Community Dynamics Research Articles

Macroalgal Biofilm Harbours a Wide Diversity of Parasitic Protists With Distinct Temporal Dynamics.

Marine macroalgae surfaces create a nutrient-rich environment that promotes the formation of epiphyte biofilms. Biofilms are complex systems that facilitate ecological interactions within the community, yet parasitism remains largely unexplored. This study describes the diversity and temporal dynamics of the microeukaryotic community in the biofilm of Mediterranean macroalgae during summer, focusing on parasitic groups. Protist diversity was assessed using metabarcoding sequencing of the V4 region of the 18S rDNA gene using primers biased against metazoans. The macroalgal biofilm exhibited dynamic shifts in the microeukaryotic community structure associated to three phases of biofilm formation. Each phase was characterised by the dominance of specific eukaryotic and parasitic groups with clear successions between them. Our study revealed a high diversity of parasitic protists from different lineages in the macroalgal biofilm. These parasites can infect a wide variety of hosts, including the basibiont, species within the biofilm (micro- and macrocolonizers), nearby marine hosts and terrestrial organisms. The highest diversity and abundance of parasites were found in the mature phase of the biofilm, where the complexity and stability of the system seem to favour parasitism. The parasite assemblage was dominated by Apicomplexa, with many corresponding to unknown diversity, demonstrating that biofilms are a hotspot of unknown parasitic interactions. These parasites could potentially affect the dynamics of these communities and facilitate ecological interactions between the biofilm and surrounding organisms, suggesting that parasitism play a key, but still unexplored role, in shaping complex marine biofilms network.

Changes in flowering phenology with altered rainfall and the potential community impacts in an annual grassland.

Shifts in the timing of life history events, or phenology, have been recorded across many taxa and biomes in response to global change. These phenological changes are often studied in a single species context, but considering the community context is essential for anticipating the cascading effects on biotic interactions that are likely to occur. Focusing on an annual grassland plant community, we examined how experimental changes in precipitation affect flowering phenology in a community context and explore the implications of these shifts for competitive interactions and species coexistence. We experimentally manipulated rainfall with rainout shelters and recorded detailed flowering phenology data for seven annual species including two grasses and five forbs. We assessed how their first and peak flowering days were affected by changes in rainfall and explored how flowering overlap between competing species changed. Changes in rainfall shifted flowering phenology of some species, but sensitivity differed among neighboring species. Four of the seven species studied started and/or peaked flowering earlier in response to reduced water availability. The idiosyncratic shifts in flowering phenology have the potential to alter existing temporal dynamics that may be maintaining coexistence, such as temporal separation of resource-use among neighbors. Our results show how species-specific phenological consequences of global change can impact community dynamics and competition between neighboring plants and warrant future research.

Introducing Vegetation Ecology and Diversity (VED)

The current issue is the first one of the journal Vegetation Ecology and Diversity, formerly Plant Sociology, the international peer-reviewed journal of the Italian Society of Vegetation Science (SISV). Vegetation Ecology and Diversity (VED) publishes original research articles covering all aspects of vegetation, ranging from plant communities to landscapes, including dynamic processes and community ecology. It prioritizes papers that emphasize plant community ecology and vegetation surveys to advance ecological models, interpret and classify vegetation, map ecosystems, assess environmental quality, manage and conserve plant biodiversity, and interpret and monitor European habitats. All the articles are freely available in Open Access (OA). In the present Editorial, we introduce the new journal name, the new Editorial Board and Social Media Team, several Topical Collections, and initiatives to support young researchers.

Synthesizing the impact of armed conflicts on food security, livelihoods and social dynamics in Amhara region, Ethiopia

