Ecological Communities Research Articles

Wind Is a Primary Driver of Fungal Dispersal Across a Mainland-Island System.

Dispersal is one of the main processes shaping ecological communities. Yet, for species-rich communities in natural systems, the role of dispersal in community assembly remains relatively less studied compared to other processes. This is the case for fungal communities, for which predictable knowledge about where and how the dispersal propagules move across space is largely lacking. We sampled fungal communities at their dispersal stage in a lake mainland-island system in Finland, using a regular grid of 18 × 18 km, including sites on the mainland, islands and over the water. Fungal communities were screened by applying DNA barcoding to air samples. To assess the factors determining fungal dispersal, we modelled aerial fungal communities with a joint species distribution model, including spore traits, weather-related predictors, and spatial predictors. We found that the probability of occurrence of most species (and consequently species richness measured as the number of OTUs per sample) was lower in low-connectivity sites (water and isolated islands) compared to high-connectivity sites (mainland). There was a strong phylogenetic signal in how the fungal species responded to connectivity, indicating that some taxonomic groups are more dispersal limited than others, although such responses were not structured by their trophic guilds. Furthermore, wind speed influenced how species with different spore sizes responded to connectivity: in low-connectivity sites, species with large sexual spores were detected especially when wind was high, whereas, in high-connectivity sites, they were detected especially when wind was low. This study demonstrates that air fungal dispersal might be more predictable than previously considered and contributes to the mechanistic understanding of fungal air dispersal.

Major global ports alter light regimes for marine biofouling communities.

Globally, there are more than 17,000 cargo-handling ports that are expected to double in capacity by 2030. Overwater structures are common in ports and create permanently shaded environments that can produce ecological shifts from primary-producer to consumer dominated communities. Yet, the extent of these structures across ports and their impact on light conditions and associated communities in different areas beneath has not been quantified. Here we quantified the spatial extent of overwater structures in 17 major global ports and found a total estimated area of >13.96km2 of seabed to be shaded. We then surveyed in situ overwater structures in Sydney Harbour, Australia, to directly measure the impacts of these structures on light intensity and marine communities. We show that overwater structures can reduce light levels between 37 and 83% and shift ecological communities from mixed algal-invertebrate communities towards invertebrate dominance. This study provides critical evidence of the impacts of port structures on natural light regimes and ecological communities, and highlights the need for sustainable solutions (e.g. light penetrating surfaces, artificial light) to restore natural light regimes to global ports to maintain algal communities and associated ecosystem services in areas that are shaded by overwater structures.

Bat coronavirus surveillance across different habitats in Yucatán, México.

Bats, which play a vital role in maintaining ecosystems, are also known as natural reservoirs of coronaviruses (CoVs), thus have raised concerns about their potential transmission to humans, particularly in light of the emergence of MERS-CoV, SARS-CoV, and SARS-CoV-2. The increasing impact of human activities and ecosystem modifications is reshaping bat community structure and ecology, heightening the risk of the emergence of potential epidemics. Therefore, continuous monitoring of these viruses in bats is necessary. Despite the rich diversity of bats species in México, few studies have been conducted to search for CoVs in these group of mammals. In the present study we conducted CoV surveillance across previously unexplored sites in the state of Yucatán, a state located within the ecologically diverse Yucatán Peninsula, a tropical region undergoing pronounced anthropogenic changes, including deforestation, agricultural expansion and urbanization. We captured 191 bats between 2021 and 2022 in three different habitats: diversified rural (Tzucacab), rural (Tizimín) and urban (Mérida). Molecular analyses had revealed a 5.4% CoV prevalence, with the diversified rural site exhibiting a notably elevated rate (26.3%). Subsequent sequencing and phylogenetic assessment revealed four distinct Alphacoronavirus genotypes, indicating host-specific clustering among Phyllostomidae bats. Notably, one was detected for the first time in a Sturnira species. Our findings suggest a reduced likelihood of transmission of these viruses to humans or other species, evidenced by clustering patterns and sequence dissimilarity with known CoVs. We emphasize that maintaining sustained virus surveillance in bats is crucial to understanding viral diversity and identifying potential risks to human and animal health.

Linking plant genes to arthropod community dynamics: Current progress and future challenges.

