Community Shifts Research Articles

Unraveling demographic patterns in tropical birds across an elevational gradient

Abstract An increasing body of evidence has displayed upslope shifts in the high-diversity avian communities of tropical mountains. Such shifts have largely been attributed to warming climates, although their actual mechanisms remain poorly understood. One likely possibility is that changes in species-specific demographic rates underlie elevational range shifts. Fine-scale population monitoring and capture–mark–recapture (CMR) analysis could shed light on these mechanisms but, until recently, analytical constraints have limited our ability to model multiple demographic rates across bird communities while accounting for transient individuals. Here, we used Bayesian hierarchical multi-species CMR models to estimate the apparent survival, recruitment, and realized population growth rates of 17 bird species along an elevational gradient in the cloud forests of Honduras. For 6 species, we also modeled demographic rates across elevation and time. Although demographic rates varied among species, population growth rates tended to be higher in lower elevation species. Moreover, some species showed higher population growth rates at higher elevations, and elevational differences in growth rates were positively associated with previous estimates of upslope shifts at the study site. We also found that demographic rates showed contrasting trends across the duration of the study, with recruitment decreasing and apparent survival increasing, and stronger effects at lower elevations. Collectively, we provide the methodological tools to encourage more multi-species demographic analyses in other systems, while highlighting the potential for the demographic impacts of global change. We provide a Spanish translation in the Supplementary Materials.

Grazing disturbance reduces biocrust-related cyanobacteria and N-fixer abundance but increases bacterial diversity: Implications for biocrust restoration in degraded drylands

Overgrazing is a major driver of dryland degradation, however, so far, there is limited understanding on how this process affects biocrust-related microbial community, and especially how the key groups respond to grazing disturbance. In this study, quantitative polymerase chain reaction (qPCR) and high throughout sequencing technologies were used to investigate the bacterial community abundance and diversity in the Horqin Sandland (China) experiencing different livestock grazing disturbances, in order to examine whether a shift in bacterial community (in particular the key biocrust components, cyanobacteria) was involved, and how this was related to biocrust development and altered soil carbon and nitrogen level. Our results revealed that a clear heterogeneous soil bacterial community was associated with grazing disturbance, which inhibited biocrust development. The decreased photosynthetic cyanobacterial abundance (81.81 % in relative abundance and 98.83 % in absolute abundance) and nitrogen-fixing genes (87.72 %), associated with the lower total carbon and nitrogen content (P<0.05), illustrated a low soil carbon and nitrogen-fixing capability and nutrient level in the grazing-disturbed soils. In particular, a switch of nitrogen-fixing dominance from cyanobacteria to proteobacteria was induced by the grazing disturbance. Compared to the grazing-disturbed soils, higher dominant cyanobacterial operational taxonomic units (OTUs) (especially the species of Nostoc and Scytonema) and lower bacterial diversity (e.g., Shannon, Ace, and Chao index) were observed in the undisturbed biocrust soils, highlighting that the dominants rather than diversity played more important roles in biocrust development. Collectively, our results demonstrate that cyanobacteria are very sensitive (even more than others, e.g., proteobacteria and actinobacteria) to grazing disturbance, therefore, we propose that cyanobacterial inoculation is likely an effective approach to supplement soil cyanobacterial abundance, which is expected to induce biocrust development and increase carbon and nitrogen level in the disturbed drylands.

The Effects of Model Insoluble Copper Compounds in a Sedimentary Environment on Denitrifying Anaerobic Methane Oxidation (DAMO) Enrichment

The contribution of denitrifying anaerobic methane oxidation (DAMO) as a methane sink across different habitats, especially those affected by anthropogenic activities, remains unclear. Mining and industrial and domestic use of metals/metal-containing compounds can all cause metal contamination in freshwater ecosystems. Precipitation of metal ions often limits their toxicity to local microorganisms, yet microbial activity may also cause the redissolution of various precipitates. In contrast to most other studies that apply soluble metal compounds, this study investigated the responses of enriched DAMO culture to model insoluble copper compounds, malachite and covellite, in simulated sedimentary environments. Copper ≤ 0.22 µm from covellite appeared to cause immediate inhibition in 10 h. Long-term tests (54 days) showed that apparent methane consumption was less impacted by various levels of malachite and covellite than soluble copper. However, the medium-/high-level malachite and covellite caused a 46.6–77.4% decline in denitrification and also induced significant death of the representative DAMO microorganisms. Some enriched species, such as Methylobacter tundripaludum, may have conducted DAMO or they may have oxidized methane aerobically using oxygen released by DAMO bacteria. Quantitative polymerase chain reaction analysis suggests that Candidatus Methanoperedens spp. were less affected by covellite as compared to malachite while Candidatus Methylomirabilis spp. responded similarly to the two compounds. Under the stress induced by copper, DAMO archaea, Planctomycetes spp. or Phenylobacterium spp. synthesized PHA/PHB-like compounds, rendering incomplete methane oxidation. Overall, the findings suggest that while DAMO activity may persist in ecosystems previously exposed to copper pollution, long-term methane abatement capability may be impaired due to a shift of the microbial community or the inhibition of representative DAMO microorganisms.