BackgroundArmed conflicts cause food insecurity and famine by triggering the disruption and destruction of food systems. The conflict that erupted in northern Ethiopia lasted from 2020 to 2022 and affected millions of people. This resulted in severe damage to the food security, livelihoods and social dynamics of communities in the Amhara region.ObjectiveThis study synthesized the impact of the conflict in northern Ethiopia on food security, livelihoods and social dynamics livelihoods in there zones, South Wello, North Wello and North Shewa zones of the Amhara Region. The conflict management response and the scope of humanitarian assistance are also analyzed.MethodsThe study used a qualitative case study design. Primary data were collected through semi-structured interviews, focus group discussions and observation. Data were collected from local authorities, representatives of displaced people, government and non-government officials who responded to the crisis and from the community members who were directly affected by the conflict. The primary data were supplemented by a review of reports from credible secondary sources. The research used thematic and narrative analysis techniques to synthesize the impact of armed conflicts on food security, livelihoods, and social dynamics in Amhara region, Ethiopia.ResultsOver 5.5 million people found to be affected by acute food insecurity and over half a million people were internally displaced due to the Northern conflict. The monetary value of the damage caused by the armed conflict is estimated at $500 million, due to the damage to basic services and the loss of 14 million quintals of agricultural production. The conflict has disrupted food systems by damaging agricultural infrastructure, causing market distortions and causing food shortages. Livelihoods were threatened by the loss of jobs and the destruction of private and municipal property. The destruction of the basic infrastructure such as health, water and sanitation, agriculture and market institutions inevitably have lasting negative impacts on the overall productivity of the community. Communities’ religious and traditional values, informal social networks ​​are affected by the impact of armed conflict, complicating communities’ reconstruction efforts.Conclusion and recommendationThe northern armed conflict has significant negative impacts on the food security, livelihoods and social dynamics of people in the Amhara region. Recognizing the multiple impacts of conflict livelihoods in the region is a critical step in developing effective responses. Government, non-governmental organizations, and community-based institutions should play a crucial role in building community resilience and support post-conflict reconstruction efforts. Future studies can capitalize on this qualitative finding and could design a large scale assessment using quantified data to further provide evidence on post-conflict reconstruction efforts.

The application of shrub willow chip organic amendments impacts soil microbial community dynamics.

Incorporating shrub willow chips into soil may improve the chemical, physical and biological properties of soils with low organic matter but the impact on soil microbial communities and their dynamics is not known. We assessed changes in the soil microbial communities in response to willow chip applied at increasing rates (0, 20, 40 and 60 Mg ha-1) in a potato-barley cropping system. Bacterial and fungal community diversity, relative abundance, and potential functions were assessed using amplicon sequencing of 16S and ITS rRNA genes at six time points. High rates (40 and 60 Mg ha-1) of willow chips had no effect on bacterial alpha diversity but significantly decreased fungal alpha diversity (Shannon) while increasing fungal richness (Chao-1). At rates of 40 Mg ha⁻¹ and higher, the relative abundance of copiotrophic bacterial groups increased, while that of copiotrophic fungal groups decreased. The relative abundance of the most dominant microbial phyla and genera varied over time, with copiotrophic groups declining and oligotrophic groups increasing. High willow chip application rates increased bacterial molecular markers related to carbon fixation and degradation, nitrogen fixation, and phosphorus solubilization, while decreasing markers related to cellobiose transport and denitrification. This study demonstrates the ability of willow chips to influence the microbial community composition and potential function over time.

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.

Enhanced pollution control using sediment microbial fuel cells for ecological remediation.

Sediment Microbial Fuel Cell (SMFC) technology is an innovative approach to facilitate the degradation of sedimentary organic matter by electroactive microorganisms, transforming chemical energy into electrical energy and modulating the redox potential at the sediment-water interface, consequently controlling the release of endogenous pollutants. The synergistic effects of various environmental factors and intrinsic conditions can significantly impact SMFC performance. This review provides a comprehensive overview of SMFC development in research and application for water environment treatment and ecological remediation, a perspective rarely explored in previous reviews. It discusses optimization strategies for SMFC implementation, emphasizing advancements in novel or cost-effective electrode materials, the dynamics of microbial communities, and the control of typical pollutants. The review suggests a virtuous cycle path for SMFC development, highlighting future research needs, including integrating cross-disciplinary approaches like artificial intelligence, genomics, and mathematical modeling, to enhance the deployment of SMFC in real-world environmental remediation.

Warming reduces bacterial diversity and stability in Lake Bosten.

Understanding the effects of warming on bacterial communities is essential for predicting microbial responses to climate change in aquatic ecosystems. However, the mechanisms through which warming influences bacterial diversity and stability in lake ecosystems remain poorly understood. To address this gap, we conducted a mesocosm experiment in Lake Bosten, a climate change hotspot, with three temperature scenarios (26°C, 29°C, and 32°C), and investigated bacterial diversity, community composition, potential functions, and stability. Our findings revealed that temperature, time, and their interactions significantly reduced bacterial α-diversity (two-way ANOVA: P<0.05). Warming altered bacterial potential metabolic functions, with decreases in methanotrophy and methylotrophy and increases in phototrophy and photoheterotrophy. Warming also increased species replacement within bacterial communities, indicating a dynamic shift in community composition. Network analysis indicated heightened complexity under higher temperatures but also a decrease in bacterial stability, evidenced by higher average variation degree (AVD), increased vulnerability, and reduced robustness. Overall, our study highlights the profound effects of warming on the ecological dynamics of lake bacterial communities, underscoring the need for further research to understand and mitigate the impacts of global climate change on aquatic ecosystems.

