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，威克瑟姆火灾（Wickersham Fire）在一片以永冻土（permafrost）为基底的开放型黑云杉林中蔓延，过火总面积达6313公顷，为探究火灾与防火隔离带（fireline）对永冻土、土壤及植被恢复速率与格局的影响提供了理想的研究场景。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后群落特征。采用重型机械修筑防火隔离带的作业流程，需将植被与土壤有机层完全移除直至矿质土壤层，该操作同样会改变火灾发生与灭火后的群落特征。本长期研究旨在对比富冰永冻土基底的防火隔离带、过火区域与未过火开放型黑云杉林的植被群落特征。本研究中，研究人员在未过火对照样地与重度过火样地内测量了树木的胸径与树高，而防火隔离带样地中无存活树木可供测量。 在威克瑟姆火灾火场的卡什曼溪（Cushman Creek）东侧样地，研究人员针对重度过火与未过火对照样地中的各树木物种，测量了其胸高位置的树高与胸径。本数据集聚焦于东侧样地（编号2004与2130）的树木观测数据，旨在验证此前已发表（Viereck, 1982；详见相关材料章节中的数据集）及待发表的关于活动层（active layer）厚度与防火隔离带地表变化的详细研究成果。