Evaluation of Rain Shelter Cultivation Mode Effects on Microecological Environment of Mountain Cultivated Ginseng Rhizosphere

Rainfall, particularly in continental climates with a monsoonal tendency, impacts the microbial niches during the growth of mountain cultivated ginseng. With shifts in the microbial community, diseases in ginseng cultivated and protected under rain shelter conditions may ultimately be altered. Such cultivation may influence microflora dynamics through variations in meteorological parameters; however, this is not yet clear. The present study found that rain shelter cultivation affected the distribution of fungal communities within mountain cultivated ginseng. This led to an improved community structure in the ginseng rhizosphere, characterized by the proliferation of antagonistic fungi and a reduction in pathogenic fungi. A correlation analysis of meteorological factors found that soil temperature and humidity were the primary meteorological factors affecting mountain cultivated ginseng. It is evident that rain shelter cultivation regulated the microecological environment of the mountain cultivated ginseng’s rhizosphere and resulted in positive outcomes. A disease investigation supported this finding. The incidence of ginseng root diseases, such as rust and root rot, was reduced by 5–6%. The incidence of ginseng leaf diseases, including gray mold and black spot, was reduced by 5–10%. This research provides evidence to address the dynamics of microbial ecology under rain shelter cultivation and its benefits for sustainable mountain cultivated ginseng management.

Colonial management drives ecological change following the exclusion of Indigenous stewardship in a Stoney Iyethka montane grassland, Canadian Rocky Mountains

Abstract For millennia, Indigenous Peoples and their ecological stewardship have kept culturally important landscapes open, diverse and productive. Under colonization which suppresses stewardship activities, landscape vegetation patterns shift and areas previously stewarded by Indigenous Peoples are now undergoing successional change. As a case study, we document ecological change on the homelands of the Stoney Iyethka Nations in the Canadian Rocky Mountains, where landscapes have changed dramatically over the past century of colonial management. On the Stoney Iyethka traditional montane Egnuck Wida grasslands, we analysed vegetation change on both the landscape and plot level. Using oblique photographs taken in 1924 paired with 2021 satellite imagery, we compared past and present landscape vegetation cover and assessed drivers of succession. We also examined differences in vegetation class cover and plant community structure between surveys conducted in 1981, 1995 and 2020. Nearly half (47%) of the landscape surveyed showed seral progression in vegetation class, which was not explained by topography, geology or climate warming. Grassland area decreased four‐fold between 1924 and 2021. Grassland retention was strongly related to management zoning, with greater losses in the crown‐managed ecological reserve than on lands that remain under Stoney Iyethka stewardship. Vegetation plots surveyed reveal changes to plant community composition and shifts in dominant vegetation class. In plots previously composed primarily of forbs and graminoids, shrubs have become the dominant groundcover. Declines in historic vegetation include a loss of culturally important food, medicine and ceremonial plants to the Stoney Iyethka Nations. The most likely explanation for these results is the displacement of Indigenous Peoples and their stewardship from the landscape. We demonstrate that the past century of colonial environmental management has altered ecological processes maintained on this landscape for millennia by Indigenous Peoples. Read the free Plain Language Summary for this article on the Journal blog.

Aerobic granular sludge enhances start-up and granulation in single-stage partial nitritation anammox granular sludge systems: Performance, mechanism, and shifts in bacterial communities

The rapid start-up and granulation of a single-stage partial nitritation anammox granular sludge (PN/AnGS) system under limited seed sludge conditions is crucial for its practical application. This study proposed an aerobic granular sludge (AGS) − based strategy, enhanced the enrichment of anammox bacteria (AnAOB), and shortened the start-up time of PN/AnGS system by 20.5%. In addition, the inoculation of AGS can ensure the stable operation of the system during the selective sludge discharge to washout the flocs. Microbial community structure, particle size distribution, morphology results showed that niche shift was the key to promote the enrichment of AnAOB and AGS played a decisive role in the particle characteristics of PN/AnGS. Since AGS can be directly obtained from full-scale AGS wastewater treatment plants, integrating PN/AnGS with AGS processes can transition wastewater treatment from a “linear economy” to a “circular economy”, enhancing nitrogen removal efficiency and delivering significant economic and environmental benefits.

