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Ectomycorrhizal (ECM) fungi are important tree symbionts within forests. The biogeography of ECM fungi remains to be investigated because it is challenging to observe and identify species. Because most ECM plant taxa have a Holarctic distribution, it is difficult to evaluate the extent to which host preference restricts the global distribution of ECM fungi. To address this issue, we aimed to assess whether host preference enhances the endemism of ECM fungi that inhabit dipterocarp rainforests. Highly similar sequences of 175 operational taxonomic units (OTUs) for ECM fungi that were obtained from Lambir Hill's National Park, Sarawak, Malaysia, were searched for in a nucleotide sequence database. Using a two‐step binomial model, the probability of presence for the query OTUs and the registration rate of barcode sequences in each country were simultaneously estimated. The results revealed that the probability of presence in the respective countries increased with increasing species richness of Dipterocarpaceae and decreasing geographical distance from the study site (i.e. Lambir). Furthermore, most of the ECM fungi were shown to be endemic to Malaysia and neighbouring countries. These findings suggest that not only dispersal limitation but also host preference are responsible for the high endemism of ECM fungi in dipterocarp rainforests. Moreover, host preference likely determines the areas where ECM fungi potentially expand and dispersal limitation creates distance–decay patterns within suitable habitats. Although host preference has received less attention than dispersal limitation, our findings support that host preference has a profound influence on the global distribution of ECM fungi. [ABSTRACT FROM AUTHOR]

The interspecific trade‐off between growth versus mortality rates of tree species is thought to be driven by functional biology and to contribute to species ecological niche differentiation. Yet, functional trait variation is often not strongly correlated with growth and mortality, and few studies have investigated the relationships of both traits and niches, specifically encompassing above and belowground resources, to the trade‐off itself. These relationships are particularly relevant for seedlings, which must often survive resource limitation to reach larger size classes.We investigated the functional basis of the interspecific growth–mortality trade‐off and its relationship with ecological niches for seedlings of 14 tree species in a tropical forest in southwest China.We found evidence for an interspecific growth–mortality trade‐off at the seedling stage using 15 functional traits and 15 ecological niche variables. None of the organ‐level traits correlated with growth, mortality, nor the trade‐off, whereas specific stem length (SSL), a biomass allocation trait, was the only trait to have a significant correlation (positive). Moreover, light‐defined niches were not correlated with growth, mortality or the trade‐off, but soil‐defined niches did. Species at the faster growth/higher mortality end of the trade‐off were associated with higher fertility defined by lower soil bulk density and slope, and higher soil organic matter concentration and soil total nitrogen.Our findings indicate the importance of stem elongation and soil fertility for growth, mortality and their trade‐off at the seedling stage in this Asian tropical forest. Our findings contrast with analogous studies in neotropical forests showing the importance of photosynthesis‐related leaf traits related to insolation. Therefore, the functional drivers of demographic rates and trade‐offs, as well as their consequences for ecological niches, can vary among forests, likely owing to differences in biogeography, canopy disturbance rates, topography and soil properties. Moreover, the effects of functional trait variation on demographic rates and trade‐offs may be better revealed when biomass allocation is accounted for in a whole‐plant context. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Labile organic carbon (LOC) is a key driver of forest ecosystem function and may mitigate global climate change through carbon sequestration. To explore the accumulation of LOC in tropical forest soils, we sampled from both planted and natural forests in Hainan Province, the southernmost province of China. We analyzed the concentrations of total organic carbon (TOC) and LOC and characterized various physicochemical properties such as pH and soil texture to understand their inter-relationships in tropical natural and plantation forests. Although the TOC concentration was higher in plantation forests (88.61 g/kg) than in natural forests (68.73 g/kg), the LOC concentration was higher in natural forests (5.12 mg/g) than in plantation forests (4.07 mg/g). Over a depth range of 0–50 cm from the surface, both forest types showed decreasing TOC and LOC concentrations with increasing soil depth, indicating surface aggregation. The soil is slightly acidic and primarily composed of sand particles. Correlation analysis showed a highly significant negative correlation between LOC concentration and soil pH in both forest types (p < 0.01). Soil LOC was positively correlated with soil clay and silt particles and negatively correlated with sand particles. This study provides valuable insights into soil carbon sequestration in tropical rainforest ecosystems in both plantation and natural tropical forests. [ABSTRACT FROM AUTHOR]

Only 20% of the estimated 5 million species of insects on Earth are named and yet insects are poorly represented in protected area assessments, and insect declines are of concern globally. Here, we explore how to increase the discovery of new species and understanding of this group through analysis of 10,097 tropical rainforest bark beetles (Scolytinae) from eight different ecological studies between 2000 and 2018 in the Australian Wet Tropics. Of the 107 species identified, 58 are undescribed: an increase of 37% on the 156 species known from Australia. Rarefaction indicates doubling sampling would increase the number of species by 17. As hypothesised, new species are significantly smaller, less abundant and less widespread than described species making them more extinction‐prone than named species. Flight interception traps collected 84% of individuals and 98% of species confirming the effectiveness of a single sampling method for some beetles. Increased locations and collection from the canopy may sample further species rather than additional collecting methods. Scolytines are relatively well studied with taxonomists at the forefront of using modern methods to resolve formerly intractable groups. Hence, these new species are more likely to be named than others in many other beetle groups where taxonomy has largely stalled. To increase species description rates and to avoid most species becoming extinct before being named, we call on taxonomists to use new character systems provided by DNA methods and advances in the rapidly developing field of artificial intelligence. [ABSTRACT FROM AUTHOR]

Tree allometric models, essential for monitoring and predicting terrestrial carbon stocks, are traditionally built on global databases with forest inventory measurements of stem diameter (D) and tree height (H). However, these databases often combine H measurements obtained through various measurement methods, each with distinct error patterns, affecting the resulting H:D allometries. In recent decades, terrestrial laser scanning (TLS) has emerged as a widely accepted method for accurate, non‐destructive tree structural measurements. This study used TLS data to evaluate the prediction accuracy of forest inventory‐based H:D allometries and to develop more accurate pantropical allometries. We considered 19 tropical rainforest plots across four continents. Eleven plots had forest inventory and RIEGL VZ‐400(i) TLS‐based D and H data, allowing accuracy assessment of local forest inventory‐based H:D allometries. Additionally, TLS‐based data from 1951 trees from all 19 plots were used to create new pantropical H:D allometries for tropical rainforests. Our findings reveal that in most plots, forest inventory‐based H:D allometries underestimated H compared with TLS‐based allometries. For 30‐metre‐tall trees, these underestimations varied from −1.6 m (−5.3%) to −7.5 m (−25.4%). In the Malaysian plot with trees reaching up to 77 m in height, the underestimation was as much as −31.7 m (−41.3%). We propose a TLS‐based pantropical H:D allometry, incorporating maximum climatological water deficit for site effects, with a mean uncertainty of 19.1% and a mean bias of −4.8%. While the mean uncertainty is roughly 2.3% greater than that of the Chave2014 model, this model demonstrates more consistent uncertainties across tree size and delivers less biased estimates of H (with a reduction of 8.23%). In summary, recognizing the errors in H measurements from forest inventory methods is vital, as they can propagate into the allometries they inform. This study underscores the potential of TLS for accurate H and D measurements in tropical rainforests, essential for refining tree allometries. [ABSTRACT FROM AUTHOR]

This research examined soil contamination and the uptake of potentially toxic elements (PTEs) by maize plants in mining communities. We collected 192 soil samples and 40 maize plant samples from two mining areas and a pristine site. We analyzed the physical properties and element content of the soil, including phosphorus, nitrogen, potassium, Fe, Zn, Co, Pb, Cd, Cr, and Ni. We also measured the elemental concentrations in the maize plants. The study found higher levels of Zn, Cu, and Pb at the mining sites compared to the control areas. The pollution factor (CF) indicated pollution with Cu > Pb > and > Zn at both mine sites. The pollution index (PLI) showed no pollution in the Nkalagu mine and control sites, but heavy and moderate pollution at the Ameka mine and control sites, respectively. The Ameka mine site was enriched with Zn. The bioaccumulation coefficient (BAC) was < 1 except for Zn at the Nkalagu mine and control site. The transfer factor for Fe and Zn from root to shoot was > 1. Pb was > 1 in all study areas except the Ameka mining areas. The results suggest remediation is needed for the two mine sites, especially at Ameka. [ABSTRACT FROM AUTHOR]

