The Role of Nurse Trees in Mitigating Fire Effects on Tropical Dry Forest Restoration: A Case Study

Background

The authors of this study initially studied differential growth rates in a reforestation project of native tree species with nurse trees(Leucaena leucocephala) and without nurse trees when the area had two fire events. However, authors took advantage of the unplanned experiment to study the effects of fire in reforestation.

Research Goals & Methods

The study area was subtropical dry forest that had mostly been converted to cattle pasture. Saplings were planted in two plots - one open and one with 100% canopy cover. Species were selected based on availability and presence in a nearby mature dry forest area.

Conclusions & Takeaways

The plot with the nurse tree did not burn in the second fire and 75% burned in the first, while in the open plot everything burned. The authors attribute this difference to a greater amount of fuel (more sapling growth) in the plot without a nurse tree. Saplings from the nearby mature forest survived better than pioneer species. Evergreen species generally survived better than deciduous species. The benefits of nurse trees were reduced mortality from fire and increased growth of native trees. The use of Leucaena leucocephala also reduced grass growth, reduced fuel loads, and caused greater postfire stem survival. Caribbean tree species have not had natural fire sources, so nurse trees and other strategies to prevent loss are important. Other studies have found generally better growth and survival of saplings under nurse trees in dry forests, so these results show another benefit of using nurse trees.