Increased fire activity due to climate change may impact the successional dynamics of boreal forests, with important consequences for caribou habitat. Early successional forests have been shown to support lower quantities of caribou forage lichens, but geographic variation in, and controls on, the rates of lichen recovery has been largely unexplored. In this study, we sampled across a broad region in northwestern Canada to compare lichen biomass accumulation in ecoprovinces, including the Saskatchewan Boreal Shield, the Northwest Territories Taiga Shield, and Northwest Territories Taiga Plains, divided into North and South. We focused on the most valuable Cladonia species for boreal and barren‐ground caribou: Cladonia mitis and C. arbuscula, C. rangiferina and C. stygia, and C. stellaris and C. uncialis. We developed new allometric equations to estimate lichen biomass from field measurements of lichen cover and height; allometries were consistent among ecoprovinces, suggesting generalizability. We then used estimates of lichen biomass to quantify patterns of lichen recovery in different stand types, ecoprovinces, and with time following stand‐replacing fire. We used a hurdle model to account both for the heterogeneous nature of lichen presence (zero inflation) and for the range of abundance in stands where lichen was present. The first component of the hurdle model, a generalized linear model, identified stand age, stand type, and ecoprovince as significant predictors of lichen presence. With a logistic growth model, a measure of lichen recovery (time to 50% asymptotic value) varied from 28 to 73 yr, dependent on stand type and ecoprovince. The combined predictions of the hurdle model suggest the most rapid recovery of lichen biomass across our study region occurred in jack pine in the Boreal Shield (30 yr), while stands located in the Taiga Plains (North and South) required a longer recovery period (approximately 75 yr). These results provide a basis for estimating future caribou habitat that encompasses some of the large variation in fire effects on lichen abundance and vegetation types across the range of boreal and barren‐ground caribou in North America.

中文翻译：

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野火后陆地地衣生物量恢复的预测模式

气候变化引起的火灾活动增加可能影响北方森林的演替动态，对北美驯鹿的生境产生重要影响。早期的演替森林已显示出支持较少数量的北美驯鹿饲草地衣，但是在很大程度上尚未探索地衣的变化和对地衣恢复速度的控制。在这项研究中，我们在加拿大西北部的广大地区进行了抽样，以比较生态省（包括萨斯喀彻温省北部盾构，西北地区大河盾和西北地区大河平原）中的地衣生物量积累，该地区分为北部和南部。我们专注于北方和贫瘠的驯鹿最有价值的Cladonia物种：Cladonia mitis和C. arbuscula，C. rangiferina和C. stygia以及C. stellaris和C. uncialis。我们开发了新的异速方程，通过对地衣覆盖物和高度的野外测量来估算地衣生物量。生态省之间的同种异形是一致的，表明具有普遍性。然后，我们使用地衣生物量的估算值来量化不同林分类型，生态省以及林分替换火灾后随时间的地衣恢复模式。我们使用障碍模型来说明地衣存在的异质性（零膨胀）和存在地衣的林分的丰度范围。障碍模型的第一个组成部分是广义线性模型，该模型将林分年龄，林分类型和生态省确定为地衣存在的重要预测指标。使用逻辑生长模型，根据林分类型和生态省，地衣恢复的量度（达到50％渐近值的时间）从28岁到73岁不等。跨栏模型的综合预测表明，我们研究区域内地衣生物量的恢复最快，发生在北盾（30年）的杰克松树中，而位于大河平原（北和南）的林分需要更长的恢复时间（大约75年）。这些结果为估算未来的北美驯鹿栖息地提供了基础，其中涵盖了北美寒带和贫瘠的北美驯鹿范围内火势对地衣丰度和植被类型的一些巨大变化。