Ecological Hypotheses Research Articles

The fish challenge to vertebrate cognitive evolution.

There is tremendous taxonomic variation in the size, shape and structure of vertebrate brains. While many studies use cross-species comparisons to aim at identifying the ecological factors (social and environmental) that explain what cognitive advantages larger brains confer, a more fundamental divide exists between endotherm and ectotherm vertebrates. Relative to body size, ectotherms have ten times smaller brains than endotherms. Existing ecological hypotheses cannot explain this divide, as some endotherm species with relatively simple social organization and diets still possess larger brains. Furthermore, research demonstrates that at least fishes possess a cognitive 'toolkit' equivalent to that of many endotherms. This is the fish challenge to vertebrate cognitive evolution. We review hypothesized consequences of brain size differences to propose two non-exclusive solutions. First, the fish brain retains modularity, but it is less efficient in problem-solving than an endothermic brain with a more domain-general organization. Second, brain size variation can be more effectively explained by sensory-motor skills and their integration rather than by cognitive processes. In that case, understanding brain size would require highlighting and emphasizing these aspects when broadly defining animal cognition. Specifically, it would be fitting to amend the classic definition of animal cognition to refer to how animals take in and process sensory information before deciding how to act on it using motor competencies.This article is part of the Theo Murphy meeting issue 'Selection shapes diverse animal minds'.

Shifts in phytoplankton community structure across oceanic boundaries.

Phytoplankton communities play an important role in marine food webs and biogeochemical cycles. The transition zones between ocean gyres and surrounding waters represent critical ecological boundaries where environmental gradients drive significant shifts in phytoplankton community structure. This study investigates how nutrient availability and temperature shape the size distribution and composition of small phytoplankton (< 5 [Formula: see text]m) communities across the North Pacific Subtropical Gyre (NPSG) boundaries, testing several ecological hypotheses that explain phytoplankton size distribution patterns in relation to environmental variability. We used high-resolution, underway flow cytometry data collected during eight oceanographic cruises from 2016 to 2021 to assess changes in phytoplankton biomass and growth rate across the gyre boundaries. The cyanobacterium Prochlorococcus dominated within the gyre, with biomass ranging from 3.2 to 13.1 [Formula: see text]gC L-1, and its relative contribution to total phytoplankton biomass varied among cruises (31% to 81%, average 60 [Formula: see text] 16%). Prochlorococcus growth rates were significantly higher within the gyre (0.43 [Formula: see text] 0.18 per day) than outside the gyre (0.28 [Formula: see text] 0.16 per day) (one-sided t-test, p < 0.001). Northward in the gyre, Prochlorococcus biomass and growth rates declined. Some variations in biomass and growth rates were observed southward and eastward, with biomass ranging from 3 to 10 [Formula: see text]gC L-1 and growth rate ranging from 0.2 to 0.6 per day. Outside the NPSG, total phytoplankton biomass increased, with nanoeukaryotes becoming the predominant contributors (up to 71%, 9.1 [Formula: see text] 7.3 [Formula: see text]gC L-1). Picoeukaryote biomass also increased outside the gyre (up to 28 [Formula: see text] 12% of total biomass). Nutrient concentrations increased by nearly two orders of magnitude outside the NPSG, coinciding with the shift towards larger phytoplankton. The dominance of Prochlorococcus within the gyre emphasizes its adaptation to oligotrophic conditions, while the shift towards larger size classes outside the gyre likely reflects the relatively higher nutrient availability. The relatively low abundance of Synechococcus even in nutrient-rich regions suggest that that factors beyond nutrient availability, such as grazing, may influence its distribution. These findings have implications for understanding how phytoplankton communities will respond to future changes in oceanographic conditions, such as warming and altered nutrient regimes.

Biodiversity Gradients: Is Diversity Greater in the Tropics?

This paper examines hypotheses explaining greater biodiversity in the tropics compared to regions located at higher latitudes. The results of studies of the biodiversity of different groups of organisms along latitudinal transects are presented to demonstrate the existence of latitudinal gradients of biodiversity. Hypotheses explaining the existence of regular gradients of biodiversity, i.e. such changes in biodiversity when it increases with approaching the equator: uneven distribution of the sizes of the tropics and temperate zones, the so-called middle domain effect, uneven latitudinal distribution of energy reaching the Earth’s surface and other evolutionary and ecological hypotheses. Moreover, explanations for reverse gradients of biodiversity are discussed. Attention is drawn to the different nature of the conditions for these explanations and to the rather large gaps in data that could be useful to resolve these issues.

