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

Summary

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).