Effectiveness of Direct Seeding for Forest Restoration on Severely Degraded Land in Lampang Province, Thailand

Abstract

This study tested the effectiveness of direct seeding to establish framework tree species, for restoring forest ecosystems at an opencast lignite mine in Lampang Province, Thailand. A randomized complete block design (RCBD) experiment tested five tree species (Afzelia xylocarpa (Kurz) Craib, Eugenia cumini (L.) Druce, Ficus racemosa Roxb., Gmelina arborea Roxb. and Schleichera oleosa (Lour.) Oken) with 5 substrate amelioration treatments and 3 replicates. Germination percent was the highest for Afzelia xylocarpa (88.1%) and lowest for Ficus racemosa (5.9%). The substrate amelioration treatments had no significant effects on both seed germination and seedling establishment for all species tested. Schleichera oleosa had the highest seedling establishment percent (45%) followed by Afzelia xylocarpa (40%). A suitability scoring system indicated that these two species were the most suitable for direct seeding to complement other techniques of mine site rehabilitation in northern Thailand, where establishment of indigenous forest tree species is required for biodiversity recovery.