The relationship between protist consumers and soil functional genes under long-term fertilization.

Protists play a crucial role in terrestrial ecosystems by participating in biogeochemical cycles and contributing to ecological balance and stability. However, much remains to be understood about the intricate interactions between soil protists and biogeochemical processes. Here, we collected rhizosphere soil samples from seven distinct fertilization treatments to investigate the responses of bacteria, protists and functional genes to these varying fertilization practices during sorghum's maturity season. The community composition of both protists and bacteria were significantly affected by different fertilization treatments, with organic fertilization increasing protist diversity but not affecting bacterial diversity. There were noticeable variations in the compositions of functional genes across different fertilization treatments, with organic fertilization enhancing the relative abundance of carbon and phosphorus cycling genes. While fertilization generally increased the relative abundance of protistan consumers, it was observed that organic fertilizers decreased the relative abundance of phototrophs. A substantial number of bacterial taxa, including Acidibacter, Steroidobacter, Lysobacter and Agromyces, which correlated positively with functional genes, were found to be prey for protistan consumers, indicating their crucial role in predicting soil functional genes. Altogether, this study highlights the significant impact of fertilization treatments, especially organic fertilization, on the diversity and functional dynamics of protist and bacterial communities, emphasizing the key role of protistan consumers in regulating the soil microbial community and modulating soil biogeochemical cycles.

Microbial community dynamics in shallow-water grass-type lakes: Habitat succession of microbial ecological assembly and coexistence mechanisms

Microbial community dynamics in shallow-water grass-type lakes: Habitat succession of microbial ecological assembly and coexistence mechanisms

Performance of mesophilic and thermophilic anaerobic digestion of food waste at varying organic loading rate: Methane production, pathogens reduction, and dominant microbial community dynamics

Performance of mesophilic and thermophilic anaerobic digestion of food waste at varying organic loading rate: Methane production, pathogens reduction, and dominant microbial community dynamics

Effects of multiple temperature variations on nitrogen removal and microbial community structure in tidal flow constructed wetlands.

Tidal-flow constructed wetlands (TFCWs) provide distinct advantages for nitrogen removal by enhancing microbial activity through dynamic water level fluctuations. However, effects of temperature on nitrogen transformation processes and microbial community dynamics in TFCWs remain unclear. We analyzed the effects of TFCWs on nitrogen transformation and microbial community structure under different temperature conditions (23, 16, 12, and 8 °C) through 140 days of temperature-controlled experiments. The nitrogen removal efficiency was considerably enhanced at 23 °C, with transformation rates for ammonia nitrogen (NH4+-N) and total nitrogen (TN) reaching 9.28 ± 0.06 g/m³/day and 8.35 ± 0.08 g/m³/day, respectively. Conversely, at 8 °C, the nitrogen removal efficiency declined, with NH4+-N and TN transformation rates decreasing to 7.38 ± 0.05 g/m³/day and 6.78 ± 0.05 g/m³/day, respectively. Temperature markedly influenced the microbial diversity and community structure, as evidenced by the considerably higher Shannon diversity indices for bacterial communities at 23 °C (5.12 ± 0.21) compared with those at 8 °C (4.52 ± 0.40). Positive microbial interactions were more prevalent at lower temperatures (12 and 8 °C), leading to stronger symbiotic relationships, although the network complexity diminished. The microbial community composition of taxa such as Firmicutes, Proteobacteria, and Thaumarchaeota exhibited greater resilience at lower temperatures. Changes in dissolved oxygen levels also drove changes in bacterial and archaeal communities. These findings underscore the pivotal role of temperature in regulating ecological function and nitrogen removal efficiency of TFCWs and highlight the importance of accounting for temperature variations in the design and management of wastewater treatment systems.

Role Identity, Loneliness, and Bereavement During the Pandemic in Japan: A Cross-Sectional Study.

