Biology subjects

Rillig, M. C.

Publications and source records attributed to Rillig, M. C..

At least 19 recordsLinked to original sources

bioRxiv2026

Combined negative effects of simultaneous perturbations on grassland functionality

1. Grassland ecosystems are pivotal for global biodiversity, carbon (C) storage and food security. This biome, however, together with the ecosystem services it provides, is threatened by global change perturbations. These perturbations rarely occur in isolation and most often affect environments simultaneously, which is a pressing issue in ecology. Nevertheless, most of the research conducted so far has focussed on single simultaneous perturbations or pairs thereof. The few examples considering the effect of more than two simultaneous perturbations focussed only on plants or soil separately, which ignores the potential buffering or feedback effects on ecosystem functioning induced by plant-soils interactions. 2. To tackle this knowledge gap, we used an experimental setup involving mesocosms (soil and plants intact) collected in an extensively managed permanent grassland. Mesocosms were arranged in a greenhouse experiment where we applied individual and combined global change perturbations (up to ten in total) including application of fertilisers, pesticides and antibiotics, simulated trampling and grazing, heat stress and drought. Measured ecosystem functions and properties included a large set of biological, physical and chemical soil and plant associated variables. 3. Results showed that multiple perturbations in most cases had negative effects irrespective of the direction found for individual perturbations. However, in contrast to previous bare soil experiments, we only found scarce evidence for substantial synergistic effects of simultaneous perturbations in our experiment conducted with mesocosms that contained vegetation. This suggests a mitigating impact of plants on soil responses to global change. Moreover, we found a strong dominative effect of drought on ecosystem functioning, driving most of the effects observed. 4. Synthesis: Our results highlight the importance of evaluating global change impacts under more realistic settings, i.e., applying multiple perturbations simultaneously and including plant-soil interactions. Mitigation of global change in terrestrial ecosystems will only be possible once we holistically understand how ecosystems respond to altered conditions.

ecology↗

bioRxiv2026

Soils from different landscape elements diverge in response to multiple global change factors

Global change factors (GCFs) are known to affect terrestrial ecosystems across a range of land-use types, including farmlands, grasslands, and forests. However, it remains unclear whether different landscape elements within the same region respond differently to the same global change pressures. Here, we investigated this question using four soils collected from co-located farmland, grassland, pine forest, and oak forest, representing distinct landscape elements under the same regional climatic conditions. Each soil was exposed to one of six individual GCFs, warming, drought, nitrogen deposition, salinity, microplastics, and antibiotics, as well as to all six factors combined. We found that landscape elements exhibited strongly divergent responses to the same GCFs. The effects on soil functions also varied among soils under combined stress, with responses diverging from different null-model predictions depending on soils and response variable. Moreover, landscape-element specific response patterns became more pronounced under multiple concurrent stressors. Overall, our findings show that landscape heterogeneity represents a mosaic of different capacities to resist and respond to global change, even under shared climatic and geographic conditions. Global change assessments and ecosystem models should therefore better account for landscape-level heterogeneity, and management strategies aimed at enhancing ecosystem resilience should be tailored to individual landscape elements.

ecology↗

bioRxiv2026

The first spectrum of spore form and function reveals constrained evolution in mycorrhizal symbiosis

Arbuscular mycorrhizal (AM) fungi form one of the oldest and most widespread obligate mutualisms on Earth, yet they must survive independently while dispersing between hosts. Spores bridge this vulnerable host-free phase, and their morphology should therefore reflect the demands of persistence, dispersal, and establishment. However, the macroevolutionary trajectories of AM spore morphology remain poorly resolved, limiting our ability to determine whether spores diversified into multiple designs or remained constrained around a common architecture. Here, we construct the first quantitative morphospace of AM fungal spores and infer macroevolutionary patterns of trait evolution. We find that AM fungal spores have diversified mainly through scaling rather than redesign. The morphospace is dominated by size, with spore dimensions and wall volume coordinated through near-isometric scaling. Shape remains predominantly near-spherical across sizes, although the largest spores allocate proportionally less material to the wall, while ornamentation and coloration form a largely independent axis of surface variation. Most species occupy a narrow region of trait space, with distantly related lineages converging on similar trait combinations. We propose that adaptive filtering and construction economy jointly maintain this architecture. Near-spherical geometry may provide an efficient solution for packaging and protecting the reserves needed to persist between hosts while minimizing investment in wall material, whereas surface traits may mediate dispersal vectors. Functionally, this architecture suggests that AM fungal spores are shaped more by persistence through time than by dispersal through wind. The AM fungal spore morphospace thus links conserved spore design to the challenge of dispersal in an obligate mutualist.

