Forest cover and snow: implications for deer habitat in southeast Alaska

Relationships between snow depth and overstory characteristics were studied on 19 0.4-ha old-growth plots and 1 60-year-old 0.4-ha 2nd-growth plot near Juneau during winter, 1983-84. Mean tree diameter at breast height (dbh), number of stems/ha, percent Sitka spruce (Picea sitchensis), mean tree height, percent timber defect, basal area, and net timber volume were measured using variable plot and point-centered quarter techniques. Canopy cover was measured from photographs of the overstory taken at each snow measurement point. Snow depth in a high-volume plot (> 100,000 board feet/ha) averaged 29% of that in an adjacent forest opening. Snow depth was correlated with net timber volume ($r_{\text{s}}=-0.90$), tree height ($r_{\text{s}}=-0.85$), basal area ($r_{\text{s}}=-0.79$), percent canopy cover ($r_{\text{s}}=-0.76$), percent spruce ($r_{\text{s}}=-0.66$), and mean tree diameter ($r_{\text{s}}=-0.65$). Old-growth plots with high net timber volume had the lowest snow depths. The low snow depths observed in high-volume, old-growth stands are attributed to the large-diameter limbs and deep crowns of older, dominant trees.