The genus Encephalartos is entirely endemic to Africa. Like most cycad species, the genus is at risk of extinction. One of the threats jeopardizing the future of the genus is reproduction failure. Our objective is to investigate what predisposes Encephalartos species to reproduction failure. We collected functional traits of 430 individuals of Encephalartos villosus, including pre-dispersal seed predation and habitat types and elevation in Origi Gorge Nature Reserve in South Africa. Then, we analysed our data by fitting a structural equation model (SEM). Surprisingly, elevation does not predict pre-dispersal seed predations, adding to the inconsistent effects of elevation on seed predation. However, there was evidence of more predated seeds on plants with more leaves, fitting the patterns of resource concentration hypothesis which predicts more insect herbivores, particularly specialist herbivores, where food resources (e.g., leaves, flowers, fruits, and seeds) are abundant. We also found that more predated seeds are in open habitats, perhaps mirroring the specialist feeding behaviour of the weevil Antliarhinus zamiae feeding on the seeds of Encephalartos spp. Furthermore, taller plants tend to bear more predated seeds, potentially because taller plants are easy located by the weevil. Finally, large canopy correlates negatively with predated seeds, mirroring our finding of increased seed predation in open habitats. Our SEM explains 67% of the variations in pre-dispersal seed predations, suggesting that this metamodel provides insights into the predisposition of cycad seed to predations. Since open habitats correlate with more seed predation, we suggest that anthropogenic activities that contribute to open forest must be avoided if we are to limit seed predations.

Past forest use often has a long-term negative impact on the recovery of the original plant composition of semi-natural grasslands, which are known as a legacy effect. This study investigates the impact of seed dispersal limitations on the restoration of grassland plant diversity on ski slopes with past forest use, highlighting the negative legacy effect on biodiversity recovery. Focusing on ski areas, our research contrasts the vegetation on ski slopes originally created on semi-natural grasslands such as pasture (pasture slopes) and constructed by clearing secondary forests or conifer plantations (forest slopes). We examined species richness and abundance, considering seed dispersal mechanisms, grassland management history and seed source proximity. We reveal that the proximity to species-rich grassland sources and sustained management for more than 50 years are pivotal for the restoration of native grassland vegetation. Particularly, wind-dispersed species show significant recovery on slopes with a history of extensive grassland management, suggesting that both the duration of management and the proximity to seed sources are critical for overcoming the legacy effects of past forest use. Our findings emphasize the importance of considering seed dispersal dynamics and management history in the restoration and conservation of grasslands and their biodiversity, particularly in landscapes experiencing past human intervention.

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

Although the postdispersal function of fruit appendages has been reported, little is known about their protective/defensive functions. In this context, diaspores with appendages (persistent inner tepals and/or fruit wings) that experienced predispersal herbivory by insects in natural populations of Rheum nanum were investigated. The seed abortion percentage, seed and embryo masses, and germination of seeds from diaspores with different categories of insect herbivory were measured and compared. Predispersal insect herbivory of R. nanum diaspores was prevalent in the four natural populations, but the percentage of diaspores with appendages (persistent inner tepals and and/or fruit wings) damaged by insects was significantly higher than that of diaspores with the pericarp damaged by insects. Seeds from diaspores with gnawed appendages experienced significantly less damage than those with gnawed pericarps. Importantly, we conclude that fruit appendages of Rheum nanum help to mechanically protect developing seeds from predispersal insect herbivory.