Fighting isn’t sexy in lekking greater sage-grouse: a relational event model approach for mating interactions

The relationship between aggression and mate choice in mating systems is critical for understanding the evolution and diversification of sexual organisms and yet remains the subject of vigorous debate. A key challenge is that traditional correlational approaches cannot distinguish underlying mechanisms of social interaction and can indicate misleading positive associations between aggression and mating events. We implement a novel relational event model (REM) incorporating temporal dependencies of events in a social network to study natural reproductive behaviour in a lek-breeding system where males gather to display and females visit to evaluate mates, often observing both male courtship displays and fights. We find that fighting is not attractive to females. Indeed, males are less likely to start and more likely to leave fights with females present, plausibly to avoid entanglement in protracted combat cycles arising from emergent social processes that reduce availability to mate. However, fighting serves other roles, e.g. to deter copulation interruptions and rebuff competitors. Our findings support the hypothesis that social systems regulating conflict and promoting females’ choice based on display are fundamental to stable lek evolution. Moreover, our analysis highlights the utility of the REM framework in testing mechanistic hypotheses in behavioural ecology and evolution.

Are Lizard Assemblages From the Atlantic Forest Under the Influence of Ecological Release?

ABSTRACTEcological release is a key concept that describes how species increase their density and expand their niche in response to reduced competition. This phenomenon is commonly studied in island systems, but its occurrence in naturally isolated habitats within continents remains underexplored. To address this gap, we compared lizard assemblages between the remnants of the coastal Atlantic Forest (non‐isolated areas) and naturally isolated forest relicts. Our predictions were that in isolated areas, lizard density and niche dimensions (e.g., diet) should be larger due to the absence of possible competitors, as well as a more generalised morphology. We verified that non‐isolated areas had greater lizard richness than naturally isolated forest relicts. However, there was no difference between the type areas in relation to the average abundance and average breadths of the lizard niches (calculated from the volume of prey in the stomachs). In contrast, the average nearest neighbour Euclidean distance of lizard assemblages (from morphological data) was lower in isolated areas (more generalised) compared to non‐isolated areas. We conclude that this study partially supports the ecological release hypothesis: the low number of competitors in naturally isolated forest enclaves (ecological opportunity) does not support density compensation and niche expansion (diet), emphasising the impact of historical factors on assemblage structure. In contrast, the more generalised morphology verified in lizards from isolated areas is considered evidence of ecological release, possibly driven by the expansion of microhabitat use. However, the lack of records on the spatial use of the studied lizards underscores the need for further research to confirm this relationship.

TadpoleTraits: A Global Database on Morphological Traits of Tadpoles of Anura

ABSTRACTMotivationFunctional diversity is an important dimension of biodiversity. In animals, most species have complex life cycles, such that the same species can display great differences in traits and ecological roles across different life history stages. Consequently, the patterns and driving factors of functional diversity can vary considerably among the different life stages. However, research on stages other than adults is rare, with data scarcity being a potential reason. The order Anura of Amphibia is a highly diverse group of terrestrial vertebrates, comprising more than 7800 species. Anurans have complex life cycles, and our knowledge about functional traits of the larval stage is extremely limited. To fill this gap, we collected morphological traits of tadpoles globally and compiled a database covering 1993 species to facilitate future studies. This database can help us gain a more comprehensive understanding of anuran biodiversity. Additionally, it offers a valuable tool for testing ecological and evolutionary hypotheses related to complex life cycles in animals.Main Types of Variables ContainedTwenty‐three traits collected from literature and 11 traits obtained by image measuring.Spatial Location and GrainGlobal.Major Taxa and Level of MeasurementAnura, species.Software Formatxlsx.

Identifying pterosaur trackmakers provides critical insights into mid-Mesozoic ground invasion.

Identifying pterosaur trackmakers provides critical insights into mid-Mesozoic ground invasion.

