Zuletzt publiziert

  • Zeitschriftenartikel

    The Effects of Diversification Activities on the Technical Efficiency of Organic Farms in Switzerland, Austria, and Southern Germany 

    Lakner, Sebastian; Kirchweger, Stefan; Hoop, Daniel; Brümmer, Bernhard; Kantelhardt, Jochen
    Sustainability 2018; 10(4): Art. 1304
    The diversification of farms can be a result of multifunctional farming, however, in some cases at the cost of lower farm efficiency. In our paper we investigate the influence of para-agricultural diversification on productivity and the technical efficiency of organic farms in Austria, Switzerland, and Southern Germany. We show the benefits and drawbacks of diversification for organic farms, which go beyond the core agricultural production (para-agriculture). We do this by estimating a Stochastic Frontier (SF) combined with a metafrontier model. The data-set consists of bookkeeping data with 1704 observations in the years 2003 to 2005. Para-agricultural diversification activities have a significant effect on both productivity and technical efficiency of organic farms: The farm output in Austria and Switzerland is positively influenced by diversification, whereas we observe a rather small effect in Southern Germany. On the other hand, diversification can reduce farms’ technical efficiency, as it is the case in Switzerland and Germany. Furthermore, our study confirms previous results that agricultural subsidies significantly influence the technical efficiency of organic farms. We also show expected changes of input use driven by increased farm diversification. View Full-Text
    Dokument ansehen Zusammenfassung
  • Zeitschriftenartikel

    Fertilizer Effect of Phosphorus Recycling Products 

    Römer, Wilhelm; Steingrobe, Bernd
    Sustainability 2018; 10(4) p.1-18: Art. 1166
    Between 2004 and 2011 the German Government funded 17 different projects to develop techniques of phosphorus recycling from wastewater, sewage sludges, and sewage sludge ashes. Several procedures had been tested, such as precipitation, adsorption, crystallization, nano-filtration, electro-dialysis, wet oxidation, pyrolysis, ion exchange, or bioleaching. From these techniques, 32 recycling products were tested by five different institutes for their agronomic efficiency, that is, their plant availability, mainly in pot experiments. This manuscript summarizes and compares these results to evaluate the suitability of different technical approaches to recycle P from wastes into applicable fertilizers. In total, 17 products of recycled sewage sludge ashes (SSA), one meat and bone meal ash, one sinter product of meat and bone meal, one cupola furnace slag, nine Ca phosphates from crystallization or from precipitation, Seaborne-Ca-phosphates, Seaborne-Mg-phosphate, and 3 different struvites were tested in comparison to controls with water soluble P, that is, either single super phosphate (SSP) or triple super phosphate (TSP). Sandy and loamy soils (pH: 4.7–6.8; CAL-P: 33–49 ppm) were used. The dominant test plant was maize. Phosphorus uptake from fertilizer was calculated by the P content of fertilized plants minus P content of unfertilized plants. Calculated uptake from all products was set in relation to uptake from water soluble P fertilizers (SSP or TSP) as a reference value (=100%). The following results were found: (1) plants took up less than 25% P in 65% of all SSA (15 products); (2) 6 products (26%) resulted in P uptake of 25 and 50% relatively to water soluble P. Only one Mg-P product resulted in an uptake of 67%. With cupola furnace slag, 24% P uptake was reached on sandy soil and nearly the same value as TSP on loamy soil. The uptake results of Ca phosphates were between 0 and 50%. Mg-P products from precipitation processes consistently showed a better P supply in relation to comparable Ca-P compounds. With struvite the same P uptake as for water soluble P was reached. The fertilizer effect of the tested P recycling products can clearly be differentiated: TSP = struvite > Mg-P = sinter-P > Ca-P, cupola-slag > thermally treated sewage sludge ashes > meat-and-bone meal ash = Fe-P.
    Dokument ansehen Zusammenfassung
  • Zeitschriftenartikel

    Improving market success of animal welfare programs through key stakeholder involvement: heading towards responsible innovation? 