ecology↗

bioRxiv2026

Root hairs and mycorrhiza represent alternative phylogenetically conserved strategies for belowground absorptive surface maximization

O_LIPlants take up nutrients from the soil while investing in absorptive root surface or mycorrhizal partners. Root hairs - a major structure for nutrient uptake and cheap to build - increase the absorptive root surface. As such they are an important component of plant resource economics but largely neglected in root economic concepts so far. C_LIO_LIThis is mainly due to data scarcity, which we set out to overcome by measuring root-hair traits on 82 European grassland species in a greenhouse experiment. Using fluorescence and light microscopy, root-hair length and incidence was measured along with mycorrhizal colonization. C_LIO_LIWe found a phylogenetically conserved trade-off between plant investment into root hairs and mycorrhiza. A similar trade-off between root-hair incidence and mycorrhiza occurred at the intraspecific level, while patterns were heterogeneous among species. Plant species with high colonization rates showed the highest variability in root-hair incidence. C_LIO_LIWe conclude that plants vary along a gradient ranging from investment into root hairs as part of a "do-it-yourself" strategy to collaboration with mycorrhizal fungi while showing intraspecific variation in root-hair incidence. These findings demonstrate that root hairs play a fundamental role in fine-root trait variation and need to be considered when studying belowground plant economic strategies. C_LI

ecology↗

bioRxiv2026

Microplastics drive both linear and threshold-type shifts in soil multifunctionality along concentration gradients

Microplastics are increasingly recognized as emerging contaminants in terrestrial ecosystems, yet their mechanistic impacts on soil multifunctionality remain poorly understood. Here, we evaluated the influence of two microplastic polymers, polyethylene terephthalate and polypropylene, on soil functioning by subjecting soils to a gradient of concentrations of these microplastics, and measuring six variables representing soil physical, chemical, and biological functions. A statistical framework combining multi-model inference with threshold detection and machine learning was implemented in this study to identify the main pathways of soil multifunctional change. Most significant responses followed nonlinear trends and threshold shifts, primarily in physical properties, indicating that microplastic stress first impacts soil structure before cascading to chemical and biological processes. We identified two system-level thresholds at 0.3% PP and 0.55% PET w/w; while random forest highlighted water-stable aggregates as the dominant predictor of overall soil multifunctionality. Our findings provide new quantitative evidence of complex soil multifunctionality responses to microplastic pollution. Most importantly, physical deterioration emerged as an early-warning signal of microplastic disturbance, thereby advancing our understanding of microplastic pollution on soil systems.

ecology↗

bioRxiv2026

Rapid evolution in necromass use under resource limitation reduces persistence in producer-decomposer microbial biospheres

This study employs a synthetic microbial biosphere model to investigate system persistence under resource limitation. Escherichia coli (E. coli) strain MC4100 was incubated in matter-closed systems in an isotonic saline solution without added nutrients for 60 days in spatially homogeneous or heterogeneous conditions. We observed phenotypic adaptive changes in E. coli populations, including loss of motility, enhanced biofilm formation, and improved growth on various carbon sources, which were specific to the spatial structure conditions. While these changes were beneficial for E. coli persistence in monoculture, during co-culture with the alga Chlamydomonas reinhardtii the adapted populations exhibited a 25% reduction in persistence under spatially heterogeneous conditions compared to co-cultures containing non-adapted E. coli populations. Critically, adaptive changes in monoculture affected the dynamics of co-cultures, demonstrating that microbial evolution can constrain coexistence with other species and may be a fundamental determinant of ecosystem sustainability.

ecology↗

bioRxiv2025

What are all these soil fungi doing? Complex carbon use ability as a predictive trait for fungal community functions

