Enrichment Planting in a Logged-Over Tropical Mixed Deciduous Forest of Laos

background

This study evaluates enrichment planting using five native species planted in degraded (logged) forests in different arrangements.

Research Goals & Methods

Pterocarpus macrocarpu, Afzelia zylocarpa, Dalbergia cochinchinensis, Dipterocarpus alatus, and Vatica cinerea were planted in 8 x 8m gaps or in 100m long lines (with 2m width), with species grouped by gap or part of the line. After seven years since planting, the survival rate did not vary by enrichment planting method, but did vary by species: P. macrocarpus and A. xylocarpa had the lowest survival (under 37%) while D. alatus and V. cinera had the highest survival (between 50 and 52%).

Conclusions & Takeaways

The trees in the gaps had higher root collar diameters and height growth than those in the line plantings. D. alatus and V. cinera had the highest root collar diameter and height growth as well, with V. cinera having the highest height in gaps (315.0cm) and D. alatus in line plantings (202.3cm). Canopy closure occurred rapidly in both lines and gaps and seems to favor the more shade-tolerant species (D. alatus and V. cinerea) in both treatments. The authors recommend larger gap sizes be used to favor a balance of both both light-demanding and shade tolerant species.