The loss of forest cover in urban landscapes alters the dynamics of spatial and food resources, challenging the maintenance of forest species, which may have their condition compromised. Dung beetles are sensitive to changes in vegetation structure and land use caused by human activities, processes that are intrinsically related to the establishment and development of cities. The aim of this study was to evaluate the effect of landscape structure on the abundance and morphological characteristics of two species of dung beetle (Dichotomius boreus and Dichotomius quadrilobatus) that inhabit forested areas in urbanized landscapes in the Amazon region. We carried out the study in 38 landscapes located in six urban regions in the central region of the Amazon. We evaluated the effect of landscape structure, at the site and city scales, on beetle abundance, individual body size, and relative horn length of males. At the local scale, landscapes with greater forest cover showed greater abundance of dung beetles, as well as greater lengths of D. boreus horns. Cities with a greater amount of forest cover had larger individuals than those with less forest cover. We conclude that forested areas in urban landscapes are a key habitat for the maintenance of dung beetle populations with a strong relationship between the amount of forest cover in the landscape. The maintenance of healthy and abundant populations of beetles in urban Amazonian landscapes guarantees the persistence of ecosystem services provided by these organisms in urban ecosystems. [ABSTRACT FROM AUTHOR]

Ecology needs a unified view of the patterns and processes of secondary succession; we addressed that on the Coiba Island, Panama. We measured tree diameters and determined the land-use histories and structural properties for nine stands. We detected land-use history-legacy gradients ranging from no-use to still-in-use sites (Linear Regressions, R2=0.87 for Above-Ground Biomass and Basal Area, n=7 stands). Three successional pathways derived from a meadow, another from shifting agriculture, another from a >400y-old forest, and four were related to a river and a camp. Our results clarify discussions like convergence-vs-divergence, organismic-vs-individualistic successions, chance-vsdeterminism, and provide land-use history-based suggestions for conservation. [ABSTRACT FROM AUTHOR]

Thismia (Thismiaceae), whose distributions are currently known from Asia, Australia, and South America, is newly recorded in the Solomon Islands. Through extensive field explorations, three new species of Thismia were discovered in the rainforest of the Solomon Islands and are herein delineated as T. occasa, T. chicoreoides, and T. solomonensis, all belonging to sect. Sarcosiphon. Comprehensive species descriptions, line drawings, and color plates are furnished for each species, accompanied by a distribution map delineating their respective ranges. [ABSTRACT FROM AUTHOR]

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Full-waveform LiDAR (FWF) offers a promising advantage over other technologies to represent the vertical canopy structure of secondary successions in the Amazon region, as the waveform encapsulates the properties of all elements intercepting the emitted beam. In this study, we investigated modifications in the vertical structure of the Amazonian secondary successions across the vegetation gradient from early to advanced stages of vegetation regrowth. The analysis was performed over two distinct climatic regions (Drier and Wetter), designated using the Maximum Cumulative Water Deficit (MCWD). The study area was covered by 309 sample plots distributed along 25 LiDAR transects. The plots were grouped into three successional stages (early—SS1; intermediate—SS2; advanced—SS3). Mature Forest (MF) was used as a reference of comparison. A total of 14 FWF LiDAR metrics from four categories of analysis (Height, Peaks, Understory and Gaussian Decomposition) were extracted using the Waveform LiDAR for Forestry eXtraction (WoLFeX) software (v1.1.1). In addition to examining the variation in these metrics across different successional stages, we calculated their Relative Recovery (RR) with vegetation regrowth, and evaluated their ability to discriminate successional stages using Random Forest (RF). The results showed significant differences in FWF metrics across the successional stages, and within and between sample plots and regions. The Drier region generally exhibited more pronounced differences between successional stages and lower FWF metric values compared to the Wetter region, mainly in the category of height, peaks, and Gaussian decomposition. Furthermore, the Drier region displayed a lower relative recovery of metrics in the early years of succession, compared to the areas of MF, eventually reaching rates akin to those of the Wetter region as succession progressed. Canopy height metrics such as Waveform distance (WD), and Gaussian Decomposition metrics such as Bottom of canopy (BC), Bottom of canopy distance (BCD) and Canopy distance (CD), related to the height of the lower forest stratum, were the most important attributes in discriminating successional stages in both analyzed regions. However, the Drier region exhibited superior discrimination between successional stages, achieving a weighted F1-score of 0.80 compared to 0.73 in the Wetter region. When comparing the metrics from SS in different stages to MF, our findings underscore that secondary forests achieve substantial relative recovery of FWF metrics within the initial 10 years after land abandonment. Regions with potentially slower relative recovery (e.g., Drier regions) may require longer-term planning to ensure success in providing full potential ecosystem services in the Amazon. [ABSTRACT FROM AUTHOR]

In closed‐canopy systems globally, plants exhibit intense competition for light, prioritizing vertical growth to attain elevated positions within the canopy. Light competition is especially intense in tropical rainforests because of their dense shaded stands, and during forest succession because of concomitant changes in vertical light profiles. We evaluated how the height growth of individual tree differs among forest light strata (canopy, sub‐canopy and understorey) and successional guilds (early, mid‐ and late successional species) during secondary succession in a Mexican rainforest. Fourteen secondary forest stands differing in time since agricultural abandonment (1–25 years) were monitored for seven consecutive years. For each stand and census year we estimated relative light intensity (RLI) for each height and categorized trees into forest light strata: understorey (RLI ≦ 33.3%), sub‐canopy (33.3% ≦ RLI ≦ 66.6%) and canopy (RLI ≧ 66.6%), and into successional guilds based on the literature. We estimated two measures of height growth: absolute height growth (HGabs, cm year−1) calculated as the difference in tree height between two consecutive censuses, and biomass partitioning to height growth (HGbp, in kg kg−1 × 100) calculated as the percentage of total aboveground biomass growth partitioned to height growth. Earlier in succession, trees for all strata had greater HGabs and HGbp, resulting in rapid vertical forest development. HGabs was fastest for canopy trees, followed by sub‐canopy and understorey trees. These differences in HGabs among strata, combined with their inter‐specific variation and continuous recruitment of small individuals, lead to a rapid differentiation in tree sizes and increase stand structural heterogeneity. HGbp was greater for understorey and sub‐canopy trees than for canopy trees, reflecting ontogenetic changes in the light competition strategy from growth to persistence. With succession, both HGabs and HGbp decreased, most strongly for canopy trees, probably because of an increased exposure to drought stress. These successional changes stabilize stand size structure and reduce the rate of development. [ABSTRACT FROM AUTHOR]

In this study, the influence of geographic isolation on the levels of morphological and genetic differentiation among populations of the karst forest-adapted Pilea pteridophylla (Urticaceae) was evaluated. Based on our results, there is a strong morphological differentiation among the only two know populations of Pilea pteridophylla. Both populations can be clearly differentiated based on vegetative and reproductive characters, and the observed variation is geographically structured. Moreover, our genetic data from the chloroplast genome show strong levels of population differentiation and no shared haplotypes were observed between populations. Also, our estimation of divergence times supports a long-term isolation hypothesis between populations. Based on our results, dispersal seed limitation, long-term forest isolation and topographic heterogeneity (local adaptation) are related to high levels of endemism and species turnover in the mountain karst forests of Mexico. [ABSTRACT FROM AUTHOR]

The genus Mullederia (Acariformes: Stigmaeidae) are free-living predatory mites with six species known in the world. In this paper, we describe and illustrate a new species, Mullederia hainanensissp. nov., from deciduous broad-leaved plants and evergreen broad-leaved plants in Hainan Province, China. Moreover, an identification key is provided for the known species of this genus. [ABSTRACT FROM AUTHOR]