The COVID-19 pandemic significantly restricted social activities, prompting a re-examination of community dynamics. In Japan, where families are central, the absence of a spouse increases susceptibility to loneliness and isolation. The loss of a spouse, especially during the pandemic, has heightened these issues among middle-aged and older individuals. Limited quantitative studies on pandemic-related bereavement in Japan underscore the need to understand the associated risks of loneliness and social isolation. This study aimed to examine the relationships between role identity as a member of the local community, loneliness, and social support among middle-aged and older adults. This study also examined whether there were differences in the relationships between those who had experienced bereavement and those who had not. An Internet survey was conducted with Japanese adults (aged 50-74 years), including those who experienced bereavement during the pandemic. The final sample included 322 participants (154 in the bereavement group and 168 in the cohabiting group). The variables, measured using psychological scales, included role identity as a local resident, social capital (trust, reciprocity, and membership), loneliness, and social support (family and friendship). The higher trust and role identity were related to lower loneliness. Membership in the cohabiting group was related to lower level of loneliness and higher level of social supports. However, membership in the bereavement group was not related to either. Furthermore, trust and reciprocity were related to loneliness and social support. These results indicated that the role identity and perception of social capital related to preventing isolation and loneliness for bereaved people.

A contrastive learning strategy for optimizing node non-alignment in dynamic community detection

A contrastive learning strategy for optimizing node non-alignment in dynamic community detection

Microbial community dynamics and mechanistic insights into rapid ammonia nitrogen removal via Acinetobacter harbinensis HITLi7T enhanced activated carbon.

The biological enhanced activated carbon (BEAC) system, utilizing the bioaugmentation with Acinetobacter harbinensis HITLi7T, demonstrated remarkable performance in removing ammonia nitrogen (NH4+-N) from aquatic environments. However, the mechanism through which HITLi7T bioaugmentation influenced microbial communities remains incompletely understood. Therefore, a comparative analysis of startup speed and NH4+-N removal efficiency was conducted between biological activated carbon (BAC) and BEAC bench-scale systems, with an in-depth examination of microbial dynamics and mechanisms within BEAC. Within 16 days post bioaugmentation, the biomass of BEAC (BEAC_1 and BEAC_2) was 4.75/9.07 times that of BAC, with NH4+-N removal efficiencies 29.36%/28.68% higher. 16-135 days, there was no significant difference in biomass among the groups. Specifically, from day 17-90, the NH4+-N removal efficiency of BEAC was still 25.80%/25.37% higher than that of BAC. After 90 days, the effluent NH4+-N levels from BEAC were more stable. In BEAC, the abundance of HITLi7T decreased while the abundance of Nitrosomonas increased, exhibiting a characteristic of "species compensation". Subsequently, Candidatus_Nitrotoga and Nitrospira became enriched. After 16 days, the total abundance of Nitrosomonas, Candidatus_Nitrotoga, and Nitrospira in BEAC was 3.21%-5.66% and 3.68%-10.07% higher than that in BAC. The microbial community in BEAC was more influenced by diffusion limitation, especially for Nitrosomonas and Nitrospira. Within the microbial co-occurrence network, while Nitrosomonas and Nitrospira lacked a direct correlation with HITLi7T, the presence of intermediates might potentially hinder the diffusion of Nitrosomonas and Nitrospira. This study deepened our understanding of how HITLi7T bioaugmentation affects microbial community structure, dynamics, and co-occurrence patterns.

Delving into the soil and phytomicrobiome for disease suppression: A case study for the control of Fusarium Head Blight of cereals.

Fusarium Head Blight is one of the most devastating fungal diseases of cereals worldwide, causing significant yield losses and affecting grain quality. The predominant role of the interactions within the Fusarium communities as well as with members of the phytomicrobiome in disease onset and development has gained increasing attention. Understanding the diversity and dynamics of bacterial and fungal communities across different substrates colonized by Fusarium spp. in wheat fields can provide valuable insights into disease ecology and lead to the discovery of native microorganisms with biocontrol potential. In this study, the bacterial and fungal communities associated with soil, maize residues, and wheat grains, were studied based on metabarcoding sequencing of 16S rRNA and ITS2 regions in six wheat fields over two years and characterized by different levels of FHB disease pressure and mycotoxin contamination. Overall, the diversity and composition of microbial communities were primarily influenced by substrate type followed by geographic origins of fields and sampling time, notably for grains and residues while the soil microbiome was less impacted by environmental fluctuations. Notably, our findings suggest that crop residues function as a transient substrate between soil and wheat microbiomes. In addition, we found several taxa either strongly negatively correlated to Fusarium spp. and/or to levels of Fusarium DNA or mycotoxins in grains or residues, including Cladosporium, Epicoccum, Paenibacillus, Curtobacterium, Pseudomonas, Pantoea, and Sphingomonas, which could be potential antagonistic agents against Fusarium spp. Altogether, these findings provide novel insights into the field microbiome functioning and their complex interactions with the Fusarium communities.

Sensitivity of communities' trait-based indices to species selection.

