Jochen Krauss

University of Wuerzburg | JMU · Department of Animal Ecology and Tropical Biology (Zoology III)

Knowledge about the phylogeny and ecology of communities along environmental gradients helps to disentangle the role of competition-driven processes and environmental filtering for community assembly. In this study, we evaluated patterns in species richness, phylogenetic structure and life-history traits of bee communities along altitudinal gradien...

Organic farming is one of the most successful agri-environmental schemes, as humans benefit from high quality food, farmers from higher prices for their products and it often successfully protects biodiversity. However there is little knowledge if organic farming also increases ecosystem services like pest control. We assessed 30 triticale fields (...

Ecology Letters (2010) 13: 597–605 Abstract Intensification or abandonment of agricultural land use has led to a severe decline of semi‐natural habitats across Europe. This can cause immediate loss of species but also time‐delayed extinctions, known as the extinction debt. In a pan‐European study of 147 fragmented grassland remnants, we found diff...

Land use change threatens global biodiversity and compromises ecosystem functions, including pollination and food production. Reduced taxonomic α‐diversity is often reported under land use change, yet the impacts could be different at larger spatial scales (i.e., γ‐diversity), either due to reduced β‐diversity amplifying diversity loss or increased...

Land use change threatens global biodiversity and compromises ecosystem functions, including pollination and food production. Reduced taxonomic α-diversity is often reported under land use change, yet the impacts could be different at larger spatial scales (i.e., γ-diversity), either due to reduced β-diversity amplifying diversity loss or increased...

Biotic interactions are crucial for determining the structure and dynamics of communities; however, direct measurement of these interactions can be challenging in terms of time and resources, especially when numerous species are involved. Inferring species interactions from species co‐occurrence patterns is increasingly being used; however, recent...

Organismal functional strategies form a continuum from slow- to fast-growing organisms, in response to common drivers such as resource availability and disturbance. However, whether there is synchronisation of these strategies at the entire community level is unclear. Here, we combine trait data for >2800 above- and belowground taxa from 14 trophic...

Context Habitat loss and degradation impose serious threats on biodiversity. However, not all habitats receive the attention commensurate with their ecological importance. Shrub ecotones (successional stages between grasslands and forests) can be highly species-diverse but are often restricted to small areas as prevalent management practices eithe...

Natural pest and weed regulation are essential for agricultural production, but the spatial distribution of natural enemies within crop fields and its drivers are mostly unknown. Using 28 datasets comprising 1204 study sites across eight Western and Central European countries, we performed a quantitative synthesis of carabid richness, activity dens...

Aim Temperature is one of the main drivers shaping species diversity and assembly processes. Yet, site‐specific effects of the local microclimate on species and trait compositions of insect communities have rarely been assessed along macroclimatic temperature clines. Location Bavarian Alps, Germany. Methods Bayesian joint species distribution mod...

Across the tree of life, organismal functional strategies form a continuum from slow-to fast-growing organisms, in response to common drivers such as resource availability and disturbance. However, the synchronization of these strategies at the entire community level is untested. We combine trait data for >2800 above-and belowground taxa from 14 tr...

The conversion of biodiversity‐rich woodland to farmland and subsequent management has strong, often negative, impacts on biodiversity. In tropical smallholder agricultural landscapes, the impacts of agriculture on insect communities, both through habitat change and subsequent farmland management, is understudied. The use of agroecological practice...

Increasing pressure on land resources necessitates landscape management strategies that simultaneously deliver multiple benefits to numerous stakeholder groups with competing interests. Accordingly, we developed an approach that combines ecological data on all types of ecosystem services with information describing the ecosystem service priorities...

Despite sometimes strong codependencies of insect herbivores and plants, the responses of individual taxa to accelerating climate change are typically studied in isolation. For this reason, biotic interactions that potentially limit species in tracking their preferred climatic niches are ignored. Here, we chose butterflies as a prominent representa...

