Fine woody detritus volume and mass from line transect inventory in WS06, WS07, WS08, and WS09 at Andrews Experimental Forest, 2002 to 2003

Three small watersheds (WS06, WS07, WS08, and WS09) at the Andrews Experimental Forest were inventoried for fine woody detritus (FWD) using the line transect method as described in Guidelines for measurements of woody detritus in forest ecosystems (Harmon and Sexton 1996). In each watershed plot, four transects of 4 meters in length were inventoried. Slopes of the transect were determined as the plots were not laid out slope corrected. The number of pieces of FWD were tallied along each transect for two size classes, 0.63-2.54 cm and 2.54-7.62 cm. Volume calculations were determined by use of the formula in Harmon and Sexton 1996. Mean bulk density was determined from samples collected and measured. Field measurements used to determine density included diameter and length. In the lab, the samples were weighed to determine wet weight and dried.本研究针对安德鲁兹实验林的4个小流域（WS06、WS07、WS08及WS09），采用《森林生态系统木质残体测量指南》（Harmon与Sexton，1996）中描述的样线法（line transect method），对细木质残体（fine woody detritus, FWD）开展清查。每个流域样地内均布设4条长度为4米的样线进行调查；因样地布设未进行坡度校正，故需测定每条样线所在的坡度。沿每条样线分别统计两个径级的细木质残体件数，径级范围分别为0.63~2.54厘米与2.54~7.62厘米。材积计算采用Harmon与Sexton（1996）提出的计算公式。平均容重通过采集并实测的样品计算得到，用于测定容重的野外实测指标包括直径与长度。实验室环节中，先称量样品鲜重，随后对样品进行烘干处理。