Degradation of oxytetracycline in soil by a Pseudomonas strain

Oxytetracycline (OTC) is used extensively in animal husbandry and enters the soil in different forms, causing severe environmental pollution. Previous studies have shown that the genus Pseudomonas can potentially degrade antibiotics in the soil environment. Environmental conditions, such as the initial concentration of antibiotics, incubation temperature and others, have significant impacts on the activity of antibiotic-degrading bacteria. However, few reports have clarified the environmental impacts on the effectiveness of Pseudomonas spp. In the present study, we investigated the effects of different initial concentrations of OTC and incubation temperatures, as well as soil sterilization, on OTC degradation by Pseudomonas <pg=>strain T4. We also focused on the microbial degradation pathways of OTC, and variations in both antibiotic resistance genes (ARGs) and microbial communities with T4 functioning under optimal conditions. The results showed that the most effective degradation occurred under an initial OTC concentration of 2.5 mg kg-1 at 30°C in unsterilized soil spiked with T4. These conditions yielded an OTC degradation rate of 69.53% within 63 days. The putative degradation pathways of OTC in the presence of T4 included dehydration, demethylation, deamination, hydroxylation, oxidation and ring opening. Bacteroidetes, Proteobacteria and Acidobacteria played key roles in the biodegradation of OTC with T4 in the soil. The results also showed that tet(G) was the most frequently detected among the 13 common tetracycline ARGs that were investigated. The bacterial community shift observed in this study may provide new insights into the microbial degradation of OTC in soil.

Experimental coral reef communities transform yet persist under mitigated future ocean warming and acidification

Coral reefs are among the most sensitive ecosystems affected by ocean warming and acidification, and are predicted to collapse over the next few decades. Reefs are predicted to shift from net accreting calcifier-dominated systems with exceptionally high biodiversity to net eroding algal-dominated systems with dramatically reduced biodiversity. Here, we present a two-year experimental study examining the responses of entire mesocosm coral reef communities to warming (+2 °C), acidification (-0.2 pH units), and combined future ocean (+2 °C, -0.2 pH) treatments. Contrary to modeled projections, we show that under future ocean conditions, these communities shift structure and composition yet persist as novel calcifying ecosystems with high biodiversity. Our results suggest that if climate change is limited to Paris Climate Agreement targets, coral reefs could persist in an altered state rather than collapse.

Current Progress on Antibiotic Resistance Genes Removal by Composting in Sewage Sludge: Influencing Factors and Possible Mechanisms

Antibiotic resistance genes (ARGs) present in sewage sludge pose significant environmental and public health challenges. Composting has emerged as a promising method to mitigate these risks by reducing ARGs. This review paper evaluated the current progress in the removal of ARGs through composting, incorporating a bibliometric analysis of 228 publications from January 2010 to January 2024. This review highlights the increasing scholarly interest in this field, with a notable rise in publications since 2010. Key mechanisms identified include the denaturation of proteins and DNA at high temperatures, the adsorption of antibiotics and heavy metals by additives like biochar, and shifts in microbial communities, all contributing to the reduction of ARGs during composting. Despite these findings, challenges remain in achieving consistent ARG removal rates, addressing the potential for ARG regrowth, and understanding horizontal gene transfer post-composting. This review suggests further research into optimizing composting conditions and integrating additional treatment methods to enhance ARG removal and minimize associated risks.

