Opening the Forest Canopy Slows Leaf Decomposition and Nutrient Cycling
Opening a forest, whether by storm damage, tree harvesting, or thinning, dries the forest floor and reduces the ability of the litter layer to retain mineral nutrients needed for tree growth. A simulated hurricane experiment in the Luquillo Experimental Forest of Puerto Rico showed that less phosphorus was conserved by fungi when the canopy was opened. The number of fungal connections between litter layers and the rate of leaf decomposition were also reduced when the canopy was opened. Nitrogen was leached into the ground water only in the simulated hurricane treatment in which limbs and leaves were transferred from the canopy to the forest floor. Leaching of nitrogen into groundwater in the simulated hurricane treatment closely matched the timing and magnitude of nitrogen transfers to ground water and losses from the ecosystem via streams that was observed after Hurricanes Hugo and George. Surprisingly, the soil microbial community responded more to differences in temperature and rainfall between years than to the canopy and debris addition treatments. This suggests that soil microbes are highly sensitive to climate change.
Forest Service Partners