Most of the original dry forest in Puerto Rico has been converted to agriculture or pastureland. The need to restore these forests is critical, but a lack of specific restoration techniques hinders its progress. Reforestation can be an important instrument for restoring these ecosystems by establishing native vegetation. However, reforestation projects are difficult without high maintenance, such as watering and grass trimming. A reforestation project started in September 2007 at the Cabo Rojo National Wildlife Refuge. The goal of this study was to compare the effects of soil preparation and planting arrangement on pasture grass control and the growth of tree saplings in abandoned tropical pasture in Puerto Rico. Saplings of six native trees were planted, totaling 600 saplings in the project, were planted in to arrangement (lines or groups) and subjected five treatments: control, irrigation only, mulch only, combination (mulch-irrigation) and combination plus grass removal by bulldozing. Growth and survival of all individuals were measured after one year.
Results/Conclusions
The overall survival rate was 94%. Treatments with mulch increased sapling growth by 50% over controls and decreased grass cover by 80%. Planting arrangement and irrigation had little effect and growth or survival or grass cover. All treatments with mulch had a positive effect on saplings growth. The results highlight the importance of reducing grass cover to improve the success of reforestation efforts. Reforestation in dry zones is particularly challenging, and identification of survival rates and successful species is important for land management.
