This project best fits the FSP 'Timber Growth and Value' program, '1.0 Basic research on tree growth and stand development' theme and '1.1 Complex Stands' topic. Here, we propose an experimental approach that will allow quantification and prediction of juvenile tree responses to different management strategies in complex structured, mixed species stands. This proposal will examine the growth responses of subalpine fir to variation in residual canopy cover, site quality and crowding. Our improved mechanistic understanding of juvenile tree growth will be linked to SORTIE-BC. SORTIE-BC is a resource-mediated, spatially explicit, mixed-species forest model that makes population dynamic forecasts for juvenile and adult trees. It has a flexible user-interface that allows the user to incorporate a wide range of silvicultural strategies (e.g., clearcutting, understory protection, understory planting, diameter limit harvesting, shelterwood, single or group selection, and variable retention). The information gathered from this project is vital to the continued development of the SORTIE_BC model because current versions are unable to accurately predict juvenile tree growth at low light levels and in dense neighbourhoods of seedlings and saplings. Our proposed research will improve our understanding of the factors affecting juvenile tree growth and enhance the model?s ability to make accurate growth predictions. It will also provide scientific information for developing guidelines and decision support tools for management of structurally complex, mixed species, multi-cohort stands. This study has received FSP support in the past. It is currently being funded in the 2004/05 FSP fiscal year as a 3 year project and has been offered extended approval to the value of $10,000 for 2005/06. However, initial results from the 2004/05 data show there is greater variability in response variables than expected, and therefore the sample size must be increased. In addition, we determined that all neighborhood trees required stem mapping rather than simple counting in order to adequately describe their neighborhoods. In order to sample the resource gradient using an adequate sample design, we require $35,000 dollars for the 2005/06 fiscal year, $20,000 for 2006/07, and $10,000 for 2007/08.
Simard, Suzanne W., Blenner-Hassett, Trevor. 2007. Improving predictions of juvenile tree growth in complex mixtures for sustainable forest management. Forest Investment Account (FIA) - Forest Science Program. Forest Investment Account Report. FIA2007MR336