The Brazilian Amazon has undergone an intense process of urbanization responsible for changes in the land use and land cover patterns in the last decades. Therefore, understanding the impacts resulting from the urbanization of Amazon become urgent, both to preserve biodiversity and associated ecosystem functions and services, since Amazon region comprise a key ecosystem regarding biodiversity and ecological dynamics. We studied, for the first time, the impact of urbanization on dung beetles, a recognized bioindicator group, in an Amazonian landscape. For this, we assessed the dung beetle taxonomic and functional responses along a preserved-rural-urban habitat gradient in an Amazonian city, and how landscape predictors affect dung beetle diversity. We found a consistent shift in species composition and reduction of both taxonomic and functional diversity from forest patches located outside the city towards those located in the city core. In addition, forest cover was the main driver of dung beetle responses at the landscape scale, where the increase of forest cover positively affected dung beetle diversity. Our results provide evidence that urbanization negatively impacts the dung beetle taxonomic and functional diversity in Amazonian cities, and reinforce the importance of maintaining forest cover to conserve dung beetles in tropical forests. Finally, the development of sustainable initiatives for the conservation of biodiversity in urban landscapes, such as public policies aimed at the maintenance of urban forest fragments, can help to maintain biodiversity and ecosystem processes within cities and to mitigate the urbanization impacts. [ABSTRACT FROM AUTHOR]

Despite the current disjoint distribution of Amazonian and Atlantic forests, evidence suggests past historical connections. Here we investigated the historical connections between three didelphid mammal species from Amazonian and Atlantic forests (Caluromys philander, Marmosa demerarae, and M. murina) using comparative phylogeography and paleodistribution models. We generated ecological niche models from the present until the Pliocene to evaluate changes in distributions over time, focusing on the previously suggested connection routes. We inferred divergence times between populations of each species using the mitochondrial Cytochrome b, estimated the phylogeographic relationships with haplotype networks, and calculated the genetic distances. All species exhibited populations that were separated between the Amazonian and Atlantic forests around 1–2 million years ago, while some populations showed more recent divergences. Paleodistributions were more extensive for periods predating the estimated times of divergence for all species, becoming narrower after this period. We suggest that the climatic oscillations during the onset of the Pleistocene largely influenced the phylogenetic structuring of these forest-dwelling species. This led to the separation of populations currently restricted to Amazonian or Atlantic forests. Our findings also point to repeated connections over time, with both North- and South-Eastern routes compatible with ancient connections. This represents the first simultaneous evaluation of past connections between Amazonian and Atlantic forests combining phylogeographic inferences with paleodistribution models for didelphid marsupials. We suggested the relation of the responses to past climate change, such as increases in the paleodistribution, and species resilience. [ABSTRACT FROM AUTHOR]

Forests help to reduce global warming by capturing and storing atmospheric carbon. Understanding the genetics of keystone species at a population level is vital for the management and sustainable utilization of forest genetic resources. A comprehensive population genetics study was carried out on Rubroshorea curtisii, an important widespread hill dipterocarp species in Peninsular Malaysia. A total of 41 populations across its distribution range in Peninsular Malaysia were collected to elucidate the genetic diversity and ultimately provide management guidelines for this species. The population samples were analysed using 10 polymorphic microsatellite loci and sequenced with three chloroplast DNA (cpDNA) regions. A total of 145 alleles were derived from the microsatellite loci, and 21 haplotypes were identified based on 1,113 bp of concatenated cpDNA sequences. The populations showed moderately high genetic diversity (mean HE = 0.627 for microsatellite gene diversity and HT = 0.574 for average haplotype diversity) but low genetic differentiation (FST = 0.036). Using Bayesian clustering, the studied populations can be divided into two groups, one of which shows further substructuring. Further sub-structuring in Cluster 1 led to sub-clustering of 1a and 1b. Bottleneck analysis did not detect any recent bottleneck events. Based on our findings, priority areas for in situ and ex situ conservation and minimum population size are recommended for the sustainable utilization of R. curtisii. [ABSTRACT FROM AUTHOR]

Introduction: Common species can predict overall species richness and composition, serving as a shortcut to biodiversity and supporting well-informed management of areas. However, the impacts of temporal variation in underlying species occurrence and imperfect detection on surrogacy effectiveness are unknown. We hypothesized that common species will represent total species composition both across sites and along environmental gradients and that this surrogacy effectiveness is maintained over time and robust to imperfect detection. Materials and methods: We sampled ground-dwelling ants using pitfall traps over 25 km2 on Amazon. We measured the congruence between a complete dataset and subsets containing a smaller number of species based on their commonness and compared the results among three sampling years. Further, we simulated virtual assemblages to determine the effect of species detection probability on surrogacy effectiveness and compared the costs associated with using all species vs. common species only. The common species composition responded to environmental gradients similarly to the overall species composition, regardless of year. The simulated data showed similar trends, although including imperfect detection increased the minimum number of common species required to recover overall patterns reasonably. Conclusion - Implications for insect conservation: This study represents the first report on the effectiveness of common species in predicting ant assemblage patterns over time. We propose that imperfect detection should be considered in biodiversity surrogacy studies, especially regarding its impact on surrogate effectiveness over time. [ABSTRACT FROM AUTHOR]

Three new species of thelotremoid lichens, Ampliotrema subglobosum Poengs. & Lumbsch, Ocellularia lichexanthonica Poengs. & Lumbsch and O. saxiprotocetrarica Poengs. & Lumbsch, are described and illustrated based on specimens from southern Thailand. Ampliotrema subglobosum is similar to A. globosum but differs by having larger ascospores with more septa. Ocellularia lichexanthonica differs from O. subdolichotata in ascomata diameter and by containing lichexanthone. Ocellularia saxiprotocetrarica is similar to O. gentingensis in ascospore length and the number of ascospore septa but has narrower ascospores and contains protocetraric acid. Fifteen species are reported for the first time for Thailand: Austrotrema bicinctulum (Nyl.) I. Medeiros et al., Baeomyces heteromorphus Nyl. ex C. Bab. & Mitt., Chapsa niveocarpa Mangold, Chiodecton sphaerale Ach., Erythrodecton malacum (Kremp.) G. Thor, Lecanora subjaponica L. Lü & H. Y. Wang, Leucodecton subcompunctum (Nyl.) Frisch, Myriotrema concretum (Fée) Hale, M. neoterebrans Frisch, Ocellularia khasiana (Patw. & Nagarkar) Kraichak et al., O. upretii S. Joshi et al., Pseudotopeliopsis scabiomarginata (Hale) Parnmen et al., Sulzbacheromyces sinensis (R. H. Petersen & M. Zang) Dong Liu & Li S. Wang, Thelotrema diplotrema Nyl., and T. isidiophorum (Kremp.) Zahlbr. Ampliotrema globosum (Hale) Poengs. & Lumbsch is proposed as a new combination. The genus Erythrodecton G. Thor is a new genus for the lichen flora of Thailand. [ABSTRACT FROM AUTHOR]

Introduction: Tropical forests are characterized by intricate mosaics of speciesrich and structurally complex forest communities. Evaluating the functional vulnerability of distinct community patches is of significant importance in establishing conservation priorities within tropical forests. However, previous assessments of functional vulnerability in tropical forests have often focused solely on isolated factors or individual disturbance events, with limited consideration for a broad spectrum of disturbances and the responses of diverse species. Methods: We assessed the functional vulnerability of woody plant communities in a 60-ha dynamic plot within a tropical montane rainforest by conducting in silico simulations of a wide range disturbances. These simulations combined plant functional traits and community properties, including the distribution of functional redundancy across the entire trait space, the distribution of abundance across species, and the relationship between species trait distinctiveness and species abundance. We also investigated the spatial distribution patterns of functional vulnerability and their scale effects, and employed a spatial autoregressive model to examine the relationships between both biotic and abiotic factors and functional vulnerability at different scales. Results: The functional vulnerability of tropical montane rainforest woody plant communities was generally high (the functional vulnerability of observed communities was very close to that of the most vulnerable virtual community, with a value of 72.41% on average at the 20m×20m quadrat scale), and they exhibited significant spatial heterogeneity. Functional vulnerability decreased with increasing spatial scale and the influence of both biotic and abiotic factors on functional vulnerability was regulated by spatial scale, with soil properties playing a dominant role. Discussion: Our study provides new specific insights into the comprehensive assessment of functional vulnerability in the tropical rainforest. We highlighted that functional vulnerabilities of woody plant communities and their sensitivity to environmental factors varied significantly within and across spatial scales in the tropical rainforest landscape. Preserving and maintaining the functionality of tropical ecosystems should take into consideration the variations in functional vulnerability among different plant communities and their sensitivity to environmental factors. [ABSTRACT FROM AUTHOR]

