Seedling survival and growth of native tree species in pastures: Implications for dry tropical forest rehabilitation in central Panama

Background

Enrichment planting of tree seedlings is a method for accelerating reforestation of pastures in Central America. Persistent presence of cattle can be an impediment to the survival of unprotected seedlings, although cattle may also be a source of nutrients. Grasses can also cause competitive pressure on newly planted seedlings.

Research goals & methods

This study tests the effects of herbicide application and cattle removal on the survival and growth of three native tree species planted in pastures within a deforested, dry tropical region of Panama. Three economically valuable tree species were chosen for the study; Cedrela odorata, Enterolobium cyclocarpum, and Copaifera aromatica. Planted seedlings were monitored for survival, root collar diameter and height growth in the presence or absence of two factors: initial herbicide application and cattle. After 16 months, subsamples of seedlings within each treatment were harvested and measured for dry masses and leaf areas.

Conclusions & takeaways

In the initial stages of development, C. odorata seedlings had the greatest growth rates with herbicide application whereas E. cyclocarpum seedlings had the greatest growth rates with cattle exclusion. The combination of these two factors yielded the best growth for both species. Of the three species, C. odorata had the lowest mortality rates and the highest growth metrics. To accelerate forest succession, herbicide should be applied initially and cattle removed before enrichment planting.