Plantation forestry and invasive pines in the Cape Floristic Region: Towards conflict resolution

Forests supply important commercial resources in the form of timber for building, furniture and packaging, and pulp for paper products. As human populations grow, the demand for these products is driving substantial growth in plantation forestry. Such plantations are necessary both to meet demand for wood-based products and to protect remaining natural forests from over-exploitation, and they are usually based on fast-growing, alien trees. Globally, forest plantations currently represent 5% of forest cover but they account for 40% of commercial wood and fibre production. As more species of alien trees are introduced and widely planted in novel environments, a proportion become invasive, spreading into adjacent landscapes where they have negative effects on biodiversity and the delivery of ecosystem services.1 Among commercial forestry species, pines (Pinus species) are especially problematic, with at least 19 invasive species in the southern hemisphere, where they cause significant problems.2 The fact that pine trees can simultaneously be useful and harmful in the same region has led to 'schizophrenia' in policy formulation and conflict between land managers.National Research Foundation (South Africa