Tree heights and diameters: Wickersham fire sites (at the Viereck thaw probe locations), 1995 and 2004

In June of 1971, the Wickersham fire burned 6313 ha in an open black spruce forest underlain with permafrost and provided an opportunity to study fire and fireline effects on the rate and patterns of permafrost, soil, and vegetation recovery. When wildfire burns through a northern black spruce forest the degree of soil organic layer consumption greatly influences the post-fire community characteristics. The construction of firelines with heavy machinery involves the complete removal of vegetation and the soil organic layer down to mineral soil and likewise affects the community characteristics after fire and fire suppression. This long-term study is part of a comparison between the vegetative communities of firelines, burned, and unburned open black spruce forests underlain by ice rich permafrost. In this study, tree diameters and heights were measured in an unburned control plot and in a heavily burned plot. There were no trees to measure in the fireline plot. Tree heights and diameters at breast height were measured for tree species in the heavily burned and unburned control sites on the east side of Cushman Creek of the Wickersham Fire Sites. This dataset focuses on the trees of the east side sites (2004 and 2130) to corroborate the detailed studies of active layer depths and fireline surface level changes previously published (Viereck, 1982; also see datasets in related material section) and in preparation.1971年6月，威克舍姆大火（Wickersham fire）在以永久冻土（permafrost）为基底的开阔黑云杉林中蔓延，过火面积达6313公顷，为探究火灾与防火线（fireline）对永久冻土、土壤及植被恢复的速率与模式的影响提供了研究契机。当野火侵袭北部黑云杉林时，土壤有机层的消耗程度会显著影响火灾后的群落特征。借助重型机械修建防火线时，需将植被及土壤有机层完全移除直至矿质土壤层，这一操作同样会对火灾后及灭火后的群落特征产生影响。本长期研究旨在对比富冰永久冻土基底上的防火线区域、火烧区域与未受干扰的开阔黑云杉林的植物群落特征。本次研究在未受干扰的对照样地与重度火烧样地中测量了树木的树高与胸径（diameter at breast height），而防火线样地内无树木可供测量。 本数据集聚焦于威克舍姆火烧点（Wickersham Fire Sites）库什曼溪（Cushman Creek）东侧编号为2004与2130的样地，旨在佐证此前已发表（Viereck，1982；另见相关材料章节中的数据集）以及待发表的有关活动层（active layer）厚度与防火线地表高程变化的详细研究成果。