Both storms and logging expose the forest floor to sun and wind, which dries the litter and reduces the activity of fungi that make nutrients available to trees. Decay fungi that produce mushrooms recycle nutrients needed for tree growth, so they are important for maintaining forest productivity. These fungi retain nitrogen, preventing losses from the forest by leaching and stream export, and also keep phosphorus in forms available to tree roots. Forest Service scientists and collaborators simulated the two main effects of hurricane damage, canopy opening and deposition of leaves and branches, in the Luquillo Experimental Forest in Puerto Rico. Treatments included an untreated control, a "hurricane simulation" (open canopy with green leaves and wood on the forest floor), canopy opening without debris (similar to common pre-planting site preparation in forestry), and debris addition under closed canopy. They found that green leaves left on the ground in the hurricane simulation protect the underlying forest floor layers from drying and provide additional nutrients. The hurricane simulation treatment performed as well as the control treatment in activity and abundance of mushroom fungi that decompose leaf litter, reduce erosion and retain nutrients, and retention of phosphorus and nitrogen in the forest floor.