Frank Jauker

Justus-Liebig-Universität Gießen | JLU · Institut für Tierökologie und Spezielle Zoologie

Pollinators differ in morphological and behavioral traits. The effect of the resulting trait variation on pollination effectiveness at the level of different species has received considerable attention, while the effect of intra-specific trait variation at the population level is largely unexplored. We examined the impact of body size variation in...

1. Agricultural intensification is considered to be a major driver of terrestrial biodiversity decline. Resulting loss, isolation and degradation of flower-rich habitats are threatening pollinators. Agri-environmental schemes (AES) aim to counteract these negative effects, including measures to enhance floral resources in agricultural landscapes. T...

There is compelling evidence that more diverse ecosystems deliver greater benefits to people, and these ecosystem services have become a key argument for biodiversity conservation. However, it is unclear how much biodiversity is needed to deliver ecosystem services in a cost-effective way. Here we show that, while the contribution of wild bees to c...

Background Insect pollinators play an important role in crop pollination, but the relative contribution of wild pollinators and honey bees to pollination is currently under debate. There is virtually no information available on the strength of pollination services and the identity of pollination service providers from Asian smallholder farming syst...

To gain insight into the drivers of pollinator loss, a holistic approach to land-use change including habitat size, isolation, habitat quality and the surrounding landscape matrix is necessary. Moreover, species’ responses to land-use change may differ depending on their life history traits such as dispersal ability, trophic level, or sociality. We...

Jahrbuch Naturschutz in Hessen (2023)

BeeContour's strip cropping system represents a pioneering approach to increase structural heterogeneity aimed at bolstering wild bee and other pollinator insect populations within agricultural landscapes. The BeeContour project collaborates with farmers to establish practical strip copping systems, adapting their management techniques and crop cho...

Agricultural intensification is a major cause for biodiversity loss in open landscapes. Intensive mowing regimes in grasslands result in homogeneous areas. The low structural diversity results in a decline in habitats and food resources for interacting species such as pollinators. Fallow strips, i.e. agricultural grasslands taken out of management,...

Agricultural intensification is a major cause for biodiversity loss in open landscapes. Intensive mowing regimes in grasslands result in homogeneous areas. The low structural diversity results in a decline in habitats and food resources for interacting species such as pollinators. Fallow strips, i.e. agricultural grasslands taken out of management,...

Agricultural intensification has been identified as a major cause of biodiversity loss. Accordingly, the biodiversity of agricultural grassland is highly dependent on management intensity. However, agri-environmental schemes aimed at maintaining grassland biodiversity must also consider grassland productivity. Fallow strips, i.e. agricultural grass...

Agricultural intensification has been identified as a major cause of biodiversity loss. Of all animal species found in Germany, 70-80 % inhabit open land biotopes. Accordingly, the biodiversity of agricultural grassland highly depends on management intensity. Mowing technique and timing have been shown to have several negative effects on the differ...

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.endend.2014.06.001. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/ourbusiness/policies/article-withdrawal.

Etwa 70-80 % der in Deutschland vorkommenden Tierarten bewohnen Offenlandbiotope. Dabei ist die Artenvielfalt auf landwirtschaftlich genutztem Grünland deutlich höher als auf Ackerland. Daher kann der Schutz der biologischen Vielfalt nicht ausschließlich in Schutzgebieten erfolgen, sondern muss sich in innovative und nachhaltige landwirtschaftliche...

Paying landowners for conservation results rather than paying for the measures intended to provide such results is a promising approach for biodiversity conservation. However, a key roadblock for the widespread implementation of such result-based payment schemes are the frequent difficulties to monitor target species for whose presence a landowner...

1. Collembola are an important potential food source for carnivorous arthropods living on the soil surface. Nevertheless, due to their effective evasive manoeuvres, Collembola are not an easy prey. Several carabid groups, however, have evolved morphological specialisations to overcome this otherwise effective defence strategy. The adaptive value of...

Seventy five percent of the world's food crops benefit from insect pollination. Hence, there has been increased interest in how global change drivers impact this critical ecosystem service. Because standardized data on crop pollination are rarely available, we are limited in our capacity to understand the variation in pollination benefits to crop y...

Larger geographical areas contain more species—an observation raised to a law in ecology. Less explored is whether biodiversity changes are accompanied by a modification of interaction networks. We use data from 32 spatial interaction networks from different ecosystems to analyse how network structure changes with area. We find that basic community...

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Wildflower plantings are an important mitigation tool within agri-environmental schemes to counter insect decline in resource-scarce agricultural landscapes. Effectiveness of wildflower plantings for insect conservation is typically studied at the community or species level. It is the individual, however, that is subject to changing abiotic and bio...

