Abstract

Whenever a new invasive forest pathogen appears, resources are put into developing countermeasures such as breeding for resistance in the affected host species and/or by developing fungicide/biocontrol treatments. In most cases, little effort is placed into analysing the likelihood of those measures being implemented. Studying the reasoning behind management reactions of forest managers whose forests had been attacked by invasive pathogens can improve implementation of measures in case of future invasions. We used grounded theory to model forest owners' reactions against chestnut blight caused by the invasive pathogen Cryphonectria parasitica. We focussed on understanding what drove some managers to keep managing chestnut forests and applying biological control, and what made others abandon or even substitute chestnut by exotics. We found that the availability of a market for chestnut products, and not the disease was the main reason for discontinuing chestnut management. The will to continue managing chestnuts was four times higher amongst managers of chestnut stands for nut production (valuable crop), than amongst managers of coppice stands producing small diameter stems, currently without a market. Requesting application of biological control against chestnut blight was four times more likely amongst forest managers obtaining monetary benefits from their land (benefits used as profit or re-investment) than those not obtaining monetary benefits or currently losing money with their land. Substitution with exotic conifers was associated with forest managers that had learned management from family and leaders of opinion, and that have either themselves or previous owners of the land planted exotics beforehand. Abandonment was associated with self-taught managers valuing non-monetary aspects of forests and having moral reasons against exotics. Our research highlights the importance of considering the socioeconomic context around the affected tree species when developing measures against invasive forest pathogens, and raises concerns about the continuity of tree species affected by invasive pathogens with little or no commercial value. (C) 2016 Elsevier B.V. All rights reserved.