Semi-natural grasslands are biodiverse ecosystems that support many threatened species , but they require management interventions to maintain their habitat characteristics. Although many semi-natural calcareous grasslands historically were grazed, mowing is often used as a substitute disturbance when livestock access is not feasible. Mowing may ha...

Arthropod diversity in agricultural landscapes is important to maintain numerous ecosystem services. Most arthropods, however, need shelter habitats for overwintering embedded in agricultural landscapes. Habitats created by perennial agri-environmental schemes (AES) such as flowering fields can provide such overwintering places in addition to nesti...

The composition and richness of herbivore and plant assemblages change along climatic gradients, but knowledge about associated shifts in specialisation is scarce and lacks controlling for the abundance and phylogeny of interaction partners. Thus, we aimed to test whether the specialisation of phytophagous insects in insect ‐ plant – interaction ne...

_________________ Full text on biorxiv: https://www.biorxiv.org/content/10.1101/2020.07.17.208199v5 ___________________ Land-use intensification has contrasting effects on different ecosystem services, often leading to land-use conflicts. While multiple studies have demonstrated how landscape-scale strategies can minimise the trade-off between agr...

Pollen beetles (Brassicogethes spp.) are the main pests of oilseed rape (OSR, Brassica napus) in Europe and responsible for massive yield losses. Upcoming pesticide resistances highlight the need for other means of crop protection, such as natural pest control. Sown flower fields aim to counteract the decrease of insect biodiversity in agricultural...

Land-use intensification is a major driver of biodiversity loss. However, understanding how different components of land use drive biodiversity loss requires the investigation of multiple trophic levels across spatial scales. Using data from 150 agricultural grasslands in central Europe, we assess the influence of multiple components of local-and l...

Across Europe, calcareous grasslands become increasingly fragmented and their quality deteriorates through abandonment and land use intensification, both affecting biodiversity. Here, we investigated local and landscape effects on diversity patterns of several taxonomic groups in a landscape of highly fragmented calcareous grassland remnants. We su...

Agricultural intensification in recent decades has led to a major loss of biodiversity in agricultural landscapes. Special agri-environmental schemes aim at restoring and protecting biodiversity. In Central Europe, the common hamster Cricetus cricetus (Linnaeus, 1758) is a prominent victim of changes in agricultural management and land-use. After c...

Significance The loss of biodiversity challenges agriculture as crop yields depend on biodiversity-mediated ecosystem services. Targeted agri-environmental schemes (AES), like sown flowering fields, provide additional food resources and shelter for wild plants and animals. Such AES have been implemented to restore biodiversity in agricultural lands...

The authors wish to make the following correction to this paper [...]

Mycotoxins in agriculturally used plants can cause intoxication in animals and can lead to severe financial losses for farmers. The endophytic fungus Epichloë festucae var. lolii living symbiotically within the cool season grass species Lolium perenne can produce vertebrate and invertebrate toxic alkaloids. Hence, an exact quantitation of alkaloid...

Land-use intensification has contrasting effects on different ecosystem services, often leading to land-use conflicts. Multiple studies, especially within the ‘land-sharing versus land-sparing’ debate, have demonstrated how landscape-scale strategies can minimise the trade-off between agricultural production and biodiversity conservation. However,...

Increasing natural pest control in agricultural fields is an important aim of ecological intensification. Combined effects of landscape context and local placement of agri‐environmental schemes (AES) on natural pest control and within‐field distance functions of natural pest control agents have rarely been addressed but might affect the distributio...

Systemic grass-endophytes of the genus Epichloë symbiotically infect the above-ground plant parts of many grass species, where they produce alkaloids in a grass- and endophyte-specific manner that are toxic or deterrent to herbivores. An increasing number of studies show cascading negative effects of endophyte-derived alkaloids that extend to highe...

Fungal endophytes of the genus Epichloë live symbiotically in cool season grass species and can produce alkaloids toxic to insects and vertebrates, yet reports of intoxication of grazing animals have been rare in Europe in contrast to overseas. However, due to the beneficial resistance traits observed in Epichloë infected grasses, the inclusion of...

