ARS | Publication request: Pine straw harvesting effects on water content of a forest soil

Submitted to: Southern Silvicultural Research Conference
Publication Type: Abstract Only
Publication Acceptance Date: July 22, 2010
Publication Date: February 22, 2011
Citation: Pote, D.H., Burner, D.M. 2011. Pine straw harvesting effects on water content of a forest soil. Southern Silvicultural Research Conference. Volume 1.

Technical Abstract: This study addresses concerns that harvesting pine straw from forests may decrease timber productivity by accelerating evaporation of soil water. Pine needles that accumulate on the forest floor help to conserve soil moisture, protect the soil surface against erosion, moderate soil temperature, inhibit weed growth, and provide soil nutrients and organic matter. These qualities make pine straw a valuable landscaping mulch that has become a multi-million dollar business in several southeastern states. However, some forest managers are concerned that removal of the protective pine straw layer from forests allows water to evaporate more quickly from the soil surface, and may decrease timber productivity in areas where pine straw has been harvested. In this study, three harvesting schedules and a control treatment (no straw harvest) were compared to determine harvesting effects on volumetric water content of the soil vadose zone in an established loblolly (Pinus taeda L.) plantation. Pine straw harvesting tended to decrease soil water content at depths below 20 cm. The effect was significant (p<0.05) primarily near the 50-cm depth in late June, when water content at this depth averaged 20.9% for soils where straw was harvested annually, and 30.2% for soils where the straw was never harvested (control). In soils where pine straw accumulated for at least a year after being harvested, average water content was not significantly different than in control plots. The results indicate that harvesting could potentially lengthen drought-stress periods for loblolly pine during the first year after pine straw removal.