This project will evaluate the effect of the residual stand edge on the growth and development of planted seedlings across two forest gaps located within the Silviculture Treatments for Ecosystem Management in the Sayward (STEMS) experiment in the Campbell River Forest District (de Montigny 2004). Seedling growth and development will be monitored in each of two half-hectare gaps, one already established at STEMS 1 in the Snowden Demonstration Forest in 2003 and the other of about the same size and orientation, at STEMS 2 at Elk Bay as yet unplanted. Each of these STEMS experiments consists of seven different silvicultural system treatments, one of which, the group selection treatment, is the unit involved in this project. At STEMS 1, the first established gap study consists of six repeated rows of four conifer species (Douglas fir, western red cedar, western hemlock and white pine), of roughly 1700 seedlings, arranged across the block perpendicular to the residual tree line on the north and south sides. Light and soil moisture are being measured continuously along a N/S transect near the E/W centre line. Estimates of photosynthetic photon flux density (PPFD) are provided by quantum sensors from an array of fixed positions across the gap and soil moisture is estimated using gypsum blocks at regular intervals from the north and south forest edges. The light environment of each seedling has been determined using hemispherical photography and seedling growth has been measured each fall since 2003. The residual trees surrounding the gap were mapped in 2004 for the purposes of light modeling. At STEMS 2, the second replication of the gap study will require planting, tagging, initial seedling measurements, the installation of sensors, dataloggers, telemetry, the collection of hemispherical photographs and residual stand mapping. Sensors will be installed to monitor vapour pressure deficit (VPD), and soil sampling will be carried out to estimate soil nitrogen. This study will allow the growth and development of individual seedlings to be correlated with its unique light environment. Light and growth data will be collected that can be used to validate model predictions using TASS III . The compact nature of the experimental area will allow stem mapping of the residual stand for spatially explicit comparisons of real and predicted light levels using tRAYci (Brunner 1996).
Fielder, Peter P.. 2007. Light as a factor in the growth and survival of four planted conifer species across forest gaps. Forest Investment Account (FIA) - Forest Science Program. Forest Investment Account Report. FIA2007MR287