Trait-based indicators offer insights into environmental impacts on communities but are often limited by the availability of species traits data, relying on subsets that may omit less studied taxa, leading to bias. To address this, we tested the species selection's influence on trait-based indices using filters based on occurrence, species' distributions, and abundance. Using data from two bottom-trawl surveys, we compiled 15 traits for the 246 most common demersal species in two temperate ecosystems in the North-East Atlantic and Mediterranean Sea. Our analyses revealed that trait data is strongly biased toward abundant and large species, particularly those of commercial importance or conservation concern. While species selection had minimal impact on community traits, excluding invertebrates strongly affected the results, highlighting their key role in community dynamics.

An Analysis of Slang Found in X Thread By K-Popers

This research focuses on using slang words in social media X, previously known as Twitter, especially in comments by K-pop fans, known as K-popers. The method used in this research is a qualitative case study, with data collected through participatory observation and content analysis of X comments posted by Kpopers. Wit a tweet on X being the primary data source. The analysis includes identifying the types of slang used and its interpretation within the cultural background according to Allan and Burridge’s theory, as well as a conceptual framework that explains linguistics in aspects of semantics. This research is expected to provide theoretical insights into linguistic dynamics in online communities and practical benefits in understanding how cultural and social identities are constructed and maintained through language.

Biodiversity of Benthic Macroinvertebrates and water quality as a tool to the ecological study of three forest streams in the littoral zone (Cameroon)

A study of the community dynamics of benthic macroinvertebrates in relation to physicochemical water quality was conducted from December 2022 to December 2023 in the Lepp-Nyock, Ndog-Bissolo, and Ngwei streams within the tropical littoral forest area of the Guinean Gulf (Edéa). Physicochemical analyses were performed and Benthic Macroinvertebrate identified following classical method. The results indicate that those waters are well-oxygenated (73.72±12.48%), slightly acidic (pH 6.87±0.42 CU) and contain very low concentrations of nitrogen compounds and heavy metals (0.29±0.28 mg/l Cu, 0.8±0.54 mg/l Zn, 0.45±0.27 mg/l Mn, 1.32±0.47 mg/l Fe, 0.81±0.38 mg/l Al, 0.18±0.2 mg/l Cd, and 0.49±0.52 mg/l Cr). Biological analysis revealed a total of 8,699 Benthic Macroinvertebrates belonging to 4 Phyla, 5 Classes, 12 Orders, 55 Families and 117 Genera. Arthropods were the most abundant, accounting for 86.67% of the total, with the insect Class (86,56%) being dominant (8 Orders, 42 Families, and 68 Genera). Gastropods (13,27%) were the second most abundant group, represented by 2 Orders, 5 Families, and 16 Genera. The Atyidae family was particularly dominant within the benthic community, with Caridina africana identified as the most prevalent species. The Shannon-Weaver diversity index (H') and Piélou equitability index (J) indicated low taxonomic diversity, while the Organic Pollution Index (OPI) suggested a less disturbed environment. Together, these findings reflect the good ecological quality of the water in the studied streams.

Maximizing resource valorization: mono- and co-digestion of food and agricultural wastes with insights into microbial community dynamics

Abstract The valorization of food processing waste is critical for sustainable development and circular economy frameworks. Although Turkish delight waste (D), a high-volume byproduct of the confectionery industry in Turkey, holds significant potential for valorization within the circular economy framework, this potential remains largely unexplored. This study evaluated the valorization potential of Turkish delight waste in anaerobic digester systems by co-digesting it with sunflower heads (S) and tea stalks (T), common agricultural wastes in Turkey, in addition to mono-digestion. Economic evaluations were also conducted on the products obtained at different stages of anaerobic digestion (AD). The highest methane yield of 388 mL CH4/g VS was obtained from Turkish delight waste in mono-digestion, and this substrate enhanced methane production when co-digested with the other substrates. However, co-digestion in the DST digester combining all three substrates yielded 234 mL CH4/g VS, indicating a limited synergistic effect. Metagenomic analyses revealed substrate-dependent variations in microbial community dynamics, particularly in digesters containing only Turkish delight waste. Acidogenic fermentation aimed at increasing VFA yield resulted in total acetic acid productions of 2828, 1707, and 1261 mg/L for D, DS, and DST, respectively. Economic assessments demonstrated that the value derived from VFA production was nearly double that obtained from methane production, even in cases where co-digestion resulted in lower overall yields. Thus, Turkish delight waste emerges as a promising candidate for both mono- and co-digestion in AD systems, offering a potentially more economically viable alternative to methane production through the generation of value-added chemicals such as VFAs. Graphical Abstract