Masquerade is a form of camouflage in which animals use their body size, shape, and coloration to resemble inanimate objects in their environment to deceive predators. However, there is a lack of experimental evidence to show that animals actively choose objects that match these body parameters. To explore how the Hainan four-eyed turtle, Sacalia insulensis, masquerades using suitable stones, we used indoor video surveillance technology to study the preferences of juvenile S. insulensis for stones of different sizes, shapes, and colors. The results indicated that under normal conditions, the turtles preferred larger oval or round brown stones. When disturbed (swinging the arm of a researcher back and forth above the experimental setup every hour to mimic a predator), the turtles showed a preference for brown stones that were closer to their size and oval in shape. These findings suggest that juvenile S. insulensis prefer stones that resemble their carapace size, shape, and color to masquerade when undisturbed, and that this preference is reinforced when they masquerade to reduce the risk of predation. To the best of our knowledge, this is the first study to provide evidence that vertebrates can recognize object shapes and selectively choose objects that resemble their own shape for masquerading to reduce predation risk.

1. Climate change is projected to increase the likelihood of extreme heat events, but it may also alter humidity levels, leading to the potential for coupled thermal and hydric stress. While increasing frequency and intensity of extreme heat events have been well-documented for their negative effects on species and their interactions, how humidity modulates the impacts of heat waves is currently unknown. 2. We investigated how humidity interacted with heat waves of different timings and durations to affect the life histories in an insect host-parasitoid interaction, comprising the Indian meal moth, Plodia interpunctella, and its endoparasitoid wasp, Venturia canescens. Hosts parasitised as 4th instar larvae and unparasitized hosts were maintained in a high humid (60.8% RH) or low-humid (32.5% RH) environment at a constant temperature of 28℃. They were then exposed to 38℃ heatwaves with a duration of 6 or 72 hours in either the 4th or 5th instar. 3. Humidity and heat waves did not affect the adult emergence of unparasitized hosts, but longer heat waves and lower humidity increased the probability that host adults emerged from parasitized hosts, indicating the negative effect of these conditions on the survival of parasitoids. Furthermore, juvenile development time and body size of hosts and parasitoids responded differently to timing and duration of heat waves, and high humidity decreased larval development time of unparasitized hosts and increased the size of both hosts and parasitoids. In addition, humidity negatively interacted with larval stage and duration of heat waves to affect the size of unparasitized hosts, but this effect was not found in parasitoids. 4. Our results show that humidity modulates the life history of hosts and parasitoids, highlighting the importance of humidity in maintaining host-parasitoid interactions. Humidity should be considered when predicting the impact of temperature extremes on species’ population dynamics and their interactions.

Experiments have shown that predation risk effects on prey fitness can be highly contingent on environmental conditions, suggesting a potential difficulty in generalizing risk effects on prey abundance in natural settings. We examine this problem with a novel approach. Rather than study the influence of a particular controlled factor, we examined the influence on risk effects of study conditions that would likely be deemed inconsequential, i.e., to factors incidental to a study. If such incidental factors influence can influence the magnitude and even direction of risk effects, this suggests risk effects on prey population density are profoundly influenced by context in natural communities. We compared results of multiple experiments conducted under similar conditions, objectives, measurables and implementation, and which captured much of the complexity of natural systems (e.g., they were performed with diverse prey assemblages (≥11 taxa) over multiple prey generations). There was consistently no risk effect of fish on some zooplankton prey abundance, but great variability effect on other prey including combinations of negative, absent or positive effects on the same prey’s abundance. We review mechanisms that could underlie these results. Our findings highlight the need to understand the mechanisms linking trait responses to fitness and, ultimately, to abundance of prey, to understand risk effects across studies and systems.

