@misc{PotapovBeaulieuBirkhoferetal., author = {Potapov, Anton and Beaulieu, Fr{\´e}d{\´e}ric and Birkhofer, Klaus and Bluhm, Sarah L. and Degtyarev, Maxim I. and Devetter, Miloslav and Goncharov, Anton A. and Gongalsky, Konstantin B. and Klarner, Bernhard and Korobushkin, Daniil I.}, title = {Feeding habits and multifunctional classification of soil-associated consumers from protists to vertebrates}, series = {Biological Reviews}, volume = {97}, journal = {Biological Reviews}, number = {3}, issn = {1469-185X}, doi = {10.1111/brv.12832}, pages = {1057 -- 1117}, abstract = {Soil organisms drive major ecosystem functions by mineralising carbon and releasing nutrients during decomposition processes, which supports plant growth, aboveground biodiversity and, ultimately, human nutrition. Soil ecologists often operate with functional groups to infer the effects of individual taxa on ecosystem functions and services. Simultaneous assessment of the functional roles of multiple taxa is possible using food-web reconstructions, but our knowledge of the feeding habits of many taxa is insufficient and often based on limited evidence. Over the last two decades, molecular, biochemical and isotopic tools have improved our understanding of the feeding habits of various soil organisms, yet this knowledge is still to be synthesised into a common functional framework. Here, we provide a comprehensive review of the feeding habits of consumers in soil, including protists, micro-, meso- and macrofauna (invertebrates), and soil-associated vertebrates. We have integrated existing functional group classifications with findings gained with novel methods and compiled an overarching classification across taxa focusing on key universal traits such as food resource preferences, body masses, microhabitat specialisation, protection and hunting mechanisms. Our summary highlights various strands of evidence that many functional groups commonly used in soil ecology and food-web models are feeding on multiple types of food resources. In many cases, omnivory is observed down to the species level of taxonomic resolution, challenging realism of traditional soil food-web models based on distinct resource-based energy channels. Novel methods, such as stable isotope, fatty acid and DNA gut content analyses, have revealed previously hidden facets of trophic relationships of soil consumers, such as food assimilation, multichannel feeding across trophic levels, hidden trophic niche differentiation and the importance of alternative food/prey, as well as energy transfers across ecosystem compartments. Wider adoption of such tools and the development of open interoperable platforms that assemble morphological, ecological and trophic data as traits of soil taxa will enable the refinement and expansion of the multifunctional classification of consumers in soil. The compiled multifunctional classification of soil-associated consumers will serve as a reference for ecologists working with biodiversity changes and biodiversity-ecosystem functioning relationships, making soil food-web research more accessible and reproducible.}, 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} } @misc{DampteyBirkhoferMenoretal., author = {Damptey, Frederick Gyasi and Birkhofer, Klaus and Menor, Imma Oliveras and Garcia de la Riva, Enrique}, title = {The functional Structure of Tropical Plant Communities and soil Properties Enhance Ecosystem Functioning and Multitunctionality in Different Ecosystems in Ghana}, series = {Forests}, volume = {13}, journal = {Forests}, number = {2}, issn = {1999-4907}, doi = {10.3390/f13020297}, pages = {20}, abstract = {Plant functional traits are useful in tracking changes in the environment, and play an important role in determining ecosystem functioning. The relationship between plant functional traits and ecosystem functioning remains unclear, although there is growing evidence on this relationship. In this study, we tested whether the functional structure of vegetation has significant effects on the provision of ecosystem services. We analysed plant trait composition (specific leaf area, leaf carbon and nitrogen ratio, isotopic carbon fraction, stem dry matter content, seed mass and plant height), soil parameters (nutrients, pH, bulk density) and proxies of ecosystem services (carbon stock, decomposition rate, invertebrate activity) in twenty-four plots in three tropical ecosystems (active restored and natural forests and an agroforestry system) in Ghana. For each plot, we measured above-ground biomass, decomposition rates of leaves and invertebrate activity as proxies for the provision of ecosystem services to evaluate (i) whether there were differences in functional composition and soil properties and their magnitude between ecosystem types. We further aimed to (ii) determine whether the functional structure and/or soil parameters drove ecosystem functions and multifunctionality in the three