A study analyzes how forest owners react when a disease affects their forests, specifically the chestnut blight, a fungus that infects chestnut. The research, led by the Forest Technological Center of Catalonia, concludes that the presence of an economic interest is the main reason for deciding whether to treat sick chestnut, to abandon it or even to replace it with exotic species such as California pine or spruce Douglas.
The availability of a market of wood or chestnuts increases four times the pressure and interest in treating chestnut disease. The study that demonstrates this is based on the interviews carried out with owners of chestnut forests infected by the chestnut blight in Catalonia and published in the journal Forest Ecology and Management.
The paper also notes the difference between the economic outputs of a chestnut forest. Forest managers destined to wood or to produce chestnuts are four times more willing to apply control treatments than those destined to obtain cutting products, such as firewood, cuttings and sticks, currently without market.
Owners play an important role
However, in the absence of economic interest, owners of chestnut trees affected by the disease opted for abandonment (65% of respondents) or for replacement by other exotic species. Abandonment is associated with self-taught naturalistic managers who have moral reasons against exotic species. Instead, the substitution is associated with family tradition managers, with experience in replacing or with a reference opinion leader who has also done so.
Understanding that forest owners react in one way or another to an invading pathogen can be used to design efficient policy measures. In this sense, Jonás Oliva, author of the article, explains that “when a new pathogen appears in the forests, the efforts are destined to develop treatments, but they are not dedicated to analyzing the probability that these will be implemented.”
The study of this case could help predict the probability of implementing measures against diseases affecting other tree species across Europe, such as elm, ash or alder. In addition, it raises concerns about the continuity of species of trees affected by pathogens that have no commercial value or are low.
In the absence of economic interest, owners of chestnut trees affected by the disease opted for abandonment or replacement by other exotic species.
Photo: Chestnut blight has become a disease that is hitting chestnut hard.
The importance of opinion leaders when it comes to choosing
Research shows that forest owners are looking at those alternatives chosen from their social environment when making a decision. Clusters, communities or social actors are relevant factors in explaining their behavior. So if you want to get the owners to trust and decide to control the disease, researchers recommend including opinion leaders. “If they believe, a good number of owners will believe, too,” Castaño explains.
The study also highlights the need to break with the belief that more management means worsening disease, as it contrasts with the scientific evidence. Therefore, they recommend visualizing the results of the treatment through demonstration plots.
In addition, few of the respondents were aware that at the time of planting species of exotic trees could introduce new invading pathogens. That is why the study also warn of the risks that substitution entails, since nursery plants are the main vector of exotic diseases worldwide. Spreading risk information in quantifiable terms can also help both managers and policy makers to assess the potential consequences of each alternative.
Source: J. Oliva, C. Castaño, E. Baulenas, G. Domínguez, J.R. González-Olabarria, D. Oliach. “The impact of the socioeconomic environment on the implementation of control measures against an invasive forest pathogen”. Forest Ecology and Management 380 (2016) 118–127 http://dx.doi.org/10.1016/j.foreco.2016.08.034
Images: Carles Castaño