Rehabilitating Degraded Forest Land in Central Vietnam with Mixed Native Species Plantings

Background

This study considers the imepdiments to reforestation presented by grasses such as Imperata cylindrica. It specifically examined the use of Acacia as a nurse crop to overcome some of the ecological and economic impediments to reforestation of degraded areas dominated by grasses.

Goals & Methods

In this study, tree species native to Vietnam (Hopea odorata, Dipterocarpus alatus, Parashorea chinensis, Tarrietia javanica, Parashorea stellata, Scaphium lychnophorum, Peltophorum dasyrhachis) were planted in 8 year old and recently thinned stands of the exotic tree Acacia auriculiformis.

Conclusions & Takeaways

The highest height growth was found in P. chinensis, P. stellata, H. odorata and P. tonkinensis. The species with the highest diameter growth were D. alatus, P. stellata and P. chinensis. H. odorata had the largest percent increase of biomass and S. lychnophorum had the lowest increase. Dipterocarpus alatus and H. odorata had lower values of growth with increasing basal area of A. auriculiformis. The authors suggest that the use of A. auriculiformis as a nurse tree to shade out the grass Imperata cylindrica was critical to the success of the native species planted subsequently. They suggest the importance of using mixed native species in forest rehabilitation, however, also highlight the role that a nurse tree that is fast growing and fixes nitrogen in overcoming the financial and ecological constraints of forest restoration.