Fungal communities in soil play important roles in decomposition processes and soil organic carbon cycling. These communities are tremendously diverse, making it challenging to assign relevant functions to individual species. Fungal communities may be differentiated at the level of functional guilds; beyond such broad classification we have little delimitation, especially in fungal taxa common in grassland and agricultural soils. To resolve the level of functional similarity in fungal communities and define traits predictive of soil carbon cycling, we characterized fungal isolates abundant in agricultural soils to test the hypotheses that (i) the majority of saprobic soil fungi have the ability to use complex carbon sources, (ii) differences in complex carbon use abilities correlate with fungal enzymatic profiles, following principles of the fungal economics spectrum and (iii) carbon use ability is a predictive trait for fungal community functions. Using specialized growth media, we isolated and characterized 105 isolates and developed a novel FungiResp approach that directly tests fungal activity on complex carbon sources. The largest amount of variance between isolates was explained by differential abilities to use cellulose and starch, with only few phylogenetically distinct fungal clades showing high respiratory activity on these biopolymers. A preference for bacterial necromass was another major distinction among taxa. These key traits correlated with soil fungal community shifts in response to carbon substrate availability. By contrast, enzymatic activity was a poor predictor of fungal carbon use ability, except for correlations in lignin use and laccase activity. The newly established functional trait of carbon use ability offers important insights into diverse fungal communities: Many taxa lack the ability to use complex carbon (on their own), while the most common enzymes analyzed in soil showed little correlation with fungal mineralization potential. The discovery of key functional traits is an important step towards predicting the significance of fungal community shifts for soil carbon cycling.

ecology↗

bioRxiv2025

Abrupt versus gradual application of pesticides: effects on soil bacterial and fungal communities

Pesticides are a major anthropogenic input to the environment and a factor in global change that puts pressure on soil microbial communities. However, the effects of different rates of pesticide application on soils remain poorly understood. This study investigates how abrupt versus gradual pesticide applications influence soil bacterial and fungal communities. Employing high-throughput sequencing, we examined the microbial diversity and community composition in response to ten commonly used pesticides. Bacterial communities exhibited minimal changes across treatments, whereas fungal communities responded strongly to pesticide exposure. Gradual applications reduced the relative abundance of dominant fungal taxa, resulting in an overall increase in community evenness. This effect was particularly pronounced for two herbicides and a triazole fungicide, which induced substantial shifts in fungal composition. Conversely, abrupt pesticide applications resulted in transient disruptions but did not promote the long-term proliferation of rare fungal variants. These findings suggest that prolonged exposure to pesticides exerts strong selective pressures on fungi, potentially altering fundamental soil functions such as nutrient cycling and decomposition. Future research should focus on the long-term responses of soil microbial communities to pesticide application and the cumulative effects of chronic low-dose exposure to provide a more comprehensive understanding of how they shape microbial communities. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=80 SRC="FIGDIR/small/644867v2_ufig1.gif" ALT="Figure 1"> View larger version (26K): org.highwire.dtl.DTLVardef@8660a8org.highwire.dtl.DTLVardef@33ce7borg.highwire.dtl.DTLVardef@139113eorg.highwire.dtl.DTLVardef@19b388b_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIFungal communities were more responsive to pesticides than bacterial communities C_LIO_LIHerbicides caused strong non-target effects, similar to those of fungicides C_LIO_LIGradual pesticide applications altered fungal diversity and community composition C_LIO_LIRare fungal taxa proliferated under gradual exposure, increasing evenness C_LIO_LIProlonged exposure exerted greater selective pressure than abrupt application C_LI

ecology↗

bioRxiv2025

Diverse crop rotations off-set yield-scaled nitrogen losses via denitrification

Denitrification, a major source of gaseous nitrogen (N) emissions from agricultural soils, is influenced by management. Practices promoting belowground diversity are suggested to support sustainable agriculture, but their ability to modulate gaseous N-losses via denitrification remains inconclusive. To fill this knowledge gap, we sampled 106 cereal fields spanning a 3,000 km North-South gradient across Europe and compiled 56 associated climatic, soil, microbial and management variables. We found that increased denitrification was associated with higher proportion of time with crop cover over the last ten years. Denitrification rates were best predicted by microbial biomass and microbial functional guilds involved in N cycling, in particular denitrification. We also show that several diversification practices affect the variation in denitrification predictors, suggesting a trade-off between agricultural diversification and gaseous N-losses via denitrification. However, increased crop diversity in rotations improved yield-scaled denitrification, highlighting the potential of this practice to minimize N losses while contributing to sustainable food production.

ecology↗

bioRxiv2024

Soil microbial responses to multiple global change factors as assessed by metagenomics

