Thunen Institute of Biodiversity

Braunschweig, Germany

Thunen Institute of Biodiversity

Braunschweig, Germany

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Dauber J.,Thunen Institute of Biodiversity | Cass S.,Trinity College Dublin | Gabriel D.,Thunen Institute of Biodiversity | Harte K.,Trinity College Dublin | And 3 more authors.
GCB Bioenergy | Year: 2015

Increasing crop productivity to meet rising demands for food and energy, but doing so in an environmentally sustainable manner, is one of the greatest challenges for agriculture to date. In Ireland, Miscanthus × giganteus has the potential to become a major feedstock for bioenergy production, but the economic feasibility of its cultivation depends on high yields. Miscanthus fields can have a large number of gaps in crop cover, adversely impacting yield and hence economic viability. Predominantly positive effects of Miscanthus on biodiversity reported from previous research might be attributable to high crop patchiness, particularly during the establishment phase. The aim of this research was to assess crop patchiness on a field scale and to analyse the relationship between Miscanthus yield and species richness and abundance of selected taxa of farmland wildlife. For 14 Miscanthus fields at the end of their establishment phase (4-5 years after planting), which had been planted either on improved grassland (MG) or tilled arable land (MT), we determined patchiness of the crop cover, percentage light penetration (LP) to the lower canopy, Miscanthus shoot density and height, vascular plants and epigeic arthropods. Plant species richness and noncrop vegetation cover in Miscanthus fields increased with increasing patchiness, due to higher levels of LP to the lower canopy. The species richness of ground beetles and the activity density of spiders followed the increase in vegetation cover. Plant species richness and activity density of spiders on both MT and MG fields, as well as vegetation cover and activity density of ground beetles on MG fields, were negatively associated with Miscanthus yield. In conclusion, positive effects of Miscanthus on biodiversity can diminish with increasing productivity. This matter needs to be considered when assessing the relative ecological impacts of developing biomass crops in comparison with other land use. © 2013 John Wiley & Sons Ltd.

PubMed | Cambridge Consultants, James Hutton Institute, University of Greenwich, Szent Istvan University and 5 more.
Type: | Journal: The Science of the total environment | Year: 2017

In legal frameworks worldwide, genetically modified plants (GMPs) are subjected to pre-market environmental risk assessment (ERA) with the aim of identifying potential effects on the environment. In the European Union, the EFSA Guidance Document introduces the rationale that GMPs, as well as their newly produced metabolites, represent the potential stressor to be evaluated during ERA. As a consequence, during several phases of ERA for cultivation purposes, it is considered necessary to use whole plants or plant parts in experimental protocols. The importance of in planta studies as a strategy to address impacts of GMPs on non-target organisms is demonstrated, to evaluate both effects due to the intended modification in plant phenotype (e.g. expression of Cry proteins) and effects due to unintended modifications in plant phenotype resulting from the transformation process (e.g. due to somaclonal variations or pleiotropic effects). In planta tests are also necessary for GMPs in which newly expressed metabolites cannot easily be studied in vitro. This paper reviews the scientific literature supporting the choice of in planta studies as a fundamental tool in ERA of GMPs in cultivation dossiers; the evidence indicates they can realistically mimic the ecological relationships occurring in their receiving environments and provide important insights into the biology and sustainable management of GMPs.

Dauber J.,Thunen Institute of Biodiversity | Miyake S.,TU Darmstadt
Energy, Sustainability and Society | Year: 2016

