From vacant to vivid: The nutritional landscape drives infant gut microbiota establishment.

From the moment of birth, the newborn gastrointestinal tract is infiltrated by various bacteria originating from both maternal and environmental sources. These colonizing bacteria form a complex microbiota community that undergoes continuous changes until adulthood and plays an important role in infant health. The maturation of the infant gut microbiota is driven by many factors and follows a distinct patterned trajectory, with specific bacterial taxa establish in the intestine in accordance with developmental milestones as the infant grows. In this review, we highlight how elements such as diet and host physiology select for specific microbial functions and shape the composition of the bacterial community in the large intestine.

Temporal dynamics of Grime's CSR strategies in plant communities during 60 years of succession.

Grime's competitive, stress-tolerant, ruderal (CSR) theory predicts a shift in plant communities from ruderal to stress-tolerant strategies during secondary succession. However, this fundamental tenet lacks empirical validation using long-term continuous successional data. Utilizing a 60-year longitudinal data of old-field succession, we investigated the community-level dynamics of plant strategies over time. Our findings reveal that while plant communities generally transitioned from ruderal to stress-tolerant strategies during succession, initial abandonment conditions crucially shaped early successional strategies, leading to varied strategy trajectories across different fields. Furthermore, we found a notable divergence in the CSR strategies of alien and native species over succession. Initially, alien and native species exhibited similar ruderal strategies, but in later stages, alien species exhibited higher ruderal and lower stress tolerance compared to native species. Overall, our findings underscore the applicability of Grime's predictions regarding temporal shifts in CSR strategies depending on both initial community conditions and species origin.

Competition for time: Evidence for an overlooked, diversity-maintaining competitive mechanism.

Understanding how diversity is maintained in plant communities requires that we first understand the mechanisms of competition for limiting resources. In ecology, there is an underappreciated but fundamental distinction between systems in which the depletion of limiting resources reduces the growth rates of competitors and systems in which resource depletion reduces the time available for competitors to grow, a mechanism we call 'competition for time'. Importantly, modern community ecology and our framing of the coexistence problem are built on the implicit assumption that competition reduces the growth rate. However, recent theoretical work suggests competition for time may be the predominant competitive mechanism in a broad array of natural communities, a significant advance given that when species compete for time, diversity-maintaining trade-offs emerge organically. In this study, we first introduce competition for time conceptually using a simple model of interacting species. Then, we perform an experiment in a Mediterranean annual grassland to determine whether competition for time is an important competitive mechanism in a field system. Indeed, we find that species respond to increased competition through reductions in their lifespan rather than their rate of growth. In total, our study suggests competition for time may be overlooked as a mechanism of biodiversity maintenance.

Inter-clonal competition over queen succession imposes a cost of parthenogenesis on termite colonies.

In social insect colonies, selfish behaviour due to intracolonial conflict among members can result in colony-level costs despite close relatedness. In certain termite species, queens use asexual reproduction for within-colony queen succession but rely on sexual reproduction for worker and alate production, resulting in multiple half-clones of a single primary queen competing for personal reproduction. Our study demonstrates that competition over asexual queen succession among different clone types leads to the overproduction of parthenogenetic offspring, resulting in the production of dysfunctional parthenogenetic alates. By genotyping the queens of 23 field colonies of Reticulitermes speratus, we found that clone variation in the queen population reduces as colonies develop. Field sampling of alates and primary reproductives of incipient colonies showed that overproduced parthenogenetic offspring develop into alates that have significantly smaller body sizes and much lower survivorship than sexually produced alates. Our results indicate that while the production of earlier and more parthenogenetic eggs is advantageous for winning the competition for personal reproduction, it comes at a great cost to the colony. Thus, this study highlights the evolutionary interplay between individual-level and colony-level selection on parthenogenesis by queens.

Long-term shift towards shady and nutrient-rich habitats in Central European temperate forests.