Anthropogenic activities impose multiple concurrent pressures on soil ecosystems at a global scale, but the response of soil microbes to multiple concurrent global change (GC) factors is poorly understood. Here, we applied 10 GC treatments individually and in random combinations of 8 factors to soil samples, and monitored their bacterial and viral composition by metagenomic analysis. The application of multiple GC factors selects for particular prokaryotic and viral communities different from the effects of any individual factor, favoring, for instance, potentially pathogenic unknown mycobacteria and novel viruses. At the functional level, multiple GC factors select for sessile and non-biofilm-forming bacteria which are metabolically diverse and show a high load of antibiotic resistance genes. Finally, we show that novel genes are also relevant for understanding microbial response to GC. Our study indicates that multiple GC factors impose directional selective pressures on soil prokaryotes and viruses not observed at the individual GC factor level, and improves our understanding of how GC interactions shape microbial communities.

ecology↗

bioRxiv2024

Revisiting soil fungal biomarkers and conversion factors: Interspecific variability in phospholipid fatty acids, ergosterol and rDNA copy numbers

The abundances of fungi and bacteria in soil are used as simple predictors for carbon dynamics, and represent widely available microbial traits. Soil biomarkers serve as quantitative estimates of these microbial groups, though not quantifying microbial biomass per se. The accurate conversion to microbial carbon pools, and an understanding of its comparability among soils is therefore needed. We refined conversion factors for classical fungal biomarkers, and evaluated the application of quantitative PCR (qPCR, rDNA copies) as a biomarker for soil fungi. Based on biomarker contents in pure fungal cultures of 30 isolates, combined with available references, we propose average conversion factors of 95.3 g fungal C g-1 ergosterol, 32.0 mg fungal C {micro}mol-1 PLFA 18:2{omega}6,9 and 0.264 pg fungal C ITS1 DNA copy-1. As expected, interspecific variability was most pronounced in rDNA copies, though qPCR results showed the least phylogenetic bias. A modeling approach based on exemplary agricultural soils further supported the hypothesis that high diversity in soil buffers against biomarker variability, whereas also phylogenetic biases impact the accuracy of comparisons in biomarker estimates. Our analyses suggest that qPCR results cover the fungal community in soil best, though with a variability only partly offset in highly diverse soils. PLFA 18:2{omega}6,9 and ergosterol represent accurate biomarkers to quantify Ascomycota and Basidiomycota. To conclude, the ecological interpretation and coverage of biomarker data prior to their application in global models is important, where the combination of different biomarkers may be most insightful.

ecology↗

bioRxiv2023

Surfactant-mediated effects on hydrological and physical soil properties: a data synthesis

Soils are under threat of a multitude of anthropogenic factors affecting the complex interplay of various physical and hydrological soil processes and properties. One such factor is the group of surface-active compounds. Surfactants have a broad range of applications, and can reduce solid-liquid interfacial forces and increase wettability and dispersion of particles. Surfactant effects are context-dependent, giving rise to a wide range of reported effects on different soil processes and properties. Here, we evaluate the evidence base of surfactant research on 11 hydrological and physical soil variables. Our goal was to identify knowledge gaps and to test the robustness of proposed surfactant effects. We found that the current knowledge base is insufficient to reach strong data-backed conclusions about effects of surfactants in soils. We identified a unique case of bias in the data as a result of conflated patterns of lab and field studies. We could not support the hypothesis that surfactant charge determines soil effects for any of the tested soil variables. We believe that further experiments on surfactant mediated effects on soil properties and processes are urgently required, paying attention in particular to improving experimental design and data reporting standards. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=59 SRC="FIGDIR/small/547370v1_ufig1.gif" ALT="Figure 1"> View larger version (18K): org.highwire.dtl.DTLVardef@13e7953org.highwire.dtl.DTLVardef@8f5fc3org.highwire.dtl.DTLVardef@d81c52org.highwire.dtl.DTLVardef@2b4dfa_HPS_FORMAT_FIGEXP M_FIG C_FIG

ecology↗

bioRxiv2023

Deep learning image analysis for filamentous fungi taxonomic classification: Dealing with small data sets with class imbalance and hierarchical grouping

