Prioritizing young western white pine stands for blister rust pruning on the warm springs reservation

Abstract

A prioritization protocol was developed on the Confederated Tribes of Warm Springs Reservation of Oregon to inventory and identify stands with young western white pine (Pinus monticola) for management of white pine blister rust (caused by Cronartium ribicola) by pruning. Pruning lower branches on young white pines has been shown to be effective in parts of the Northwest for prevention and suppression of blister rust. Analysis of current inventory and light detection and ranging (LiDAR) data was completed to identify stands based on the abundance and height of white pine present. Once a list of candidate stands was generated, a field-based inventory of those stands was completed to determine blister rust infection levels. Data from the surveys were analyzed, and a decision tree was used to prioritize stands for pruning based on the number of prunable white pine present and blister rust infection levels. Spatial trends in current infection levels showed that blister rust was more damaging in the two northern areas than in the southern area included in analysis. Twenty-one stands were designated as being high priority for blister rust pruning. This process could aid other tribes and land managers in the conservation and management of western white pine in the presence of white pine blister rust.