    Purwins, Nina; Schulze-Ehlers, Birgit
    International Food and Agribusiness Management Review 2018; 21(4) p.543-558
    acceptance among both farmers and consumers. We contend that this lock-in originates from a lack of market orientation and consequential neglect of key stakeholders’ preferences in program design. Considering the case of a retailer-owned meat brand, we demonstrate the relevance of stakeholders’ inclusion when establishing animal welfare programs for pigs. Surveys among 62 farming members of a pig trading cooperative and 692 supermarket customers reveal the heterogeneity of beliefs and acceptance within both groups. While a Responsible Innovation approach, including key actors from the initial criteria selection, could be effective for raising acceptance, it would likely lead to lengthy time-to-market, prohibiting first-mover advantages. We suggest instead that beliefs and acceptance among farmers may be influenced through a communication strategy based on survey results and experimental research, as well as facilitating positive word-of-mouth.
    Dokument ansehen Zusammenfassung
  • Zeitschriftenartikel

    Using Acceleration Data to Automatically Detect the Onset of Farrowing in Sows. 

    Traulsen, Imke; Scheel, Christoph; Auer, Wolfgang; Burfeind, Onno; Krieter, Joachim
    Sensors 2018; 18(1) p.1-13: Art. 170
    The aim of the present study was to automatically predict the onset of farrowing in crate-confined sows. (1) Background: Automatic tools are appropriate to support animal surveillance under practical farming conditions. (2) Methods: In three batches, sows in one farrowing compartment of the Futterkamp research farm were equipped with an ear sensor to sample acceleration. As a reference video, recordings of the sows were used. A classical CUSUM chart using different acceleration indices of various distribution characteristics with several scenarios were compared. (3) Results: The increase of activity mainly due to nest building behavior before the onset of farrowing could be detected with the sow individual CUSUM chart. The best performance required a statistical distribution characteristic that represented fluctuations in the signal (for example, 1st variation) combined with a transformation of this parameter by cumulating differences in the signal within certain time periods from one day to another. With this transformed signal, farrowing sows could reliably be detected. For 100% or 85% of the sows, an alarm was given within 48 or 12 h before the onset of farrowing. (4) Conclusions: Acceleration measurements in the ear of a sow are suitable for detecting the onset of farrowing in individually housed sows in commercial farrowing crates.
    Dokument ansehen Zusammenfassung
  • Zeitschriftenartikel

    Impact of Pore-Scale Wettability on Rhizosphere Rewetting 

    Benard, Pascal; Zarebanadkouki, Mohsen; Carminati, Andrea
    Frontiers in Environmental Science 2018; 6: Art. 16
    Vast amounts of water flow through a thin layer of soil around the roots, the rhizosphere, where high microbial activity takes place—an important hydrological and biological hotspot. The rhizosphere was shown to turn water repellent upon drying, which has been interpreted as the effect of mucilage secreted by roots. The effects of such rhizosphere water dynamics on plant and microbial activity are unclear. Furthermore, our understanding of the biophysical mechanisms controlling the rhizosphere water repellency remains largely speculative. Our hypothesis is that the key to describe the emergence of water repellency lies within the microscopic distribution of wettability on the pore-scale. At a critical mucilage content, a sufficient fraction of pores is blocked and the rhizosphere turns water repellent. Here we tested whether a percolation approach is capable to predict the flow behavior near the critical mucilage content. The wettability of glass beads and sand mixed with chia seed mucilage was quantified by measuring the infiltration rate of water drops. Drop infiltration was simulated using a simple pore-network model in which mucilage was distributed heterogeneously throughout the pore space with a preference for small pores. The model approach proved capable to capture the percolation nature of the process, the sudden transition from wettable to water repellent and the high variability in infiltration rates near the percolation threshold. Our study highlights the importance of pore-scale distribution of mucilage in the emergent flow behavior across the rhizosphere.
    Dokument ansehen Zusammenfassung
  • Zeitschriftenartikel

    Meat Quality Derived from High Inclusion of a Micro-Alga or Insect Meal as an Alternative Protein Source in Poultry Diets: A Pilot Study 