Wildflower areas have become a staple tool within agro-environmental schemes (AES) to counteract pollinator declines. While their role in providing food resources to resident flower-visiting insects is unambiguous, the conservation effectiveness in a landscape context is less clear. Particularly, how multiple vs. single wildflower area utilization...

The importance of wild bees for crop pollination is well established, but less is known about which species contribute to service delivery to inform agricultural management, monitoring and conservation. Using sites in Great Britain as a case study, we use a novel qualitative approach combining ecological information and field survey data to establi...

Extensively managed and flower-rich mountain hay meadows, hotspots of Europe's biodiversity, are subject to environmental and climatic gradients linked to altitude. While the shift of pollinators from bee-to fly-dominated communities with increasing elevation across vegetation zones is well established, the effect of highland altitudinal gradients...

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Closely related species are often assumed to be functionally similar. Phylogenetic information is thus widely used to infer functional diversity and assembly of communities. In contrast, evolutionary processes generating functional similarity of phylogenetically distinct taxa are rarely addressed in this context. To investigate the impact of conver...

Subsidized wildflower strips aim at counteracting insect species loss in agricultural landscapes. Little is known yet about their effects on insects that not only feed on pollen and nectar but also hunt for arthropod prey for larval nutrition. Here, we provide new evidence that wildflower strips may benefit the provisioning of larval prey for spide...

How ecological communities of the future will be structured is of key relevance to human welfare (Hooper et al. 2005). The necessary mechanistic understanding of how global change drives compositional changes in these communities, however, addresses only one side of the coin. Phenotypic alterations at the community and population level, and ultimat...

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...

How insects promote crop pollination remains poorly understood in terms of the contribution of functional trait differences between species. We used meta-analyses to test for correlations between community abundance, species richness and functional trait metrics with oilseed rape yield, a globally important crop. While overall abundance is consiste...

The risk of ecosystem function degradation with biodiversity loss has emerged as a major scientific concern in recent years. Possible relationships between taxonomic diversity and magnitude and stability of ecosystem processes build upon species’ functional characteristics, which determine both susceptibility to environmental change and contributio...

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...

https://authors.elsevier.com/c/1YOsG1R~eAtIg (free access until March 03, 2019). Agri-environmental schemes aim to promote biodiversity in agricultural landscapes. However, knowledge about the impact of these measures on diversity components beyond species richness, especially for non-target species and their ecological functions, is still very poo...

Summary In Mid July 2015, an assemblage of Ectemnius cavifrons (Thomson, 1870) nests in the decaying trunk of a dead tree was observed at the Hoherodskopf (Vogelsbergkreis, Hessen). The proximity to the research station "Künanzhaus" (University of Giessen, Department of Animal Ecology) allowed for detailed examination of the foraging behaviour of t...

Habitat fragmentation causes species loss in agroecosystems. Subsidized wildflower strips are thought to counteract this loss and promote ecosystem services. While studies on their benefits for pollen-collecting insects are multifarious, there is a gab of knowledge about other ecosystem service providers and the development of insect populations ov...

Habitat fragmentation is a primary threat to biodiversity, but how it affects the structure and stability of ecological networks is poorly understood. Here, we studied plant–pollinator and host–parasitoid networks on 32 calcareous grassland fragments covering a size gradient of several orders of magnitude and with amounts of additional habitat avai...

1. Sown wildflower strips can support insects that collect pollen for their larvae. How these strips affect flower visitors with carnivorous larvae, however, is almost unknown. We studied the impact of wildflower strips and their surroundings on two common solitary wasps: the caterpillar-hunting Ancistrocerus nigricornis Curtis and the spider-hunting...

Adaptive Food Webs is a synthesis of talks from the fourth decadal conference on food webs, after the publishing of the seminal book by Robert May entitled Stability and Complexity in Model Ecosystems. It embraces the notion of food webs as being complex adaptive systems by exploring dynamic structures and processes, through both changes in externa...

The conversion of semi-natural habitats and land-use intensification are major threats to terrestrial biodiversity. While the decline in insects and particularly wild bees seems to be ongoing in agricultural landscapes, there is evidence for the persistence of rare species, and even generalists performing better, in urban areas. This seems surprisi...

Pollination by insects is key for the productivity of many fruit and non-graminous seed crops, but little is known about the response of pollinators to landscapes dominated by small-holder agriculture. Here we assess the relationships between landscape context, pollinator communities (density and diversity) and pollination of oilseed rape in 18 lan...

Biotic pollination is an important factor for ecosystem functioning and provides a substantial ecosystem service to human food security. Not all flower visitors are pollinators, however, and pollinators differ in their pollination performances. In this study, we determined the efficiencies of flower visitors to the plant species Malva sylvestris, B...

