Effects of Swiss Needle Cast on the Profitability and Optimal Management of Douglas-fir Plantations in Western Oregon

Abstract

Abstract This study conducts an economic analysis to evaluate the impact of Swiss needle cast (SNC) caused by Nothophaeocryptopus gaeumannii on Douglas-fir (Pseudotsuga menziesii) plantations at the stand level in western Oregon. We examine timber and nontimber benefits across varying degrees of SNC severity considering timber benefits and carbon sequestration benefits. By comparing these values with unaffected Douglas-fir stands, our aim is to quantify the economic losses associated with SNC in terms of the land expectation values. The total land expectation value for a stand affected by SNC ranges from $556 to $2,179/ac, representing an average decrease of 50% ($1,066/ac) in economic revenues compared with a Douglas-fir stand without SNC infestation. Engaging in cost-effective annual management activities, with maximum costs of $43–$56/ac, could offset the profitability decline. On average, the total losses in profits for the current plantations affected by SNC are estimated to be around $206.5–430 million. Study Implications: In this study, we examine the economic impacts of Swiss needle cast (SNC) on the profitability of western Douglas-fir in Oregon. Our results reveal that profits for landowners can be, on average, reduced by $1,066/ac when their stand is infested by SNC, representing a 50% loss in profitability. Landowners could potentially mitigate these losses by engaging in annual management activities aimed at preventing Douglas-fir infestation, incurring a cost ranging between $43–56/ac, which could offset the reduction in profitability.