    Altmann, Brianne; Neumann, Carmen; Velten, Susanne; Liebert, Frank; Mörlein, Daniel
    Foods 2018; 7(3): Art. 34
    The effects on meat quality resulting from alternative dietary protein sources (Spirulina and Hermetia meal) in poultry diets are studied to determine the overall suitability of these ingredients considering state-of-the-art packaging practices—highly oxygenated modified atmosphere packaging (HiOx MAP). We monitored standard slaughterhouse parameters, such as live weight, carcass weight, dressed yield, and pH at 20 min and 24 h post mortem. In addition, we studied the effects that 3 and 7-day storage in HiOx MAP has on the overall product physico-chemical and sensory properties. In addition to previously supported effects of HiOx MAP, we found that meat quality could be improved when Spirulina replaces 50% of the soy protein in broiler diets; however, this substitution results in a dark reddish-yellowish meat colour. On the other hand, the substitution with Hermetia larval meal results in a product that does not differ from the standard fed control group, with the exception that the breast filet has a more intense flavour that decreases over storage time. All-in-all Spirulina and Hermetia meal have the potential to replace soybean meal in broiler diets without deteriorating meat quality.
    Dokument ansehen Zusammenfassung
  • Zeitschriftenartikel

    Birds of primary and secondary forest and shrub habitats in the peat swamp of Berbak National Park, Sumatra 

    Darras, Kevin; Rahman, Dedi; Sugito, Waluyo; Mulyani, Yeni; Prawiradilaga, Dewi; Rozali, Agus; Fitriawan, Irfan; Tscharntke, Teja
    F1000Research 2018; 7: Art. 229
    Background: Tropical lowland rainforests are threatened by deforestation and degradation worldwide. Relatively little research has investigated the degradation of the forests of South-east Asia and its impact on biodiversity, and even less research has focused on the important peat swamp forests of Indonesia, which experienced major losses through severe fires in 2015. Methods: We acoustically sampled the avifauna of the Berbak National Park in 2013 in 12 sites split in three habitats: primary swamp forest, secondary swamp forest, and shrub swamp, respectively representing non-degraded, previously selectively logged, and burned habitats. We analysed the species richness, abundance, vocalisation activity, and community composition across acoustic counts, sites, feeding guilds and IUCN Red List categories. We also analysed community-weighted means of body mass, wing length, and distribution area. Results: The avifauna in the three habitats was remarkably similar in richness, abundance and vocalisation activity, and communities mainly differed due to a lower prevalence of understory insectivores (Old-World Babblers, Timaliidae) in shrub swamp. However primary forest retained twice as many conservation-worthy species as shrub swamp, which harboured heavier, probably more mobile species, with larger distributions than those of forest habitats. Conclusions: The National Park overall harboured higher bird abundances than nearby lowland rainforests. Protecting the remaining peat swamp forest in this little-known National Park should be a high conservation priority in the light of the current threats coming from wildlife trade, illegal logging, land use conversion, and man-made fires.
    Dokument ansehen Zusammenfassung
  • Zeitschriftenartikel

    DArT, SNP, and SSR analyses of genetic diversity in Lolium perenne L. using bulk sampling. 

    Liu, Siyang; Feuerstein, Ulf; Luesink, Wilbert; Schulze, Sabine; Asp, Torben; Studer, Bruno; Becker, Heiko C.; Dehmer, Klaus J.
    BMC Genetics 2018; 19(1): Art. 10
    BACKGROUND: Lolium perenne L. is the most important forage grass species in temperate regions. It is also considered as a sustainable source of biomass for energy production. However, improvement in biomass yield has been limited by comparison with other major crops. More efficient utilisation of genetic resources and improved breeding schemes are required to advance L. perenne breeding. In an attempt to elucidate the extent of genetic diversity in L. perenne, 1384 DArT, 182 SNP and 48 SSR markers were applied to 297 accessions (Set I) contributed by three German breeding companies and the IPK Genebank. Due to the heterogeneous nature of Lolium accessions, bulk samples were used. Apart from germplasm set I, additional set II and set III was used to determine the reproducibility of marker system and judge the feasibility of bulk strategy in this study. RESULTS: By assessing different bulk sizes, 24 individuals per sample were shown to be a representative number of plants to discriminate different accessions. Among the 297 accessions, all marker types revealed a high polymorphism rate; 1.99, 2.00 and 8.19 alleles, were obtained per locus on average using DArTs, SNPs and SSRs, respectively. The Jaccard distance for DArT markers ranged from 0.00 to 0.73, the Modified Roger's distance (MRD) for SNP markers ranged from 0.03 to 0.52, and for SSR markers from 0.26 to 0.76. Gene diversity for dominant DArT and co-dominant SNP and SSR markers was found to be 0.26, 0.32 and 0.45, respectively. DArT markers showed the highest consistency and reproducibility. CONCLUSION: The resulting data were evaluated using a number of different classification methods, but none of the methods showed a clear differentiation into distinct genetic pools. With regard to hybrid breeding, this will possibly impede substantial progress towards increased biomass yields of L. perenne by utilising heterosis.
    Dokument ansehen Zusammenfassung
  • Zeitschriftenartikel