ecosystem types. For functional composition, both the leaf economic spectrum and seed mass dimension clearly separated the ecosystem types. The natural forest was more dominated by acquisitive plants than the other two ecosystem types, while the non-natural forests (agroforest and restored forest) showed higher variation in the functional space. The natural forest had higher values of soil properties than the restored forest and the agroforestry system, with the differences between the restored and agroforestry systems driven by bulk density. Levels of ecosystem service proxies and multifunctionality were positively related to the functional richness of forest plots and were mainly explained by the differences in site conditions. Our study demonstrated the effects of functional forest structure on ecosystem services in different forest ecosystems located in the semi-deciduous forest zone of Ghana.}, language = {en} } @misc{HeckerWaetzoldYangetal., author = {Hecker, Lutz Philip and W{\"a}tzold, Frank and Yang, Xueyan and Birkhofer, Klaus}, title = {Squeeze it or leave it? An ecological-economic assessment of the impact of mower conditioners on arthropod populations in grassland}, series = {Journal of Insect Conservation}, volume = {26}, journal = {Journal of Insect Conservation}, number = {3}, issn = {1572-9753}, doi = {10.1007/s10841-022-00392-5}, pages = {463 -- 475}, abstract = {This study addresses the use of conditioners as a driver of arthropod loss in agricultural landscapes. Conditioners compress the freshly cut mowing material mechanically to destroy the evaporation-inhibiting wax layer of the grass material. This compression potentially increases the physical damage to several arthropod groups during the mowing process. We have combined an ecological field study on the impact of conditioners on arthropods at the plot level with an analysis of the economic rationale of applying conditioners in differently managed grasslands in the study region, in order to understand the impact of applying conditioners on the damage to arthropods at the landscape level. The use of conditioners in the mowing process significantly increased the overall percentage of damaged individuals by 18\% from 52\% without to 70\% with conditioner use. Aphids and plant lice, beetles, thrips and mites were most severely affected by additional damage. We also found that the use of conditioners takes place on substantially more than 20\% of all grasslands in the study region. Depending on the respective grassland area managed with conditioners in the future, grasslands could be losing an additional 4\% to 18\% of their overall arthropod numbers only due to the use of conditioners compared to a scenario without conditioners. As the damage due to the use of conditioners is presumably higher in extensively managed grasslands, and the profit of their use is higher in intensively managed grasslands, we suggest, as an implication for insect conservation, concentrating measures to disincentivise the use of conditioners on extensively managed grassland.}, language = {en} } @misc{BirkhoferDjoudiSchnerchetal., author = {Birkhofer, Klaus and Djoudi, El Aziz and Schnerch, Benjamin and Michalko, Radek}, title = {Climatic conditions and functional traits affect spider diets in agricultural and non-agricultural habitats worldwide}, series = {Ecography}, journal = {Ecography}, number = {3}, issn = {1600-0587}, doi = {10.1111/ecog.06090}, pages = {12}, abstract = {Spiders are dominant predators in terrestrial ecosystems and feed on prey from the herbivore and detritivore subsystem (dual subsystem omnivory) as well as on other predators (intraguild predation). Little is known about how global change potentially affects the importance of different prey groups in predator diets. In this meta-analysis we identify the impact of climatic conditions, land-use types and functional traits of spider species on the relative importance of Hemiptera, Araneae and Collembola prey in spider diets. We use a dataset including 78 publications with 149 observational records of the diet composition of 96 spider species in agricultural and non-agricultural habitats in 24 countries worldwide. The importance of Hemiptera prey was not affected by climatic conditions and was particularily high in smaller spider species in agricultural habitats. Araneae prey was most important for actively hunting, larger spider species in non-agricultural habitats. Collembola prey was most important for small, actively hunting spider species in regions with higher temperature seasonality. Spider species with a higher importance of Araneae prey for their diet also had higher importances of Collembola and lower importances of Hemiptera prey. Future increases of temperature seasonality predicted for several regions worldwide may go along with an increasing importance of Collembola prey which also related to a higher importance of intraguild prey here. Two global change drivers predicted for many regions of the world (increasing climatic seasonality and ongoing conversion of non-agricultural to agricultural land) both hold the potential to increase the importance of Collembola prey in spider diets. The importance of Hemiptera and Araneae prey may however show contrasting responses to these two drivers. These complex potential effects of global change components and their impact on functional traits in spider communities highlight the importance to simultaneously consider multiple drivers of global change to better understand future predator-prey interactions.