Biodiversity is severely declining in intensively managed agriculture worldwide. In response, land-management strategies for biodiversity conservation on farmland are in debate, namely ecological intensification and land sparing vs. land sharing. In parallel, there is a recent food vs. energy debate stimulated by an increasing competition for land resources. Despite clear overlaps between these two debates, they were rarely connected in previous research. This paper aims to stimulate a discussion by providing a contextual link between biodiversity conservation strategies and options for future energy crop deployment. Therefore, nine conceptual land-use scenarios are developed, and then, the potential biodiversity implications are discussed based on the findings from past and ongoing research. These scenarios include the integration and segregation of both food and energy crops on lands with a range of productivity and suitability for agricultural production. We assume that the clear segregation between food crops on productive land and energy crops on marginal land is less likely to be a solution of mitigating the problems related to the biodiversity decline, especially in the European agricultural landscape context. In contrast, the integration of food and energy crop production systems at the farm to landscape scale has greater potential for ecological intensification, although conflicts with traditional nature conservation targets may arise. We conclude that broadening the perspectives of biodiversity conservation in agriculture is crucial, and the inclusion of energy crop production into the recent debates on biodiversity conservation strategies is helpful. © 2016, The Author(s).

Hemkemeyer M.,Thunen Institute of Biodiversity | Christensen B.T.,University of Aarhus | Martens R.,Thunen Institute of Biodiversity | Tebbe C.C.,Thunen Institute of Biodiversity
Soil Biology and Biochemistry | Year: 2015

Due to differences in mineralogical composition and organic matter density, soil particle size fractions (PSF) provide different surface properties and micro-environments, which may affect the adsorption of chemicals and select for distinct microbial communities. Using soils from a long-term fertilisation experiment, we examined the structural diversity of microbial communities associated with different PSF and their potential to mineralise two organic pollutants (phenol and 2,4-dichlorophenol (DCP)). The soils were taken from 0 to 18 cm depth of arable field plots that have been kept unfertilised (UNF), mineral fertilised (NPK), or treated with animal manure (AM) for 117 years. Sand, including particulate organic matter (POM), coarse silt, fine silt, and clay were isolated by gentle ultra-sonication, wet-sieving and centrifugation. Animal manuring increased the abundance of the three microbial domains Bacteria, Archaea and Fungi, with coarse silt being most responsive. The impact of manuring declined with decreasing particle size. Genetic profiling indicated that the composition of the bacterial communities was primarily shaped by soil particle size classes, while archaea responded predominantly to fertilisation. Particle size as well as fertilisation was equally important in structuring the fungal communities. All PSF showed capacity for phenol mineralisation with rates correlating negatively with particle size (except for the sand-POM fraction), and long-term fertilisation enhanced the mineralisation potential. In contrast, DCP mineralisation was associated with the clay fraction only and was highest for soil treated with mineral fertiliser. This study demonstrates that PSF harbour structurally distinct microbial communities with different functional potentials for mineralising organic pollutants. © 2015 Elsevier Ltd.

Petersen U.,University of Gottingen | Petersen U.,Thunen Institute of Biodiversity | Wrage-Monnig N.,University of Gottingen | Wrage-Monnig N.,Rhine-Waal University of Applied Sciences | Isselstein J.,University of Gottingen
International Journal of Biodiversity Science, Ecosystems Services and Management | Year: 2013

Herbicide application on permanent grassland to reduce weeds and improve forage quality is common agricultural practice. However, it still remains unclear how long it takes for the herbicide-disturbed swards to recover in terms of yield and forage quality. In a removal experiment in the Solling Uplands (Germany), the sward composition of permanent grassland had been manipulated by herbicides in order to obtain either relatively pure grass swards or swards with comparatively large amounts of forbs and legumes, in addition to untreated control swards. The short-term resilience of these sward types was examined under a gradient of management intensity regulated by both cutting regime and fertilizer supply. In the next growing season, the yield did not differ among any of the three sward types regardless of the management regime. All disturbed swards showed a complete recovery in terms of biomass. Yield was only influenced by functional sward characteristics across all disturbance treatments; the growth form of the dominant species determined the yield in fertilized plots. For the variation in forage quality (crude protein, water-soluble carbohydrates and fibre content), the functional group identity of the remaining vegetation was important, but management had a much larger influence than vegetation. © 2013 Copyright Taylor and Francis Group, LLC.

