Towards sustainable management of forest plantations in south-east Queensland. II: Protecting soil and water values during second rotation Pinus plantation management

Abstract

For the purpose of reviewing sustainable plantation management, it is convenient to separate a plantation estate into three components: hillslopes, watercourses and the roading and tracking system, as these are routinely demarcated and separately managed. Within this context, the major objectives of sustainable plantation management can be defined as: (i) managing hillslopes to maintain site fertility while avoiding a diffuse source of pollutants to watercourses; (ii) protecting watercourses from bank and bed instability while maintaining water quality and in-stream values; and (iii) ensuring that the roading system is properly designed, constructed, stabilised and maintained in order to avoid point sources of pollutants. This paper is specifically concerned with assessing how well the first two of these are achieved in Queensland Department of Primary Industries-Forestry (QDPI-F) Pinus plantations. Practices for protecting hillslopes are evaluated in terms of avoiding excessive compaction, depletion of soil organic matter and excessive erosion; and practices for protecting watercourses are evaluated in terms of their ability to avoid bed and bank erosion, minimise the movement of soil into watercourses, and protect riparian systems. Finally, challenges to fulfilling both objectives in QDPI-F Pinus plantations are identified.