Enrichment Planting of Dipterocarps in Logged-Over Secondary Forests: Effect of Width, Direction and Maintenance Method of Planting Line on Selected Shorea Species

background

In this study, three different planting design experiements were conducted using three Dipterocarp tree species planted in a heavily logged area of South Kalimantan. The area was logged in 1979 and used for shifting cultivation until 1988.

Research Goals & Methods

For the first experiment, Shorea johorensis and Shorea parvifolia were planted in lines arranged in four different directions with 10m spacing between lines and 2m spacing between trees. For the second experiment, Shorea johorensis, Shorea leprosula, and Shorea parvifolia were planted in lines 1m wide, 2m wide, and 3 m wide (with a control of planting directly under secondary forest without opening the canopy on the line). In the third experiment, all three species were planted and underwent four different maintenance treatments: control, vertical (removing branches blocking overhead light), horizontal (cleaning weedy species around the planted trees), and combined vertical and horizontal treatments. After two years since establishment, the height, diameter, and survivability were evaluated for the planted species.

Conclusions & Takeaways

The authors suggest that the results of these tests indicate good prospects for planting dipterocarps in lines in low-volume secondary forests. Survival was not significantly affected by line width and line mantenance, however growth (height and diameter) of the three species was higher in lines 2 and 3m wide and lines that underwent horizontal maintenance. Unlike prior studies, the authors explain that their results indicate that opening up the canopy along the line before planting is more effective, as long as the planting line is protected on either side by secondary woody vegetation.