Initial Performance and Reforestation Potential of 24 Tropical Tree Species Planted Across a Precipitation Gradient in the Republic of Panama

background

The authors of this study  planted trees from 22 native species and two exotic species to use in selection trials testing the growth and survivability of trees in plantations in three different sites.

Research Goals & Methods

The sites were chosen for their precipitation gradient from Soberania National Park (2226mm mean annual rainfall), Los Santos (1946mm rainfall), and Rio Hato (1107mm rainfall). Survival, basal diameter, height, crown diameter and wood volume index (VI) were calculated after two years of growth.

Conclusions & Takeaways

Survival was over 80% for all sites. The survival and growth were highest in Soberania National Park and lowest in Rio Hato, following the precipitation gradient. Acacia mangium (exotic) and Ochroma pyramidale (native) had the tallest trees with mean heights over 5m. Albizia guachapele and Samanea saman also had high growth at the driest site (Rio Hato) and Spondias mombin and Guazuma ulmifolia grew well at the wetter sites. The largest basal area was reported for A. mangium, Pachira quinata, and O. pyramidale. Copaifera aromatica, inga punctata, and Dipteryx panamensis had the smallest height and diameter growth. Acacia mangium, Diphysa robinoides (nitrogen fixing), Gliricidia sepium (nitrogen fixing), Guazuma ulmifolia and Ochroma pyramidale had the most dense canopy. The authors recommend that the growth and canopy of these species make them favorable selections for soil stabilization and crown cover. They assert that the results of these selection trials can advise plantation design in Panama, but should be considered with caution because of the early age of the plantation.