Evaluation of reforestation potential of 83 tree species planted on Imperata cylindrica dominated grassland – A case study from South Kalimantan,Indonesia

Survival and growth of 83 tree species were tested in three separate species elimination trials on Imperata cylindrica dominated grassland in South Kalimantan, Indonesia. The trial layout was randomized complete blocks design with 6–8 replications of 5-tree line plots. At the age of two years exotics, like several Acacia species (A. mangium, A. crassicarpa, A. auriculiformis, A. cincinnata, A. leptocarpa), as well as Gmelina arborea, Paraserianthes falcataria and Cassia siamea had survival rates of 90–100%, crown width of 3–6 m and mean height of 5–8 m. Among the most promising local species were Anthocephalus chinensis, Peronema canescens and Parkia roxburghii but their growth was inferior compared to exotics. Eucalypts and pines were not among the highest ranking trees and cannot be recommended for initial grassland reforestation. At the age of 7–8 years the same species were still dominating, but increasing mortality of several species was observed. Especially Acacia crassicarpa and A. cincinnata of the exotics were affected, and indigenous Anthocephalus chinensis almost perished. Since fast early growth is necessary in first rotation reforestation of grasslands, fast growing exotic species provide a reliable basis for further activities. Final performance of reforestation species has to be confirmed in stand-level experiments and pilot plantations. Intensive work on integrating local tree species in reforestation of grasslands in the long run is recommended.