Neumann D.,Thunen Institute of Biodiversity | Heuer A.,Thunen Institute of Biodiversity | Hemkemeyer M.,Thunen Institute of Biodiversity | Martens R.,Thunen Institute of Biodiversity | Tebbe C.C.,Thunen Institute of Biodiversity
ISME Journal | Year: 2014

Many organic pollutants are readily degradable by microorganisms in soil, but the importance of soil organic matter for their transformation by specific microbial taxa is unknown. In this study, sorption and microbial degradation of phenol and 2,4-dichlorophenol (DCP) were characterized in three soil variants, generated by different long-term fertilization regimes. Compared with a non-fertilized control (NIL), a mineral-fertilized NPK variant showed 19% and a farmyard manure treated FYM variant 46% more soil organic carbon (SOC). Phenol sorption declined with overall increasing SOC because of altered affinities to the clay fraction (soil particles <2 mm in diameter). In contrast, DCP sorption correlated positively with particulate soil organic matter (present in the soil particle fractions of 63-2000 μm). Stable isotope probing identified Rhodococcus, Arthrobacter (both Actinobacteria) and Cryptococcus (Basidiomycota) as the main degraders of phenol. Rhodococcus and Cryptococcus were not affected by SOC, but the participation of Arthrobacter declined in NPK and even more in FYM. 14 C-DCP was hardly metabolized in the NIL variant, more efficiently in FYM and most in NPK. In NPK, Burkholderia was the main degrader and in FYM Variovorax. This study demonstrates a strong effect of SOC on the partitioning of organic pollutants to soil particle size fractions and indicates the profound consequences that this process could have for the diversity of bacteria involved in their degradation. © 2014 International Society for Microbial Ecology. All rights reserved.

Hendriksma H.P.,University of Würzburg | Hendriksma H.P.,Hebrew University of Jerusalem | Kuting M.,Thunen Institute of Biodiversity | Hartel S.,University of Würzburg | And 4 more authors.
PLoS ONE | Year: 2013

Honey bee pollination is a key ecosystem service to nature and agriculture. However, biosafety research on genetically modified crops rarely considers effects on nurse bees from intact colonies, even though they receive and primarily process the largest amount of pollen. The objective of this study was to analyze the response of nurse bees and their gut bacteria to pollen from Bt maize expressing three different insecticidal Cry proteins (Cry1A.105, Cry2Ab2, and Cry3Bb1). Naturally Cry proteins are produced by bacteria (Bacillus thuringiensis). Colonies of Apis mellifera carnica were kept during anthesis in flight cages on field plots with the Bt maize, two different conventionally bred maize varieties, and without cages, 1-km outside of the experimental maize field to allow ad libitum foraging to mixed pollen sources. During their 10-days life span, the consumption of Bt maize pollen had no effect on their survival rate, body weight and rates of pollen digestion compared to the conventional maize varieties. As indicated by ELISA-quantification of Cry1A.105 and Cry3Bb1, more than 98% of the recombinant proteins were degraded. Bacterial population sizes in the gut were not affected by the genetic modification. Bt-maize, conventional varieties and mixed pollen sources selected for significantly different bacterial communities which were, however, composed of the same dominant members, including Proteobacteria in the midgut and Lactobacillus sp. and Bifidobacterium sp. in the hindgut. Surprisingly, Cry proteins from natural sources, most likely B. thuringiensis, were detected in bees with no exposure to Bt maize. The natural occurrence of Cry proteins and the lack of detectable effects on nurse bees and their gut bacteria give no indication for harmful effects of this Bt maize on nurse honey bees. © 2013 Hendriksma et al.

Mueller A.L.,Thunen Institute of Biodiversity | Dauber J.,Thunen Institute of Biodiversity
Agricultural and Forest Entomology | Year: 2016