    Building Adaptive Capacity in Changing Social-Ecological Systems: Integrating Knowledge in Communal Land-Use Planning in the Peruvian Amazon 

    Rodríguez, Lily; Cisneros, Elías; Pequeño, Tatiana; Fuentes, Maria; Zinngrebe, Yves
    Sustainability 2018; 10(2): Art. 511
    Building resilient sustainable social-ecological systems (SES) requires communities to enhance their adaptive capacities. Communal participative land-use planning (Zonificación Participativa Comunal—ZPC) is a tool designed for communities to integrating local and scientific knowledge to sustainably organize and manage their SES. Between 2006 and 2011, a ZPC was developed with communities in the buffer zone of Cordillera Azul National Park (Peru), where rapid demographic changes are converting pre-montane seasonally dry forest into agricultural land. Herein, we analyse how the ZPC enhanced adaptive capacity, enabling the SES to cope with environmental, political and economic changes. Based on qualitative, semi-structured interviews, communities are analysed along their capacities in the dimensions social capital, learning, adaptive management and governance. An analysis of yearly high-resolution forest cover data supports our findings. Deforestation activities in biologically sensitive zones decreased rapidly during the time of the ZPC implementation. We find that particularly the long-term presence of the bridging institution and the continuous testing and reflection of the integrated “hybrid knowledge” enabled communities to develop adaptive capacities. The analysis of ZPC our results reveals the enabling conditions for promoting the learning process to develop a sustainable land-use management in the context of migration and rapid changes.
    Dokument ansehen Zusammenfassung
  • Zeitschriftenartikel

    How plant reproductive success is determined by the interplay of antagonists and mutualists 

    Grass, Ingo; Bohle, Victoria; Tscharntke, Teja; Westphal, Catrin
    Ecosphere 2018; 9(2): Art. e02106
    Plant reproductive success is often the outcome of mutualistic and antagonistic plant–animal interactions, which can be moderated by landscape composition. Studies addressing single plant–animal interactions are common, but studies simultaneously considering multiple plant–animal interactions in a landscape context are still scarce. We selectively excluded flower-visiting insects on phytometer plants and quantified how mutualistic and antagonistic interactions shaped the reproductive success of a common annual plant, wild mustard (Sinapis arvensis). Floral herbivory by larvae of rape pollen beetles (Meligethes spp.) strongly reduced fruit production, but could be minimized by insecticide application. Total seed production (the product of fruit production and seeds per fruit) strongly increased with pollinator visitation. On average, pollinator access to plants enhanced seed numbers by 754%. Insecticide treatment almost redoubled this number. The landscape composition (proportion of semi-natural habitats in 1000 m radius) surrounding phytometer plants did not affect plant–animal interactions, presumably due to the high dispersal ability of both the pollen beetles and the major pollinators (syrphid flies, bumblebees). In conclusion, pest control increased reproductive success only in the case of sufficient pollination.
    Dokument ansehen Zusammenfassung
  • Zeitschriftenartikel

    Efficiency of different strategies to mitigate ascertainment bias when using SNP panels in diversity studies. 

