You are here: Home / Research Topics / Research Highlights / Individual Highlight

Research Highlights

Individual Highlight

Leaves Left on the Ground After Storm Damage or Logging Lead to Faster Forest Recovery

Photo of Leaf decomposition baskets hold apart the leaf litter layers in a hurricane simulation experiment in the Luquillo Experimental Forest of Puerto Rico. Leaf decomposition and nutrient cycling were studied in decomposition baskets with screens placed between layers to measure decay rates, nutrient movement between layers, phosphorus retention, and number of mushroom fungal connections between litter layers. Placement of green ‘hurricane' leaves (top layer) over freshly fallen senesced leaves (middle layer) and the forest floor (bottom layer) protected the underlying litter and decay fungi from drying when the canopy was opened by trimming tree branches. D. Jean Lodge, Forest ServiceLeaf decomposition baskets hold apart the leaf litter layers in a hurricane simulation experiment in the Luquillo Experimental Forest of Puerto Rico. Leaf decomposition and nutrient cycling were studied in decomposition baskets with screens placed between layers to measure decay rates, nutrient movement between layers, phosphorus retention, and number of mushroom fungal connections between litter layers. Placement of green ‘hurricane' leaves (top layer) over freshly fallen senesced leaves (middle layer) and the forest floor (bottom layer) protected the underlying litter and decay fungi from drying when the canopy was opened by trimming tree branches. D. Jean Lodge, Forest ServiceSnapshot : 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. Forest Service scientists and partners found that allowing green leaves to remain on the forest floor in a wet subtropical forest in Puerto Rico compensated for and buffered the litter layer below from the negative effects of canopy opening, allowing the forest to retain nutrients and the tree trunks to grow faster.

Principal Investigators(s) :
Lodge, D. Jean 
Research Location : Luquillo Experimental Forest, Puerto Rico.
Research Station : Northern Research Station (NRS)
Year : 2014
Highlight ID : 611

Summary

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.

Additional Resources

Publication(external web site)
Publication(external web site)
Publication(external web site)

Forest Service Partners

External Partners

  • Dr. Grizelle Gonzalez, International Institute of Tropical Forestry,
  • Dr. Marirosa Molina and Dr. Mike J. Cyterski, US EPA, Athens, GA.
  • Dr. Sharon A. Cantrell & Dr. José R. Pérez-Jiménez,, Universidad del Turabo, Gurabo, Puerto Rico

Strategic
Program Areas

Priority
Areas