Deep learning applications in taxonomic classification for animals and plants from images have become popular, while those for microorganisms are still lagging behind. Our study investigated the potential of deep learning for the taxonomic classification of hundreds of filamentous fungi from colony images, which is typically a task that requires specialized knowledge. We isolated soil fungi, annotated their taxonomy using standard molecular barcode techniques, and took images of the fungal colonies grown in petri dishes (n = 606). We applied a convolutional neural network with multiple training approaches and model architectures to deal with some common issues in ecological datasets: small amounts of data, class imbalance, and hierarchically structured grouping. Model performance was overall low due mainly to the relatively small data set, class imbalance, and the high morphological plasticity exhibited by fungal colonies. However, our approach indicates that morphological features such as color, patchiness, and colony extension rate, could be used for the recognition of fungal colonies at higher taxonomic ranks (i.e., phylum, class, and order). Model explanation implies that image recognition characters appear at different positions within the colony (e.g., outer or inner hyphae), depending on the taxonomic resolution. Our study suggests the potential of deep learning applications for better understanding the taxonomy and ecology of filamentous fungi amenable to axenic culturing. Meanwhile, our study also highlights some technical challenges in deep learning image analysis in ecology, highlighting that the domain of applicability of these methods needs to be carefully considered.

microbiology↗

bioRxiv2022

Fungal traits help to understand the decomposition of simple and complex plant litter

Litter decomposition is a key ecosystem process, responsible for the release and storage of nutrients and carbon. Soil fungi are one of the dominant drivers of organic matter decomposition, but fungal taxa differ substantially in their functional ability to decompose plant litter. We used a trait-based approach to better understand functional differences among saprotrophic soil fungi (originating from a natural grassland ecosystem) in decomposing leaf and wood litter. Decomposition strongly varied among phyla and isolates, with Ascomycota decomposing the most and Mucoromycota decomposing the least. In this study, the phylogeny of the fungi in our dataset, but also the ability of fungi to use more complex carbon were important predictors for decomposition. While some enzymes (e.g. laccase and cellulase) influenced decomposition, the majority of enzyme activities was not correlated with decomposition. Thus, we suggest using more directly assessed traits as predictors for decomposition, such as the ability to use carbon substrates, rather than a single enzyme activity, which could misrepresent the degradation potential of certain isolates. The findings of our study offer important new insights for the trait-based prediction of fungal litter decomposition in grassland soils.

ecology↗

bioRxiv2022

Legacy effect of microplastics on plant-soil feedbacks

Microplastics are a complex contaminant suite that are now understood to affect plants and soil biota and the processes they drive. However, the role of microplastic in plant-soil feedbacks, a key feature in plant-soil interactions, is still unknown. We address this here, using soil from a previous experiment, which has been conditioned with 12 different microplastic types including fibers, films, foams, and fragments. To evaluate the feedback effect, we grew a native and a range-expanding plant species with inocula extracted from each one of these soils. At harvest, plant biomass and root morphological traits were measured. Films gave rise to a positive feedback on shoot mass (higher mass with soil inocula conditioned with microplastics than without), likely via negative effects on harmful soil biota. Foams and fragments also caused positive feedback on shoot mass likely via effects on enzymatic activities and mutualistic soil biota. Fibers led to negative feedback on root mass as they may promote the abundance of soil pathogens. Microplastics also have a legacy effect on root traits: Daucus had thicker roots probably for promoting mycorrhizal associations while Calamagrostis had reduced root diameter probably for diminishing pathogenic infection. Microplastic legacy on plants is species-specific and may affect plant biomass primarily via root traits. Microplastics, as a function of their shape and polymer type, have a feedback effect on plant performance.

ecology↗

bioRxiv2021

Effects of perfluoroalkyl and polyfluoroalkyl substances on soil structure and function

Soils are impacted at a global scale by several anthropogenic factors, including chemical pollutants. Among those, perfluoroalkyl and polyfluoroalkyl substances (PFAS) are of concern due to their high environmental persistence, and as they might affect soil health and functions. However, data on impacts of PFASs on soil structure and microbially-driven processes are currently lacking. This study explored the effects of perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA) and perfluorobutanesulfonic acid (PFBS) at environmental-relevant nominal concentrations (1 ~ 1000 ng g-1) on soil functions, using a 6-week microcosm experiment. We measured soil respiration, litter decomposition, enzyme and microbial activities, soil aggregates, and bacterial abundance. PFAS (even at 1 ng g-1 for PFBS) significantly increased litter decomposition, associated with positive effects on bacterial abundance, and {beta}-glucosidase activities. This effect increased with PFAS concentrations. Soil respiration was significantly inhibited by PFAS in the 3rd week, while this effect was more variable in week 6. Water-stable aggregates were negatively affected by PFOS and PFOA, possibly related to microbial shifts. The general microbial activities and {beta}-D-cellobiosidase and phosphatase activities were barely affected by PFAS treatments. Our work highlights the potential effects of PFAS on soil health, and we argue that this substance class could be a factor of environmental change of potentially broad relevance in terrestrial ecosystem functioning. SynopsisPFAS are likely to affect soil health. Abstract Art O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=124 SRC="FIGDIR/small/465889v2_ufig1.gif" ALT="Figure 1"> View larger version (52K): org.highwire.dtl.DTLVardef@88c630org.highwire.dtl.DTLVardef@18b985corg.highwire.dtl.DTLVardef@1bfdc81org.highwire.dtl.DTLVardef@125b09e_HPS_FORMAT_FIGEXP M_FIG C_FIG

