The effects of nutrients and disturbance on dry grass-dominated vegetation

While the development objective of my Ph.D.-study was to investigate the importance of disturbance and productivity for the shaping of dry grass-dominated plant communities, the specific objectives were to test a number of hypotheses regarding vegetation development in hedgerow vegetation and experimental vegetation in response to experimental treatments. I combined field studies with experiments. Firstly, field vegetation data and explanatory variables were collected in organic and conventional hedgerows (Paper I and II). Secondly, an outdoor factorial microcosm experiment was carried out in order to test the influence of nutrients, defoliation and vascular plant species composition on the recruitment and diversity of bryophytes (Paper III). Finally, a full factorial experiment was established in order to test the separate and interaction effect of nutrient enrichment and herbicide disturbance on biomass, species diversity and frequency of bryophytes (Paper IV). While nutrient gradients were simulated by differential nutrient addition, disturbance took the form of herbicide application and repeated defoliation (simulated grazing)

Flora og insekter i hegn på økologiske og konventionelle bedrifter

The aim of the project was to compare flora and insect fauna of organic and conventional hedgerows and to study whether the drift of herbicides into hedgerows alone or in combination with differences in fertiliser application may explain any differences. The project consequently consisted of two parts, viz. collection of flora and insect data in existing hedgerows (multi-row hedgerows, age 10-15 years) on two soil types and an experiment in which a sown grassland vegetation was treated with combinations of glyphosate (0-25% label rate) and nitrogen (0-100 kg N/ha/year) as a simulation of the most important agricultural conditions having an effect on flora and insect fauna in different agricultural systems. In the experiment flora and insect fauna were studied for three years. In the hedgerows clear differences in the floral composition were found, with more plant species in hedgerows at organically grown fields than at conventionally grown fields, on both sandy and loamy soils. The insect fauna was correlated with the flora, but no clear differences were found between the two agricultural systems. Apart from the hedgerow flora, also the type of crop grown on the adjacent fields affected the abundance of herbivorous insects, especially bugs and weevils. In the experiment the effects of glyphosate and nitrogen treatments interacted strongly. In unfertilised plots the number of plant species decreased at increasing glyphosate dosages, whereas plant biomass was virtually unaffected, and litter biomass decreased. For plant and litter biomass the glyphosate effect increased at increasing fertiliser levels, i.e. there was a severe decrease in both plant and litter biomass as a consequence of glyphosate treatment. For numbers of plant species the interactive effect was opposite, as the glyphosate effect decreased at increasing fertiliser levels. Insect abundance and species numbers followed the picture seen for plant biomass, but with differences between insect groups

Mere natur i økologiske hegn

Hegn i Danmark forbindes i høj grad med læ. Specielt i Jylland har læhegn været af stor betydning for landbruget. I dag har hegnene en bredere betydning, men der er kun lille viden om naturværdierne. DMU har i en undersøgelse vist overraskende klare forskelle på især plantelivet i hegn på økologiske og konventionelle bedrifter

Naturindholdet i hegn på økologiske og konventionelle bedrifter

Many attempts have been suggested to reduce the impact of modern conventional farming on the environment and semi-natural ecosystems. One of the attempts has been to introduce organic farming, which is known primarily for the absence of pesticides and artificial fertilising. The objective of this paper is to present differences found in the spontaneous vegetation and associated arthropods of comparable hedgerows situated within organic and conventional farming systems. We found significantly more plant and moss species in organic hedges, both in the individual plots, the individual hedges and when comparing the farming systems. Six species (Brachythecium rutabulum, Cerastium fontanum, Ranunculus repens, Cirsium arvense, Sonchus arvensis, Plantago lanceolata) were found to be indicators of organic hedges. Arthropods were distributed in relation to the same parameters as the flora (mainly soil characteristics and farming practice). However, differences between the two farming systems were smaller than for plants. The occurrence of herbivorous groups as a total correlate significantly with the major plant gradients and weevils correlate significantly with grass lay fields beneath the hedges and organic farming. Psylloidae, Syrphidae and the weevils (Curculionidae) Ceutorrhynchus floralis and Apion virens proved to indicate organic farming

Dataset on species incidence, species richness and forest characteristics in a Danish protected area

The data presented in this article are related to the research article entitled “Restoring hydrology and old-growth structures in a former production forest: Modelling the long-term effects on biodiversity” (A. Mazziotta, J. Heilmann-Clausen, H. H.Bruun, Ö. Fritz, E. Aude, A.P. Tøttrup) [1]. This article describes how the changes induced by restoration actions in forest hydrology and structure alter the biodiversity value of a Danish forest reserve. The field dataset is made publicly available to enable critical or extended analyses

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Sensitive detection methods are key to identify secondary EGFR c.2369C>T p.(Thr790Met) in non-small cell lung cancer tissue samples

Background: Correct identification of the EGFR c.2369C>T p.(Thr790Met) variant is key to decide on a targeted therapeutic strategy for patients with acquired EGFR TKI resistance in non-small cell lung cancer. The aim of this study was to evaluate the correct detection of this variant in 12 tumor tissue specimens tested by 324 laboratories participating in External Quality Assessment (EQA) schemes. Methods: Data from EQA schemes were evaluated between 2013 and 2018 from cell lines (6) and resections (6) containing the EGFR c.2369C>T p.(Thr790Met) mutation. Adequate performance was defined as the percentage of tests for w

ATP-dependent and independent functions of Rad54 in genome maintenance

Rad54’s ATPase activity does not affect accumulation of homologous recombination proteins in repair foci, but influences its dissociation and that of Rad51