Novel Insights and Genomic Characterization of Coral-Associated Microorganisms from Maldives Displaying Antimicrobial, Antioxidant, and UV-Protectant Activities

Coral reef survival is crucial for the socio-ecological interest of many countries, particularly for the Republic of Maldives, whose reef integrity influences the country’s livelihoods and economy. These ecosystems are being severely impacted by multiple stressors, leading to declines in biodiversity. In the last few decades, researchers have focused on studying coral-associated microorganisms (CAMs) and their symbiotic role in coral health and resilience. Metabarcoding analysis has been widely utilized to study CAM diversity under various conditions but provides limited information on their functional roles. Therefore, cultivation of bacterial strains remains indispensable for validating ecological and biotechnological hypotheses. In this study, we investigated the microbial community associated with two abundant corals in Maldives, Porites lobata and Acropora gemmifera, and evaluated the antimicrobial, antioxidant, and UV-protectant properties of 10 promising isolated strains. The selected CAMs, Pseudoalteromonas piscicida 39, Streptomyces parvus 79, Microbacterium sp. 92 (a potential novel species), and Micromonospora arenicola 93, exhibited antibiotic activity against a panel of pathogenic strains (MIC from 0.01 to 500 µg/mL), antioxidant (comparable effect to that of Trolox and ascorbic acid), and UV-screen activities (protection of human keratinocytes at 200 µg/mL). Genomes revealed their dual potential in contributing to coral restoration and drug discovery strategies. These findings highlight the biotechnological relevance of CAMs, representing an important step toward the identification of novel and bioactive bacterial species beneficial for coral reef ecosystems and human health.

Testing the role of biotic interactions in shaping elevational diversity gradients: An ecological metabolomics approach.

Seminal hypotheses in ecology and evolution postulate that stronger and more specialized biotic interactions contribute to higher species diversity at lower elevations and latitudes. Plant-chemical defenses mediate biotic interactions between plants and their natural enemies and provide a highly dimensional trait space in which chemically mediated niches may facilitate plant species coexistence. However, the role of chemically mediated biotic interactions in shaping plant communities remains largely untested across large-scale ecological gradients. Here, we used ecological metabolomics to quantify the chemical dissimilarity of foliar metabolomes among 473 tree species in 16 tropical tree communities along an elevational gradient in the Bolivian Andes. We predicted that tree species diversity would be higher in communities and climates where co-occurring tree species are more chemically dissimilar and exhibit faster evolution of secondary metabolites (lower chemical phylogenetic signal). Further, we predicted that these relationships should be especially pronounced for secondary metabolites known to include antiherbivore and antimicrobial defenses relative to primary metabolites. Using structural equation models, we quantified the direct effects of rarefied median chemical dissimilarity and chemical phylogenetic signal on tree species diversity, as well as the indirect effects of climate. We found that chemical dissimilarity among tree species with respect to all metabolites and secondary metabolites had positive direct effects on tree species diversity, and that climate (higher temperature and precipitation, and lower temperature seasonality) had positive indirect effects on species diversity by increasing chemical dissimilarity. In contrast, chemical dissimilarity of primary metabolites was unrelated to species diversity and climate. Chemical phylogenetic signal of all metabolite classes had negative direct effects on tree species diversity, indicating faster evolution of metabolites in more diverse communities. Climate had a direct effect on species diversity but did not indirectly affect diversity through chemical phylogenetic signal. Our results support the hypothesis that chemically mediated biotic interactions shape elevational diversity gradients by imposing stronger selection for chemical divergence in more diverse communities and maintaining higher chemical dissimilarity among species in warmer, wetter, and more stable climates. Our study also illustrates the promise of ecological metabolomics in the study of biogeography, community ecology, and complex species interactions in high-diversity ecosystems.

Urbanization strengthens vertical stratification of ant nutrient preferences in a temperate forest ecosystem.