Biodiversity world-wide has been under increasing anthropogenic pressure in the past century. The long-term response of biotic communities has been tackled primarily by focusing on species richness, community composition and functionality. Equally important are shifts between entire communities and habitat types, which remain an unexplored level of biodiversity change. We have resurveyed > 2000 vegetation plots in temperate forests in central Europe to capture changes over an average of five decades. The plots were assigned to eight broad forest habitat types using an algorithmic classification system. We analysed transitions between the habitat types and interpreted the trend in terms of changes in environmental conditions. We identified a directional shift along the combined gradients of canopy openness and soil nutrients. Nutrient-poor open-canopy forest habitats have declined strongly in favour of fertile closed-canopy habitats. However, the shift was not uniform across the whole gradients. We conclude that the shifts in habitat types represent a century-long successional trend with significant consequences for forest biodiversity. Open forest habitats should be urgently targeted for plant diversity restoration through the implementation of active management. The approach presented here can be applied to other habitat types and at different spatio-temporal scales.

Dynamics and drivers of mycorrhizal fungi after glacier retreat.

The development of terrestrial ecosystems depends greatly on plant mutualists such as mycorrhizal fungi. The global retreat of glaciers exposes nutrient-poor substrates in extreme environments and provides a unique opportunity to study early successions of mycorrhizal fungi by assessing their dynamics and drivers. We combined environmental DNA metabarcoding and measurements of local conditions to assess the succession of mycorrhizal communities during soil development in 46 glacier forelands around the globe, testing whether dynamics and drivers differ between mycorrhizal types. Mycorrhizal fungi colonized deglaciated areas very quickly (< 10 yr), with arbuscular mycorrhizal fungi tending to become more diverse through time compared to ectomycorrhizal fungi. Both alpha- and beta-diversity of arbuscular mycorrhizal fungi were significantly related to time since glacier retreat and plant communities, while microclimate and primary productivity were more important for ectomycorrhizal fungi. The richness and composition of mycorrhizal communities were also significantly explained by soil chemistry, highlighting the importance of microhabitat for community dynamics. The acceleration of ice melt and the modifications of microclimate forecasted by climate change scenarios are expected to impact the diversity of mycorrhizal partners. These changes could alter the interactions underlying biotic colonization and belowground-aboveground linkages, with multifaceted impacts on soil development and associated ecological processes.

Trees adjust nutrient acquisition strategies across tropical forest secondary succession.

Nutrient limitation may constrain the ability of recovering and mature tropical forests to serve as a carbon sink. However, it is unclear to what extent trees can utilize nutrient acquisition strategies - especially root phosphatase enzymes and mycorrhizal symbioses - to overcome low nutrient availability across secondary succession. Using a large-scale, full factorial nitrogen and phosphorus fertilization experiment of 76 plots along a secondary successional gradient in lowland wet tropical forests of Panama, we tested the extent to which root phosphatase enzyme activity and mycorrhizal colonization are flexible, and if investment shifts over succession, reflective of changing nutrient limitation. We also conducted a meta-analysis to test how tropical trees adjust these strategies in response to nutrient additions and across succession. We find that tropical trees are dynamic, adjusting investment in strategies - particularly root phosphatase - in response to changing nutrient conditions through succession. These changes reflect a shift from strong nitrogen to weak phosphorus limitation over succession. Our meta-analysis findings were consistent with our field study; we found more predictable responses of root phosphatase than mycorrhizal colonization to nutrient availability. Our findings suggest that nutrient acquisition strategies respond to nutrient availability and demand in tropical forests, likely critical for alleviating nutrient limitation.

Species pool, local assembly processes: Disentangling the mechanisms determining bacterial α- and ß-diversity during forest secondary succession.