Microbial community acclimation during anaerobic digestion of high-oil food waste

Anaerobic digestion is one of the most promising options for the disposal of biodegradable food waste. However, the relatively high content of oil in food waste inhibits the conversion efficiency of anaerobic digestion because of the accumulation of long-chain fatty acids (LCFAs). In this study, activated anaerobic sludge was acclimated to accommodate high-oil conditions. The methane yield of high-oil food waste digested by the acclimated sludge increased by 24.9% compared to that digested by the raw sludge. To determine the internal changes in the acclimated sludge, the shifts in the microbial communities during the acclimation period were investigated via high-throughput sequencing (HTS) based on the 16 S rRNA gene. The results indicated that Bacteroidetes, Firmicutes, Chloroflexi and Proteobacteria were the dominant bacteria at the phylum level. The acclimation time allows some functional bacterial taxa to proliferate, such as Clostridium and Longilinea, which are able to degrade LCFAs and turn them into small organic molecules that also have nutrient value for other bacteria. Among the archaeal communities, the hydrogenotrophic methanogen Methanobacterium nearly supplanted the acetotrophic methanogen Methanosaeta. The time profiles of volatile fatty acids (VFAs) and pH during this period provided additional evidence for the success of the acclimation. This study demonstrated the effectiveness of acclimation and the dynamic of microbial communities, which further contributed to the management and resource utilization of high-oil food waste.

Shift of bacterial and fungal communities upon soil amelioration is driven by carbon degradability of organic amendments

The structural response of bacterial and fungal soil communities to four carbon-rich organic amendments of increasing recalcitrance was investigated. Wheat straw, green compost, a mixed product based on biogas residues, and a fermented biochar were applied to a sandy agricultural soil of low organic carbon content. After laboratory incubation for 6 months, the community structure was investigated via DNA sequencing. All amendments caused changes in the communities of bacteria and fungi, but to different extents, with the communities exposed to more recalcitrant amendments showing the least variation compared to the non-amended soil. Changes in species composition as well as their relative abundances were observed. While the straw had a pronounced effect on bacteria (e.g., the highest number of indicator species), effects of the composted, fermented, or pyrolyzed materials were minor. Hierarchical clustering showed that the fungal communities were more different from each other than the bacterial ones with the straw-soil being most different and the biochar-soil least different from the non-amended soil. While the abundant fungal species in biochar-soil and non-amended soil were very alike, especially rare fungal species shifted upon addition of biochar. An indicator species analysis identified specific taxonomic groups which were triggered by the different organic materials. We conclude that bacterial and fungal communities strongly change upon input of degradable carbon (straw), while fungi in particular respond to the application of processed organic materials. With this study, we report the consequences of applying organic materials for the microbial community in one soil. We provide these data for meta-analyses that are required to unravel all relevant interactions across different soils, organic materials, and time. This will allow to better understand and predict the effects of organic soil amelioration measures on soil microorganisms.

Coral high molecular weight carbohydrates support opportunistic microbes in bacterioplankton from an algae-dominated reef.

Dissolved organic matter (DOM) released by benthic primary producers fuels coral reef food webs. Anthropogenic stressors cause shifts from coral to algae dominance on many reefs, and resulting alterations in the DOM pool can promote opportunistic microbes and potential coral pathogens in reef water. To better understand these DOM-induced effects on bacterioplankton communities, we compared the carbohydrate composition of coral- and macroalgae-DOM and analyzed the response of bacterioplankton from an algae-dominated reef to these DOM types. In line with the proposed microbialization of reefs, coral-DOM was efficiently utilized, promoting energy transfer to higher trophic levels, whereas macroalgae-DOM likely stimulated microbial respiration over biomass production. Contrary to earlier findings, coral- and not algal-DOM selected for opportunistic microbial taxa, indicating that a change in the prevalent DOM composition, and not DOM type, may promote the rise of opportunistic microbes. Presented results may also apply to other coastal marine ecosystems undergoing benthic community shifts.

Warming increases CH4 emissions from rice paddies through shifts in methanogenic and methanotrophic communities

Warming often stimulates methane (CH4) emissions from rice paddies, one of the largest anthropogenic sources of CH4 emissions. However, the responses of methanogenic and methanotrophic communities to warming, particularly within active communities, remain unclear. Therefore, based on a field warming experiment in a rice-wheat system, we investigated the effects of warming on methanogenic and methanotrophic communities, using the DNA stable-isotope probing technology. Our results indicated that warming increased CH4 emissions by 27–49% over two rice growing seasons compared to ambient conditions. Warming significantly increased the abundance of methanogens by 53%, whereas did not affect activities of methanogens and active methanogenic community. Conversely, warming did not influence the abundance of methanotrophs, but reduced activities of methanotrophs by 44%. Notably, warming led to a significant rise in the relative abundance of the active type II methanotrophic community, which exhibits lower CH4 oxidation efficiency. These findings suggest that the observed increase in CH4 emissions under warming conditions is primarily driven by the enhanced abundance of methanogens and the increased presence of less efficient active type II methanotrophs. This study underscores the critical role of active microbial communities in understanding and managing CH4 emissions from rice paddies in a warming world.

