Model of ecological resilience in Hyrcanian forests that combines the decision-making trial and evaluation method (DEMATEL) and system dynamics

The present study assessed the resilience model of Hyrcanian forests with Navroud-Asalem watershed as a case study. The Navroud-Assalem watershed was selected for study because of its special environmental characteristics and access to relatively acceptable information. In order to model resilience, the appropriate indices influencing resilience in Hyrcanian forests were identified and selected. The criteria of biological diversity and forest health and vitality were selected along with the indices of species diversity, forest-type diversity, mixed stands, and the infected area percentage forests with disturbance factors. Thirteen sub-indices and 33 variables were determined and the relationship between the indices and criteria was identified by developing a questionnaire using the decision-making trial and evaluation laboratory (DEMATEL) method. The weights of each index were estimated in Vensim software using the fuzzy analytic hierarchy process. Collecting and analyzing the regional information, the conceptual model was developed and formulated quantitatively and mathematically and was entered into Vensim for resilience modeling of the selected parcels. The DEMATEL method indicated that the species diversity indices and the percentage of affected forests had the greatest influence and interaction with other factors in the system. The parcels studied had different slopes and were affected by the input variables. They were considered as resilient if they were found to maintain current conditions. Avoidance of exploitation, infestation by pests, severe fires in the region, and increased livestock grazing compared to the existing situation were among the prerequisites for resilience in the region. Vensim modeling represents that in control parcel no. 232 the nondimensional resilience parameter is 3025 (the most resilient parcel), while in the disturbed parcel no. 278 this amount is 1775 (the least resilient parcel).