Across ecology, and particularly within microbial ecology, there is limited understanding how the generation and maintenance of diversity. Although recent work has shown that both local assembly processes and species pools are important in structuring microbial communities, the relative contributions of these mechanisms remain an important question. Moreover, the roles of local assembly processes and species pools are drastically different when explicitly considering the potential for saturation or unsaturation, yet this issue is rarely addressed. Thus, we established a conceptual model that incorporated saturation theory into the microbiological domain to advance the understanding of mechanisms controlling soil bacterial diversity during forest secondary succession. Conceptual model hypotheses were tested by coupling soil bacterial diversity, local assembly processes and species pools using six different forest successional chronosequences distributed across multiple climate zones. Consistent with the unsaturated case proposed in our conceptual framework, we found that species pool consistently affected α-diversity, even while local assembly processes on local richness operate. In contrast, the effects of species pool on ß-diversity disappeared once local assembly processes were taken into account, and changes in environmental conditions during secondary succession led to shifts in ß-diversity through mediation of the strength of heterogeneous selection. Overall, this study represents one of the first to demonstrate that most local bacterial communities might be unsaturated, where the effect of species pool on α-diversity is robust to the consideration of multiple environmental influences, but ß-diversity is constrained by environmental selection.

Local climate modulates the development of soil nematode communities after glacier retreat.

The worldwide retreat of glaciers is causing a faster than ever increase in ice-free areas that are leading to the emergence of new ecosystems. Understanding the dynamics of these environments is critical to predicting the consequences of climate change on mountains and at high latitudes. Climatic differences between regions of the world could modulate the emergence of biodiversity and functionality after glacier retreat, yet global tests of this hypothesis are lacking. Nematodes are the most abundant soil animals, with keystone roles in ecosystem functioning, but the lack of global-scale studies limits our understanding of how the taxonomic and functional diversity of nematodes changes during the colonization of proglacial landscapes. We used environmental DNA metabarcoding to characterize nematode communities of 48 glacier forelands from five continents. We assessed how different facets of biodiversity change with the age of deglaciated terrains and tested the hypothesis that colonization patterns are different across forelands with different climatic conditions. Nematodes colonized ice-free areas almost immediately. Both taxonomic and functional richness quickly increased over time, but the increase in nematode diversity was modulated by climate, so that colonization started earlier in forelands with mild summer temperatures. Colder forelands initially hosted poor communities, but the colonization rate then accelerated, eventually leveling biodiversity differences between climatic regimes in the long term. Immediately after glacier retreat, communities were dominated by colonizer taxa with short generation time and r-ecological strategy but community composition shifted through time, with increased frequency of more persister taxa with K-ecological strategy. These changes mostly occurred through the addition of new traits instead of their replacement during succession. The effects of local climate on nematode colonization led to heterogeneous but predictable patterns around the world that likely affect soil communities and overall ecosystem development.

The biological controls of soil carbon accumulation following wildfire and harvest in boreal forests: A review.

Boreal forests are frequently subjected to disturbances, including wildfire and clear-cutting. While these disturbances can cause soil carbon (C) losses, the long-term accumulation dynamics of soil C stocks during subsequent stand development is controlled by biological processes related to the balance of net primary production (NPP) and outputs via heterotrophic respiration and leaching, many of which remain poorly understood. We review the biological processes suggested to influence soil C accumulation in boreal forests. Our review indicates that median C accumulation rates following wildfire and clear-cutting are similar (0.15 and 0.20 Mg ha-1 year-1, respectively), however, variation between studies is extremely high. Further, while many individual studies show linear increases in soil C stocks through time after disturbance, there are indications that C stock recovery is fastest early to mid-succession (e.g. 15-80 years) and then slows as forests mature (e.g. >100 years). We indicate that the rapid build-up of soil C in younger stands appears not only driven by higher plant production, but also by a high rate of mycorrhizal hyphal production, and mycorrhizal suppression of saprotrophs. As stands mature, the balance between reductions in plant and mycorrhizal production, increasing plant litter recalcitrance, and ectomycorrhizal decomposers and saprotrophs have been highlighted as key controls on soil C accumulation rates. While some of these controls appear well understood (e.g. temporal patterns in NPP, changes in aboveground litter quality), many others remain research frontiers. Notably, very little data exists describing and comparing successional patterns of root production, mycorrhizal functional traits, mycorrhizal-saprotroph interactions, or C outputs via heterotrophic respiration and dissolved organic C following different disturbances. We argue that these less frequently described controls require attention, as they will be key not only for understanding ecosystem C balances, but also for representing these dynamics more accurately in soil organic C and Earth system models.

