Title : Deciphering stand structure and conservation pathways for the habitat restoration of Indopiptadenia oudhensis, an endangered species endemic to the Terai–Bhabhar ecotone
Abstract:
Indopiptadenia oudhensis (Brandis) Brenan is a monotypic, endangered forest tree species endemic to the Terai-Bhabhar ecotone along the Indo-Nepal border. This ecologically sensitive transitional landscape, recognised by the IPCC as highly vulnerable to climate change, remains inadequately represented in systematic biodiversity assessments, thereby constraining evidence-based conservation and restoration planning. While the species’ evolutionary history underscores its considerable scientific and phylogenetic value, its ecological roles, habitat preferences, and potential economic significance remain enigmatic, highlighting critical lacuna and suggesting the urgent need for comprehensive research and targeted conservation efforts. The present study adopts a restoration-ecology framework to assess stand structure, regeneration dynamics, and conservation pathways for I. oudhensis, with a particular focus on identifying recruitment bottlenecks and informing habitat restoration interventions. Field surveys conducted in the Tuligad and Sukhidhang beats of the Champawat Forest Division (Uttarakhand, India) revealed severe anthropogenic disturbances, notably lopping, recurrent fire incidences, and extraction pressure. Current population density was critically low (~7 trees ha?¹) compared to earlier reports (~440 stems ha?¹), indicating pronounced stand depletion. Diameter-class distribution exhibited a conspicuous deficit of individuals in intermediate size classes, suggesting poor conversion of seedlings into saplings and adult trees, and consequently, disrupted stand continuity. Despite structural decline, seeds collected during May demonstrated high viability, achieving 100% germination under controlled incubator conditions and approximately 80% germination in nursery trials when sown within one week of harvesting. Satisfactory natural seedling emergence was also observed in forest sites. However, high post-germination mortality and low recruitment success indicate that regeneration failure is primarily driven by postestablishment constraints rather than seed limitation. To mitigate this risk, conservation seed storage was undertaken, and a germplasm repository was established to safeguard genetic resources and support future restoration and assisted regeneration programmes. The study also highlights the importance of integrating seed-based conservation, belowground biodiversity, facilitative plant interactions, and root network dynamics into science-driven habitat restoration frameworks. Incorporating such ecological processes is essential for enhancing recruitment success and designing climate-resilient forest management strategies. These preliminary insights further underscore the importance of long-term ecological monitoring to assess restoration outcomes, track population recovery, and ensure the long-term persistence of I. oudhensis within the Terai-Bhabhar landscape.