}, language = {en} } @misc{FengLysakowskiEisenschmidtetal., author = {Feng, Lanya and Lysakowski, Bartosz and Eisenschmidt, Jenny and Birkhofer, Klaus}, title = {The impact of wildfire and mammal carcasses on beetle emergence from heathland soils}, series = {Ecological Entomology}, volume = {47}, journal = {Ecological Entomology}, number = {5}, issn = {1365-2311}, doi = {10.1111/een.13179}, pages = {883 -- 894}, abstract = {Wildfires alter the composition of insect communities due to fire-induced mortality, and the post-fire vegetation and soil conditions also affect the initial re-colonisation and subsequent local emergence of adults from burnt soils. However, the impact of wildfires on re-colonisation and emergence of carrion-associated scavenging species from soils has previously been neglected. We established an experiment in an unmanaged heathland area that was affected by a severe wildfire in 2017 by adding wild boar carcasses to burnt and unburnt areas 204 days after the wildfire. Adult beetles were then collected with emergence tents at paired sites with and without carcasses and in burnt and unburnt areas from 27 April to 10 August 2018. The wildfire did not significantly affect the diversity or abundance of soil-emerging beetles. Community composition in the burnt area differed significantly from the unburnt area with higher numbers of Staphylinidae and lower numbers of phytophagous beetle families (Curculionidae and Elateridae) emerging from soils, probably reflecting the structurally simpler vegetation and reduced litter one year after the wildfire. Scavenging beetles generally colonise mammal carcasses in burnt areas to the same extent as in unburnt areas, but the post-fire conditions favoured some species with very specialised habitat preferences. A few rare species of conservation concern almost exclusively occurred in the burnt area and in most cases in combination with the presence of a carcass. This result highlights the joint importance of heathland wildfires and carcass resources for species conservation in beetle communities.}, language = {en} } @misc{BirkhoferBaulechnerDiekoetteretal., author = {Birkhofer, Klaus and Baulechner, Dennis and Diek{\"o}tter, Tim and Zaitsev, Andrey S. and Wolters, Volkmar}, title = {Fertilization Rapidly Alters the Feeding Activity of Grassland Soil Mesofauna Independent of Management History}, series = {Frontiers in Ecology and Evolution}, volume = {10}, journal = {Frontiers in Ecology and Evolution}, issn = {2296-701X}, doi = {10.3389/fevo.2022.864470}, pages = {1 -- 10}, abstract = {Nitrogen fertilization of permanent grasslands affects soil fauna communities by modifying their taxonomic composition, population dynamics and feeding activity. However, it is not well understood if the edaphic fauna adapts to these external inputs so that the immediate response to fertilizer application depends on the long-term nutrient management strategy. We performed a field experiment in permanent grasslands under agricultural management in three regions across Germany. We used experimental fertilization with an organic plant-sourced fertilizer along a long-term nutrient management gradient to study the immediate and long-term effects of fertilization and their interdependence on the taxonomic composition and feeding activity of the soil mesofauna (Nematoda, Oribatida, and Collembola). Sampling season, soil properties, vegetation structure, and geographic location were considered as additional predictor variables to reflect heterogeneity in environmental conditions. The taxonomic composition, richness and total abundance of soil mesofauna communities were significantly affected by long-term nutrient management, but not by experimental fertilization. However, N pulses rapidly (within days) reduced the feeding activity estimated with bait-lamina strips independent of long-term nutrient management strategies. Experimental addition of organic plant-sourced fertilizer may have led to a rapid build-up of microbial biomass, providing alternative food sources for the soil mesofauna and causing a shift away from the bait-lamina substrate. Our study indicates that community changes associated with the long-term nutrient management regime in permanent grasslands do not alter the strong functional response of the soil mesofauna to N pulses. There is an urgent need to develop nutrient management strategies for permanent grasslands that take into account both the conservation of the edaphic faunal community and changes of ecosystem functions caused by rapid responses of the soil mesofauna to fertilizer inputs.