Global dominance of lianas over trees is driven by forest disturbance, climate and topography.

Growing evidence suggests that liana competition with trees is threatening the global carbon sink by slowing the recovery of forests following disturbance. A recent theory based on local and regional evidence further proposes that the competitive success of lianas over trees is driven by interactions between forest disturbance and climate. We present the first global assessment of liana-tree relative performance in response to forest disturbance and climate drivers. Using an unprecedented dataset, we analysed 651 vegetation samples representing 26,538 lianas and 82,802 trees from 556 unique locations worldwide, derived from 83 publications. Results show that lianas perform better relative to trees (increasing liana-to-tree ratio) when forests are disturbed, under warmer temperatures and lower precipitation and towards the tropical lowlands. We also found that lianas can be a critical factor hindering forest recovery in disturbed forests experiencing liana-favourable climates, as chronosequence data show that high competitive success of lianas over trees can persist for decades following disturbances, especially when the annual mean temperature exceeds 27.8°C, precipitation is less than 1614 mm and climatic water deficit is more than 829 mm. These findings reveal that degraded tropical forests with environmental conditions favouring lianas are disproportionately more vulnerable to liana dominance and thus can potentially stall succession, with important implications for the global carbon sink, and hence should be the highest priority to consider for restoration management.

Des preuves de plus en plus nombreuses suggèrent que la competition entre lianes et les arbres menace le puits de carbone mondial en ralentissant la récupération des forêts après une perturbation. Une théorie récente, fondée sur des observations locales et régionales, propose en outre que le succès compétitif des lianes sur les arbres est dû aux interactions entre la perturbation forestière et le climat. Nous présentons la première évaluation mondiale de la performance relative des lianes par rapport aux arbres en réponse aux perturbations forestières et aux facteurs climatiques. En utilisant un ensemble de données sans précédent, nous avons analysé 651 échantillons de végétation représentant 26,538 lianes et 82,802 arbres, issus de 556 emplacements uniques dans le monde entier, tirés de 83 publications. Les résultats montrent que les lianes ont de meilleure performances par rapport aux arbres (augmentation du ratio liane-arbre) lorsque les forêts sont perturbées, sous des zones chaudes aves précipitations faibles, et vers les basses altitudes tropicales. Nous avons également constaté que les lianes peuvent être un facteur critique entravant la récupération des forêts dans les forêts perturbées connaissant des climats favorables aux lianes, car les données de chronoséquence montrent que le succès compétitif élevé des lianes sur les arbres peut persister pendant des décennies après les perturbations, surtout lorsque la température annuelle moyenne dépasse 27.8°C, que les précipitations sont inférieures à 1614 mm et que le déficit hydrique climatique est supérieur à 829 mm. Ces découvertes révèlent que les forêts tropicales dégradées avec des conditions environnementales favorables aux lianes sont disproportionnellement plus vulnérables à la dominance des lianes, et peuvent ainsi potentiellement entraver la succession, avec d'importantes implications pour le puits de carbone mondial et devraient donc être la plus haute priorité à considérer pour la gestion de la restauration.

Fire-modulated fluctuations in nutrient availability stimulate biome-scale floristic turnover in time, and elevated species richness, in low-nutrient fynbos heathland.

