Survival and Growth of Under-Planted Trees: A Meta-Analysis Across four Biomes

background

This article is a meta-analysis synthesizing the results of survival and growth of under-planted trees in forests in tropical, temperate coastal, boreal, and temperate deciduous forests. Additionally, the survival and growth of these underplanted trees are evaluated according to the silvicultural treatment affecting density of the overstory: uncut, dense shelterwood, intermediate density shelterwood, light density shelterwood, clear cut.

Conclusions & Takeaways

The survival of underplanted seedlings was lowest in the tropical ecosystem. Nevertheless, the annual increment (growth) of the underplantings was highest in the tropical biome, followed by temperate coastal forest. In the temperate and boreal biomes, survival increased with moderate thinning and remained high at light densities of overstory trees. In tropical forests, the survival was optimized in the intermediate density shelterwood but decreased in the lighter density and clear cut stands. The authors recommend an intermediate level density created from a shelterwood thinning. This level appears to balance the increased light needed by underplanted trees while also protecting against climatic stresses. They highlight that light density shelterwoods and clear cuts appeared to offer no definite advantage in growth or survival across the four biomes.