}, language = {en} } @misc{RaabRaabBonhageetal., author = {Raab, Thomas and Raab, Alexandra and Bonhage, Alexander and Schneider, Anna and Hirsch, Florian and Birkhofer, Klaus and Drohan, Patrick J. and Wilmking, Martin and Kreyling, J{\"u}rgen and Malik, Ireneusz and Wistuba, Małgorzata and Maaten, Ernst van der and Maaten-Theunissen, Marieke van der and Urich, Tim}, title = {Do small landforms have large effects? A review on the legacies of pre-industrial charcoal burning}, series = {Geomorphology}, volume = {413}, journal = {Geomorphology}, issn = {0169-555X}, doi = {10.1016/j.geomorph.2022.108332}, pages = {16}, abstract = {Relict charcoal hearths (RCHs) are small, anthropogenic landforms resulting from past charcoal burning and reaching significant land coverage in pre-industrial mining areas. We review three coupled legacies linked by RCH development: (i) a landscape-scale geomorphic effect, (ii) a unique soil fingerprint, and (iii) an evolving novel ecosystem. The history and technique of charcoal production are described to clarify legacy effects. Applying a recently presented morpho-genetic catalogue is useful for classified mapping of RCH findings. The RCH numbers and calculated RCH densities per study region vary greatly and impose uncertainties due to insufficient methods causing over- or underestimations. Areas with high RCH densities between 50 and 500 RCH/km2 seem reasonable. Machine learning-based remote sensing techniques are promising approaches with which to better assess the full scale of charcoal burning legacies. RCH soil properties feature dark charcoal-rich technogenic substrate layers classified as Auh horizons according to the World Reference Base with significantly increased C contents. These Auh horizons can also exhibit specific physical and chemical properties, such as relatively low bulk density, high porosity, high plant available water content, low thermal conductivity and differences in cation exchange capacity or nutrient status. However, relevant studies are rare, and thus, the effects may differ by study region. Regarding vegetation, there seem to be four main effects: changes in forest structure, species composition, recruitment pattern and productivity. The number of studies on this issue is, however, also very limited. Even fewer studies have examined the soil fauna in RCHs; thus, the reported effects cannot be used to draw general conclusions. Notably, RCH research has made considerable progress in the last five years, especially in the Light Detection and Ranging-based mapping of these small landforms and identification of RCH-specific soil properties, but ecological legacies are not well understood; thus, more interdisciplinary and integrative studies are needed.}, language = {en} } @misc{MuellerBrandlCadotteetal., author = {M{\"u}ller, J{\"o}rg and Brandl, Roland and Cadotte, Marc W. and Heibl, Christoph and B{\"a}ssler, Claus and Weiß, Ingmar and Birkhofer, Klaus}, title = {A replicated study on the response of spider assemblages to regional and local processes}, series = {Ecological Monographs}, volume = {92}, journal = {Ecological Monographs}, number = {3}, issn = {1557-7015}, doi = {10.1002/ecm.1511}, pages = {1 -- 19}, abstract = {Understanding species richness variation among local communities is one of the central topics in ecology, but the complex interplay of regional processes, environmental filtering, and local processes hampers generalization on the importance of different processes. Here, we aim to unravel drivers of spider community assembly in temperate forests by analyzing two independent data sets covering gradients in elevation and forest succession. We test the following four hypotheses: (H1) spider assemblages within a region are limited by dispersal, (H2) local environment has a dominant influence on species composition and (H3) resources, and (H4) biotic interactions both affect species richness patterns. In a comprehensive approach, we studied species richness, abundance, taxonomic composition, and trait-phylogenetic dissimilarity of assemblages. The decrease in taxonomic similarity with increasing spatial distance was very weak, failing to support H1. Functional clustering of species in general and with canopy openness strongly supported H2. Moreover, this hypothesis was supported by a positive correlation between environmental and taxonomic similarity and by an increase in abundance with canopy openness. Resource determination of species richness (H3) could be confirmed only by the decrease of species richness with canopy cover. Finally, decreasing species richness with functional clustering indicating effects of biotic interactions (H4) could only be found in one analysis and only in one data set. In conclusion, our findings indicate that spider assemblages within a region are mainly determined by local environmental conditions, while resource availability, biotic interactions and dispersal play a minor role. Our approach shows that both the analysis of different aspects of species diversity and replication of community studies are necessary to identify the complex interplay of processes forming local assemblages.