Rapid shifts in grassland communities driven by climate change.

Many terrestrial plant communities, especially forests, have been shown to lag in response to rapid climate change. Grassland communities may respond more quickly to novel climates, as they consist mostly of short-lived species, which are directly exposed to macroclimate change. Here we report the rapid response of grassland communities to climate change in the California Floristic Province. We estimated 349 vascular plant species' climatic niches from 829,337 occurrence records, compiled 15 long-term community composition datasets from 12 observational studies and 3 global change experiments, and analysed community compositional shifts in the climate niche space. We show that communities experienced significant shifts towards species associated with warmer and drier locations at rates of 0.0216 ± 0.00592 °C yr-1 (mean ± s.e.) and -3.04 ± 0.742 mm yr-1, and these changes occurred at a pace similar to that of climate warming and drying. These directional shifts were consistent across observations and experiments. Our findings contrast with the lagged responses observed in communities dominated by long-lived plants and suggest greater biodiversity changes than expected in the near future.

Control of dissolved H2 concentration enhances electron generation, transport and TCE reduction by indigenous microbial community

Electrokinetic enhanced bioremediation (EK-Bio) is practical for trichloroethene (TCE) dechlorination because the cathode can produce a wide range of dissolved H2 (DH) concentrations of 1.3–0 mg/L from the electrode to the aquifer. In this study, TCE dechlorination was investigated under different DH concentrations. The mechanisms were discussed by analyzing the microbial community structure and abundance of organohalide-respiring bacteria (OHRB) using 16S rRNA, and the gene abundances of key enzymes in the TCE electron transport chain using metagenomic analysis. The results showed that the moderate DH concentration of 0.19–0.53 mg/L exhibited the most pronounced TCE dechlorination, even better than the higher DH concentrations, due to the optimal redox environment, the enrichments of OHRB, reductive dehalogenase (rdhA) genes and key enzyme genes in the electron generation and transport chain. More electrons were obtained from H2 metabolism by Dehalobacter by promoting the formation of [NiFe] hydrogenase (HupS/L/C) or from glycolysis by versatile OHRB by stimulating the formation of formate and enriching formate dehydrogenase (FDH) under moderate DH conditions. In addition, the enhanced amino acid metabolism improved the vitamin K cycle for electron transport and enriched the reductive dechlorinating enzyme (RDase) genes. This study identifies the optimal DH concentration that facilitates bioremediation efficiency, provides insights into microbial community shifts and key enzymatic pathways in EK-Bio remediation.

Glacier Retreat Induces Contrasting Shifts in Bacterial Biodiversity Patterns in Glacial Lake Water and Sediment

Glacial lake ecosystems are experiencing rapid changes due to accelerated glacier retreat. As glaciers recede, their influence on downstream habitats diminishes, potentially affecting the biodiversity of glacial lake microbial communities. However, there remains a knowledge gap regarding how bacterial biodiversity patterns in glacial lakes are altered by diminishing glacial influence. Here, we investigated shifts in bacterial communities in paired water and sediment samples collected from seven glacial lakes on the Tibetan Plateau, using a space-for-time substitution approach to understand the consequences of glacier retreat. Our findings reveal that bacterial diversity in lake water increases significantly with a higher glacier index (GI), whereas sediment bacterial diversity exhibits a negative correlation with GI. Both the water and sediment bacterial communities display significant structural shifts along the GI gradient. Notably, reduced glacial influence decreases the complexity of bacterial co-occurrence networks in lake water but enhances the network complexity in sediment. This divergence in diversity and co-occurrence patterns highlights that water and sediment bacterial communities respond differently to changes in glacial influence in these lake ecosystems. This study provides insights into how diminishing glacial influence impacts the bacterial biodiversity in glacial lake water and sediments, revealing contrasting patterns between the two habitats. These findings emphasize the need for comprehensive monitoring to understand the implications of glacier retreat on these fragile ecosystems.

Microbial Gatekeepers of Fertility in the Female Reproductive Microbiome of Cattle.