BACKGROUND AND AIMS: In many systems, postfire vegetation recovery is characterized by temporal changes in plant species composition and richness. We attribute this to changes in resource availability with time since fire, with the magnitude of species turnover determined by the degree of resource limitation. Here, we test the hypothesis that postfire species turnover in South African fynbos heathland is powered by fire-modulated changes in nutrient availability, with the magnitude of turnover in nutrient-constrained fynbos being greater than in fertile renosterveld shrubland. We also test the hypothesis that floristic overlaps between fynbos and renosterveld are attributable to nutritional augmentation of fynbos soils immediately after fire. METHODS: We use vegetation survey data from two sites on the Cape Peninsula to compare changes in species richness and composition with time since fire. KEY RESULTS: Fynbos communities display a clear decline in species richness with time since fire, whereas no such decline is apparent in renosterveld. In fynbos, declining species richness is associated with declines in the richness of plant families having high foliar concentrations of nitrogen, phosphorus and potassium and possessing attributes that are nutritionally costly. In contrast, families that dominate late-succession fynbos possess adaptations for the acquisition and retention of sparse nutrients. At the family level, recently burnt fynbos is compositionally more similar to renosterveld than is mature fynbos. CONCLUSIONS: Our data suggest that nutritionally driven species turnover contributes significantly to fynbos community richness. We propose that the extremely low baseline fertility of fynbos soils serves to lengthen the nutritional resource axis along which species can differentiate and coexist, thereby providing the opportunity for low-nutrient extremophiles to coexist spatially with species adapted to more fertile soil. This mechanism has the potential to operate in any resource-constrained system in which episodic disturbance affects resource availability.

Environmental DNA metabarcoding reveals temporal dynamics but functional stability of arthropod communities in cattle dung.

Terrestrial invertebrates are highly important for the decomposition of dung from large mammals. Mammal dung has been present in many of Earth's ecosystems for millions of years, enabling the evolution of a broad diversity of dung-associated invertebrates that process various components of the dung. Today, large herbivorous mammals are increasingly introduced to ecosystems with the aim of restoring the ecological functions formerly provided by their extinct counterparts. However, we still know little about the ecosystem functions and nutrient flows in these rewilded ecosystems, including the dynamics of dung decomposition. In fact, the succession of insect communities in dung is an area of limited research attention also outside a rewilding context. In this study, we use environmental DNA metabarcoding of dung from rewilded Galloway cattle in an experimental set-up to investigate invertebrate communities and functional dynamics over a time span of 53 days, starting from the time of deposition. We find a strong signal of successional change in community composition, including for the species that are directly dependent on dung as a resource. While several of these species were detected consistently across the sampling period, others appeared confined to either early or late successional stages. We believe that this is indicative of evolutionary adaptation to a highly dynamic resource, with species showing niche partitioning on a temporal scale. However, our results show consistently high species diversity within the functional groups that are directly dependent on dung. Our findings of such redundancy suggest functional stability of the dung-associated invertebrate community, with several species ready to fill vacant niches if other species disappear. Importantly, this might also buffer the ecosystem functions related to dung decomposition against environmental change. Interestingly, alpha diversity peaked after approximately 20-25 days in both meadow and pasture habitats, and did not decrease substantially during the experimental period, probably due to preservation of eDNA in the dung after the disappearance of visiting invertebrates, and from detection of tissue remains and cryptic life stages.

Changes in Microbial Composition During the Succession of Biological Soil Crusts in Alpine Hulun Buir Sandy Land, China.

Biological soil crusts (biocrusts) are considered "desert ecosystem engineers" because they play a vital role in the restoration and stability maintenance of deserts, including those cold sandy land ecosystems at high latitudes, which are especially understudied. Microorganisms participate in the formation and succession of biocrusts, contributing to soil properties' improvement and the stability of soil aggregates, and thus vegetation development. Accordingly, understanding the composition and successional characteristics of microorganisms is a prerequisite for analyzing the ecological functions of biocrusts and related applications. Here, the Hulun Buir Sandy Land region in northeastern China-lying at the highest latitude of any sandy land in the country-was selected for study. Through a field investigation and next-generation sequencing (Illumina MiSeq PE300 Platform), our goal was to assess the shifts in diversity and community composition of soil bacteria and fungi across different stages during the succession of biocrusts in this region, and to uncover the main factors involved in shaping their soil microbial community. The results revealed that the nutrient enrichment capacity of biocrusts for available nitrogen, total nitrogen, total phosphorus, total content of water-soluble salt, available potassium, soil organic matter, and available phosphorus was progressively enhanced by the succession of cyanobacterial crusts to lichen crusts and then to moss crusts. In tandem, soil bacterial diversity increased as biocrust succession proceeded but fungal diversity decreased. A total of 32 bacterial phyla and 11 fungal phyla were identified, these also known to occur in other desert ecosystems. Among those taxa, the relative abundance of Proteobacteria and Cyanobacteria significantly increased and decreased, respectively, along the cyanobacterial crust-lichen-moss crust successional gradient. However, for Actinobacteria, Chloroflexi, and Acidobacteria their changed relative abundance was significantly hump-shaped, increasing in the shift from cyanobacterial crust to lichen crust, and then decreasing as lichen crust shifted to moss crust. In this process, the improved soil properties effectively enhanced soil bacterial and fungal community composition. Altogether, these findings broaden our understanding about how soil microbial properties can change during the succession of biocrusts in high-latitude, cold sandy land ecosystems.