Earthworms represent a crucial taxon in soil ecosystems in terms of biomass and ecological functions. Knowledge of their diversity is growing, but the understanding of the ecological and evolutionary mechanisms underlying this diversity and its distribution patterns remains poorly understood. This is partly due to a lack of community data available on a large scale, particularly in the natural ecosystems of the most diverse tropical regions. Here we describe a large dataset containing records of 3555 georeferenced earthworm specimens, sampled in 125 one-hectare plots distributed in different habitats and localities across French Guiana. Each of these specimens was DNA barcoded targeting the cytochrome C Oxidase I subunit barcode region (COI), and these sequences were clustered into molecular operational taxonomic units (OTUs) that we used as species proxy to describe community taxonomic composition and diversity. Each community is associated in the dataset with climate and elevation data, and soil properties are also available for part of them. This dataset represents a unique opportunity for analyzing community diversity and phylogeographic patterns in neotropical rainforests.

Model projections predict tropical forests will experience longer periods of drought and more intense precipitation cycles under a changing climate. Such transitions have implications for structure-function relationships within microbial communities. We examine how throughfall exclusion might reshape prokaryotic and fungal communities across four lowland forests in Panama with a wide variation in mean annual precipitation and soil fertility. Four sites were established across a 1000 mm span in Mean Annual Precipitation (MAP: 2335–3421 mm). We expected microbial communities at sites with lower MAP to be less sensitive to throughfall exclusion than sites with higher MAP and fungal communities to be more resistant to disturbance than prokaryotes. At each location, partial throughfall exclusion structures were established over 10 × 10 m plots to reduce direct precipitation input. After short-term (∼3–9 months) throughfall exclusion, prokaryotic communities showed no change in composition. However, prolonged (12–18 months) throughfall exclusion resulted in divergent prokaryotic community responses, reflecting MAP and soil fertility. We observed the emergence of a “drought microbiome” within infertile sites, whereby the community structure of the experimental throughfall exclusion plots at the lower MAP sites diverged from their respective control sites and converged towards overlapping assemblages. Furthermore, under throughfall exclusion, taxa increasing in relative abundance at the wettest site reflected that endemic to control plots at the lowest MAP site, suggesting a shift toward communities with life-history traits selected for under a lower MAP. By contrast, fungal community composition across sites was resilient to throughfall exclusion; however, biomass diverged in response to throughfall exclusion, increasing at two sites while decreasing in the other two. Broadly, our results suggest that microbial communities' sensitivity to frequent drying and rewetting periods in tropical forest soils will depend on climate history and soil fertility, with infertile sites likely to respond readily to changes in precipitation.

As the final layer for precipitation interception in forests, the litter layer is crucial to the vertical structure of forest ecosystems, situated between the forest vegetation and soil layers. Exploring the litter accumulation and water retention characteristics in different tropical rainforest stands is essential for assessing their water conservation functions. This study focused on three forest stands (primary forest, secondary forest, and rubber plantation) within Qixianling Hot Springs National Forest Park in Hainan, China. The immersion method was used to measure litter accumulation and water retention characteristics, exploring variations among these forest stands. Results revealed (1) significant differences in litter accumulation among the stands, with the primary forest having the highest litter accumulation (2.791 t/hm2), followed by the secondary forest (2.077 t/hm2) and rubber plantation (1.660 t/hm2). Litter moisture content followed the order: primary forest (57.57%) > secondary forest (48.33%) > rubber plantation (46.44%). (2) Regarding water retention and water retention rate, both primary and secondary forests showed an increasing trend with immersion time, with the primary forest exhibiting higher water retention and retention rates than the secondary forest. In contrast, rubber plantations showed no clear trends in water retention or retention rates over time. The relation between litter water absorption rate and immersion time followed a well-fitted power function. The maximum water retention capacities were in the order of primary forest (8.041 t/hm2) > secondary forest (6.251 t/hm2) > rubber plantation (4.896 t/hm2). (3) In terms of water absorption and water loss rates, the rubber plantation had the highest water loss rate, followed by the secondary forest and the primary forest. The maximum water loss was observed in the primary forest (5.225 t/hm2) > secondary forest (4.626 t/hm2) > rubber plantation (4.079 t/hm2), and the maximum water loss rates followed the order: rubber plantation (246.319%) > secondary forest (222.649%) > primary forest (189.748%). The forest litter layer's water retention capacity and storage are closely related, with larger litter reserves correlating with greater water retention. Therefore, among the three forest types, the maximum and effective water interception capacities exhibited the following trend: primary forest > secondary forest > rubber plantation. The maximum and effective interception rates show the pattern: primary forests ≈ rubber plantations > secondary forests. The water conservation function of litter is reflected in its water retention capacity and rate of water loss. Given that primary forests exhibit a higher water retention capacity and lower water loss rates, litter accumulation in primary forests is more conducive to forest water conservation functions. Hence, future efforts should focus on protecting litter from primary forests. Conversely, the litter in rubber plantations tends to have a higher rate of water loss, resulting in poorer water conservation. Therefore, future considerations should include planting understory vegetation in rubber plantations to enhance litter water-conservation capabilities and prevent soil erosion. These findings provide crucial theoretical guidance for forest management and the enhancement of water conservation in tropical regions.

Edaphic specialization is considered to promote ecological differentiation among closely related species of Damburneya (Lauraceae) occurring in sympatry. However, little is known about the effects of soil and other key environmental factors like climate on the ecological niche and distributionof these tree species. Here, we assessed the role of climate and soil on niche divergence and potential distribution of four Damburneya species whose distributions span Central America and Mexico. We performed ecological niche modeling with MaxEnt using three sets of environmental data: climatic-only, edaphic-only, and a combination of both, to characterize species niches and suitable distribution areas. Niche overlap was quantified, and niche similarity was tested to assess niche differentiation among species. Climate and soil determined species’ potential distribution. While climatic niches were mostly similar, edaphic niches tended to differ. Warm and moist tropical forests with no water deficit and low seasonality in precipitation are the most suitable environments for the four species. This study supports previous reports of wide ecological plasticity of Damburneya salicifolia based on its distribution and leaf trait variation, as it occurred in drier environments with wider temperature and soil pH ranges than the other species. The observed patterns of niche similarity did not reflect the phylogenetic relationships between species, suggesting that the modeled niches do not necessarily reflect past evolutionary processes but rather the current environmental variation across the geographical ranges of the species. The results suggest that the studied species are similarly constrained by climate and toleratewide edaphic variation, supporting a potential role for soils on ecological divergence within the genus. On the other hand, performance and predictions varied between models built with different datasets. This research supports the utility of including climate and soil data in ecological niche models to comprehensively analyze the niche and distribution of plant species.