ecology↗

bioRxiv2021

Non-mycorrhizal root associated fungi of a tropical montane forest are relatively robust to the long-term addition of moderate rates of nitrogen and phosphorus

Andean forests are biodiversity hotspots and globally important carbon (C) repositories. This status might be at risk due to increasing rates of atmospheric nutrient deposition. As fungal communities are key in the recirculation of soil nutrients, assessing their responses to soil eutrophication can help establish a link between microbial biodiversity and the sustainability of the C sink status of this region. Beyond mycorrhizal fungi, which have been studied more frequently, a wide range of other fungi associate with the fine root fraction of trees. Monitoring these communities can offer insights into how communities composed of both facultative and obligate root associated fungi are responding to soil eutrophication. Here we document the response of non-mycorrhizal root associated fungal (RAF) communities to a long-term nutrient manipulation experiment. The stand level fine root fraction of an old growth tropical montane forest was sampled after seven years of nitrogen (N) and phosphorus (P) additions. RAF communities were characterized by a deep sequencing approach. As per the resource imbalance model, we expected that asymmetries in the availability of C, N and P elicited by fertilization will lead to mean richness reductions and alterations of the community structure. We recovered moderately diverse fungal assemblages composed by sequence variants classified within a wide set of trophic guilds. While mean richness remained stable, community composition shifted, particularly among Ascomycota and after the addition of P. Fertilization factors, however, only accounted for a minor proportion of the variance in community composition. These findings suggest that, unlike mycorrhizal fungi, RAF communities are less sensitive to shifts in soil nutrient availability. A plausible explanation is that non-mycorrhizal RAF have fundamentally different nutrient acquisition and life history traits, thus allowing them greater stoichiometric plasticity and an array of functional acclimation responses that collectively express as subtle shifts in community level attributes.

microbiology↗

bioRxiv2021

Soil conditions drive belowground trait space in temperate agricultural grasslands

O_LIPlant belowground organs perform essential functions, including water and nutrient uptake, anchorage, vegetative reproduction and recruitment of mutualistic soil microbiota. Determining how belowground traits jointly determine dimensions of the trait space and how these dimensions are linked to environmental conditions would further advance our understanding of plant functioning and community assembly. C_LIO_LIHere, we investigated belowground plant-trait dimensionality and its variation along 10 soil and land-use parameters in 150 temperate grasslands plots. We used eight belowground traits collected in greenhouse and common garden experiments, as well as bud-bank size and specific leaf area from databases, for a total of 313 species, to calculate community weighted means (CWMs). C_LIO_LIUsing PCA, we found that about 55% of variance in CWMs was explained by two main dimensions, corresponding to a mycorrhizal collaboration and a resource conservation gradient. Frequently overlooked traits such as rooting depth, bud-bank size and root branching intensity were largely integrated in this bidimensional trait space. The two plant-strategy gradients were partially dependent on each other, with outsourcing communities along the collaboration gradient being more often slow. These outsourcing communities were also more often deep-rooting, and associated with soil parameters, such as low moisture and sand content, high topsoil pH, high C:N and low {delta}15N. Slow communities had large bud-banks and were associated with low land-use intensity, high topsoil pH, and low nitrate but high ammonium concentrations in the soil. We did not find a substantial role of phosphorus-availability as an indicator along the collaboration gradient. C_LIO_LIIn conclusion, the collaboration and conservation gradients previously identified at the species level scale up to community level in grasslands, encompass more traits than previously described, and vary with the environment. C_LI

ecology↗