Plant genetic variation can play a key role in shaping ecological communities. Prior work investigated the effects of coarse-grain variation among plant genotypes on their diverse arthropod communities. Several recent studies, however, have leveraged the boom of genomic resources to study how genome-wide plant variation influences associated communities. These studies have demonstrated that the effects of plant genomic variation are not just detectable but can be important drivers of arthropod communities in natural ecosystems. Field common gardens and lab-based mesocosm experiments are also revealing candidate genes that have large effects on arthropod communities. While we highlight these exciting results, we also discuss key challenges to address in future research. We argue that a major hurdle lies in the integration of genomic tools with hierarchical models of species communities (HMSC). HMSC are generative models that provide the opportunity to not only better understand the processes underlying community change, but to also predict community dynamics. We also advocate for future research to apply models of genomic prediction to explore the genetic architecture of arthropod community phenotypes. We hypothesize that this genetic architecture will follow an exponential distribution, where a few genes of large effect, but also many genes of small effect, contribute to variation in arthropod communities. The next generation of studies linking plant genes to community dynamics will require interdisciplinary collaborations to build truly predictive models of plant genetic and arthropod community change.

Artificial light at night reduces predation and herbivory rates in a nearshore reef.

Artificial light at night (ALAN) is an escalating anthropogenic stressor that can affect ecological communities over a range of spatial scales by altering key ecological processes, such as predation and herbivory. Shallow subtidal reefs are highly diverse and productive habitats that are vulnerable to ALAN. We investigated rates of consumption by fish (predation and herbivory) under different light treatments (ALAN, dark and daylight conditions) using standardised bioassay methods, i.e. squidpops and Ulva pops in situ. We also used GoPros to record predator identity, number of strikes and time to strike in ALAN and daylight treatments. Contrary to previous studies, we found that predation and herbivory rates were significantly lower in ALAN treatments than in daytime and dark treatments. The highest predation and herbivory rates were observed in daytime treatments. The identity of predator species, time to strike and number of strikes also differed between daytime and ALAN treatments. Due to low light conditions, dark treatments were not filmed. Our findings suggest that ALAN can alter predation in unexpected ways, depending on the environmental conditions and species affected. Future coastal management strategies need to account for light pollution as a major stressor to preserve valuable ecological resources.

Rebuilding microbiomes: Facilitating animal-microbe interactions through ecological restoration and rewilding.

Restoring degraded ecosystems is a complex process that involves rebuilding myriad species interactions that make a functioning ecological community. Microorganisms are key to robust ecological restoration - their mutualisms with above-ground communities drive community assembly and increase host fitness. However, microbes are largely ignored during restoration and there is a significant knowledge gap regarding how to restore their interactions with above-ground communities. Here, we tested whether we could enhance interactions between microbes and their invertebrate hosts by reintroducing, or 'rewilding', leaf litter and soil from remnant sites containing species-rich microbial communities, into species poor and geographically isolated revegetated farmland sites. We sequenced both the soil microbiome and the gut microbiome of two dominant invertebrates: native Ecnolagria grandis beetles and introduced Ommatoiulus moreleti millipedes. We sampled 35 months after the initial reintroduction event in remnant (conservation area and source of litter and soil transplant), rewilding transplant (revegetation site with transplant), and control sites (revegetation with no transplant). We found that even ∼20 years after revegetation, restoration sites had distinct microbial communities compared to remnant areas. Although litter and soil transplants failed to increase soil microbial community similarity towards remnant sites, we found marked increases in the diversity and richness of E. grandis microbiomes and a greater degree of overlap with soil microbiomes within rewilding transplant sites relative to control sites. In contrast, there were few changes in O. moreleti microbiomes. Overall, our results suggest rewilding can recover some species interactions during restoration but may not influence all host-microbe systems.

EKOLOGI KALDE FEMINISME MELAYU DETERMENISME, EKOTURISME MELAYU DAMPAK GLOBALISASI

This study aims to examine the relationship between Kalde ecology, Malay feminism, cultural determinism, ecotourism, and the impact of globalization on Malay society. This study is qualitative with a descriptive-analytical design that aims to explore in depth the views and experiences of Malay society in managing ecosystems, the role of women, and the impact of global culture. This study also explores the potential of Malay ecotourism as a tool to strengthen ecological sustainability and community economic empowerment, amidst the flow of globalization that brings significant changes to local cultural and economic values. The research methods used include in-depth interviews, participant observation, and surveys to obtain data from Malay society involved in ecotourism activities. The results of the study are expected to provide insight into how ecology and feminism are interconnected in maintaining cultural and environmental sustainability, and how the impact of globalization affects Malay cultural identity.