Animal pollination is of major importance to wild plants and a wide variety of crops, yet agricultural intensification has led to pollinator declines and yield gaps in agroecosystems. Agri-environment schemes (AES) aim to restore biodiversity and ecosystem services by providing suitable habitats and key resources. Sown flower fields are often imple...

Predation on pest organisms is an essential ecosystem function supporting yields in modern agriculture. However, assessing predation rates is intricate, and they can rarely be linked directly to predator densities or functions. We tested whether sentinel prey aphid cards are useful tools to assess predation rates in the field. Therefore, we looked...

Many aphid species reproduce parthenogenetically throughout most of the year, with individuals having identical genomes. Nevertheless, aphid clones display a marked polyphenism with associated behavioural differences. Pea aphids (Acyrthosiphon pisum), when crowded, produce winged individuals, which have a larger dispersal range than wingless indivi...

Severe problems of livestock intoxication from Epichloë -infected forage grasses have been reported from New Zealand, Australia, and the United States, but much less frequently from Europe, and particularly not from Germany. Nevertheless, it is important to monitor infection rates and alkaloids of grasses with Epichloë fungi to estimate possible in...

Extinction debt refers to delayed species extinctions expected as a consequence of ecosystem perturbation. Quantifying such extinctions and investigating long‐term consequences of perturbations has proven challenging, because perturbations are not isolated and occur across various spatial and temporal scales, from local habitat losses to global war...

Managing agricultural landscapes to support biodiversity and ecosystem services is a key aim of a sustainable agriculture. However, how the spatial arrangement of crop fields and other habitats in landscapes impacts arthropods and their functions is poorly known. Synthesising data from 49 studies (1515 landscapes) across Europe, we examined effects...

Managing agricultural landscapes to support biodiversity and ecosystem services is a key aim of a sustainable agriculture. However, how the spatial arrangement of crop fields and other habitats in landscapes impacts arthropods and their functions is poorly known. Synthesising data from 49 studies (1515 landscapes) across Europe, we examined effects...

Context Habitat loss and fragmentation are major threats to biodiversity and can change community composition, species traits and intraspecific morphology. Calcareous grasslands are hotspots of diversity for plants and invertebrates in Europe, but habitat area and habitat amount declined strongly over the last century. Objectives It is controversi...

Induced or constitutive production of secondary metabolites is a successful plant defence strategy against herbivores which can be mediated by plant associated micro-organisms. Several grass species can be associated with an endophytic fungus of the genus Epichloë which produces herbivore toxic or deterring alkaloids. Besides these direct defences,...

Background Pitfall traps are commonly used to assess ground dwelling arthropod communities. The effects of different pitfall trap designs on the trapping outcome are poorly investigated however they might affect conclusions drawn from pitfall trap data greatly. Methods We tested four pitfall trap types which have been used in previous studies for...

Activity densities of staphylinid beetles and spiders. site = study sites. type: A = customary, B = plastic rim, C = V shaped guidance barrier, D = X shaped guidance barrier.

Carabid species richness and activity densities. site = study sites. type: A = customary, B = plastic rim, C = V shaped guidance barrier, D = X shaped guidance barrier.

Rising demands for agricultural products and high environmental costs of intensive agriculture reinforce the need for ecological replacements in agricultural management. In Europe, agri‐environmental schemes (AES) are implemented to enhance species richness and provision of ecosystem services, but the effectiveness of different AES types and the sp...

Epichloë endophytes associated with cool-season grass species can protect their hosts from herbivory and can suppress mycorrhizal colonization of the hosts’ roots. However, little is known about whether or not Epichloë endophyte infection can also change the foliar fungal assemblages of the host. We tested 52 grassland study sites along a land-use...

OTU matrix of fungal OTUs isolated from Lolium perenne leaves Table includes total OTU reads per each L. perenne sample, location/region, Epichloë infection state and taxonomic detail to the single OTUs.

