Effects of nutrient supply, light availability and herbivory on the growth of heather and three competing grass species

摘要: Grasses are becoming more abundant in areas NE Scotland which until recently were dominated by heather (Calluna vulgaris). However, it is not clear if grasses aggressive competitors now able to outcompete the dwarf shrub due changes environmental factors (such as grazing pressure and increasing nutrient inputs), or just opportunistic invaders, occupying gaps canopy occur when reaches degenerate stage. Experiments turves field plots carried out order investigate performance of three grass species, Nardus stricta, Deschampsia cespitosa flexuosa growing competition with heather. These species selected because they differ their requirements, palatability herbivores tolerance shading. The planted canopies different structure, either height age, moorland without heavy sheep deer. Fertiliser (NPK) was applied half experimental plants. growth response fertiliser treatments measured, together light levels penetrating received