    Malomane, Dorcus Kholofelo; Reimer, Christian; Weigend, Steffen; Weigend, Annett; Sharifi, Ahmad Reza; Simianer, Henner
    BMC Genomics 2018; 19(1): Art. 22
    BACKGROUND: Single nucleotide polymorphism (SNP) panels have been widely used to study genomic variations within and between populations. Methods of SNP discovery have been a matter of debate for their potential of introducing ascertainment bias, and genetic diversity results obtained from the SNP genotype data can be misleading. We used a total of 42 chicken populations where both individual genotyped array data and pool whole genome resequencing (WGS) data were available. We compared allele frequency distributions and genetic diversity measures (expected heterozygosity (He), fixation index (FST) values, genetic distances and principal components analysis (PCA)) between the two data types. With the array data, we applied different filtering options (SNPs polymorphic in samples of two Gallus gallus wild populations, linkage disequilibrium (LD) based pruning and minor allele frequency (MAF) filtering, and combinations thereof) to assess their potential to mitigate the ascertainment bias. RESULTS: Rare SNPs were underrepresented in the array data. Array data consistently overestimated Hecompared to WGS data, however, with a similar ranking of the breeds, as demonstrated by Spearman's rank correlations ranging between 0.956 and 0.985. LD based pruning resulted in a reduced overestimation of Hecompared to the other filters and slightly improved the relationship with the WGS results. The raw array data and those with polymorphic SNPs in the wild samples underestimated pairwise FSTvalues between breeds which had low FST(<0.15) in the WGS, and overestimated this parameter for high WGS FST(>0.15). LD based pruned data underestimated FSTin a consistent manner. The genetic distance matrix from LD pruned data was more closely related to that of WGS than the other array versions. PCA was rather robust in all array versions, since the population structure on the PCA plot was generally well captured in comparison to the WGS data. CONCLUSIONS: Among the tested filtering strategies, LD based pruning was found to account for the effects of ascertainment bias in the relatively best way, producing results which are most comparable to those obtained from WGS data and therefore is recommended for practical use.
    Dokument ansehen Zusammenfassung
  • Zeitschriftenartikel

    Preliminary Investigation of Species Diversity of Rice Hopper Parasitoids in Southeast Asia. 

    Sann, Christina; Wemheuer, Franziska; Beaurepaire, Alexis; Daniel, Rolf; Erler, Silvio; Vidal, Stefan
    Insects 2018; 9(1) p.1-12
    Ongoing intensification of rice production systems in Southeast Asia is causing devastating yield losses each year due to rice hoppers. Their continuing development of immunity to resistant rice varieties and pesticide applications further complicates this problem. Hence, there is a high demand for biological control agents of rice hoppers. Egg parasitoid wasps are among the most important natural enemies of rice hoppers, such asNilaparvata lugensandNephotettixspp. However, our knowledge of their diversity is still very limited, due to their small size and the lack of available morphological information. Classifying these parasitoids is the first step to properly understanding their role in the rice agroecosystem. We used traditional morphological identification, as well as DNA sequencing of the 28S rRNA and the COI genes, to investigate the diversity of four important hopper egg parasitoid genera in the Philippines. Parasitoids of the generaAnagrus,Oligosita,Gonatocerus, andParacentrobiawere collected in eight study landscapes located in Luzon. Our findings illustrate that characterization of species diversity using morphological and molecular analyses were concordant only for the genusParacentrobia. The generaAnagrusandGonatocerusexhibited more genetic diversity than estimated with the morphological analysis, while the opposite was observed forOligosita. This is the first study investigating the molecular diversity of rice hopper parasitoids in the Philippines. More research combining morphological, behavioral, and molecular methods, as well as the establishment of a comprehensive DNA database, are urgently needed to assess the performance and suitability of these organisms as biocontrol agents.
    Dokument ansehen Zusammenfassung
  • Zeitschriftenartikel

    Root-derived carbon and nitrogen from beech and ash trees differentially fuel soil animal food webs of deciduous forests. 

    Zieger, Sarah L; Ammerschubert, Silke; Polle, Andrea; Scheu, Stefan
    PloS one 2017; 12(12) p.1-14: Art. e0189502
    Evidence is increasing that soil animal food webs are fueled by root-derived carbon (C) and also by root-derived nitrogen (N). Functioning as link between the above- and belowground system, trees and their species identity are important drivers structuring soil animal communities. A pulse labeling experiment using 15N and 13C was conducted by exposing beech (Fagus sylvatica) and ash (Fraxinus excelsior) seedlings to 13CO2 enriched atmosphere and tree leaves to 15N ammonium chloride solution in a plant growth chamber under controlled conditions for 72 h. C and N fluxes into the soil animal food web of beech, associated with ectomycorrhizal fungi (EMF), and ash, associated with arbuscular mycorrhizal fungi (AMF), were investigated at two sampling dates (5 and 20 days after labeling). All of the soil animal taxa studied incorporated root-derived C, while root-derived N was only incorporated into certain taxa. Tree species identity strongly affected C and N incorporation with the incorporation in the beech rhizosphere generally exceeding that in the ash rhizosphere. Incorporation differed little between 5 and 20 days after labeling indicating that both C and N are incorporated quickly into soil animals and are used for tissue formation. Our results suggest that energy and nutrient fluxes in soil food webs depend on the identity of tree species with the differences being associated with different types of mycorrhiza. Further research is needed to prove the generality of these findings and to quantify the flux of plant C and N into soil food webs of forests and other terrestrial ecosystems.
    Dokument ansehen Zusammenfassung
  • Zeitschriftenartikel

    Using 13C in cattle hair to trace back the maize level in the feeding regime-A field test. 

