Early height growth patterns of planted white spruce seedlings in Interior Alaska

Abstract

This study looked at early height growth of planted white spruce Picea glauca (Moench) Voss around the Fairbanks area. The effort focused on two Levels-of-Growing-Stock (LOGS) experimental plantations located in the Bonanza Creek Experimental Forest that incorporated an espacement study. Annual total height was also measured on 16 operational plantations and then compared to LOGS plantations. Average annual total height at Site 2 of the LOGS plantations was significantly greater than at Site 1. A significant difference in height growth between these sites was attributed to differences in aspect. Results showed significant annual total height differences among the espacement plots within the LOGS plantation. The narrowest spacing 1.2 X 1.2 m and widest spacing 3.7 X 3.7 showed a lower annual total height while spacings 1.8 X 1.8 m, 2.4 X 2.4 m, and 3.0 X 3.0 m showed a greater annual total height at age ten. The range of annual total height found at the LOGS sites was not significantly different than the range of annual total height found at the 16 operational plantations. Additionally, path analysis was used to quantify the direct and indirect effects of multiple environmental variables (i.e., percent slope, slope position, competition, aspect, and soil moisture) on growth rate at the operational plantations. It was found that slope position, percent slope, and competition had significant direct effects on growth rate. These results provide insight for resource managers when predicting the height growth of planted white spruce.