Warming and cooling catalyse widespread temporal turnover in biodiversity.

Turnover in species composition through time is a dominant form of biodiversity change, which has profound effects on the functioning of ecological communities1-4. Turnover rates differ markedly among communities4, but the drivers of this variation across taxa and realms remain unknown. Here we analyse 42,225 time series of species composition from marine, terrestrial and freshwater assemblages, and show that temporal rates of turnover were consistently faster in locations that experienced faster temperature change, including both warming and cooling. In addition, assemblages with limited access to microclimate refugia or that faced stronger human impacts on land were especially responsive to temperature change, with up to 48% of species replaced per decade. These results reveal a widespread signal of vulnerability to continuing climate change and highlight which ecological communities are most sensitive, raising concerns about ecosystem integrity as climate change and other human impacts accelerate.

The impact of structured higher-order interactions on ecological network stability

The impact of higher-order interactions, those involving more than two species, is increasingly appreciated as having the potential to strongly influence the dynamics of complex ecological systems. However, although the critical importance of the structure of pairwise interaction networks is well established, studies of higher-order interactions still largely assume random structures. Here, we demonstrate the strong impact of structured higher-order interactions on simulated ecological communities. We focus on effects caused by interaction modifications within food webs, where a consumer resource interaction is modified by a third species, and for which plausible structures can be hypothesised. We show how interaction modifications introduced under a range of non-random distributions may impact the overall network structure. Local stability and the size of the feasibility domain are critically dependent on the inter-relationship between trophic and non-trophic effects. Where interaction modifications are structured into mutual interference motifs (associated with consumers switching between resources) synergistic signs and topological effects have particularly consequential impacts. Furthermore, we show that previous results of the impact of higher-order interactions on diversity-stability relationships can be reversed when higher-order interactions are structured, not random. Empirical data on interaction modifications will be a key part of improving understanding the dynamics of communities, particularly the distribution of interaction modification signs across networks.

Biodiversity within phytoplankton-associated microbiomes regulates host physiology, host community ecology, and nutrient cycling.

As evidence is emerging of the key roles that host-associated microbiomes often play in regulating the physiology, fitness, and ecology of their eukaryotic hosts, human activities are causing declines in biological diversity, including within the microbial world. Here, we use a multifactorial manipulative experiment to test the effects of declining diversity within host microbiomes both alone and in tandem with the effects of emerging global changes, including climate warming and shifts in nutrient bioavailability, which are inflicting increasing abiotic stress on host organisms. Using single-celled eukaryotic phytoplankton that harbor an external microbiome as a model system, we demonstrate that diversity within host-associated microbiomes impacts multiple tiers of biological organization, including host physiology, the host population and community ecology, and ecosystem nutrient cycling. Notably, these microbiome diversity-driven effects became magnified in abiotically stressful environments, suggesting that the importance of microbiome diversity may have increased over time during the Anthropocene.

Ecological filters shape arbuscular mycorrhizal fungal communities in the rhizosphere of secondary vegetation species in a temperate forest.

The community assembly of arbuscular mycorrhizal fungi (AMF) in the rhizosphere results from the recruitment and selection of different AMF species with different functional traits. The aim of this study was to analyze the relationship between biotic and abiotic factors and the AMF community assembly in the rhizosphere of four secondary vegetation (SV) plant species in a temperate forest. We selected four sites at two altitudes, and we marked five individuals per plant species at each site. Soil rhizosphere samples were collected from each SV plant species, during the rainy and dry seasons. Soil samples from the rhizosphere of each plant species were analyzed for AMF spores, organic matter (OM), pH, soil moisture, and available phosphorus, and nitrogen. Three ecological filters influenced the AMF community assembly: host plant identity, abiotic factors, and AMF species co-occurrence. This assembly consisted of 61 AMF species, with different β-diversity values among plant species across seasons and altitudes. Canonical correspondence analysis revealed that AMF community composition is linked to OM and available P and N, with only a few AMF species co-occurring, while most do not. Our study highlights how ecological filters shape AMF structure, which is essential for understanding how soil and environmental factors affect AMF in SV plant species across seasons and altitudes.