    Hammes, Verena; Nüsse, Olaf; Isselstein, Johannes; Kayser, Manfred
    PloS one 2017; 12(11) p.1-14: Art. e0188926
    Sections from cattle hair serve as an isotopic archive-they contain information on the cattle diet from different time periods. We tested the reliability of 13C signatures (δ13C) in cattle tail switch hair to retrospectively trace back the annual dietary proportion of maize of different production systems without having to sample and analyze the feed. Furthermore, we investigated if differences in dietary proportion of maize during summer and winter feeding can be detected in a single tail switch hair by sampling hair only once a year. We sampled hair and obtained information on management and annual composition of diets on 23 cattle farms in northern Germany. Farms differed in dietary proportions of maize, grass and concentrates as well as in grazing regime (year-round grazing, summer grazing, no grazing). We found that the annual mean δ13C values (δ13CY) of two hair sections that contain the isotopic information of summer and winter feeding is a robust indicator for the annual proportion of maize in cattle diet on a farm. The grazing regimes could clearly be distinguished by analyzing seasonal mean δ13C values (δ13CS). We could also demonstrate short term changes in the diet changes by means of δ13CS. We conclude that the method can be used in different cattle production systems to check on dietary proportions of maize for a period of one year before sampling of hair.
    Dokument ansehen Zusammenfassung
  • Zeitschriftenartikel

    Carbon sequestration and turnover in soil under the energy crop Miscanthus: repeated 13C natural abundance approach and literature synthesis 

    Zang, Huadong; Blagodatskaya, Evgenia; Wen, Yuan; Xu, Xingliang; Dyckmans, Jens; Kuzyakov, Yakov
    GCB Bioenergy 2017; 10(4) p.262-271
    The stability and turnover of soil organic matter (SOM) are a very important but poorly understood part of carbon (C) cycling. Conversion of C3 grassland to the C4 energy crop Miscanthus provides an ideal opportunity to quantify medium-term SOM dynamics without disturbance (e.g., plowing), due to the natural shift in the d13C signature of soil C. For the first time, we used a repeated 13C natural abundance approach to measure C turnover in a loamy Gleyic Cambisol after 9 and 21 years of Miscanthus cultivation. This is the longest C3–C4 vegetation change study on C turnover in soil under energy crops. SOM stocks under Miscanthus and reference grassland were similar down to 1 m depth. However, both increased between 9 and 21 years from 105 to 140 mg C ha 1 (P < 0.05), indicating nonsteady state of SOM. This calls for caution when estimating SOM turnover based on a single sampling. The mean residence time (MRT) of old C (>9 years) increased with depth from 19 years (0–10 cm) to 30–152 years (10–50 cm), and remained stable below 50 cm. From 41 literature observations, the average SOM increase after conversion from cropland or grassland to Miscanthus was 6.4 and 0.4 mg C ha 1, respectively. The MRT of total C in topsoil under Miscanthus remained stable at ~60 years, independent of plantation age, corroborating the idea that C dynamics are dominated by recycling processes rather than by C stabilization. In conclusion, growing Miscanthus on C-poor arable soils caused immediate C sequestration because of higher C input and decreased SOM decomposition. However, after replacing grasslands with Miscanthus, SOM stocks remained stable and the MRT of old C3-C increased strongly with depth.
    Dokument ansehen Zusammenfassung
  • Zeitschriftenartikel

    Defoliating Insect Mass Outbreak Affects Soil N Fluxes and Tree N Nutrition in Scots Pine Forests. 

