Bonanza Creek LTER Photo Monitoring

This data file represents a photo monitoring project in large reference stands at Bonanza Creek Long Term Ecological Research Site (BNZ LTER) 26 km southwest of the University of Alaska Fairbanks campus, Fairbanks, Alaska. The photo monitoring took place in six mapped and measured reference stands representing white spruce, Alaska birch, and aspen-dominated stands, with one stand in the mature or old growth condition and a comparable site that was the same forest type until a high-severity, stand-replacing crown fire in 1983, for a total of 6 initial stands. The 1983 Rosie Creek Fire was a human-caused wildfire that burned 8,600 acres including about 1/3 of the Bonanza Creek Experimental Forest. The old growth white spruce reference stand was expanded by 1.0 ha to two contiguous hectares, and the burned aspen stand by 0.25 ha to one full hectare (initial) plus an adjacent quarter-hectare. Since 1993 the second old-growth white spruce hectare and second burned aspen quarter-hectare received the full photo-monitoring protocol as the original 6 reference hectares, making a total of 8 photo stand locations.

本数据集对应位于阿拉斯加州费尔班克斯市阿拉斯加费尔班克斯大学校园西南26公里处的博南扎溪长期生态研究站（Bonanza Creek Long Term Ecological Research Site，BNZ LTER）的大型参照样地（reference stand）照片监测项目。本次照片监测覆盖6个经测绘与量测的参照样地，涵盖白云杉、阿拉斯加桦木以及以颤杨为主的林分（stand）类型；其中1个样地为成熟林或原始林状态，另有1个同林分型对照样地，该样地在1983年遭遇高强度、林分替换型冠火（crown fire）前，与前述样地林型完全一致，初始共计6个样地。1983年的罗西溪火灾（Rosie Creek Fire）是一起人为引发的野火，过火面积达8600英亩，波及博南扎溪实验林约三分之一的区域。原始白云杉参照样地的面积由1.0公顷扩展为两块相邻的公顷级样地，总面积达2公顷；受火烧的颤杨参照样地则由初始1公顷，追加0.25公顷的相邻区域，最终总面积为1.25公顷（初始样地为1公顷，附加相邻0.25公顷区域）。自1993年起，新增的第二块原始白云杉公顷级样地与第二块受火烧颤杨样地（0.25公顷）均按照初始6个参照样地的完整照片监测规程开展监测，最终共计8个照片监测样地点位。