Does UNESCO designation enhance forest protection? Evidence from the Hyrcanian national forest inventory

Abstract

The Hyrcanian Forests in the North of Iran, recognized as a UNESCO World Natural Heritage (UNWH) site, represent a globally significant ancient temperate forest ecosystem. This study assessed whether the UNWH designation has influenced anthropogenic pressures and forest recovery. Using data from the Hyrcanian National Forest Inventory (HNFI) across three time points (1996, 2006, and 2023), cumulative link and generalized linear mixed models (CLMM and GLMM) were applied to evaluate trends in grazing intensity and illegal logging (timber smuggling), and a linear mixed-effects model (LMM) was used to assess changes in regeneration density across four growth stages. Results indicate that the likelihood of illegal logging was not significantly different between Reg-UNWH and Non-UNWH sites, although it decreased with increasing altitude. Grazing intensity also did not differ between site types but was also negatively associated with altitude. Regeneration density declined significantly over time in both Reg-UNWH and Non-UNWH sites, particularly in sapling and small pole stages. Altitude had a consistent positive effect on regeneration, and significant interactions between Year and Growth Stage revealed distinct temporal dynamics. Additionally, the study discusses the influence of legislative initiatives, such as the removal of livestock from forests (PEDAF) and the cessation of commercial logging (CHFL), on human-forest interactions. These findings indicate that the UNWH designation has not mitigated anthropogenic pressures. Effective conservation will require strengthened enforcement, better integration of local communities, and consistent monitoring to secure long-term ecological outcomes.