Rosa laevigata, being the only species in the Rosa genus within the Rosaceae family, possesses significant nutritional and medicinal value. Moreover, it exhibits a vast genetic diversity, particularly among wild populations. Such abundant genetic variability provides favorable conditions for the cultivation, development, and utilization of superior Rosa laevigata varieties in China. In this research, 265 records of geographic distribution and 47 environmental variables were collected. These data were then combined with the future climate predictions generated by the general circulation model (GFDL-ESM4) and three Shared Socio-economic Pathways (SSP1_RCP2.6, SSP3_RCP7.0, SSP5_RCP8.5) to forecast the current and future geographical distribution of Rosa laevigata. The results indicate a consistently high yield of Rosa laevigata in China, both presently and in the future. The optimal parameter combination, determined by using the corrected Akaike Information Criterion as the index, was selected as the feature class LQ with a regularized multiplier of 1.0. According to these findings, Rosa laevigata is currently distributed across the southern provinces of China, with Chongqing, Sichuan, Guizhou, and Guangxi being the most suitable regions. Furthermore, compared to the current climatic conditions, the growing area of Rosa laevigata is expected to expand in the future. This expansion primarily occurs in a north-western direction, resulting in an overall increase in the plant’s distribution area. Notably, Qinghai experienced a reduction in its low-impact zone area. Several variables such as annual potential evapotranspiration (annualPET), isothermality (Bio3), mean daily maximum air temperature of the warmest month (Bio5), precipitation seasonality (Bio15), and snow cover days (scd), among others, greatly influence the potential distribution of Rosa laevigata.

Phenotypic covariation among suites of traits may constrain or promote diversification both within and between species, yet few studies have empirically investigated this relationship. In this study we investigate whether phenotypic covariation of craniofacial traits is associated with diversification in an adaptive radiation of pupfishes found only on San Salvador Island, Bahamas (SSI). The full radiation of pupfishes includes generalist, durophagous, and lepidophagous pupfish species. We compare phenotypic variation and covariation (i.e., P matrix) between 1) allopatric populations of generalist pupfish from neighboring islands and estuaries in the Caribbean, 2) SSI pupfish populations not containing the full radiation of fishes, and 3) SSI pupfish populations containing the full radiation in sympatry. Additionally, we interrogate the patterns observed in the P-matrices of two independent F2 hybrid crosses derived from the two most morphologically distinct members of the radiation to make inferences about the underlying mechanisms contributing to the variation in craniofacial traits in SSI pupfishes. We found that the P matrix of SSI generalist populations not found in sympatry with specialists exhibited higher levels of mean trait correlation, constraints, and integration with simultaneously lower levels of flexibility compared to generalist populations on other Caribbean islands and sympatric populations of all three species found on SSI. We also document that while many craniofacial traits appear to be produced via additive genetic effects, variation in key traits such as head depth, maxilla length, and lower jaw length may be produced via non-additive genetic mechanisms. Ultimately, this study suggests that differences in phenotypic covariation significantly contribute to producing and maintaining organismal diversity.

AIM: Changes in bird clutch and egg sizes across geographical gradients are issues often debated among ecologists, where latitudinal cline is a central issue in several discussions. There is an understanding that these patterns are primarily driven by climatic characteristics, where latitude acts as a proxy. Many studies attempt to analyse local climatic factors causing variation in life history traits but face methodological limitations. Here, as few studies have been able to, we achieve a robust dataset that covers a large territorial extent to answer this main biogeographical question. LOCATION: American continent (New World). METHODS: We approached the geographically widespread Tyrannus genus (kingbirds) and collected breeding data from 35 scientific egg collections in South and Central America, USA, and Europe. After several data checking layers, including spatial, temporal and taxonomic checking, we analysed the relationship between kingbird’s clutch and egg sizes with different climatic scales. RESULTS: The analyses of 1358 clutches and 4750 eggs confirmed that kingbird’s clutch and egg sizes increase towards the poles. Both breeding traits vary according to main climates, regional sub-climates, and local temperature and precipitation conditions. Regions with more climatic variation had the largest clutches, but sites with colder winters did not have the largest clutches. Tyrannus egg size increased in environments with less extreme dry periods. The increase of egg size with latitude can be explained by the significant relationship between larger eggs with sites with lower temperatures. MAIN CONCLUSIONS: Our findings suggest a robust correlation of residual variation in breeding traits with climatic conditions at both regional and local levels. Highly locally adapted species using climatic parameters as cues should also respond to interannual weather variations. With current discussions about climate change’s effects on ecosystems, the insights provided in this work can assist in understanding how species will cope under future climate scenarios.