Urban modernization and economic globalization have led to significant changes in traditional natural landscapes. The unregulated and large-scale expansion of rubber plantations in Xishuangbanna has resulted in water and scenic forests being replaced by rubber forests and the complex rainforest ecosystem being replaced by simple artificial forests. This has resulted in increasingly prominent ecological problems such as soil erosion, regional microclimate changes, and sharp declines in biodiversity. The ecological security pattern is an important way to protect regional ecological sustainability. Taking the tropical rainforest in Xishuangbanna as an example, this study identified ecological sources through the evaluation of the importance of ecosystem services, constructed resistance surfaces through ecological sensitivity evaluation, and used circuit theory to simulate ecological processes in heterogeneous landscapes by calculating "electricity" or "resistance", thereby identifying ecological corridors and key ecological nodes. The results identified 31 ecological source areas, 65 key ecological corridors, 7 potential ecological corridors, 37 ecological pinch points, and 99 ecological barriers. The overall distribution of ecological sources was scattered, with higher density in the northwest and southeast regions. Ecological corridors were distributed along high mountains, and both ecological sources and corridors were mainly composed of forest land. Based on circuit theory, this study filled the gap in the MCR model's inability to identify the true width of corridors due to ignoring the randomness of biological migration. It determined the spatial range of ecological corridors and the specific locations of ecological nodes and barriers, providing a reference for solving ecological problems in Xishuangbanna, such as "rainforest fragmentation". [ABSTRACT FROM AUTHOR]

Questions: Agricultural expansion is one of the dominant drivers of forest and biodiversity loss, and shifting cultivation is the most widely used form of agriculture in many tropical forest regions. Where forests have been cleared, they have the potential to recover once the land is abandoned. However, legacies of land use are often overlooked in successional studies, and a deeper understanding of this legacy effect is needed to define efficient restoration practices using natural or assisted regeneration. Here, we analysed how land‐use history affects soil properties and early succession on abandoned agricultural fields in two contrasting Mexican socio‐ecological systems. Location: Mexico, Oaxaca and Chiapas. Methods: We sampled soil and monitored vegetation for 2 years after agricultural abandonment, and interviewed landowners about their land‐use practices. Results: Land‐use practices were clearly influenced by landowners' social context (residence time, rural or urban origin), and topography and soil type also constrained or facilitated land‐use practices. Soil characteristics were strongly affected by three land‐use practices: mechanical tillage decreased soil N and K; frequent herbicide and pesticide use increased N and K; and for pasture systems, stocking density increased soil bulk density and decreased pH and N. High‐intensity land management practices, specifically use of machinery, had the highest impact on early forest succession. When machinery was not used, the frequency of land‐use practices, particularly weeding frequency, is the main factor influencing tree cover and sapling diversity. Conclusions: To facilitate post‐agricultural forest recovery, we recommend restoration efforts using natural regeneration in areas with low previous land‐use intensity and frequency. [ABSTRACT FROM AUTHOR]

As the final layer for precipitation interception in forests, the litter layer is crucial to the vertical structure of forest ecosystems, situated between the forest vegetation and soil layers. Exploring the litter accumulation and water retention characteristics in different tropical rainforest stands is essential for assessing their water conservation functions. This study focused on three forest stands (primary forest, secondary forest, and rubber plantation) within Qixianling Hot Springs National Forest Park in Hainan, China. The immersion method was used to measure litter accumulation and water retention characteristics, exploring variations among these forest stands. Results revealed (1) significant differences in litter accumulation among the stands, with the primary forest having the highest litter accumulation (2.791 t/hm2), followed by the secondary forest (2.077 t/hm2) and rubber plantation (1.660 t/hm2). Litter moisture content followed the order: primary forest (57.57%) > secondary forest (48.33%) > rubber plantation (46.44%). (2) Regarding water retention and water retention rate, both primary and secondary forests showed an increasing trend with immersion time, with the primary forest exhibiting higher water retention and retention rates than the secondary forest. In contrast, rubber plantations showed no clear trends in water retention or retention rates over time. The relation between litter water absorption rate and immersion time followed a well-fitted power function. The maximum water retention capacities were in the order of primary forest (8.041 t/hm2) > secondary forest (6.251 t/hm2) > rubber plantation (4.896 t/hm2). (3) In terms of water absorption and water loss rates, the rubber plantation had the highest water loss rate, followed by the secondary forest and the primary forest. The maximum water loss was observed in the primary forest (5.225 t/hm2) > secondary forest (4.626 t/hm2) > rubber plantation (4.079 t/hm2), and the maximum water loss rates followed the order: rubber plantation (246.319%) > secondary forest (222.649%) > primary forest (189.748%). The forest litter layer's water retention capacity and storage are closely related, with larger litter reserves correlating with greater water retention. Therefore, among the three forest types, the maximum and effective water interception capacities exhibited the following trend: primary forest > secondary forest > rubber plantation. The maximum and effective interception rates show the pattern: primary forests ≈ rubber plantations > secondary forests. The water conservation function of litter is reflected in its water retention capacity and rate of water loss. Given that primary forests exhibit a higher water retention capacity and lower water loss rates, litter accumulation in primary forests is more conducive to forest water conservation functions. Hence, future efforts should focus on protecting litter from primary forests. Conversely, the litter in rubber plantations tends to have a higher rate of water loss, resulting in poorer water conservation. Therefore, future considerations should include planting understory vegetation in rubber plantations to enhance litter water-conservation capabilities and prevent soil erosion. These findings provide crucial theoretical guidance for forest management and the enhancement of water conservation in tropical regions. [ABSTRACT FROM AUTHOR]

Globally, arthropod populations are declining at alarming rates, but the causes are rarely understood. Our research details and examines possible causes for fluctuations in the size of a Costa Rican population of golden silk orbweaver spiders (Trichonephila clavipes (Linnaeus, 1767)). Over a seven-year period from 2013–2019, we noted a sharp decline and then partial recovery of the study population during the wet season (June, July), but then failed to locate any spiders during a brief survey in June 2022 when they would otherwise be abundant. We monitored webs daily during 2013–2019 to test whether variation in prey capture, competitors, female size, male availability, predation, temperature, or rainfall related to population fluctuations. We were unable to explain T. clavipes population trends with the collected data. Future studies are needed to determine whether the extremely low population densities we witnessed in 2017 and 2022 can be interpreted as the lowest values of this species' normal population fluctuation cycle or whether these extremes are part of a long-term spider decline. [ABSTRACT FROM AUTHOR]

Diplogyniopsis fluctuosumsp. nov. associated with passalid beetles is described based on females from China on undermined passalid beetles, as well as on females and males from Thailand on Aceraius helferi (Coleoptera: Passalidae). The species represents the second known species of Diplogyniopsis Trägårdh, prompting us to redefine the genus diagnosis. [ABSTRACT FROM AUTHOR]

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Previous studies on global carbon emissions from forest loss have been marked by great discrepancies due to uncertainties regarding the lost area and the densities of different carbon pools. In this study, we employed a new global 30 m land cover dynamic dataset (GLC_FCS30D) to improve the assessment of forest loss areas; then, we combined multi-sourced carbon stock products to enhance the information on carbon density. Afterwards, we estimated the global carbon emissions from forest loss over the period of 1985–2020 based on the method recommended by the Intergovernmental Panel on Climate Change Guidelines (IPCC). The results indicate that global forest loss continued to accelerate over the past 35 years, totaling about 582.17 Mha and leading to total committed carbon emissions of 35.22 ± 9.38 PgC. Tropical zones dominated global carbon emissions (~2/3) due to their higher carbon density and greater forest loss. Furthermore, global emissions more than doubled in the period of 2015–2020 (1.77 ± 0.44 PgC/yr) compared to those in 1985–2000 (0.69 ± 0.21 PgC/yr). Notably, the forest loss at high altitudes (i.e., above 1000 m) more than tripled in mountainous regions, resulting in more pronounced carbon emissions in these areas. Therefore, the accelerating trend of global carbon emissions from forest loss indicates that great challenges still remain for achieving the COP 26 Declaration to halt forest loss by 2030. [ABSTRACT FROM AUTHOR]

Introduction: To achieve effective conservation objectives, it is crucial to map biodiversity patterns and hotspots while considering multiple influencing factors. However, focusing solely on biodiversity hotspots is inadequate for species conservation on a landscape scale. This emphasizes the importance of integrating hotspots with the home ranges of species to identify priority conservation areas. Methods: Compiling the vegetation data with environmental and anthropogenic disturbance data collected from kilometer-grid plots in Bawangling Nature Reserve, Hainan, China, we analyzed the spatial distribution of plant diversity (species richness and Shannon-Wiener index), as well as the main drivers affecting these patterns. We also investigated the spatial distribution of hotspots using a threshold approach and compared them with the home ranges of the flagship species, Hainan gibbon (Nomascus hainanus). Result: Climate and soil are predominant drivers shaping the spatial pattern of plant diversity in Bawangling Nature Reserve, surpassing the influence of anthropogenic disturbance and topographic factors. Both diversity indices exhibit a generally similar pattern with exceptions in surrounding areas of Futouling and Elongling. The hotspots identified by the Shannon-Wiener index showed a higher spatial overlap with the home ranges of Hainan gibbon compared to the species richness hotspots. The recently established Hainan gibbon Group E in 2019, located 8 km away from the original Futouling habitat, does not coincide with identified hotspots. Discussion: Our findings indicate that the hotspots of plant diversity within the habitat of Hainan gibbon Group E are relatively limited, emphasizing the necessity of giving precedence to its conservation. Integrating hotspots with the home ranges of critically endangered species offers decision-makers valuable information to establish rational conservation networks in the context of changing environments, as well as a reference for habitat restoration of species. [ABSTRACT FROM AUTHOR]

