Effect of elevation on soil quality under bamboo (Bambusa teres Buch.-Ham. ex Munro) stands outside forest areas in Eastern Nepal

Abstract

Bamboo dynamics in non-forest areas remain relatively underexplored, despite over 50 % of the global bamboo population being found in degraded, marginal or agricultural lands outside forests. To address this, we investigated soil quality dynamics under isolated bamboo stands (Bambusa teres) across three elevation regions: lower (0–400 m), middle (400–800 m), and higher (800–1200 m) in Katari, Udayapur, Nepal. Stratified sampling, followed by purposive sampling, was used to account for elevation variation and bamboo's scattered distribution. A total of thirty 100 m² circular plots (10 per elevation stratum) were sampled at two soil depths (0–15 cm and 15–30 cm) to assess soil quality, using various indicators based on published literature from Nepal. At middle elevation, organic carbon, nitrogen and potassium were significantly higher at 0–15 cm, while phosphorus and pH were higher at 15–30 cm (p ≤ 0.05). A fair soil quality rating (SQI: 0.48 –0.57) was observed in the study area. Elevation significantly (p ≤ 0.05) affected SQI at 0 –15 cm depth, with higher SQI at middle elevation (0.57) and lower SQI at lower elevation (0.48). For effective bamboo management and land-use planning, it is important to consider elevation-specific zoning. Middle and higher elevations should be prioritized for bamboo plantations, incorporating management activities and agroforestry integration to enhance soil productivity. Further studies with larger samples and broader geographic coverage, incorporating additional soil indicators and environmental variables is recommended.