Towards recovery of native dry forest in the Colombian Andes: a plantation experiment for ecological restoration

Background

Regeneration of native forest after disturbances, especially in arid and semi-arid regions, often progresses slowly or is arrested at a successional stage. This study evaluates the effectiveness of native tree plantings as a restoration strategy in a semi-arid Andean valley.

Research goals & methods

Nine tree species were tested including three pioneer species and six late-successional species over a four-year study period. Plots were established in abandoned pastures and in an early-successional scrub forest, with greenhouse-grown seedlings of all nine species planted in each plot. Fertilizers and stone mulch were applied to test plots.

Conclusions & takeaways

Dodonaea viscosa seedlings had the highest survival rates of 90% in pasture plots, while Myrsine guianensis had the lowest survival rates (below 35%). Pioneer species had higher survival rates in pasture than in scrub forest, while late-successional species grew poorly in both environments. High mortality rates are thought to be due to night frost, drought, and competition from Acacia decurrens, a fast-spreading localized exotic. The study concludes that succession in semi-arid tropics may be accelerated by mixed plantations, but a longer study period would enable further monitoring of successional dynamics.