Resource and nutrient availability varies spatially and influences animal foraging patterns. Under the compensation hypothesis, animals should preferentially forage for the most limiting nutrient in the environment. Animal nutrient preferences have been well studied in the tropics, where terrestrial and arboreal fauna are clearly differentiated and limited by different nutrients. In temperate forests, vertical stratification of the fauna may be less pronounced and its role in foraging ecology is poorly understood. Here, we examine nutrient preference patterns over a vertical gradient in temperate forests and nearby urban centers in North Carolina, USA. Using a bait-choice experiment and novel bait design, we measured ant community nutrient preferences in the canopy and on the ground of 83 trees across 14 sites and assessed ant diversity and community composition. Ant diversity did not differ across the vertical strata or habitat types, but species turnover altered community composition to create four distinct assemblages. In temperate forests, ants did not prefer a particular nutrient in either stratum, likely due to extensive foraging across strata. In urban habitats, however, ant nutrient preferences matched patterns well known from tropical systems: arboreal animals preferred protein, while terrestrial animals preferred carbohydrates. Rather than stratum-specific nutrient limitations, however, we attribute the differences in urban preference patterns to changes in native species' foraging intensity and the addition of uniquely urban species with specific nutrient preferences. These results underscore the necessity of testing ecological hypotheses across biomes and suggest that urbanization may produce established ecological patterns via novel mechanisms.

Anthocyanin Impacts Multiple Plant-Insect Interactions in a Carnivorous Plant.

Abstract Although there are many hypothesized ecological functions of plant coloration, they have been only partly resolved by examining ecological hypotheses in isolation. Multiple ecological interactions may act in concert or in opposition to fix or maintain variation in plant coloration, that is, via ecological pleiotropy. To investigate the adaptive value of red plant pigment (anthocyanin) in a carnivorous plant, we compared insect prey capture, herbivore damage, and recruitment of specialist insect larvae in naturally occurring sympatric red and green color morphs of the pitcher plant Sarracenia purpurea. We integrated field and laboratory bioassays, visual modeling, chemical analysis of anthocyanins, and a long-term demographic study to investigate multiple ways anthocyanins mediate plant-insect interactions. In support of ecological pleiotropy, each morph performed better in one or more ecological contexts, providing evidence for ecological interactions exerting opposing selection on plant color and thus maintaining variation. The mixture of both ecological benefits and costs to anthocyanin production is further supported by stable color polymorphism and seed set data consistent with balancing selection. More broadly, this work reveals the impacts of a single anthocyanin compound on multiple key plant-insect interactions, demonstrating evidence for ecological pleiotropy maintaining intraspecific diversity in plant color.

CaecilianTraits, an individual level trait database of Caecilians worldwide

Functional traits differ among species, which determine the ecological niche a species occupies and its ability to adapt to environment. However, differences in traits also exist at intraspecific level. Such variations shape differences in individual survival capabilities. Investigating intraspecific differences of functional traits is important for ecology, evolutionary biology and biodiversity conservation. Individual trait-based approaches have been applied in plant ecology. But for animals, most databases only provide data at the species level. In this study, we presented a global database of morphological traits for caecilians (Amphibia, Gymnophiona) at both species and individual level. Caecilians are a unique group of amphibians characterized by their secretive habits, which have limited our understanding of this taxon. We compiled the most comprehensive database covering 218 out of 222 known species, with 215 of them have individual level data. This database will facilitate research in the ecology, evolutionary biology, conservation biology, and taxonomy of caecilians. Furthermore, this dataset can be utilized to test ecological and evolutionary hypotheses at the individual level.

Cranial morphology in flying squirrels: diet, shape, and size disparity across tropical and temperate biomes

BackgroundSpecies richness increases gradually as latitude decreases, however, the explanation for this phenomenon remains unclear. Ecological hypotheses suggest that greater niche diversity in tropical biomes may facilitate the coexistence of a larger number of species. The close relationship between species morphology and ecology can lead to a greater morphological disparity in tropical biomes.MethodsIn this study, we used 2D geometric morphometric techniques on the ventral view of the cranium of flying squirrels (Pteromyini, Sciuridae) to determine the relationship between diet and cranial morphology and to evaluate if morphological disparity is higher in tropical biomes.ResultsThe results show that diet has a significant impact on cranial shape and size, with large, wide and robust crania in folivorous and generalist species, while frugivorous species tend towards smaller and narrower crania, and nucivorous have a wide variability. This suggests that biomes with more available dietary niches would show greater morphological disparity. However, we found no statistical differences in shape and size disparity among biomes or between observed and simulated disparity based on species richness.ConclusionsOur results show that there are not disparity differences between tropical and temperate biomes, even when temperate biomes are less rich than tropical ones, suggesting that the quantity of available niches may not be the key factor in generating morphological disparity. Instead, it could be the presence of extreme niches that demand specialised adaptations for exploitation, which might be of greater significance. A greater importance of size-changing adaptations would decrease shape disparity in biomes with many niches.

