Volume and mass of decaying logs in an upland old-growth redwood forest

Abstract

A line intersect technique was used to determine the volume and mass of dead, naturally fallen logs at least 25 cm in diameter and 4 m or more in length over an 80-ha mesic, upland old-growth redwood forest in northwestern California. Each log was identified to species and placed in one of three decay classes: sound logs, moderately decayed logs, and logs in an advanced state of decay. Only logs of redwood (Sequoiasempervirens (D. Don) Endl.), Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), and western hemlock (Tsugaheterophylla (Raf.) Sarg.) met the dimension requirements of sampling. Redwood logs in the middle decay class had the greatest volume (528 m3/ha) and mass (116 t/ha). The total volume and mass of all logs were 957 m3/ha and 200 t/ha, respectively. The total volume and mass of decaying logs in this redwood stand exceeded averages typical of other kinds of low-elevation coniferous forests in the Douglas-fir region.