    Grüning, Maren M.; Simon, Judy; Rennenberg, Heinz; L-M-Arnold, Anne
    Frontiers in plant science 2017; 8: Art. 954
    Biotic stress by mass outbreaks of defoliating pest insects does not only affect tree performance by reducing its photosynthetic capacity, but also changes N cycling in the soil of forest ecosystems. However, how insect induced defoliation affects soil N fluxes and, in turn, tree N nutrition is not well-studied. In the present study, we quantified N input and output fluxes via dry matter input, throughfall, and soil leachates. Furthermore, we investigated the effects of mass insect herbivory on tree N acquisition (i.e., organic and inorganic 15N net uptake capacity of fine roots) as well as N pools in fine roots and needles in a Scots pine (Pinus sylvestris L.) forest over an entire vegetation period. Plots were either infested by the nun moth (Lymantria monacha L.) or served as controls. Our results show an increased N input by insect feces, litter, and throughfall at the infested plots compared to controls, as well as increased leaching of nitrate. However, the additional N input into the soil did not increase, but reduce inorganic and organic net N uptake capacity of Scots pine roots. N pools in the fine roots and needles of infested trees showed an accumulation of total N, amino acid-N, protein-N, and structural N in the roots and the remaining needles as a compensatory response triggered by defoliation. Thus, although soil N availability was increased via surplus N input, trees did not respond with an increased N acquisition, but rather invested resources into defense by accumulation of amino acid-N and protein-N as a survival strategy.
    Dokument ansehen Zusammenfassung
  • Zeitschriftenartikel

    Analyzing job satisfaction and preferences of employees: the case of horticultural companies in Germany 

    Meyerding, Stephan G. H.
    International Food and Agribusiness Management Review 2017; 20(5) p.765-788
    German horticulture, as well as horticulture and agriculture in other industrialized countries, faces increasing skilled labor shortage. Additionally family run businesses in horticulture and agriculture are lacking a new generation of entrepreneurs, leading to increased structural change. Insights about job attributes attractiveness as well as their impact on job satisfaction lead to a more transparent environment in which employers and employees can make better-informed decisions and redesign the professional environment, resulting in increased job satisfaction, performance and career sustainability. For this purpose, a survey was undertaken from August 2013 to February 2015 through a questionnaire examining the preferences and perception of employees (N=229) regarding job characteristics. The theoretical background of the study is Warr’s vitamin model, which assumes non-linear relationships between job characteristics and job satisfaction. The strongest connections with job satisfaction among employees are with future prospects and conflict between work-andfamily. The study is one of the first of its kind to provide a detailed overview of job satisfaction of different groups of employees in German horticulture.
    Dokument ansehen Zusammenfassung
  • Zeitschriftenartikel

    Alterations in the Rumen Liquid-, Particle- and Epithelium-Associated Microbiota of Dairy Cows during the Transition from a Silage- and Concentrate-Based Ration to Pasture in Spring. 

    Schären, Melanie; Kiri, Kerstin; Riede, Susanne; Gardener, Mark; Meyer, Ulrich; Hummel, Jürgen; Urich, Tim; Breves, Gerhard; Dänicke, Sven
    Frontiers in microbiology 2017; 8: Art. 744
    In spring dairy cows are often gradually transitioned from a silage- and concentrate-based ration (total mixed ration, TMR) to pasture. Rumen microbiota adaptability is a key feature of ruminant survival strategy. However, only little is known on the temporal and spatial microbial alterations involved. This study aims to investigate how the rumen liquid (LAAB), particle (PAAB), and epithelium (EAAB) associated archaea and bacteria are influenced by this nutritional change. A 10-wk trial was performed, including 10 rumen-fistulated dairy cows, equally divided into a pasture- and a confinement- group (PG and CG). The CG stayed on a TMR-based ration, while the PG was gradually transitioned from TMR to pasture (wk 1: TMR-only, wk 2: 3 h/day on pasture, wk 3 & 4: 12 h/day on pasture, wk 5-10: pasture-only). In wk 1, wk 5, and wk 10 samples of solid and liquid rumen contents, and papillae biopsies were collected. The DNA was isolated, and PCR-SSCP and 16S rRNA gene amplicon sequencing analysis were performed. Cluster analysis revealed a higher similarity between LAAB and PAAB, compared to the EAAB, characterized by higher species diversity. At all three locations the microbiota was significantly influenced by the ration change, opposite the generally acknowledged hypothesis that the EAAB remain more consistent throughout dietary changes. Even though the animals in the PG were already on a full-grazing ration for 4-6 days in wk 5, the microbiota at all three locations was significantly different compared to wk 10, suggesting an adaptation period of several days to weeks. This is in line with observations made on animal level, showing a required time for adaptation of 2-3 weeks for production and metabolic variables. A large part of the rumen prokaryote species remained unaltered upon transition to pasture and exhibited a strong host influence, supporting the hypothesis that the rumen microbiota consists of a core and a variable microbiota. For the effect of the location as well as the ration change either very similar or opposite trends among member species of common taxa were observed, demonstrating that microbes that are phylogenetically close may still exhibit substantially different phenotypes and functions.
    Dokument ansehen Zusammenfassung
  • Zeitschriftenartikel