Distinct foliar fungal communities in Pinus contorta across native and introduced ranges: evidence for context dependency of pathogen release

Inter-continental study systems are crucial for testing ecological hypotheses, such as the widely cited Enemy Release Hypothesis (ERH), which seeks to explain the superior performance of plant species when they are introduced to new regions. Pinus contorta (lodgepole pine), native to North America, has been extensively introduced to Europe and the Southern Hemisphere, making it an ideal tree species for studying invasion hypotheses from a biogeographical perspective. We compared foliar fungal communities, especially pathogens, of P. contorta across two native–introduced region pairs (NIRPs): a northern NIRP (from Canada to Sweden) and a southern NIRP (from the USA to Patagonia), while also examining the differences between source plantations and invasion fronts within Patagonia. P. contorta underwent significant fungal community shifts and experienced pathogen release during its large-scale introduction from North America to Sweden and Patagonia. The fungal richness and relative abundance changes were more pronounced for the southern NIRP pair, where no closely related tree species to P. contorta are present in Patagonia. In Sweden, the presence of the phylogenetically related P. sylvestris and its associated local fungal community appears to play a role in influencing the foliar fungal communities associated with introduced P. contorta. In Patagonia, the incomplete co-invasion of fungal taxa from the USA emerges as a principal driver of the observed variability in fungal community composition and pathogen release following the introduction of P. contorta. In Patagonia, fungal community composition differences between source plantations and invasion fronts provided insufficient evidence that pathogen release occurs at this local scale. Integrating both biogeographical and phylogenetic perspectives, our study suggests that priority effects of local fungi appear to be a dominant community assembly process when introduction is done in a phylogenetically similar community; whereas, co-invasion of fungal communities is the dominant process in phylogenetically distant communities.

Selection, evolution and persistence of paleoecological systems

The Phanerozoic fossil record can be organized as a nested set of persistent paleoecological units, ranging from paleocommunities to Sepkoski’s Evolutionary Faunas. This paper argues that the basis for ecological persistence on geological timescales is rooted in the robustness of ecological communities, that is, the resistance and resilience of communities when perturbed by the environment. Here I present the Ecological Functional Networks Hypothesis (EFNH) that proposes that networks of species functions, or Ecological Functional Networks (EFNs), underlie ecological stasis and persistence, and that EFNs are both subject to selection and evolve. An EFN varies if the species composition and hence functional structures of its constituent communities vary, and EFNs may differ from each other based on the robustness of those constituent communities, numerical representation, and biogeographic distribution. That variation is subject to selection acting on EFN community composition, and determines both the persistence of an EFN and the differential persistence among multiple EFNs. Selection pressures on EFNs in turn exert top-down influence on species evolution and extinction. Evidence is presented to both establish the reality of EFNs in the fossil record, for example, community structures that persist even as species composition changes, and the selection of EFNs, which is apparent during and after episodes of severe biotic turnover such as mass extinctions. Finally, tests are suggested that make the EFNH falsifiable, including testing the correlation between EFNs or EFN emergent traits and geological persistence, and using models of paleocommunity dynamics to examine the relationship between community or EFN robustness and geological persistence. The tests should be applied broadly throughout the Phanerozoic and diverse environments. The EFNH is part of a growing body of hypotheses that address the selection, evolution and persistence of non-reproducing systems, including ecosystems and entire biospheres, and addresses those concepts on geological timescales.

Enabling high-throughput quantitative wood anatomy through a dedicated pipeline.