We sampled Lolium perenne, a cool season grass species in three different regions in Germany (Biodiversity exploratories) and determined infection frequencies and alkaloid contents of the samples.

Timing seasonal events, like reproduction or diapause, is crucial for the survival of many species. Global change causes phenologies worldwide to shift, which requires a mechanistic explanation of seasonal time measurement. Day length (photoperiod) is a reliable indicator of winter arrival, but it remains unclear how exactly species measure day len...

The systemic grass endophyte Epichloë festucae var. lolii produces alkaloids which can protect the host grass Lolium perenne from herbivory. Alkaloid concentrations depend on genetic predisposition of grass and endophyte, and are affected by the environment. However, the role of plant age and seasonal timing remains unknown. We monitored monthly en...

The common forage grass Lolium perenne has evolved with the systemic fungal endophyte Epichloë festucae var. lolii. The endophyte provides herbivore resistance to the grass due to defensive alkaloids, some of which are toxic to grazing livestock. In this field study, we determine whether distribution of the endophyte-grass association changes along...

Despite the evidence that increased frequency and magnitude of extreme climate events (ECE) considerably affect plant performance, there is still a lack of knowledge about how these events affect mountain plant biodiversity and mountain ecosystem functioning. Here, we assessed the short-term (one vegetation period) effects of simulated ECEs [extrem...

Natural enemies have been shown to be effective agents for controlling insect pests in crops. However, it remains unclear how different natural enemy guilds contribute to the regulation of pests and how this might be modulated by landscape context. In a field exclusion experiment in oilseed rape (OSR), we found that parasitoids and ground-dwelling...

Phenology shifts and range expansions cause organisms to experience novel day length - temperature correlations. Depending on the temporal niche, organisms may benefit or suffer from changes in day length, thus potentially affecting phenological adaptation. We assessed the impact of day length changes on larvae of Chrysoperla carnea (Stephens) and...

Global warming can disrupt mutualistic interactions between solitary bees and plants when increasing temperature differentially changes the timing of interacting partners. One possible scenario is for insect phenology to advance more rapidly than plant phenology. However, empirical evidence for fitness consequences due to temporal mismatches is lac...

Agricultural intensification is a leading cause of global biodiversity loss, which can reduce the provisioning of ecosystem services in managed ecosystems. Organic farming and plant diversification are farm management schemes that may mitigate potential ecological harm by increasing species richness and boosting related ecosystem services to agroec...

Plants have developed a variety of defence strategies against herbivores. One possible strategy is the induced production of metabolites following herbivore attack. Plant‐associated micro‐organisms can be the source of such defensive compounds. For example, cool‐season grasses can be associated with systemic endophytic fungi of the genus Epichloё ,...

Climate change leads to phenology shifts of many species. However, not all species shift in parallel, which can desynchronize interspecific interactions. Within trophic cascades, herbivores can be top–down controlled by predators or bottom–up controlled by host plant quality and host symbionts, such as plant-associated micro-organisms. Synchronizat...

The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used t...

Figure S1: Database schema. Diversity data in yellow, GIS data in green and Catalogue of Life data in blue. The diversity tables datasource, study, site, measuredtaxon and diversitymeasurement follow the structure described in ‘Methods’ in the main text and in Hudson et al. (2014): a datasource is associated with one or more study records, each of...

The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used t...

The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used t...

Land-use intensification is a major driver of biodiversity loss. Alongside reductions in local species diversity, biotic homogenization at larger spatial scales is of great concern for conservation. Biotic homogenization means a decrease in β-diversity (the compositional dissimilarity between sites). Most studies have investigated losses in local (...

Semi-natural grasslands in Europe are insect biodiversity hotspots and important source habitats delivering ecosystem services to adjacent agricultural land by species spillover. However, this spillover might also occur in the opposite direction, affecting the diversity of semi-natural grasslands. This opposite spillover has got little attention in...