Urbanization is one the main threats to biodiversity and its effects are projected to increase in magnitude, hence stressing the importance to better understand how urbanization may affect vital ecosystem services, such as pollination. Studies on the impact of urbanization have largely focused on only one aspect of the pollination process (e.g. pollinator visitation, pollen deposition), potentially misrepresenting the full complexity of urbanization effects on pollination services. Evaluating impacts across multiple components of pollination can also help pinpoint the underlying mechanisms driving urbanization effects. This study evaluates how urbanization affects multiple aspects of the pollination process in common milkweed populations, including pollinator community composition and visitation rate, pollen removal and deposition on stigmas. Urbanization altered floral visitor composition, with small bees having a larger presence in urbanized areas. Insect visitation rate and pollen removal were also higher in more urbanized areas, perhaps suggesting a positive impact of urbanization as predicted by the intermediate disturbance hypothesis. However, pollen deposition on stigmas, which is a key component of fertilization success, was not different between natural and urbanized sites. Our findings highlight the complexity evaluating urbanization effects on pollination, as these likely depend on the specific aspect of pollination evaluated and on the of the intensity of disturbance. Our study thus stresses the importance of evaluating multiple components of the pollination process in order to fully understand overall effects and the mechanisms underlying urbanization effects on this vital ecosystem service

Livestock grazing can strongly determine how grasslands function and their role in carbon cycle. However, how ecosystem carbon exchange responds to grazing and the underlying mechanisms remain unclear. We measured ecosystem carbon fluxes to explore the changes in carbon exchange and their driving mechanisms in a 16-year long term experiment with different grazing intensities in a desert steppe grassland. We found that grazing intensity influenced above- and belowground biomass during the peak growing season, primarily by decreasing shrubs and semi-shrubs and perennial forbs. Furthermore, alter patterns of net ecosystem exchange primarily via their negative influence on the biomass of shrub and semi-shrub. In addition, grazing-induced reduction belowground biomass, as well as in total plant nitrogen and soil ammonium nitrogen, can strongly influence ecosystem carbon exchange and soil respiration. When nitrogen is lost from the soil due to grazing, plants reallocate resources belowground to maintain growth and development, thus promoting photosynthesis and respiration. Our study indicates that soil available nitrogen and shrubs and semi-shrubs are important factors in regulating ecosystem carbon exchange under grazing disturbance in the desert steppe, which provide a basis for grazing management.

1. Fucoid forests are areas dominated by marine brown seaweed in the taxonomic order Fucales that, like the better-known marine foundation species - corals, kelps, seagrasses, salt marshes, and mangroves - are threatened by anthropogenic stressors. 2. Fucoid forests are fabulous and important because they, like the better-known marine foundation species (i) span large areas, bioregions, and ecosystems, (ii) provide ecological functions such as high productivity and biodiversity, and (iii) support a variety of ecosystem services including habitat for commercial fishery species, food for humans and cultural values. 3. Fucoid forests are, based on a new citation analysis, forgotten worldwide, because they are described orders of magnitude less than the better-known marine foundation species, in ecology and marine biology textbooks, in Google Scholar and Scopus databases over scientific literature, and in recent reports and reviews about seaweed forests. 4. Fucoid forests would be less forgotten if more people acknowledge their biological importance and societal value more often and equate their importance to that of the better-known marine foundation species. Perhaps name-recognition would also improve if fucoids are unified under a non-taxonomic common name across teaching, research, management, and conservation, like the better-known marine foundation species. We agree with the marine scientists that have used ‘rockweed’ as such a common name to describe all fucoids, but other seaweed-experts disagree because they (a) do not agree fucoids are forgotten, (b) dislike common names or (c) argue rockweed should only describe fucoid species in the family Fucaceae.