An increasing production of annual bioenergy crops such as maize has led to regional land-use changes, causing further shortages of already scarce floral resources for pollinators. Diversification of energy crop production with flowering crops is discussed as a mitigation strategy. The perennial Silphium perfoliatum, characterized by a flowering period between July and September, represents a promising candidate crop. The present study aimed to investigate the management and landscape conditions under which a cultivation of S. perfoliatum could be an effective measure for pollinator conservation. In this context, hoverflies served as suitable indicators as a result of the different feeding behaviours of adults (floral resources) and larvae (mostly zoophagous or microphagous). We compared abundance and species richness of adult hoverflies in 15 flowering S. perfoliatum fields in Germany with that in neighbouring habitats (maize fields, ditches/brooks and forest edges) and tested whether the landscape composition influenced local abundance and species richness in S. perfoliatum fields depending on larval feeding type. Only microphagous hoverflies were more abundant in S. perfoliatum fields than in neighbouring habitats, primarily in mid-September. This might be explained by the different activity periods and adaptations to flower traits of the two hoverfly groups. Although the abundance of zoophagous hoverflies was positively influenced by a higher crop diversity, the abundance and species richness of microphagous hoverflies responded positively to higher proportions of semi-natural habitats in the surroundings. Silphium perfoliatum can support certain hoverfly groups when it is harvested late to ensure a flower supply through to September and when semi-natural habitats are maintained in agricultural landscapes. © 2016 The Royal Entomological Society

Klimek S.,Thunen Institute of Biodiversity | Lohss G.,Thunen Institute of Biodiversity | Gabriel D.,Thunen Institute of Biodiversity
Biological Conservation | Year: 2014

Spatial targeting of conservation actions is indispensable to protect and maintain farmland biodiversity and associated ecosystem services. To implement region-specific conservation actions, information on the spatial distribution of farmland biodiversity and its major drivers is a prerequisite. Here, we model the spatial distribution of species-rich farmland (defined by a minimum number of indicator plant species) and landscape elements (e.g. hedgerows, ditches, patches of woodland or scrub) at the national level by combining field-based survey data from a biological monitoring programme with agri-environmental variables. Adopting factor analysis and mixed effect models, we show that the percentage cover of species-rich farmland and landscape elements can be predicted by a combination of factors describing the intensity of arable farming, topography, low-input grassland farming, landscape structure and the intensity of livestock farming. Our results demonstrate that the relative importance of these factors differed between species-rich farmland and landscape elements. The share of species-rich farmland was highest in upland and structurally complex grassland-dominated regions where extensive livestock production is practised; whereas landscape elements were most likely to occur within flat regions where edge density tends to be high.In a policy context, our generated maps contribute to identifying priority regions for conservation actions. It is proposed that in regions with high coverage of species-rich farmland priority should be given to sustaining low-input grassland farming by keeping farmers in business and preventing farmland abandonment. We conclude that this modelling approach could be adapted for application in other European countries to facilitate spatial targeting of conservation actions. © 2014 Elsevier Ltd.

Strohbach M.W.,University of Massachusetts Amherst | Strohbach M.W.,Thunen Institute of Biodiversity | Lerman S.B.,University of Massachusetts Amherst | Warren P.S.,University of Massachusetts Amherst
Landscape and Urban Planning | Year: 2013

Green space is an important component of the urban landscape, providing ecosystem services for city dwellers and supporting biodiversity. In many cities, green space is concentrated in large areas, while the rest is dispersed in small patches like pocket parks, gardens or street trees. Such small-scale green space is often the target of greening initiatives but little is known about their value for supporting and conserving biodiversity. To assess the value of such initiatives for biodiversity, we used birds as an indicator. We examined bird communities at small greening projects (n=12), nearby randomly chosen urban sites (n=12), and large parks (n=6) in Boston, MA, in relationship to underlying landscape patterns. Our results show that large parks harbor a distinct and rich bird community. The other sites, regardless of the presence of greening projects, were very similar to each other. However, most sites with greening projects had higher species richness than the random urban site in their vicinity. The main factor associated with this appears to be the patch size of green space and to a lesser extent, tree cavities. Even small increases of a few hundred square meters were associated with an increase in bird richness. Having more trees with cavities was also beneficial for species richness. Small greening projects appear to be most valuable for urban biodiversity if they target preserving, increasing and connecting existing green space. This may represent a tradeoff with environmental justice criteria for new green space. © 2013 Elsevier B.V.

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