Trees and shrubs as a component of buffer zones: advantages and disadvantages in P-retention

Trees and shrubs are potential components for construction of buffer zones, especially for reducing phosphorus levels in soil. Woody species appear to be less efficient in capturing nutrients from overland flow, at least outside the growing season. Tree seedlings prevent effective mowing and removal of hay, which may lead to an accumulation of dead hay on the zone. Therefore woody species should mainly be used in places where yearly mowing and removal of hay is not feasible.