A Novel Computational Model of Insulin-Glucose Chaotic System to representβ-Cells Effects, Type 1 Diabetes Mellitus (T1DM) and Hyperglycemia

The math model is a very good way to look at how glucose and insulin work together. This work brings in a new math model of control of insulin and glucose in the human body, based on the well-known Prey-Predator model. Chaos is one of the known things in bio systems and hard systems from the info that is out there. The results of this study match up similarly with the known results, showing that the insulin-glucose control system is a very hard one in different backgrounds. This study, then, might make an extra part of seeing how reg system work in diabetes; mainly Type 1 diabetes and hyperinsulinemia.

Symmetry-based approach to species-rich ecological communities

Symmetry-based approach to species-rich ecological communities

Bowel preparation before colonoscopy: Consequences, mechanisms, and treatment of intestinal dysbiosis.

The term "gut microbiota" primarily refers to the ecological community of various microorganisms in the gut, which constitutes the largest microbial community in the human body. Although adequate bowel preparation can improve the results of colonoscopy, it may interfere with the gut microbiota. Bowel preparation for colonoscopy can lead to transient changes in the gut microbiota, potentially affecting an individual's health, especially in vulnerable populations, such as patients with inflammatory bowel disease. However, measures such as oral probiotics may ameliorate these adverse effects. We focused on the bowel preparation-induced changes in the gut microbiota and host health status, hypothesized the factors influencing these changes, and attempted to identify measures that may reduce dysbiosis, thereby providing more information for individualized bowel preparation for colonoscopy in the future.

Asynchronous effects of heat stress on growth rates of massive corals and damselfish in the Red Sea.

Climate change is imposing multiple stressors on marine life, leading to a restructuring of ecological communities as species exhibit differential sensitivities to these stressors. With the ocean warming and wind patterns shifting, processes that drive thermal variations in coastal regions, such as marine heatwaves and upwelling events, can change in frequency, timing, duration, and severity. These changes in environmental parameters can physiologically impact organisms residing in these habitats. Here, we investigate the synchrony of coral and reef fish responses to environmental disturbance in the Red Sea, including an unprecedented combination of heat stress and upwelling that led to mass coral bleaching in 2015. We developed cross-dated growth chronologies from otoliths of 156 individuals of two planktivorous damselfish species, Pomacentrus sulfureus and Amblyglyphidodon flavilatus, and from skeletal cores of 48 Porites spp. coral colonies. During and immediately after the 2015 upwelling and bleaching event, damselfishes exhibited a positive growth anomaly but corals displayed reduced growth. Yet, after 2015-2016, these patterns were reversed with damselfishes showing a decline in growth and corals rebounding to pre-disturbance growth rates. Our results reveal an asynchronous response between corals and reef fish, with corals succumbing to the direct effects of heat stress, and then quickly recovering when the heat stress subsided-at least, for those corals that survived the bleaching event. Conversely, damselfish growth temporarily benefited from the events of 2015, potentially due to the increased metabolic demand from increased temperature and increased food supply from the upwelling event, before declining over four years, possibly related to indirect effects associated with habitat degradation following coral mortality. Overall, our study highlights the increasingly complex, often asynchronous, ecological ramifications of climate extremes on the diverse species assemblages of coral reefs.

Ecological communities in white‐sand Amazonian rainforests are sensitive to deforestation—A dung beetle case

Abstract Campinarana is a fragile white‐sand rainforest ecosystem in Amazonia, where mining activities have been an important driver of landscape transformation, threatening biodiversity. Despite its importance for biodiversity, few studies have investigated insects' response to environmental disturbance in campinaranas. Here, we assess the differences between the dung beetle assemblages of undisturbed and disturbed campinaranas. The studied campinaranas differ substantially in their vegetation structure, the disturbed one strongly affected by mining activities. Dung beetle taxonomic diversity, abundance, biomass, and assemblage structure (species' distribution and relative abundances) from total and functional group perspective and indicator species were recorded in undisturbed and disturbed campinaranas. A total of 1592 beetles belonging to 42 species were collected in undisturbed campinaranas and 459 beetles from 11 species in disturbed campinaranas. Undisturbed campinaranas encompassed higher diversity, abundance, number of indicator species, and biomass, and their assemblages' structure were distinct from disturbed campinaranas. The abundance of roller dung beetles was the only parameter that was not affected by habitat type. Our results suggest that undisturbed campinaranas host sensitive ecological communities, with most of the species unable to cope with the changes brought by mining activities. In addition, dung beetle species can be a useful indicator for monitoring environmental disturbance in campinaranas. Considering the extension of the latter across the Amazon, this study provides information to support public policies to mitigate losses caused by deforestation in this hyperdiverse area.

