Assessing the impact of differential protection regimes on tree diversity and composition in the Western Ghats: insights for conservation strategies

Human impact in forest ecosystems remains widespread and continues to persist even in the face of formal conservation initiatives. This is evident in the Northern Western Ghats (NWG), where forest patches fall under diverse protection regimes including legal (Protected Areas and Reserved Forests), community-managed (Sacred Groves), and private ownership. However, comparative data on tree diversity and community structure across these regimes are limited. To address this gap, we assessed woody plant diversity, composition, and structural attributes across four protection regimes using a standardized transect–quadrat sampling design (four 20 × 20 m quadrats per 140 m transect). We recorded species richness, individual abundance, girth at breast height (GBH), basal area, and a Combined Disturbance Index (CDI). Approximately 50% species overlap was observed across all regimes. Protected Areas (PA) and Reserved Forests (RF) supported higher tree densities, while Sacred Groves (SG) showed older individuals and the highest basal area despite experiencing greater disturbance. In contrast, Private Forests (PV) had fewer evergreen and endemic species. Although overall species composition was broadly similar among regimes, significant variation was found in species richness and structural parameters. These findings highlight the importance of regime-specific conservation strategies and underscore the ecological value of Sacred Groves and community involvement in sustaining biodiversity in the NWG.