Sacred groves are remnants of primary forests with rich biological diversity, protected by indigenous communities. Their role in carbon sequestration and provision of other ecosystem services is being recognized. We investigated four sacred groves (Idanre Hills, Igbo-Olodumare, Ogun-Onire, and Osun-Osogbo) in southwestern Nigeria for biodiversity conservation, biomass production, and carbon storage. A total of 32 temporary sample plots of 800 m2 each were laid across all the sacred groves. Within each plot, all trees with dbh greater or equal to 10 cm were identified, and their diameters and heights measured. Saplings and seedlings were assessed within 100 m2 and 25 m2 sub-plots, respectively. Non-destructive methods were employed in estimating volume, biomass production, and carbon storage. Shannon–Wiener diversity index, Margalef index, and tree species richness in the four groves ranged from 2.63–3.55, 5.64–10.02, and 41–85, respectively, and differed significantly. The four groves were sanctuaries for many indigenous tree species of immense social, religious, ecological, and socio-economic importance. The high densities of seedling and sapling, together with the inverted-J tree diameter distributions, are indications of active regeneration and healthy ecosystem. Mean volume was high (range 244.99 to 343.08 m3 ha−1). The biomass (range 87.8 to 231.85 t ha−1) and carbon stock (range 43.9 to 115.9 t ha−1) of the groves revealed their potentials for climate change mitigation through atmospheric CO2 sequestration. Thus, besides being an effective biodiversity conservation method, sacred groves are important carbon sink. This calls for further conservation of sacred groves to serve as long-term carbon storage mechanism. [ABSTRACT FROM AUTHOR]

This study confirms Mount Cameroon as an unprecedented hotspot for the diversity of many-plumed moths, with the discovery and description of nine new species: Alucita fako Ustjuzhanin & Kovtunovich, sp. nov., Alucita pyrczi Ustjuzhanin & Kovtunovich, sp. nov., Alucita sroczki Ustjuzhanin & Kovtunovich, sp. nov., Alucita potockyi Ustjuzhanin & Kovtunovich, sp. nov., Alucita sedlaceki Ustjuzhanin & Kovtunovich, sp. nov., Alucita tonda Ustjuzhanin & Kovtunovich, sp. nov., Alucita erzayi Ustjuzhanin & Kovtunovich, sp. nov., Alucita sokolovi Ustjuzhanin & Kovtunovich, sp. nov., and Alucita hirsuta Ustjuzhanin & Kovtunovich, sp. nov. Additionally, four additional species are reported from the Mount Cameroon area as new for the country: Alucita agassizi, Alucita dohertyi, Alucita plumigera, and Alucita rhaptica. Of the 89 Alucitidae known from the Afrotropics, the studied area hosts 36 species, most of which are endemic to the area. This unprecedented level of diversity and endemism within this lepidopteran family highlights Mount Cameroon's significance as a stronghold for specialised insect taxa. Efficient conservation efforts are necessary to protect these ecosystems and their associated unique microlepidopteran diversity. [ABSTRACT FROM AUTHOR]

Tropical rainforests are subject to changes over time, further accelerated under anthropic pressure. We investigated the influence of anthropogenic disturbances and vegetation cover on the taxonomic and functional structure of assemblages of bryophytes in three rainforests in Brazil. The parameters analyzed were richness, composition and beta diversity. Temporal changes in floristic dissimilarity were explained by species turnover, while those in functional dissimilarity by were explained nestedness and turnover. Only the increase in species richness was significantly influenced by the increase in matrix forest cover and changes in the degree of chronic anthropogenic disturbance. In scenarios of slight increase in matrix forest cover associated with increase in anthropogenic disturbances, we found a loss of functional diversity due to the loss of moisture- and shade-demanding species, which were replaced with species that are generalist as to light requirements and species with high reproductive capacity (monoicous). In turn, in scenarios of increase in forest cover and decrease in chronic disturbances, there was an increase in demanding species, implying greater functional diversity. Thus, efforts to increase the vegetation cover and decrease anthropogenic pressures, especially chronic disturbances, can improve the environmental quality and favor the conservation of the diversity of more demanding species. [ABSTRACT FROM AUTHOR]

Lipids may play an important role in preventing gas embolisms by coating nanobubbles in xylem sap. Few studies on xylem sap lipids have been reported for temperate plants, and it remain unclear whether sap lipids have adaptational significance in tropical plants. In this study, we quantify the lipid composition of xylem sap for angiosperm species from a tropical savanna (seven species) and a seasonal rainforest (five species) using mass spectrometry. We found that all twelve species studied contained lipids in their xylem sap, including galactolipids, phospholipids and triacylglycerol, with a total lipid concentration ranging from 0.09 to 0.26 nmol/L. There was no difference in lipid concentration or composition between plants from the two sites, and the lipid concentration was negatively related to species’ open vessel volume. Furthermore, savanna species showed little variation in lipid composition between the dry and the rainy season. These results support the hypothesis that xylem sap lipids are derived from the cytoplasm of individual conduit cells, remain trapped inside individual conduits, and undergo few changes in composition over consecutive seasons. A xylem sap lipidomic data set, which includes 12 tropical tree species from this study and 11 temperate tree species from literature, revealed no phylogenetic signals in lipid composition for these species. This study fills a knowledge gap in the lipid content of xylem sap in tropical trees and provides additional support for their common distribution in xylem sap of woody angiosperms. It appears that xylem sap lipids have no adaptive significance.

Selective logging is the most widespread driver of land‐use change in biodiverse and carbon‐rich tropical forests. However, the effects of selective logging on biodiversity are less than those associated with other drivers of forest degradation. A suite of recent research has shown that reduced‐impact logging (RIL) results in few or no changes to biological assemblages. But because this logging technique is relatively new, most studies have only considered short‐term impacts.We address this research gap by quantifying changes in biodiversity assemblage as a result of RIL over the longer term. We comprehensively sampled bird and bat assemblages pre‐logged, 1 year after, and 10 years after RIL in Guyana, using a before‐after control‐impact (BACI) sampling design. We compared bird and bat assemblages in each timeframe, and additionally appraised the impact of time since logging, and the number of trees harvested across the suite of species which we further divided between different feeding guilds, disturbance sensitivity and vertical stratification of forest use.We found that 1 year after logging only minor changes could be detected, but 10 years later richness had slightly declined in some groups, while others had shown complete recovery. Nectivorous and insectivorous birds, and carnivorous bats declined in richness, while carnivorous birds, showed a clear recovery to a state akin to pre‐logging. This indicates that for some niches a subtle, but long‐term relaxation effect may be occurring, whereby extinction debts are realized long after the initial disturbance, while other groups have either recovered or not changed after logging.Assemblage changes were also predicted by vertical stratification of forest use, with avian species using the understorey and mid–upper levels of the forest being most affected.Synthesis and applications: Our study demonstrates how best practice forestry and logging can maintain healthy vertebrate populations over the long term. Forestry concessions that adopt techniques of low‐harvest RIL and are managed for their long‐term timber provision through extension of regeneration times beyond 10 years after harvest, are likely to benefit from the ecosystem services provided by biodiversity, while also making a valuable contribution to the global conservation estate. [ABSTRACT FROM AUTHOR]

