• Energy Research

Climatic changes will affect the occurrence probability of extreme windstorms. Consequently, management of uneven-aged forests can only be optimized correctly if changes in climatic conditions are considered. This article determines the optimal management regime of uneven-aged forests in the presence of climatic changes affecting windstorm occurrence probabilities, and takes into account the risk preferences of the forest owner. This study analyzes optimal harvesting of uneven-aged stands by applying a Markov Decision Processes (MDP) framework and an economic description of uneven-aged forestry. Two management types are considered: the exact uneven-aged forest management model in which the forest owner jointly manages all the different stand plots, and the independent uneven-aged forest management model that assumes that the forest owner separately and independently manages each plot of the forest. The MDP framework is applied to a non-industrial private forest owner located in North-East of France. We show that the forest owner tends to converge toward a forest structure which is very close to a normal forest. We also find that the independent model can be seen as a poor approximation of the exact model because of strong incidence in terms of optimal harvesting policy. We also show that the optimal decisions depend on risk preferences but not on the considered levels of windstorm probability possibly resulting from climate change.

Climatic changes will affect the occurrence probability of extreme windstorms. Consequently, management of uneven-aged forests can only be optimized correctly if changes in climatic conditions are considered. This article determines the optimal management regime of uneven-aged forests in the presence of climatic changes affecting windstorm occurrence probabilities, and takes into account the risk preferences of the forest owner. This study analyzes optimal harvesting of uneven-aged stands by applying a Markov Decision Processes (MDP) framework and an economic description of uneven-aged forestry. Two management types are considered: the exact uneven-aged forest management model in which the forest owner jointly manages all the different stand plots, and the independent uneven-aged forest management model that assumes that the forest owner separately and independently manages each plot of the forest. The MDP framework is applied to a non-industrial private forest owner located in North-East of France. We show that the forest owner tends to converge toward a forest structure which is very close to a normal forest. We also find that the independent model can be seen as a poor approximation of the exact model because of strong incidence in terms of optimal harvesting policy. We also show that the optimal decisions depend on risk preferences but not on the considered levels of windstorm probability possibly resulting from climate change.

181 catastrophes naturelles ont été recensées dans le monde en 2018, selon le réassureur Swiss Re. Par catastrophe naturelle, on considère tous les événements d’origine naturelle, survenant brutalement et générant d’importants dommages matériels et humains. Pour cette même année 2018, les dommages économiques qui leur sont imputables sont estimés à 155 milliards USD (soit 0,19 % du PIB mondial) dont 76 milliards étaient assurés contre ces catastrophes. 181 natural disasters were recorded worldwide in 2018, according to the reinsurer Swiss Re. By natural disaster, we consider all events of natural origin, occurring suddenly and generating significant material and human damage. For the same year 2018, the economic damage attributable to them is estimated at 155 billion USD (i.e. 0.19% of world GDP), of which 76 billion was insured against these disasters.

181 catastrophes naturelles ont été recensées dans le monde en 2018, selon le réassureur Swiss Re. Par catastrophe naturelle, on considère tous les événements d’origine naturelle, survenant brutalement et générant d’importants dommages matériels et humains. Pour cette même année 2018, les dommages économiques qui leur sont imputables sont estimés à 155 milliards USD (soit 0,19 % du PIB mondial) dont 76 milliards étaient assurés contre ces catastrophes. 181 natural disasters were recorded worldwide in 2018, according to the reinsurer Swiss Re. By natural disaster, we consider all events of natural origin, occurring suddenly and generating significant material and human damage. For the same year 2018, the economic damage attributable to them is estimated at 155 billion USD (i.e. 0.19% of world GDP), of which 76 billion was insured against these disasters.

Forests are increasingly threatened by windthrows but those com-posed of uneven-aged stand plots are generally less impacted bytheir effects. As a consequence, the management of such forestsshould be based on a joint management of all their differentuneven-aged stand plots. This article determines the optimal man agement regime of uneven-aged forests under risk of windthrowand furthermore takes the risk preferences of the forest owner intoaccount. This study analyzes optimal harvesting of uneven-agedstand plots by applying a Markov decision process (MDP) frame-work using an economic description of uneven-aged forestry. Twomanagement types are considered: the joint uneven-aged forestmanagement model in which the forest owner jointly managesall the different stand plots, and the independent uneven-agedforest management model that assumes that the forest ownerindependently manages each plot of the forest. The MDP frame-work is applied to a non-industrial private forest owner located innortheastern France. First, we show that the forest owner tends toconverge toward a forest structure that is close to a normal forestin the joint uneven-aged forest management model. Second, wefind that the independent uneven-aged forest management modelpoorly approximates the optimal multi-stand harvesting policy.Third, and more surprisingly, the levels of windthrow probability changes considered have little influence on the optimal harvestingstrategies of the forest owner. Lastly, in contrast, the forest owner’srisk aversion is shown to have a strong influence on the optimalpolicy.

Forests are increasingly threatened by windthrows but those com-posed of uneven-aged stand plots are generally less impacted bytheir effects. As a consequence, the management of such forestsshould be based on a joint management of all their differentuneven-aged stand plots. This article determines the optimal man agement regime of uneven-aged forests under risk of windthrowand furthermore takes the risk preferences of the forest owner intoaccount. This study analyzes optimal harvesting of uneven-agedstand plots by applying a Markov decision process (MDP) frame-work using an economic description of uneven-aged forestry. Twomanagement types are considered: the joint uneven-aged forestmanagement model in which the forest owner jointly managesall the different stand plots, and the independent uneven-agedforest management model that assumes that the forest ownerindependently manages each plot of the forest. The MDP frame-work is applied to a non-industrial private forest owner located innortheastern France. First, we show that the forest owner tends toconverge toward a forest structure that is close to a normal forestin the joint uneven-aged forest management model. Second, wefind that the independent uneven-aged forest management modelpoorly approximates the optimal multi-stand harvesting policy.Third, and more surprisingly, the levels of windthrow probability changes considered have little influence on the optimal harvestingstrategies of the forest owner. Lastly, in contrast, the forest owner’srisk aversion is shown to have a strong influence on the optimalpolicy.

Abstract We develop a multiple forest use model to determine the optimal harvest date for a forest stand producing both timber and carbon benefits under a risk of fire. An empirical application is provided for a forest owner producing maritime pine in Southwest of France. Our results indicate that a higher risk of fire will decrease the optimal rotation period. On the contrary, higher carbon prices increase the optimal harvesting age. To investigate the contradictory effects of fire risk and carbon price on forest rotation, we identify the set of carbon prices and fire risks that lead to a given rotation age. We also show that forest owner's willingness to pay for a risk reduction can be substantial (37.33 euros by ha and by year to reduce the annual fire risk from 1.26% to 0.07%).