Silviculture and Sustainability

Abstract

Based on world experience, the priorities for improving productivity of plantation forests are selection of the correct species, ensuring the site has no major nutrient deficiencies and an adequate rooting depth, using good planting stock, good planting methods, weed control, the optimum initial stocking level and rotation length and having a tree breeding programme. The decisions as to what specific silvicultural practices are employed are then determined for any site by economic factors, including not only financial but also environmental and social considerations. Because plantation forestry is a relatively long-term enterprise, only limited information is available to assess whether or not it is being done around the world in a sustainable fashion. Some long-term studies have found no loss of productivity over several rotations, covering perhaps 50–100 years. Often there has been an increase in production with time, probably reflecting improved silvicultural practice that may in fact hide some site degradation. Considerable effort is being made to develop criteria by which long-term sustainability of forestry practices might be judged, together with indicators (that is, specific measurements) to assess whether or not those criteria are being met. Whilst plantation forestry is often hailed as a potential saviour of the remaining native forests of the world, forests that have been cleared and exploited ruthlessly in the past, much work remains to be done to ensure it is a long-term, sustainable supplier of wood and other social and environmental benefits.