The importance of scale when investigating ecological patterns and processes is recognised across many species. In marine ecosystems, the processes that drive species distribution have a hierarchical structure over multiple nested spatial and temporal scales. Hence, multi-scale approaches should be considered when developing accurate distribution models to identify key habitats, particularly for populations of conservation concern. Here, we propose a modelling procedure to identify the best spatial and temporal scale for each modelled and remotely sensed oceanographic variable to model harbour porpoise (Phocoena phocoena) distribution. Harbour porpoise sightings were recorded during dedicated line-transect aerial surveys conducted in the summer of 2016, 2021 and 2022 in the northeast Atlantic. Binary generalised additive models were used to assess the relationships between porpoise presence and oceanographic variables at different spatial (5, 20 and 40 km) and temporal (daily, monthly and across survey period) scales. Selected variables included sea surface temperature, thermal fronts, chlorophyll-a, sea surface height, mixed layer depth and salinity. A total of 30,514 km was covered on-effort with 216 harbour porpoise sightings recorded. Overall, the best spatial scale corresponded to the coarsest resolution considered in this study (40 km), while porpoise presence showed stronger association with oceanographic variables summarised at a longer temporal scale (monthly and averaged over survey period). Habitat models including covariates at coarse spatial and temporal scales may better reflect the processes driving availability and abundance of prey resources at the large scales covered during the surveys. These findings support the hypothesis that a multi-scale approach should be applied when investigating species distribution. Identifying suitable spatial and temporal scale would improve the functional interpretation of the underlying relationships, particularly when studying how a small marine predator interacts with its environment and responds to climate and ecosystem changes.

1. Herbivores adopt foraging strategies to maximize efficiency in diverse, resource-constrained environments. However, the effectiveness of these strategies may be more constrained by their capacity for energy cost rather than their ability to acquire resources. The swift utilization of resources during acquisition is crucial for optimizing energy conversion efficiency in animals. Nonetheless, the energy expended in this process inherently limits food conversion efficiency (FCE), an aspect that remains insufficiently explored in current research. 2. In this study, we introduced a concept framework that integrates harvest rate (HR) and energy expenditures (EE) into evaluating herbivore FCE. Utilizing high-resolution tri-axial accelerometry within a grazing treatments platform, we analyzed the behaviors of herbivores (Ovis aries) to determine the energy costs and time allocation for both lamb and dry ewe groups. 3. Our analysis demonstrated an inverse correlation between HR and EE, exhibiting both positive and negative influences on FCE. Notably, the impact of EE was more pronounced in larger-sized grazers (dry ewes), while HR significantly influenced smaller-sized grazers (lambs). However, the interaction effects between these variables tended to neutralize the variations in FCE observed across both groups. 4. Our research highlights how the behavioral patterns of grazers, in terms of resource acquisition and relative energy costs, are pivotal in determining resource utilization efficiency. Additionally, it reveals the trade-offs in these behaviors, which transition from being beneficial to restrictive as the body grows. This finding substantiates the theory that the behavior of herbivores is a reliable predictor of their efficiency in resource utilization.

Climate change is projected to alter the structure of plant communities due to increasing temperatures and changes to precipitation patterns, particularly in midlatitude dryland ecosystems. Modifications to climatic suitability may lead to major community changes such as altered dominant plant functional types. Previous studies have indicated that climatic suitability is likely to increase for C4 grasses and decrease for C3 grasses in the western United States. However, if no C4 grass species currently exist to serve as a propagule source, expansion into areas of increased suitability will be limited. We conducted a field and modeling study in the Upper Green River Basin (UGRB) of western Wyoming to determine if 1) C4 grasses are present to provide a propagule source and 2) C4 grasses are likely to increase in importance relative to C3 grasses due to climatic changes. We searched 44 sites for C4 grasses to establish presence, and modeled suitability at 35 sites using 17 Global Climate Models, two greenhouse gas Representative Concentration Pathways (RCPs; 4.5 and 8.5), and two time-periods (mid- and late-century; 2030-2060 and 2070-2099, respectively). We found C4 grasses at 10 of the 44 sites, indicating that there is a present propagule source. Our model projected increases in suitability for both C3 and C4 grasses across sites for all RCPs and time-periods. In the mid-century RCP 4.5 scenario, the C3 functional type increased in projected biomass in 29 of 35 sites, and the C4 type increased in 31 sites. In this scenario, C3 grasses increased in projected biomass by a median 4 gm-2 (5% change), and C4 grass biomass increased by a median 8 gm-2 (21% change). Our study suggests that climate change will increase climatic suitability for grasses across the UGRB, and that all requirements are in place for C4 grasses to increase in abundance.

