Restoring and Enhancing Productivity of Degraded Tephra-Derived Soils

Soil restoration (sometimes termed enhancement) is an important strategy for sustaining the productivity of managed forest landscapes. Tephra-derived soils have unique physical and chemical characteristics that affect their response to disturbance and restoration. A variety of factors reduce forest productivity on degraded soils. Site-specific information on soil physical conditions, organic matter, and nutrient status is required for efficient soil restoration, but only limited research is available to help interpret such information and guide efforts to restore tephra-derived soils. Based on site-specific conditions, reclamation treatments can be identified to control water, till compacted soils, restore organic matter, and revegetate disturbed areas. Successful reclamation investments will often involve simple treatments focusing on low cost options such as decompaction, topsoil replacement, fertilization, and tree planting. Avoiding difficult sites such those in high elevation environments, wet areas or fine textured soils is recommended where possible, as treatments to overcome such problems are likely to be expensive and have uncertain outcomes. Restoration efforts in volcanic terrain likely need to be accompanied by programs to monitor the beneficial effects of treatments on forest productivity, in relation to their costs.