This review paper delves into the intricate relationship between the genital microbiome and fertility outcomes in livestock, with a specific focus on cattle. Drawing upon insights derived from culture-independent metagenomics studies, the paper meticulously examines the composition and dynamics of the genital microbiome. Through advanced techniques such as high-throughput sequencing, the review illuminates the temporal shifts in microbial communities and their profound implications for reproductive health. The analysis underscores the association between dysbiosis-an imbalance in microbial communities-and the development of reproductive diseases, shedding light on the pivotal role of microbial gatekeepers in livestock fertility. Furthermore, the paper emphasizes the need for continued exploration of uncharted dimensions of the female reproductive microbiome to unlock new insights into its impact on fertility. By elucidating the complex interplay between microbial communities and reproductive health, this review underscores the importance of innovative strategies aimed at enhancing fertility and mitigating reproductive diseases in livestock populations.

Moisture-mineral interactions drive bacterial and organic matter turnover in glacier-sourced riparian sediments undergoing pedogenesis

Glacial recession is occurring at unprecedented rates resulting in increased sediment accumulations in some riverine ecosystems providing new mineral surfaces for soil formation. Soils and sediments have an enormous potential to retain carbon (C), predominantly due to sorption to mineral surfaces. However, C persistence may be sensitive to climate-change induced temperature and moisture variations. We coupled ultrahigh resolution organic matter composition classification with bacterial characterization and respiration measurements to test the combined pedogenic effects of temperature (4 vs 20 °C) and moisture (50 vs 100% water-filled pore space) on C turnover in sediments maintained under different mineralogical conditions (illite-amended vs non-amended). Here we show that the inhibition of CO2 emissions from the combined effect of increased moisture content and illite was reflected in the turnover of key molecular signatures, such as the nominal oxidation state of C, often irrespective of temperature. However, shifts in bacterial communities from a coupled moisture-mineral interaction, were temperature-dependent. Our results highlight the importance of moisture in driving mineral-organic interactions and suggest that C in clay-rich, water-saturated sediments is both thermodynamically unfavorable and mineral-protected from microbial consumption.

Temperature sensitivity of soil respiration declines with climate warming in subalpine and alpine grassland soils

AbstractWarming as a climate change phenomenon affects soil organic matter dynamics, especially in high elevation ecosystems. However, our understanding of the controls of soil organic matter mineralization and dynamics remains limited, particularly in alpine (above treeline) and subalpine (below treeline) grassland ecosystems. Here, we investigated how downslope (warming) and upslope (cooling) translocations, in a 5-years reciprocal transplanting experiment, affects soil respiration and its temperature sensitivity (Q10), soil aggregation, and soil organic matter carbon (C) and nitrogen (N) composition (C/N ratio). Downslope translocation of the alpine (2440 m a.s.l.) and subalpine (1850 m a.s.l.) to the lowland site (350 m a.s.l.) resulted in a temperature change during the growing seasons of + 4.4K and + 3.3K, respectively. Warming of alpine soils (+ 4.4K) reduced soil organic carbon (SOC) content by 32%, which was accompanied by a significant decrease of soil macroaggregates. Macroaggregate breakdown induced an increased respiration quotient (qCO2) by 27% following warming of alpine soils. The increase in qCO2 respiration was associated with a significant decrease (from 2.84 ± 0.05 to 2.46 ± 0.05) in Q10, and a change in soil organic matter composition (lower C/N ratios). Cooling did not show the opposite patterns to warming, implying that other mechanisms, such as plant and microbial community shifts and adaptation, were involved. This study highlights the important role of SOC degradability in regulating the temperature response of soil organic matter mineralization. To predict the adverse effect of warming on soil CO2 release and, consequently, its negative feedback on climate change, a comprehensive understanding of the mechanisms of C storage and turnover is needed, especially at high elevations in the Alps that are particularly affected by rising temperatures.

The Impact of Microbial Interactions on Ecosystem Function Intensifies Under Stress.

A major challenge in ecology is to understand how different species interact to determine ecosystem function, particularly in communities with large numbers of co-occurring species. We use a trait-based model of microbial litter decomposition to quantify how different taxa impact ecosystem function. Furthermore, we build a novel framework that highlights the interplay between taxon traits and environmental conditions, focusing on their combined influence on community interactions and ecosystem function. Our results suggest that the ecosystem impact of a taxon is driven by its resource acquisition traits and the community functional capacity, but that physiological stress amplifies the impact of both positive and negative interactions. Furthermore, net positive impacts on ecosystem function can arise even as microbes have negative pairwise interactions with other taxa. As communities shift in response to global climate change, our findings reveal the potential to predict the biogeochemical functioning of communities from taxon traits and interactions.