@misc{KozjekKundelKKushwahaetal., author = {Kozjek, Katja and Kundel, Dominika and K. Kushwaha, Sandeep and Olsson, P{\aa}l Axel and Ahr{\´e}n, Dag and Fliessbach, Andreas and Birkhofer, Klaus and Hedlund, Katarina}, title = {Long-term agricultural management impacts arbuscular mycorrhizal fungi more than short-term experimental drought}, series = {Applied Soil Ecology}, journal = {Applied Soil Ecology}, number = {168}, issn = {0929-1393}, doi = {10.1016/j.apsoil.2021.104140}, abstract = {Agricultural management practices and extreme weather events associated with climate change can influence the diversity and abundance of arbuscular mycorrhizal fungi (AMF) with potential consequences for crop production. However, the importance of the interactive effects of long-term agricultural management and extreme weather events on AMF communities in agricultural soils is not yet fully explored. A short-term drought experiment with rainout-shelters was performed in winter wheat fields in a long-term agricultural trial with organic (biodynamic) and conventional management practices. During four months of the winter wheat growing period (March-June 2017), the rainout-shelters reduced the ambient precipitation by 65\% on average. At two sampling dates, the AMF diversity and community composition were assessed using a single-molecule real-time (SMRT) DNA sequencing. A total of 955 amplicon sequence variants (ASVs), belonging to twelve genera were identified. The long-term farming systems and the short-term experimental drought did not affect AMF ASV diversity levels. The AMF community composition at the genus level differed between the organic and the conventional farming systems, but no distinctive communities were found in response to the experimental drought. The three most abundant genera Acaulospora, Paraglomus and Funneliformis were correlated to the two farming practices. Our study demonstrates that AMF communities in agricultural soils are responsive to long-term farming systems, and are resistant to one short-term summer drought event.}, language = {en} } @misc{KundelBodenhausenBrachtJorgensenetal., author = {Kundel, Dominika and Bodenhausen, Natacha and Bracht J{\o}rgensen, Helene and Truu, Jaak and Birkhofer, Klaus and Hedlund, Katarina and M{\"a}der, Paul and Fliessbach, Andreas}, title = {Effects of simulated drought on biological soil quality, microbial diversity and yields under long-term conventional and organic agriculture}, series = {FEMS Microbiology Ecology}, volume = {96}, journal = {FEMS Microbiology Ecology}, number = {12}, issn = {1574-6941}, doi = {doi: 10.1093/femsec/fiaa205}, pages = {12}, abstract = {Drought and agricultural management influence soil microorganisms with unknown consequences for the functioning ofagroecosystems. We simulated drought periods in organic (biodynamic) and conventional wheat fields and monitoredeffects on soil water content, microorganisms and crops. Above the wilting point, water content and microbial respirationwere higher under biodynamic than conventional farming. Highest bacterial and fungal abundances were found inbiodynamically managed soils, and distinct microbial communities characterised the farming systems. Most biological soilquality parameters and crop yields were only marginally affected by the experimental drought, except for arbuscularmycorrhizal fungi (AMF), which increased in abundance under the experimental drought in both farming systems. AMFwere further strongly promoted by biodynamic farming resulting in almost three times higher AMF abundance underexperimental drought in the biodynamic compared with the conventional farming system. Our data suggest an improvedwater storage capacity under biodynamic farming and confirms positive effects of biodynamic farming on biological soilquality. The interactive effects of the farming system and drought may further be investigated under more substantialdroughts. Given the importance of AMF for the plant's water supply, more in-depth studies on AMF may help to clarify theirrole for yields under conditions predicted by future climate scenarios.}, language = {en} } @misc{Gavin‐CentolSerranoCarneroMontserratetal., author = {Gav{\´i}n-Centol, Mar{\´i}a Pilar and Serrano-Carnero, Diego and Montserrat, Marta and Meyer, Svenja and Scheu, Stefan and Kundel, Dominika and Fliessbach, Andreas and Truu, Jaak and Birkhofer, Klaus and S{\´a}nchez-Moreno, Sara and Moya-Lara{\~n}o, Jordi}, title = {Severe drought and conventional farming affect detritivore feeding activity and its vertical distribution}, series = {Basic and Applied Ecology}, volume = {69}, journal = {Basic and Applied Ecology}, issn = {1439-1791}, doi = {10.1016/j.baae.2023.03.006}, pages = {49 -- 59}, abstract = {Soil invertebrates are key to decomposition, a central ecosystem process related to soil health. In many temperate areas climate change will decrease soil water content, which strongly modulates biological activity. However, data are lacking on how shifts in rainfall patterns affect soil biota and the ecosystem processes they provide. Here, we used the bait-lamina test to experimentally assess how a severe drought event influenced detritivore feeding activity, during a wheat growing season, in soils under long-term organic or conventional farming. Additionally, biotic and abiotic soil parameters