Dynamics of plant communities in field boundaries : restoration of biodiversity

Abstract

The field boundary, the strip of semi-natural vegetation bordering arable fields, can be considered as an important area for plant species survival in landscapes dominated by agriculture. In the last decennia, the natural plant species diversity has been reduced in many agricultural landscapes. Therefore, the objective of this thesis is to analyse factors determining biodiversity in field boundaries such as nutrient deposition from the arable field, mowing regime, level of disturbance and boundary dimensions. For this purpose a simulation model was constructed that comprises the processes and factors that determine the dynamics of the field boundary vegetation.This model is the result of the integration of three new models: a plant competition model based on eco-physiological principles, a spatially explicit population dynamical model and a seed dispersal model. The models were parameterized and evaluated with experimental data that were largely obtained from experiments described this thesis. Experimental research, therefore, was focussed on plant characteristics determining competition, succession and dispersal. Simulations and experimental results indicated that to enhance the diversity of the field boundary vegetation the following measures should be taken:Preventing all nutrient inputs from the arable field.Mowing and removal of the cuttings.Keeping the disturbance level under 20% of the area (y-1).Keeping the boundary as wide as possible but at at least wider than the maximum fertilizer misplacement.</ol