The drivers behind plant‐pollinator interactions still need to be fully understood. Previous research has suggested that observed interactions result from either neutral interaction between species based on their abundance or from niche‐based processes, which are reflected in the adaptations of both plants and pollinators. Furthermore, the importance of both scenarios can differ depending on seasonal dynamics translated into differences in resource availability. Extensive research has been conducted on New‐World hummingbirds (Trochilidae), whereas much less is known about Old World nectar‐feeding sunbirds (Nectariniidae). Our study aimed to explore whether sunbird‐plant interactions are explained by neutral and/or niche‐based processes. Thus, we tested the effects of abundance, morphology, and nectar sugar content on the observed interactions and the link between sunbirds and plant traits. Moreover, we explored the effects of robbing on these mechanisms. Finally, we investigated the partitioning of bird pollination niches, based on floral traits. We used a dataset of sunbird‐plant interactions collected at Mount Cameroon during two seasons (dry and wet seasons). Our study shows that sunbird‐plant interactions are influenced by both neutral and niche‐based processes. Neutral processes and nectar reward were the main mechanisms underlaying the observed interactions in the dry season. However, as more ornithophilous plants bloom during the rainy season, morphological trait‐matching becomes more important. We found a correlation between bill length and floral tube dimensions and observed niche overlap among the sunbird species. Considering this and other research, we suggest that plant‐pollinator interactions are influenced by a combination of both neutral and niche‐based processes. [ABSTRACT FROM AUTHOR]

Summary: Understanding the long‐term impact of projected climate change on tropical rainforests is critical given their central role in the Earth's system. Palaeoecological records can provide a valuable perspective on this problem. Here, we examine the effects of past climatic changes on the dominant forest type of Southeast Asia – lowland dipterocarp forest.We use a range of proxies extracted from a 1400‐yr‐old lacustrine sedimentary sequence from north‐eastern Philippines to determine long‐term vegetation responses of lowland dipterocarp forest, including its dominant tree group dipterocarps, to changes in precipitation, fire and nutrient availability over time.Our results show a positive relationship between dipterocarp pollen accumulation rates (PARs) and leaf wax hydrogen isotope values, which suggests a negative effect of drier conditions on dipterocarp abundance. Furthermore, we find a positive relationship between dipterocarp PARs and the proxy for phosphorus availability, which suggests phosphorus controls the productivity of these keystone trees on longer time scales. Other pollen taxa show widely varying relationships with the abiotic factors, demonstrating a high diversity of plant functional responses.Our findings provide novel insights into lowland dipterocarp forest responses to changing climatic conditions in the past and highlight potential impacts of future climate change on this globally important ecosystem. See also the Commentary on this article by Utteridge 240: 2176–2178. [ABSTRACT FROM AUTHOR]

Introduction: To achieve effective conservation objectives, it is crucial to map biodiversity patterns and hotspots while considering multiple influencing factors. However, focusing solely on biodiversity hotspots is inadequate for species conservation on a landscape scale. This emphasizes the importance of integrating hotspots with the home ranges of species to identify priority conservation areas. Methods: Compiling the vegetation data with environmental and anthropogenic disturbance data collected from kilometer-grid plots in Bawangling Nature Reserve, Hainan, China, we analyzed the spatial distribution of plant diversity (species richness and Shannon-Wiener index), as well as the main drivers affecting these patterns. We also investigated the spatial distribution of hotspots using a threshold approach and compared them with the home ranges of the flagship species, Hainan gibbon (Nomascus hainanus). Result: Climate and soil are predominant drivers shaping the spatial pattern of plant diversity in Bawangling Nature Reserve, surpassing the influence of anthropogenic disturbance and topographic factors. Both diversity indices exhibit a generally similar pattern with exceptions in surrounding areas of Futouling and Elongling. The hotspots identified by the Shannon-Wiener index showed a higher spatial overlap with the home ranges of Hainan gibbon compared to the species richness hotspots. The recently established Hainan gibbon Group E in 2019, located 8 km away from the original Futouling habitat, does not coincide with identified hotspots. Discussion: Our findings indicate that the hotspots of plant diversity within the habitat of Hainan gibbon Group E are relatively limited, emphasizing the necessity of giving precedence to its conservation. Integrating hotspots with the home ranges of critically endangered species offers decision-makers valuable information to establish rational conservation networks in the context of changing environments, as well as a reference for habitat restoration of species. [ABSTRACT FROM AUTHOR]

Soil nutrients and their stoichiometry are important indicators of nutrient biogeochemical cycles and various ecological processes. Soil nutrients are heterogeneously distributed and can be influenced by plants through litterfall and root activity. To explore the associations between soil nutrients and relationships between soil nutrients and plant characteristics, we selected three canopy tree categories based on abundance as dominant, common, and rare, with different plant sizes based on DBH (diameter at breast height, cm) for each species from three 1 ha tropical forest sites (Bu-Beng, P55, and Na-Ban-He forests), and collected the topsoil (0–10 cm) for physiochemical analysis. The results showed that soil nutrient concentrations were significantly different among the three forest sites. For soil total C, N, and P associations, soil total C and N had significant associations at all three sites; however, the associations of soil total C-P and N-P varied among sites. The plant category had significant relationships with soil stoichiometry, whereas plant size had significant relationships with soil nutrient concentrations; these relationships varied among the three sites. The results indicate that soil nutrient heterogeneity is influenced by tree category and size. Future studies should include a larger sample size to further validate these results. [ABSTRACT FROM AUTHOR]

Southern Mexico's tropical forests are home to the country's highest richness of mammal species; La Chinantla region is situated within this area, its name from the indigenous group residing in the area and holding territorial ownership, namely the Chinantecos. In La Chinantla, there are no Protected Areas; instead, there are Areas Destined Voluntarily for Conservation (ADVC) and "Voluntary Conservation Areas" (VCA), that are managed by local inhabitants through social consensus. These ADVC may function as an archipelago reserve, which represents regional diversity, including the social context, through complementarity. To verify its biodiversity, we analyzed the richness, composition, distribution, and conservation of wild mammals in the region. Records were obtained from four sources-primary data collection, databases, scientific literature, and community monitoring-and were organized into four zones based on altitudinal and vegetation gradients. We compared the diversity between zones for three categories of mammals: small (<100 gr.), bats, and medium and large (>100 gr.). 134 species were identified comprising 11 orders, 26 families and 86 genera. The zone with highest elevation presented the greatest species richness for the assemblage of mammals and terrestrial mammals, while the zone with the lowest elevation had the highest richness of bats. For each mammal category, the zone with the most species also registered the highest number of exclusive species. For the assemblage of mammals and for medium and large mammals, the similarity index was highest between the two intermediate zones, while for small mammals and bats, the greatest similarity occurred between the areas of higher altitude. The study region was found to have the second highest richness of mammals in Mexico. Finally, we suggest that the conservation proposals by indigenous people could function as a set of "islands" that promote the conservation of biodiversity, possibly as an Archipelago Reserve. [ABSTRACT FROM AUTHOR]

In ecological communities, the relationships between interacting species are very complex, resulting in nonlinear or even chaotic oscillations. Human activities, such as habitat destruction and fragmentation, overexploitation of natural resources, and noise and light pollution, have been shown to influence species interactions. However, the pattern of impact of these activities on fig wasps remains unclear. In this study, we analyzed the network relationships associated with fig wasps at six different sites, including both human-disturbed habitats and primary rainforests in Xishuangbanna, tropical China. Our analysis revealed that the pollinator Ceratosolen fusciceps had complex non-linear relationships with five species of non-pollinator wasps in the primary rainforests. The connectivity and complexity of species networks were reduced in human-disturbed habitats, particularly regarding the number and strength of associations of the key pollinator, Ceratosolen fusciceps, with other non-pollinator wasps. Additionally, we separately analyzed the association networks of male and female fig wasps and found that human disturbance had a greater impact on female wasps, as evidenced by a more pronounced decrease in edges in the female network compared to the male network. The positive correlation between females and males was weakened in different populations under the influence of human interference, while it was strengthened in different sexes of the same species. Overall, human disturbances altered fig wasp numerical relationships, reducing connectivity and complexity in species networks. This impacted fig-fig wasp mutualism, especially involving Ceratosolen fusciceps and non-pollinator wasps. These findings may contribute to our understanding of the coevolution between fig-fig wasp mutualism.

