Future alternatives to the use of herbicides in British forestry

Abstract

Weed control is often crucial for successful tree establishment in British forestry. Herbicides currently offer the most cost-effective means available for achieving this, but research into alternatives is required. Recent experiments have been conducted by the Great Britain Forestry Commission investigating the use of 19 alternative ground cover and silvicultural treatments for newly planted ash (Fraxinus excelsior L.) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) established on fertile lowland ex-agricultural sites. Most ground cover treatments proved difficult to establish and were more competitive to trees than naturally occurring vegetation. White clover (Trifolium repens L.) showed some potential for suppressing weed vegetation without reducing tree growth. Closer initial tree planting densities appeared to offer a practical means of reducing herbicide inputs, whilst still permitting good rates of growth. It is concluded that a comprehensive review of other alternative methods of weed control is now required to set a framework for future Great Britain Forestry Commission research in this field.