At deep-sea hydrothermal vents, deprived of light, most living communities are fuelled by chemosynthetic microorganisms. These can form symbiotic associations with metazoan hosts, which are then called holobionts. Among these, two endemic shrimp of the Mid-Atlantic Ridge (MAR), Rimicaris exoculata and Rimicaris chacei are colonized by dense and diversified chemosynthetic symbiotic communities in their cephalothoracic cavity and their digestive system. Although both shrimp harbor similar communities, they exhibit widely different population densities, distribution patterns at small scale and diet, as well as differences in post-settlement morphological modifications leading to the adult stage. These contrasting biological traits may be linked to their symbiotic development success. Consequently, key questions related to the acquisition of the symbionts and the development of the holobiont are still open. Here we examined symbiotic development in juveniles of R. exoculata and R. chacei from TAG and Snake Pit using 16S metabarcoding to identify which symbiotic lineages are present at each juvenile stage. In addition, we highlighted the abundance and distribution of microorganisms at each stage using Fluorescence in situ Hybridization (FISH) and Scanning Electron Microscopy (SEM). For the first time, Candidatus Microvillispirillaceae (midgut tube), Candidatus Foregutplasma rimicarensis and Candidatus BG2-rimicarensis (foregut) were identified in late juveniles stages. However, these lineages were absent in early juveniles stages, which coincides for the midgut tube with our observations of an immature tissue, devoid of microvilli. Conversely, symbiotic lineages from the cephalothoracic cavity were present from the earliest juvenile stages of both species and their overall diversities were similar to those of adults. These results suggest different symbiont acquisition dynamics between the cephalothoracic cavity and the digestive system, which may also involve distinct transmission mechanisms.

Anopheles mosquitos are the primary vectors for the rapid spread of malaria in Limpopo, South Africa, negatively impacting all malaria elimination agenda; particularly for a country with vector control as one of the major malaria elimination strategies. The implementation of vector control strategies, however, depends on the accurate identification of mosquito vectors, which has been lacking in Limpopo as a result of earlier studies that mainly relied on morphological identification of vectors, which has numerous drawbacks that lead to misidentification of mosquitoes, thus resulting in the development and assignment of ineffective control strategies. All this together set back elimination strategies and programs. The present study therefore aimed to molecularly identify mosquitoes collected from various regions within Limpopo province. This was accomplished by examining genetic composition of mosquitos from different regions within Limpopo province, using molecular genetics techniques such as 18S rDNA-based PCR analysis, 18S rDNA sequencing, etc. This investigation was successful since 18S rDNA was able to identify every one of the 42 mosquito samples that were analysed, revealing that the samples belonged to 7 different Anopheles species and the majority of the species were molecularly demonstrated to have been misidentified morphologically. The outcomes of the molecular analysis, which involved comparing the query sequences to the sequences in GenBank, were supported by the close relationship among mosquitoes of the same species in maximum likelihood trees and the presence of high to 100% bootstrap support values, giving confidence to conclude that mosquitoes of the same species under study are genetically related. Due to a number of constraints covered in this study, morphological identification of mosquitoes is prone to misidentification of species, hence genetic characterization is recommended to be used as a confirmatory approach in the identification of the species.