}, language = {en} } @misc{ArvidssonMontesBirkhofer, author = {Arvidsson, Fredrik and Montes, Melanie S. and Birkhofer, Klaus}, title = {Microhabitat conditions affect web-building spider communities and their prey independent of effects of short-term wildlife fencing on forest vegetation}, series = {Journal of Arachnology}, volume = {50}, journal = {Journal of Arachnology}, number = {3}, issn = {1937-2396}, doi = {10.1636/JoA-S-21-046}, pages = {308 -- 313}, abstract = {Spiders play a key role in forest food webs, where they regulate decomposer populations and may act as predators of pests and disease vectors. Spider community composition is determined in part by vegetation structure. Therefore, the exclusion of large mammals, such as deer and wild boar, through wildlife fencing may affect the composition of spider communities and their prey in forest ecosystems. Web-building spiders and their prey were hand-collected in plots that had been fenced for three years, as well as adjacent unfenced plots in a mixed temperate forest in north-eastern Germany. Additionally, spiders in the leaf litter were sampled in fenced and unfenced subareas by sieving litter. Wildlife fencing did not significantly affect spider densities or community composition per microhabitat. However, fencing affected the cover of different microhabitats significantly as there was a higher density of larger trees and higher leaflitter cover in fenced plots while there was a higher percentage of bare ground and deadwood in unfenced plots. Spider communities and their prey composition differed significantly between microhabitats (deciduous trees, coniferous trees, dead wood, understory vegetation, leaf litter) independent of fencing. Thysanoptera prey was mainly caught by spiders on coniferous trees and in the understory vegetation. Heteroptera prey were captured most frequently in the understory vegetation while Hymenoptera (excl. Formicidae) prey were mostly caught on deciduous trees. Several spider species showed a preference between deciduous and coniferous trees in the mixed forest. Wildlife fencing alters the vegetation structure of mixed forests and has indirect effects on spider communities and their role in forest food webs due to alteration of microhabitat availability.}, language = {en} } @misc{FotangDuttonBroeringetal., author = {Fotang, Chefor and Dutton, Paul and Br{\"o}ring, Udo and Roos, Christian and Willie, Jacob and Angwafo, Tsi Evaristus and Chuo, Mvo Denis and Kamgang, Serge Alexis and Enoguanbhor, Evidence Chinedu and Schierack, Peter and Birkhofer, Klaus}, title = {Tool use by Nigeria-Cameroon chimpanzees for driver ant predation in Kom-Wum Forest Reserve, North-West Region Cameroon}, series = {Folia Primatologica}, volume = {94}, journal = {Folia Primatologica}, number = {1}, issn = {1421-9980}, doi = {10.1163/14219980-bja10006}, pages = {73 -- 85}, abstract = {Chimpanzees feed on driver ants (Dorylus sp.) using different tools and predation techniques that vary among populations and can be affected by availability of ant species as well as ecological and social-learning factors. At the Kom-Wum Forest Reserve (KWFR) in Cameroon, we investigated tool use behavior in Nigerian-Cameroon chimpanzees (Pan troglodytes ellioti), examining the characteristics of tools used in driver ant predation, looking for possible seasonal patterns and comparing our results to those from other study sites. We recovered 83 tools along line transects and recces (reconnaissance) during two seasons. We found that chimpanzees used tools with blunting and dirty ends (possible digging and probing tools) and tools without (dipping tools), in driver ant predation. Tools with dirty ends tended to be thicker (N = 52), and thinner tools were less likely to have dirt (N = 31). Tools recovered in the wet season (N = 62), were significantly shorter and thicker than those recovered in the dry season (N = 21). Furthermore, driver ant tools recovered at KWFR are on average the longest yet recorded insect dipping tools for chimpanzees comparable to those used in North Uele. We found no evidence of nut-cracking, tool use for honey bee nor termite consumption and did not observe the potential prey remains in chimpanzee faeces despite their presence in the reserve. Our results suggest that seasonality significantly contributes to a divergence in the form of tools selected for driver ant predation.}, language = {en} }