Abstract Background Xylaria is a diverse and ecologically important genus in the Ascomycota. This paper describes the xylariaceous fungi present in an Ecuadorian Amazon Rainforest and investigates the decay potential of selected Xylaria species. Fungi were collected at Yasuní National Park, Ecuador during two collection trips to a single hectare plot divided into a 10-m by 10-m grid, providing 121 collection points. All Xylaria fruiting bodies found within a 1.2-m radius of each grid point were collected. Dried fruiting bodies were used for culturing and the internal transcribed spacer region was sequenced to identify Xylaria samples to species level. Agar microcosms were used to assess the decay potential of three selected species, two unknown species referred to as Xylaria 1 and Xylaria 2 and Xylaria curta, on four different types of wood from trees growing in Ecuador including balsa (Ochroma pyramidale), melina (Gmelina arborea), saman (Samanea saman), and moral (Chlorophora tinctoria). ANOVA and post-hoc comparisons were used to test for differences in biomass lost between wood blocks inoculated with Xylaria and uninoculated control blocks. Scanning electron micrographs of transverse sections of each wood and assay fungus were used to assess the type of degradation present. Results 210 Xylaria collections were sequenced, with 106 collections belonging to 60 taxa that were unknown species, all with less than 97% match to NCBI reference sequences. Xylaria with sequence matches of 97% or greater included X. aff. comosa (28 isolates), X. cuneata (9 isolates) X. curta and X. oligotoma (7 isolates), and X. apiculta (6 isolates)., All Xylaria species tested were able to cause type 1 or type 2 soft rot degradation in the four wood types and significant biomass loss was observed compared to the uninoculated controls. Balsa and melina woods had the greatest amount of biomass loss, with as much as 60% and 25% lost, respectively, compared to the controls. Conclusions Xylaria species were found in extraordinary abundance in the Ecuadorian rainforest studied. Our study demonstrated that the Xylaria species tested can cause a soft rot type of wood decay and with the significant amount of biomass loss that occurred within a short incubation time, it indicates these fungi likely play a significant role in nutrient cycling in the Amazonian rainforest.

Full-waveform LiDAR (FWF) offers a promising advantage over other technologies to represent the vertical canopy structure of secondary successions in the Amazon region, as the waveform encapsulates the properties of all elements intercepting the emitted beam. In this study, we investigated modifications in the vertical structure of the Amazonian secondary successions across the vegetation gradient from early to advanced stages of vegetation regrowth. The analysis was performed over two distinct climatic regions (Drier and Wetter), designated using the Maximum Cumulative Water Deficit (MCWD). The study area was covered by 309 sample plots distributed along 25 LiDAR transects. The plots were grouped into three successional stages (early—SS1; intermediate—SS2; advanced—SS3). Mature Forest (MF) was used as a reference of comparison. A total of 14 FWF LiDAR metrics from four categories of analysis (Height, Peaks, Understory and Gaussian Decomposition) were extracted using the Waveform LiDAR for Forestry eXtraction (WoLFeX) software (v1.1.1). In addition to examining the variation in these metrics across different successional stages, we calculated their Relative Recovery (RR) with vegetation regrowth, and evaluated their ability to discriminate successional stages using Random Forest (RF). The results showed significant differences in FWF metrics across the successional stages, and within and between sample plots and regions. The Drier region generally exhibited more pronounced differences between successional stages and lower FWF metric values compared to the Wetter region, mainly in the category of height, peaks, and Gaussian decomposition. Furthermore, the Drier region displayed a lower relative recovery of metrics in the early years of succession, compared to the areas of MF, eventually reaching rates akin to those of the Wetter region as succession progressed. Canopy height metrics such as Waveform distance (WD), and Gaussian Decomposition metrics such as Bottom of canopy (BC), Bottom of canopy distance (BCD) and Canopy distance (CD), related to the height of the lower forest stratum, were the most important attributes in discriminating successional stages in both analyzed regions. However, the Drier region exhibited superior discrimination between successional stages, achieving a weighted F1-score of 0.80 compared to 0.73 in the Wetter region. When comparing the metrics from SS in different stages to MF, our findings underscore that secondary forests achieve substantial relative recovery of FWF metrics within the initial 10 years after land abandonment. Regions with potentially slower relative recovery (e.g., Drier regions) may require longer-term planning to ensure success in providing full potential ecosystem services in the Amazon.

Zamia magnifica (Zamiaceae), a new species endemic to Sierra Norte, Oaxaca, Mexico, is described. Zamia magnifica is characterized by having a rupicolous habit, pendent leaves bearing leaflets that are densely tomentose and pink to caramel in color when emerging, and broad oblong leaflets that are coriaceous in texture with few non-prominent denticulations and ovulate strobili with short (Z. furfuracea and Z. meermanii, the Mesoamerican Zamia species to which it shares the closest morphological resemblance.

Southern Mexico’s tropical forests are home to the country’s highest richness of mammal species; La Chinantla region is situated within this area, its name from the indigenous group residing in the area and holding territorial ownership, namely the Chinantecos. In La Chinantla, there are no Protected Areas; instead, there are Areas Destined Voluntarily for Conservation (ADVC) and “Voluntary Conservation Areas” (VCA), that are managed by local inhabitants through social consensus. These ADVC may function as an archipelago reserve, which represents regional diversity, including the social context, through complementarity. To verify its biodiversity, we analyzed the richness, composition, distribution, and conservation of wild mammals in the region. Records were obtained from four sources—primary data collection, databases, scientific literature, and community monitoring—and were organized into four zones based on altitudinal and vegetation gradients. We compared the diversity between zones for three categories of mammals: small (100 gr.). 134 species were identified comprising 11 orders, 26 families and 86 genera. The zone with highest elevation presented the greatest species richness for the assemblage of mammals and terrestrial mammals, while the zone with the lowest elevation had the highest richness of bats. For each mammal category, the zone with the most species also registered the highest number of exclusive species. For the assemblage of mammals and for medium and large mammals, the similarity index was highest between the two intermediate zones, while for small mammals and bats, the greatest similarity occurred between the areas of higher altitude. The study region was found to have the second highest richness of mammals in Mexico. Finally, we suggest that the conservation proposals by indigenous people could function as a set of “islands” that promote the conservation of biodiversity, possibly as an Archipelago Reserve.

Background: Xylaria is a diverse and ecologically important genus in the Ascomycota. This paper describes the xylariaceous fungi present in an Ecuadorian Amazon Rainforest and investigates the decay potential of selected Xylaria species. Fungi were collected at Yasuní National Park, Ecuador during two collection trips to a single hectare plot divided into a 10-m by 10-m grid, providing 121 collection points. All Xylaria fruiting bodies found within a 1.2-m radius of each grid point were collected. Dried fruiting bodies were used for culturing and the internal transcribed spacer region was sequenced to identify Xylaria samples to species level. Agar microcosms were used to assess the decay potential of three selected species, two unknown species referred to as Xylaria 1 and Xylaria 2 and Xylaria curta, on four different types of wood from trees growing in Ecuador including balsa (Ochroma pyramidale), melina (Gmelina arborea), saman (Samanea saman), and moral (Chlorophora tinctoria). ANOVA and post-hoc comparisons were used to test for differences in biomass lost between wood blocks inoculated with Xylaria and uninoculated control blocks. Scanning electron micrographs of transverse sections of each wood and assay fungus were used to assess the type of degradation present. Results: 210 Xylaria collections were sequenced, with 106 collections belonging to 60 taxa that were unknown species, all with less than 97% match to NCBI reference sequences. Xylaria with sequence matches of 97% or greater included X. aff. comosa (28 isolates), X. cuneata (9 isolates) X. curta and X. oligotoma (7 isolates), and X. apiculta (6 isolates)., All Xylaria species tested were able to cause type 1 or type 2 soft rot degradation in the four wood types and significant biomass loss was observed compared to the uninoculated controls. Balsa and melina woods had the greatest amount of biomass loss, with as much as 60% and 25% lost, respectively, compared to the controls. Conclusions: Xylaria species were found in extraordinary abundance in the Ecuadorian rainforest studied. Our study demonstrated that the Xylaria species tested can cause a soft rot type of wood decay and with the significant amount of biomass loss that occurred within a short incubation time, it indicates these fungi likely play a significant role in nutrient cycling in the Amazonian rainforest. [ABSTRACT FROM AUTHOR]