Data from: Ecological legacies of anthropogenic burning in a British Columbia coastal temperate rain forest

Aim
Few long-term fire histories have been reconstructed in coastal temperate rain forests, and little is known regarding the spatial and temporal characteristics of lightning and human ignitions. We use a multidisciplinary approach to assess the impact, scale and ecological legacies of historic fires.
Location
We focus on perhumid temperate rain forests located on the central coast of British Columbia, Canada.
Methods
We reconstructed 700 years of temporal and spatial aspects of fire activity with 30 plots on Hecate Island using fire scars and forest-stand establishment. We then conducted a paired study of 20 former indigenous habitation and control sites on 15 islands to relate fire activity to patterns of human settlement. We mapped 15 years of lightning strike densities and use mixed-effects modelling to assess whether fire activity predicted the distribution and abundance of traditional plants.
Results
Sixteen low- and mixed-severity fires were recorded from 1376 to 1893. The abundance of traditional plants and the density of western redcedar trees were best predicted by the location of former habitation sites and shorter mean fire intervals. Lightning is too rare to explain the pattern of fire activity in the study area. No fire activity was detected after 1893, coinciding with the relocation of indigenous groups from the study area.
Main conclusions
Fire was strongly associated with former indigenous habitation sites during the periods of occupation. People likely utilized fire as a tool for resource management to influence the densities of specific plants by creating mosaics of vegetation in different stages of succession. By assessing the ecological impacts of historic fire events, we gain a better understanding of the abrupt changes that occurred in the 20th century. Our ability to understand present-day temperate rain forest ecosystems may be compromised if we underestimate the role of humans in driving historic fire activity.

研究目的：迄今针对海岸温带雨林的长期火灾历史重建研究较为匮乏，学界对雷击火源与人类火源的时空特征亦知之甚少。本研究采用多学科研究方法，旨在评估历史火灾的影响、波及范围及生态遗留效应。
研究区域：本研究聚焦于加拿大不列颠哥伦比亚省（British Columbia）中部沿岸的极湿润温带雨林。
研究方法：本研究依托赫卡特岛（Hecate Island）上的30个样地，通过火灾疤痕与林分建立记录，重建了700年的火灾活动时空序列。随后，在15座岛屿上设置20处原住民居址与对照样地的配对研究，以分析火灾活动与人类定居模式的关联。此外，本研究绘制了15年间的雷击密度分布图，并采用混合效应模型（mixed-effects modelling）评估火灾活动是否能够预测传统植物的分布与丰度。
研究结果：1376年至1893年间，共记录到16起低烈度与混合烈度火灾。传统植物丰度与西部红杉（western redcedar）种群密度的最佳预测因子为原住民居址位置与更短的平均火灾间隔期。雷击发生频率极低，不足以解释研究区域内的火灾活动格局。1893年后未检测到任何火灾活动，这与原住民群体从研究区域外迁的时间相吻合。
主要结论：在原住民定居时期，火灾活动与原住民居址存在显著关联。人类或曾将火作为资源管理工具，通过营造不同演替阶段的植被镶嵌体，调控特定植物的种群密度。通过评估历史火灾事件的生态影响，本研究可更好地理解20世纪发生的生态突变。若低估人类在历史火灾活动中的驱动作用，我们对当前温带雨林生态系统的认知或存在偏差。