were measured. Feeding activity was reduced under extreme drought and conventional management, although no climate-management synergies were found. Vertical migrations of Collembola and Oribatida partially explained the unexpectedly higher bait consumption at shallower depths in response to drought. Exploratory mixed-effects longitudinal random forests (a novel machine learning technique) were used to explore whether the relative abundances of meso‑, microfauna and microbes of the decomposer food web, or abiotic soil parameters, affected the feeding activity of detritivores. The model including meso‑ and microfauna selected four Nematoda taxa and explained higher variance than the model with only microbiota, indicating that detritivore feeding is closely associated with nematodes but not with microbes. Additionally, the model combining fauna and microbiota explained less variance than the faunal model, suggesting that microbe-fauna synergies barely affected detritivore feeding. Moreover, soil water and mineral nitrogen contents were found to strongly determine detritivore feeding, in a positive and negative way, respectively. Hence, our results suggest that severe drought and conventional farming impair the feeding activity of soil detritivores and thus, probably, decomposition and nutrient mineralization in soils. Furthermore, machine learning algorithms arise as a powerful technique to explore the identity of potential key drivers relating biodiversity to ecosystem functioning.}, language = {en} } @misc{KundelMeyerBirkhoferetal., author = {Kundel, Dominika and Meyer, Svenja and Birkhofer, Herbert and Fliessbach, Andreas and M{\"a}der, Paul and Scheu, Stefan and Kleunen, Mark van and Birkhofer, Klaus}, title = {Design and Manual to Construct Rainout-Shelters for Climate Change Experiments in Agroecosystems}, series = {Frontiers in Environmental Science}, volume = {6}, journal = {Frontiers in Environmental Science}, issn = {2296-665X}, doi = {10.3389/fenvs.2018.00014}, pages = {9}, abstract = {Climate change models predict reduced summer precipitations for most European countries, including more frequent and extreme summer droughts. Rainout-shelters which intercept part of the natural precipitation provide an effective tool to investigate effects of different precipitation levels on biodiversity and ecosystem functioning. In this study, we evaluate and describe in detail a fixed-location rainout-shelter (2.5 × 2.5 m) with partial interception of natural rainfall. We provide a complete parts list, a construction manual and detailed CAD drawings allowing to rebuild and use these shelters for rainfall manipulation studies. In addition, we describe a rainout-shelter control treatment giving the possibility to quantify and account for potential shelter artifacts. To test the rainout-shelters, we established the following three treatments each in eight winter wheat plots of the agricultural long-term farming system comparison trial DOK in Therwil (Switzerland): (1) A rainout-shelter with 65\% interception of rainfall, (2) a rainout-shelter control without interception of rainfall, and (3) an ambient control. The rainout-shelter effectively excluded 64.9\% of the ambient rainfall, which is very close to the a priori calculated exclusion of 65.1\%. In comparison to the ambient control plots, gravimetric soil moisture decreased under the rainout-shelter by a maximum of 11.1 percentage points. Air temperature under the rainout-shelter differed little from the ambient control (-0.55°C in 1.2 m height and +0.19°C in 0.1 m height), whereas soil temperatures were slightly higher in periods of high ambient temperature (+1.02°C), but remained basically unaffected in periods of low ambient temperature (+0.14°C). A maximum edge effect of 0.75 m defined a sampling area of 1 × 1 m under the rainout-shelter. The rainout-shelters presented here, proved to sustain under heavy weather and they were well-suited to be used in agricultural fields where management operations require the removal of the rainout-shelters for management operations. Overall, the results confirmed the good performance of the presented rainout-shelters regarding rainout-shelter artifacts, predictable rain exclusion, and feasibility for experimental studies in agricultural fields.}, language = {en} } @misc{BirkhoferFliessbachGavin‐Centoletal., author = {Birkhofer, Klaus and Fliessbach, Andreas and Gav{\´i}n-Centol, Mar{\´i}a Pilar and Hedlund, Katarina and Ingimarsd{\´o}ttir, Mar{\´i}a and Bracht J{\o}rgensen, Helene and Kozjek, Katja and Meyer, Svenja and Montserrat, Marta and S{\´a}nchez-Moreno, Sara and Moya Lara{\~n}o, Jordi and Scheu, Stefan and Serrano-Carnero, Diego and Truu, Jaak and Kundel, Dominika}, title = {Conventional agriculture and not drought alters relationships between soil biota and functions}, series = {Scientific Reports}, journal = {Scientific Reports}, number = {11}, issn = {2045-2322}, doi = {10.1038/s41598-021-03276-x}, abstract = {Soil biodiversity constitutes the biological pillars of ecosystem services provided by soils worldwide. Soil life is threatened by intense agricultural management and shifts in climatic conditions as two important global change drivers which are not often jointly studied under field conditions. We addressed the effects of experimental short-term drought over