Phototrophic Nitrogen Fixation, a Neglected Biogeochemical Process in Mine Tailings?

Biological nitrogen fixation (BNF) has important ecological significance in mine tailing by contributing to the initial accumulation of nitrogen. In addition to chemolithotrophic and heterotrophic BNF, light may also fuel BNF in oligotrophic mine tailings. However, knowledge regarding the occurrence and ecological significance of this biogeochemical process in mine tailings remains ambiguous. The current study observed phototrophic BNF in enrichment cultures established from three primary successional stages (i.e., original tailings, biological crusts, and pioneer plants) of tailings. Notably, phototrophic BNF in tailings may be more active at vegetation stages (i.e., biological crusts and pioneering plants) than in bare tailings. DNA-stable isotope probing identified Roseomonas species as potential aerobic anoxygenic phototrophs responsible for phototrophic BNF. Furthermore, metagenomic binning as well as genome mining revealed that Roseomonas spp. contained essential genes involved in nitrogen fixation, anoxygenic photosynthesis, and carbon fixation, suggesting their genetic potential to mediate phototrophic BNF. A causal inference framework equipped with the structural causal model suggested that the enrichment of putative phototrophic diazotrophic Roseomonas may contribute to an elevated total nitrogen content during primary succession in these mine tailings. Collectively, our findings suggest that phototrophic diazotrophs may play important roles in nutrient accumulation and hold the potential to facilitate ecological succession in tailings.

Isopod mouthpart traits respond to a tropical forest recovery gradient.

Functional trait ecology has the potential to provide generalizable and mechanistic predictions of ecosystem function from data of species distributions and traits. The traits that are selected should both respond to environmental factors and influence ecosystem functioning. Invertebrate mouthpart traits fulfill these criteria, but are seldom collected, lack standardized measurement protocols, and have infrequently been investigated in response to environmental factors. We surveyed isopod species that consume plant detritus, and tree communities in 58 plots across primary and secondary forests in Singapore. We measured body dimensions (body size traits), pereopod and antennae lengths (locomotory traits), dimensions of mandible structures (morphological mouthpart traits), and mechanical advantages generated by mandible shape (mechanical mouthpart traits) for six isopod species found in these plots and investigated if these traits respond to changes in tree community composition, tree diversity, and forest structure. Morphological mouthpart traits responded to a tree compositional gradient reflecting forest recovery degree. Mouthpart features associated with greater consumption of litter (broader but less serrated/rugose lacinia mobilis [an important cutting and chewing structure on the mandible]) were most prevalent in abandoned plantation and young secondary forests containing disturbance-associated tree species. Feeding strategies associated with fungi grazing (narrower and more serrated/rugose lacinia mobilis) were most prevalent in late secondary forests containing later successional tree species. Since morphological mouthpart traits likely also predict consumption and excretion rates of isopods, these traits advance our understanding of environment-trait-ecosystem functioning relationships across contrasting tropical forest plots that vary in composition, disturbance history, and post-disturbance recovery.

Light competition drives species replacement during secondary tropical forest succession.