Introduction Trophic interactions are one of the most important aspects shaping ecological communities, and the food-web paradigm has played a major role in the development of ecology as a science. Early food-web models attempted to simulate the flow of energy and biomass within local communities (Odum, 1956) or describe the structure of feeding re...

Context In modern agricultural landscapes, fragmentation of partial habitats is a significant filter for multi-habitat users, reducing local taxonomic and functional diversity. There is compelling evidence that small species are more susceptible than large species. The impact of habitat fragmentation on intraspecific body-size distribution, however...

One goal of wildflower plantings is to promote biodiversity in intensively managed agricultural landscapes. Flower visitors of wildflower plantings encompass many ecologically and economically important species. However, most studies on flower-visitors of wildflower plantings have focussed on single or few prominent taxa (e.g., wild bees and hoverf...

Nature Communications 6: Article number: 741410.1038/ncomms8414 (2015); Published: June162015; Updated: February182016. The authors inadvertently omitted Kimiora L. Ward, who managed and contributed data, from the author list. This has now been corrected in both the PDF and HTML versions of the Article.

Significance Many of the world’s crops are pollinated by insects, and bees are often assumed to be the most important pollinators. To our knowledge, our study is the first quantitative evaluation of the relative contribution of non-bee pollinators to global pollinator-dependent crops. Across 39 studies we show that insects other than bees are effic...

Habitat fragmentation constitutes a main driver of biodiversity decline in agroecosystems. Subsidized flowering fields are thought to counteract this decline. While their benefits for pollen-collecting insects are obvious, little is known about their effects on flower visitors with carnivorous larvae. Here, we studied whether flowering fields provi...

Being among the most important soil engineers, the potential of earthworms to beneficially affect carbon storage and cycling in tropical rice‐based ecosystems is poorly understood, as most studies are biased towards their perception as pests. We carried out a microcosm experiment to quantify the impact of a tropical earthworm on C turnover in paddy...

The aim of agri-environmental schemes is to support biodiversity by funding farmers for environmentally friendly management. Sown wild-flower fields are an established method for promoting pollinators by counteracting detrimental effects of habitat fragmentationand resource limitation in homogeneous landscapes. While it has already been shown that...

Considerable uncertainties exist on how increased biofuel cropping affects biodiversity. Regarding oilseed rape, the most common biofuel crop in the EU, positive responses of flower-visiting insects to plentiful nectar and pollen seem apparent. However, previous investigations on this insect guild revealed conflicting results, potentially because t...

Rice production consumes about 30% of all freshwater used worldwide and 45% in Asia. Turning away from permanently flooded rice cropping systems for mitigating future water scarcity and reducing methane emissions, however, will alter a variety of ecosystem services with potential adverse effects to both the environment and agricultural production....

Providing ample nectar and pollen, mass-flowering crops were suggested to counteract ongoing pollinator declines in modern agro-ecosystems. Lately, however, positive effects were shown to be transient and highly trait-specific within the social bumblebees. Contrary to bumblebees, solitary wild bees may benefit more sustainably from mass-flowering c...

Declining numbers in honeybees and various wild bee species pose a threat to global pollination services. The identification and quantification of the pollination service provided by different taxa within the pollinator guild is a prerequisite for the successful establishment of nature conservation and crop management regimes. Wild bees and hoverfl...

1. New incentives at the national and international level frequently lead to substantial structural changes in agricultural landscapes. Subsidizing energy crops, for example, recently fostered a strong increase in the area cultivated with oilseed rape Brassica napus across the EU. These changes in landscape structure affect biodiversity and associa...

Background/Question/Methods Lately mass flowering crops (i.e. oilseed rape) have been shown to positively affect colony growth and densities of bumblebees. Consequently these highly rewarding crops have been suggested to be important for sustaining vital pollination services in agroecosystems. So far, however, no attention has been directed to pot...

Semi-natural habitats provide essential resources for pollinators within agricultural landscapes and may help maintain pollination services in agroecosystems. Yet, whether or not pollinators disperse from semi-natural habitat elements into the adjacent agricultural matrix may to a large extent depend on the quality of this matrix and the correspond...

Hoverflies (Diptera: Syrphidae) in agroecosystems have gained much attention recently because the larvae of some species are efficient control agents of crop aphids, and adult hoverflies provide pollination services to wild flowers and flowering crops. We assessed the density and species richness of hoverflies in 32 calcareous grasslands, which con...

Understanding the consequences of declining diversity and abundance of pollinators for crops and floral biodiversity is a major challenge for current conservation ecology. However, most studies on this issue focus on bees, while other invertebrate taxa are largely ignored. We investigated the pollination efficiency of the globally abundant hover fl...