Responses of 20 Native Tree Species to Reforestation Strategies for Abandoned Farmland in Panama

Background

In the tropics, deforestation often leads to unproductive agriculture and results in degraded grasslands. This study seeks to understand why forests fail to regenerate naturally in these ecosystems. 

Research Goals & Methods

To evaluate forest regeneration, the researches planted over 1,500 seeds of twenty native species in a abandoned pasture in Panama that was dominated by  Saccharum spontaneum, an exotic grass. Seed selection trials were conducted to test how native tree species grew in stands of the invasive grass Saccharum spontaneum with varying shade and mowing treatments.

Conclusions & Takeaways

​Most tree species responded favorably to treatments that reduced the grass biomass. In many cases germination was higher with shading treatments. Mowing increased light availability, but also increased temperature and decreased soil moisture. Some species did not respond favorably to this reduced protection from irradiation and moisture loss. The species tested germinated under different treatments. General trends: small-seeded species responded best with 75% shade; light demanding species germinated best in thrice-mown treatments; shade tolerant and small-seeded species germinated best with only shading treatments; large-seeded species germinated among the grass with less treatment needed.