the wheat growing season on soil organisms and ecosystem functions under organic and conventional farming in a Swiss long term trial. Our results suggest that activity and community metrics are suitable indicators for drought stress while microbial communities primarily responded to agricultural practices. Importantly, we found a significant loss of multiple pairwise positive and negative relationships between soil biota and process-related variables in response to conventional farming, but not in response to experimental drought. These results suggest a considerable weakening of the contribution of soil biota to ecosystem functions under long-term conventional agriculture. Independent of the farming system, experimental and seasonal (ambient) drought conditions directly affected soil biota and activity. A higher soil water content during early and intermediate stages of the growing season and a high number of significant relationships between soil biota to ecosystem functions suggest that organic farming provides a buffer against drought effects.}, language = {en} } @misc{MeyerKundelBirkhoferetal., author = {Meyer, Svenja and Kundel, Dominika and Birkhofer, Klaus and Fliessbach, Andreas and Scheu, Stefan}, title = {Soil microarthropods respond differently to simulated drought in organic and conventional farming systems}, series = {Ecology and Evolution}, volume = {11}, journal = {Ecology and Evolution}, number = {15}, issn = {2045-7758}, doi = {10.1002/ece3.7839}, pages = {10369 -- 10380}, abstract = {In Central Europe, summer droughts are increasing in frequency which threatens production and biodiversity in agroecosystems. The potential of different farming systems to mitigate detrimental drought effects on soil animals is largely unknown. We investigated the effects of simulated drought on the abundance and community composition of soil microarthropods (Collembola and Oribatida and Meso-, Pro-, and Astigmata) in winter wheat fields under long-term conventional and organic farming in the DOK trial, Switzerland. We simulated drought by excluding 65\% of the ambient precipitation during the wheat-growing season from March to June 2017. The abundance of Collembola and Oribatida declined more consistently in conventionally managed fields compared to organically managed fields under simulated drought. The abundance of Collembola as well as Meso-, Pro- and Astigmata, but not the abundance of Oribatida, increased in deeper soil layers due to simulated drought, suggesting vertical migration as a drought avoidance strategy. The species composition of Oribatida communities, but not of Collembola communities, differed significantly between drought treatments and between farming systems. Soil carbon content was a major factor structuring Oribatida communities. Our results suggest that organic farming buffers negative effects of drought on soil microarthropods, presumably due to higher soil carbon content and associated higher soil moisture and improved soil structure. This potential of organic farming systems to mitigate consequences of future droughts on soil biodiversity is promising and needs further exploration across larger climatic and spatial scales and should be extended to other groups of soil biota.}, language = {en} } @misc{MeyerKundelBirkhoferetal., author = {Meyer, Svenja and Kundel, Dominika and Birkhofer, Klaus and Fliessbach, Andreas and Scheu, Stefan}, title = {Trophic niche but not abundance of Collembola and Oribatida changes with drought and farming system}, series = {PeerJ}, volume = {10}, journal = {PeerJ}, number = {12}, issn = {2167-8359}, doi = {10.7717/peerj.12777}, abstract = {Higher frequencies of summer droughts are predicted to change soil conditions in the future affecting soil fauna communities and their biotic interactions. In agroecosystems drought effects on soil biota may be modulated by different management practices that alter the availability of different food resources. Recent studies on the effect of drought on soil microarthropods focused on measures of abundance and diversity. We here additionally investigated shifts in trophic niches of Collembola and Oribatida as indicated by stable isotope analysis (13C and 15N). We simulated short-term summer drought by excluding 65\% of the ambient precipitation in conventionally and organically managed winter wheat fields on the DOK trial in Switzerland. Stable isotope values suggest that plant litter and root exudates were the most important resources for Collembola (Isotoma caerulea, Isotomurus maculatus and Orchesella villosa) and older plant material and microorganisms for Oribatida (Scheloribates laevigatus and Tectocepheus sarekensis). Drought treatment and farming systems did not affect abundances of the studied species. However, isotope values of some species increased in organically managed fields indicating a higher proportion of microorganisms in their diet. Trophic niche size, a measure of both isotope values combined, decreased with drought and under organic farming in some species presumably due to favored use of plants as basal resource instead of algae and microorganisms. Overall, our results suggest that the flexible usage of resources may buffer effects of drought and management practices on the abundance of microarthropods in agricultural systems.}, language = {en} }