Analysis of productivity of radiata pine plantations under different silvicultural regimes using the 3-PG process-based

Summary The effects of crown structure and management of site resources on production of wood were studied. Growth and development of three stands with agroforestry management were compared with a traditionally managed stand. The 3-PG model, validated through stem analysis, was used to estimate growth. It was concluded that the leaf area index was strongly controlled by the plantation design and final stand density. The fertilisation regime had positive effects on leaf area index but its potential was limited by crown structure. In the traditional forestry regime, increment of stem wood biomass was strongly related to leaf area index. In stands with agroforestry management, however, stem increment was associated with changes in allocation of carbohydrate from the biomass of fine roots, caused by fertilisation. Final production of wood is more affected by thinning, because of the effect of thinning on crown structure, than by the availability of site resources. The maximisation of wood production will depend upon the combined management of site resources and the intensity and opportunity of thinning