Throughout their lifetime, trees store valuable environmental information within their wood. Unlocking this information requires quantitative analysis, in most cases of the surface of wood. The conventional pathway for high-resolution digitization of wood surfaces and segmentation of wood features requires several manual and time consuming steps. We present a semi-automated high-throughput pipeline for sample preparation, gigapixel imaging, and analysis of the anatomy of the end-grain surfaces of discs and increment cores. The pipeline consists of a collaborative robot (Cobot) with sander for surface preparation, a custom-built open-source robot for gigapixel imaging (Gigapixel Woodbot), and a Python routine for deep-learning analysis of gigapixel images. The robotic sander allows to obtain high-quality surfaces with minimal sanding or polishing artefacts. It is designed for precise and consistent sanding and polishing of wood surfaces, revealing detailed wood anatomical structures by applying consecutively finer grits of sandpaper. Multiple samples can be processed autonomously at once. The custom-built open-source Gigapixel Woodbot is a modular imaging system that enables automated scanning of large wood surfaces. The frame of the robot is a CNC (Computer Numerical Control) machine to position a camera above the objects. Images are taken at different focuspoints, with a small overlap between consecutive imagesin the X-Y plane, and merged by mosaic stitching, into a gigapixel image. Multiple scans can be initiated through the graphical application, allowing the system to autonomously image several objects and large surfaces. Finally, a Python routine using a trained YOLOv8 deep learning network allows for fully automated analysis of the gigapixel images, here shown as a proof-of-concept for the quantification of vessels and rays on full disc surfaces and increment cores. We present fully digitized beech discs of 30-35cm diameter at a resolution of 2.25 m, for which we automatically quantified the number of vessels (up to 13 million) and rays. We showcase the same process for five 30cm length beech increment cores also digitized at a resolution of 2.25 m, and generated pith-to-bark profiles of vessel density. This pipeline allows researchers to perform high-detail analysis of anatomical features on large surfaces, test fundamental hypotheses in ecophysiology, ecology, dendroclimatology, and many more with sufficient sample replication.

Variation in Defensive Strategies of Brown Frogs against Conspecific and Heterospecific Alarm Cues

Chemical cues released upon injury play a crucial role in mediating antipredator responses in many aquatic species. Prey populations capable of exploiting information from different sources may enhance their fitness, although the factors determining this ability are not always clear. In this study, we investigated the antipredator responses to both conspecific and heterospecific injury cues (i.e., alarm cues) in three brown frog species: Rana dalmatina, Rana latastei, and Rana temporaria. We recorded two tadpole defensive behaviours: the proportion of time spent inactive and the distance covered. Responses to a native odonate predator were used as a positive control. Tadpoles of R. dalmatina showed a clear decrease in activity in response to both con- and heterospecific cues, similar to their reaction to predator cues. Tadpoles of R. latastei slightly decreased activity in response to alarm cues from both agile frog species but did not react to common frog cues. Finally, R. temporaria exhibited high sensitivity to conspecific cues and a weak response to heterospecific cues. The phylogenetic-relatedness hypothesis seems to explain the observations for both R. latastei and R. temporaria, while for R. dalmatina, the ecological coexistence hypothesis, given its overlapping distribution with the other two species, seems to better explain the data. However, since the invoked hypotheses are not mutually exclusive, further analysis of other populations of these species is necessary to confirm the generality of these findings and to better understand the role of environmental factors in shaping these antipredator responses.

Energy Availability and Spatial Effect Determine the Multi‐Scale Distributional Patterns of Multi‐Dimensional Diversity of Amphibians in China

ABSTRACTAimThis work focused on the multi‐scale distributional patterns of multi‐dimensional diversity among different groups of amphibians in China and systematically investigated the underlying environmental driving mechanisms by evaluating the performance of multiple ecological hypotheses.LocationChina.TaxonAmphibians.MethodsWe examined the effects of different spatial scales on the distribution patterns of taxonomic, functional and phylogenetic diversity of amphibians. Additionally, we assessed the relative importance of eight hypotheses in explaining these multi‐scale diversity patterns using hierarchical partitioning.ResultsThe spatial distributional patterns of amphibian taxonomic, functional and phylogenetic diversity exhibited scale dependency. Generally, the explanatory powers of hypotheses‐related covariates increased with larger spatial grain sizes. Across eight spatial grains (ranging from 0.25 to 2 arc‐degree), energy availability and spatial effect emerged as principal determinants for different amphibian groups in China. This was consistent for all species (469 species), as well as endemic, threatened and both endemic and threatened species.Main ConclusionMulti‐group biodiversity patterns are characterised by multi‐dimensional components and exhibit multi‐scale dependency. Our study highlights the significant influences of spatial scale on biodiversity pattern and on the explanatory power of ecological hypotheses. These findings provide valuable insights for future conservation planning of amphibians in China.