Clustered warming tolerances and the nonlinear risks of biodiversity loss on a warming planet.

Anthropogenic climate change is projected to become a major driver of biodiversity loss, destabilizing the ecosystems on which human society depends. As the planet rapidly warms, the disruption of ecological interactions among populations, species and their environment, will likely drive positive feedback loops, accelerating the pace and magnitude of biodiversity losses. We propose that, even without invoking such amplifying feedback, biodiversity loss should increase nonlinearly with warming because of the non-uniform distribution of biodiversity. Whether these non-uniformities are the uneven distribution of populations across a species' thermal niche, or the uneven distribution of thermal niche limits among species within an ecological community, we show that in both cases, the resulting clustering in population warming tolerances drives nonlinear increases in the risk to biodiversity. We discuss how fundamental constraints on species' physiologies and geographical distributions give rise to clustered warming tolerances, and how population responses to changing climates could variously temper, delay or intensify nonlinear dynamics. We argue that nonlinear increases in risks to biodiversity should be the null expectation under warming, and highlight the empirical research needed to understand the causes, commonness and consequences of clustered warming tolerances to better predict where, when and why nonlinear biodiversity losses will occur.This article is part of the discussion meeting issue 'Bending the curve towards nature recovery: building on Georgina Mace's legacy for a biodiverse future'.

Extinction of experience among ecologists.

Fieldwork-based research and education in ecology are under multiple threats and are progressively declining. We call for greater attention to this ongoing loss of direct field experience within the ecology community, as it could have widespread consequences for science and education, ultimately hindering efforts to address the ongoing biodiversity crisis.

Effects of reduced flow gradient on benthic biofilm communities' ecological network and community assembly.

The intensification of human activities has led to flow reduction and cut-off in most global rivers, seriously affecting riverine organisms and the biogeochemical processes. As key indicators of river ecosystems' structure and function, benthic biofilms play a critical role in driving primary production and material cycling in rivers. This research aimed to investigate the characteristics of microbial communities' complexity and stability during river flow reduction. Benthic biofilms were grown in artificial channels and subjected to eight gradients of flow reduction (represented by flow velocity from 0.4 to 110cm/s). Biofilms' biodiversity, ecological networks and community assembly of bacteria, fungi and algae were investigated by high-throughput sequencing. Results showed significant differences in community composition and structure under different flow conditions. The eight flow gradients' microbial communities were divided into three groups: low, medium and high flows. The flow reduction led to significant decreases in bacterial and fungal communities' Chao1 index. Low flow conditions enriched the bacterial phyla Oxyphotobacteria, Alphaproteobacteria and Mollicutes, but significantly decreased the fungal phylum Chytridiomycota. Lowering flow reduced the fungal network's number of nodes and increased the algal network's number of edges. Cross-domain interactions network analysis showed a gradual increase in node and edge numbers with decreasing flow, while decreasing average path length. The neutral model predicted stochastic processes primarily drove biofilm community assembly, and that model's explanations decreased as the flow gradient decreased. The null model analysis revealed diffusion limitation as the most common stochastic ecological process for bacterial and algal communities, with reduced flow reducing heterogeneous selection and increasing diffusion-limited processes. This study provides an in-depth analysis of flow reduction's effects on biofilm communities' ecological networks and community assembly.

A Probabilistic View of Forbidden Links: Their Prevalence and Their Consequences for the Robustness of Plant-Hummingbird Communities.

The presence in ecological communities of unfeasible species interactions, termed forbidden links, due to physiological or morphological exploitation barriers has been long debated, but little direct evidence has been found. Forbidden links are likely to make ecological communities less robust to species extinctions, stressing the need to assess their prevalence. Here, we used a dataset of plant-hummingbird interactions, coupled with a Bayesian hierarchical model, to assess the importance of exploitation barriers in determining species interactions. We found evidence for exploitation barriers between flowers and hummingbirds across the 32 studied communities; however, the proportion of forbidden links changed drastically among communities because of changes in trait distributions. The higher the proportion of forbidden links, the more they decreased network robustness because of constraints on interaction rewiring. Our results suggest that exploitation barriers are not rare in plant-hummingbird communities and have the potential to limit the rescue of species experiencing partner extinction.