Pure and Mixed Forest Plantations with Native Species of the Dry Tropics of Costa Rica: A Comparison of Growth and Productivity

background

This research monitored the growth and survival of 13 natives species in pure and mixed-species plantations, and compared the results to measurements of T. grandis, an exotic species commonly planted in the area.

Research Goals & Methods

Two plantations were established and divided into single- and mixed-species plots; one plantation contained 7 slower growing native species and the other contained 7 relatively faster growing native species. T. grandiswas planted in a single-species plot trial and was found to have significantly higher productivity than all of the native species.

Conclusions & Takeaways

In the slow growth plantation, D. retusa and S. saman had the highest survival rates and the best growth rates, while S. parahyba and C. odorata had the highest mortality rates. In the fast growth plantation, P. guachapele had the highest survival rate while all other species showed high moratality rates; S. parahyba exhibited the highest growth rates. Of the native species, S. saman, D. retusa, and S. macrophylla were the most productive, with the highest recorded basal areas besides T. grandis., when planted in single-species plots. Most species, in both plantation types, tended to have faster growth in mixed-species plots, with the exception of P. pinnatum and S. saman. The high mortality of C. odorata may have resulted from its sensitivity to drought during establishment and multiple shoot borer attacks. The authors recommend the use of mixed-species plantations as opposed to pure stands given the superior growth that was observed and the provision of multiple goods and services that they provide.