five forests reserves across Penang. A total of 1,161 individuals of trees and lianas belonging to 54 different families and 284 species were enumerated in all the studied forests. Euphorbiaceae, Clusiaceae and Dipterocarpaceae were the most prominent families with highest number of species. Vatica bella was the most abundant plant with 127 individuals. Knema curtisii, Gluta elegans, Mangifera gracilipes and Callerya atropurpurea were more common to all the forests. All the forests could be described as highly rich in woody plant species and diverse due to the high diversity indices estimated. There is virtually no much difference in the diversity indices between the primary and old secondary forests probably due to the recuperating nature of the old secondary forests after years of abandonment.

Conversion of tropical forests into oil palm plantations reduces the habitats of many species, including primates, and frequently leads to human–wildlife conflicts. Contrary to the widespread belief that macaques foraging in the forest–oil palm matrix are detrimental crop pests, we show that the impact of macaques on oil palm yield is minor. More importantly, our data suggest that wild macaques have the potential to act as biological pest control by feeding on plantation rats, the major pest for oil palm crops, with each macaque group estimated to reduce rat populations by about 3,000 individuals per year (mitigating annual losses of 112 USD per hectare). If used for rodent control in place of the conventional method of poison, macaques could provide an important ecosystem service and enhance palm oil sustainability.

Rattan is an important climbing palm taxon in Malaysian tropical rain forests. Many rattan species have unique structures directly associated with certain ant species. In this study, four rattan species (Daemonorops lewisiana, Calamus castaneus, Daemonorops geniculata and Korthalsia scortechinii) were inspected and documented in a field survey concerning their relationships with several ant species. We noticed that two rattan species (D. lewisiana and C. castaneus) were more likely to be associated with ants compared to their neighbouring rattan (Plectomia griffithii). However, D. lewisiana and C. castaneus did not directly provide shelters for ant colonies, but possessed unique structures: upward-pointing spines and funnel-shaped leaves, which are equipped to collect more litter than P. griffithii. To test our litter collecting hypothesis, we measured the inclination of spines from the stem. Our results showed the presence of ant colonies in the litter-collecting rattans (D. lewisiana and C. castaneus), which was significantly higher compared to a non-litter-collecting rattan (P. griffithii). We propose a complex and novel type of adaptation (litter-collection and provision of nesting materials) for rattans, which promotes interactions between the rattan and ants through the arrangements of leaves, leaflets, and spines. In return, the rattan may benefit from ants' services, such as protection, nutrient enhancement, and pollination.