Light competition is thought to drive successional shifts in species dominance in closed vegetations, but few studies have assessed this for species-rich and vertically structured tropical forests. We analyzed how light competition drives species replacement during succession, and how cross-species variation in light competition strategies is determined by underlying species traits. To do so, we used chronosequence approach in which we compared 14 Mexican tropical secondary rainforest stands that differ in age (8-32 year-old). For each tree, height and stem diameter were monitored for 2 years to calculate relative biomass growth rate (RGR, the aboveground biomass gain per unit aboveground tree biomass per year). For each stand, 3D light profiles were measured to estimate individuals' light interception to calculate light interception efficiency (LIE, intercepted light per unit biomass per year) and light use efficiency (LUE, biomass growth per intercepted light). Throughout succession, species with higher RGR attained higher changes in species dominance and thus increased their dominance over time. Both light competition strategies (LIE and LUE) increased RGR. In early succession, a high LIE and its associated traits (large crown leaf mass and low wood density) are more important for RGR. During succession, forest structure builds up, leading to lower understory light levels. In later succession, a high LUE and its associated traits (high wood density and leaf mass per area) become more important for RGR. Therefore, successional changes in relative importance of light competition strategies drive shifts in species dominance during tropical rainforest succession.

Divide and conquer: Spatial and temporal resource partitioning structures benthic cyanobacterial mats.

Benthic cyanobacterial mats are increasing in abundance worldwide with the potential to degrade ecosystem structure and function. Understanding mat community dynamics is thus critical for predicting mat growth and proliferation and for mitigating any associated negative effects. Carbon, nitrogen, and sulfur cycling are the predominant forms of nutrient cycling discussed within the literature, while metabolic cooperation and viral interactions are understudied. Although many forms of nutrient cycling in mats have been assessed, the links between niche dynamics, microbial interactions, and nutrient cycling are not well described. Here, we present an updated review on how nutrient cycling and microbial community interactions in mats are structured by resource partitioning via spatial and temporal heterogeneity and succession. We assess community interactions and nutrient cycling at both intramat and metacommunity scales. Additionally, we present ideas and recommendations for research in this area, highlighting top-down control, boundary layers, and metabolic cooperation as important future directions.

Deciphering the influence of salinity stress on the biological aniline degradation system: Pollutants degradation performance and microbial response.

In order to evaluate the impact of salinity gradients on the aniline biodegradation system, six reactors at salinity concentrations (0%-5%) were established. The results presented the salinity except for 5% imposed negligible effects on aniline degradation performance. Nitrification had prominent resistance to salinity (0%-1.5%) while were significantly restrained when salinity increased. The total nitrogen (TN) removal efficiency of Z4 (1.5%) was 20.5% higher than Z1 (0%) during the stable operation phase. Moreover, high throughput sequencing analysis showed that halophilic bacterium, such as Halomonas, Rhodococcus, remained greater survival advantages in high salinity system. The substantial enrichment of Flavobacterium, Dokdonella, Paracoccus observed in Z4 ensured its excellent nitrogen removal performance. The close cooperation among dominant functional bacteria was strengthened when salt content was below 1.5% while exceeding 1.5% led to the collapse of metabolic capacity through integrating the toxicity of aniline and high osmotic pressure.

Spatial and temporal patterns of phytoplankton community succession and characteristics of realized niches in Lake Taihu, China.

Understanding the dynamics and succession of phytoplankton in large lakes can help inform future lake management. The study analyzed phytoplankton community variations in Lake Taihu over a 21-year period, focusing on realized niches and their impact on succession. The study developed a niche periodic table with 32 niches, revealing responses to environmental factors and the optimal number of niches. Results showed that the phytoplankton in Lake Taihu showed significant spatial and temporal heterogeneity, with biomass decreasing as one moved from the northwest to the southeast and expanding towards central lake area, and towards autumn and winter. Different phytoplankton groups in Lake Taihu occupied realized niches shaped by temperature, nitrate, and phosphate. To predict the response of eutrophic freshwater lake ecosystems to human activities and climate change, it is critical to interpret the law of phytoplankton bloom and niche succession.