    Genomic Comparison of Indigenous African and Northern European Chickens Reveals Putative Mechanisms of Stress Tolerance Related to Environmental Selection Pressure. 

    Fleming, Damarius S.; Weigend, Steffen; Simianer, Henner; Weigend, Annett; Rothschild, Max; Schmidt, Carl; Ashwell, Chris; Persia, Mike; Reecy, James; Lamont, Susan J.
    G3 (Bethesda, Md.) 2017-05-05; 7(5) p.1525-1537
    Global climate change is increasing the magnitude of environmental stressors, such as temperature, pathogens, and drought, that limit the survivability and sustainability of livestock production. Poultry production and its expansion is dependent upon robust animals that are able to cope with stressors in multiple environments. Understanding the genetic strategies that indigenous, noncommercial breeds have evolved to survive in their environment could help to elucidate molecular mechanisms underlying biological traits of environmental adaptation. We examined poultry from diverse breeds and climates of Africa and Northern Europe for selection signatures that have allowed them to adapt to their indigenous environments. Selection signatures were studied using a combination of population genomic methods that employed FST , integrated haplotype score (iHS), and runs of homozygosity (ROH) procedures. All the analyses indicated differences in environment as a driver of selective pressure in both groups of populations. The analyses revealed unique differences in the genomic regions under selection pressure from the environment for each population. The African chickens showed stronger selection toward stress signaling and angiogenesis, while the Northern European chickens showed more selection pressure toward processes related to energy homeostasis. The results suggest that chromosomes 2 and 27 are the most diverged between populations and the most selected upon within the African (chromosome 27) and Northern European (chromosome 2) birds. Examination of the divergent populations has provided new insight into genes under possible selection related to tolerance of a population's indigenous environment that may be baselines for examining the genomic contribution to tolerance adaptions.
    Dokument ansehen Zusammenfassung
  • Zeitschriftenartikel

    A Nonsense Variant in the ST14 Gene in Akhal-Teke Horses with Naked Foal Syndrome. 

    Bauer, Anina; Hiemesch, Theresa; Jagannathan, Vidhya; Neuditschko, Markus; Bachmann, Iris; Rieder, Stefan; Mikko, Sofia; Penedo, M Cecilia; Tarasova, Nadja; Vitková, Martina; et al.
    Sirtori, NicolòRoccabianca, PaolaLeeb, TossoWelle, Monika M.
    G3 (Bethesda, Md.) 2017; 7(4) p.1315-1321
    Naked foal syndrome (NFS) is a genodermatosis in the Akhal-Teke horse breed. We provide the first scientific description of this phenotype. Affected horses have almost no hair and show a mild ichthyosis. So far, all known NFS affected horses died between a few weeks and 3 yr of age. It is not clear whether a specific pathology caused the premature deaths. NFS is inherited as a monogenic autosomal recessive trait. We mapped the disease causing genetic variant to two segments on chromosomes 7 and 27 in the equine genome. Whole genome sequencing of two affected horses, two obligate carriers, and 75 control horses from other breeds revealed a single nonsynonymous genetic variant on the chromosome 7 segment that was perfectly associated with NFS. The affected horses were homozygous for ST14:c.388G>T, a nonsense variant that truncates >80% of the open reading frame of the ST14 gene (p.Glu130*). The variant leads to partial nonsense-mediated decay of the mutant transcript. Genetic variants in the ST14 gene are responsible for autosomal recessive congenital ichthyosis 11 in humans. Thus, the identified equine ST14:c.388G>T variant is an excellent candidate causative variant for NFS, and the affected horses represent a large animal model for a known human genodermatosis. Our findings will enable genetic testing to avoid the nonintentional breeding of NFS-affected foals.
    Dokument ansehen Zusammenfassung

View more