Preserving Sri Lanka&amp;rsquo;s indigenous healing heritage: An updated checklist of medicinal plants and conservation priorities

The fundamental information provided by plant checklists serves as the foundation for additional ecological, evolutionary, and biodiversity conservation hypothesis. Here, we compiled a comprehensive and taxonomically verified updated checklist of the medicinal plant species occurring in Sri Lanka. Updates include the addition of species recorded from Sri Lanka and the inclusion of synonyms and conservation status. Further, as many of these medicinal plants are collected from the wild, their conservation status is an important criterion in initiating future conservation actions. The present study focuses on collating all the documented updating of the existing checklists of medicinal plants occurring in Sri Lanka, documenting conservation status of these medicinal plants, identifying the most commonly used medicinal plant species, and the challenges associated in the medicinal herbal industry. A questionnaire survey was conducted with selected government Ayurveda and traditional practitioners, herbal collectors, and Ayurveda officers throughout the country. According to the findings, a total of 1476 plant species (Angiosperm: 1448, Gymnosperm: 04, Fern: 24) were recognized as plants with medicinal value used in Sri Lanka, with 969 of them being native in origin. Hundred and ninety-five of them are endemic to the country. About thirty-one percent of the native medicinal plants (n= 307 species) were identified as threatened. According to the survey, a total of 252 species (in 95 families) are utilized regularly, with the family Fabaceae predominating. Out of these, 50 species from 34 families are heavily utilized, and 34% of those are threatened species. The study also identified the most significant challenge faced by the medicinal plant industry among the various challenges it revealed. A compiled list of medicinal plants in Sri Lanka would provide an up-to-date inventory and essential information, crucial for initiating conservation efforts to preserve these valuable plant species in the country. Preserving medicinal plants in Sri Lanka is a complex endeavor that necessitates collaboration among government authorities, local communities, and a diverse array of stakeholders. It should balance the preservation of traditional healing practices and the sustainable use of these valuable plant resources.

Ethnobotanical Study of Medicinal Shrubs and Herbs Used by Forest-Fringe Communities of Ghana.

Documenting and quantitatively assessing medicinal plants and indigenous knowledge in different social contexts is critical in providing nature-based solutions to contemporary issues. Therefore, our study quantitatively evaluated medicinal shrubs and herbs in forest-fringe communities of Ghana and tested the versatility, ecological apparency and sociodemographic traits and knowledge dynamics hypotheses. Structured questionnaires, interviews and field visits were used to conduct an ethnobotanical survey involving 78 respondents, selected based on random and snowball sampling techniques. The data were analysed using quantitative indices such as indigenous knowledge index (IKI), species use value (SUV), informant agreement ratio (IAR) and ethnobotanical importance value (EIV). To test the versatility and sociodemographic traits and knowledge dynamics hypotheses, linear mixed-effects regressions were conducted, while one-way ANOVA was used to test the ecological apparency hypothesis. The Jaccard dissimilarity index was used to assess the degree of uniqueness of diseases treated by plants. We found 69 medicinal shrubs and herbs, belonging to 35 plant families, used to treat 101 diseases in the study area. Paullinia pinnata L. recorded the highest SUV (18.2) values, whereas Momordica charantia L. recorded the highest EIV (22.326) values. We found support for the versatility and sociodemographic traits and knowledge dynamics hypotheses, but no support for the ecological apparency hypothesis. The IAR of the 16 disease categories evaluated in this study ranged from 0.50 to 0.77. The Jaccard index showed that diseases treated by using introduced or native plants were 65.6% dissimilar. Our findings have implications for the achievement of SDG 3 (good health and well-being). We concluded that sociodemographic traits influence ethnobotanical knowledge dynamics, while plants with multiple useful parts are the most versatile and recommend the conservation of biodiversity to enhance diversity of treatment options.