Erosion and Compaction on a Hiking Trail in the Humid Tropics: Hawal'Iloa Ridge Trail, O'Ahu, Hawai'i

摘要

Recent increases in recreational activities throughout the U.S. have caused serious environmental degradation, particularly accelerated soil erosion. An 800 m section of a hiking trail near Honolulu was surveyed and the vegetation along the trail was characterized. A detailed, transect-oriented, systematic sampling design was used to characterize soil physical, chemical, and hydrologic properties on-trail and off-trail at 40 sites, 20 m apart. Mean bulk density, penetration resistance, and shear strength were greater on-trail, while mean soil water content, organic matter, and saturated hydraulic conductivity were lower on-trail. The robustness of these parameters as surrogates for erosion and compaction is discussed. Three anomalous on-trail sites had off-trail characteristics. Two of these sites were almost completely dominated by ironwood trees (Casuarina equisetifolia) and the remaining site by guava trees (Psidium cattleianum). The introduction of these aggressive exotics is now generally regretted; however, trail managers must consider whether some kind of resistant/resilient vegetation should be propagated on trails to prevent accelerated erosion and compaction.