What about other conifers? We have developed changes for Pl but Sx and Fd grow with pine especially in the wetter zones like the SBS However, we have limited information on Fd and Sx – Research studies provide some insight EP operational studies have early growth response EP (SBSdw2) has an example of Fd surviving extremely dense aspen stands where pine died EP1080 (SBSmk1) has provided us with data on SX growth under different levels of aspen competition – Various models have been developed – some validated in the ecosystems of interest – Applicable literature will be reviewed 1

2 Free Growing spruce (SBSdw1) Spruce under some completion (SBSdw1) EP : SBSdw1&2

Aspen and Douglas-fir on EP (SBSdw2): age 24

25 year old aspen canopy at Sheridan (SBSdw2) Models We can use this information to project the competitive environment that aspen creates in different ecosystems. Light models help us to forecast the amount of light found under and within aspen canopies (ex. Some suggest spruce needs 65 – 75% full sunlight to achieve 80% maximum growth) Others can assist in prediction of growth and development (ex. MGM)