The effects of climate on plant species ranges are well appreciated, but the effects of other processes, such as fire, on plant species distribution are less well understood. We used a dataset of 561 plots 0.1 ha in size located throughout Yosemite National Park, in the Sierra Nevada of California, USA, to determine the joint effects of fire and climate on woody plant species. We analyzed the effect of climate (annual actual evapotranspiration [AET], climatic water deficit [Deficit]) and fire characteristics (occurrence [BURN] for all plots, fire return interval departure [FRID] for unburned plots, and severity of the most severe fire [dNBR]) on the distribution of woody plant species. Of 43 species that were present on at least two plots, 38 species occurred on five or more plots. Of those 38 species, models for the distribution of 13 species (34%) were significantly improved by including the variable for fire occurrence (BURN). Models for the distribution of 10 species (26%) were significantly improved by including FRID, and two species (5%) were improved by including dNBR. Species for which distribution models were improved by inclusion of fire variables included some of the most areally extensive woody plants. Species and ecological zones were aligned along an AET-Deficit gradient from cool and moist to hot and dry conditions. In fire-frequent ecosystems, such as those in most of western North America, species distribution models were improved by including variables related to fire. Models for changing species distributions would also be improved by considering potential changes to the fire regime.

中文翻译：

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美国优胜美地国家公园中与气候和火灾有关的木本物种分布

气候对植物种类范围的影响已广为人知，但诸如火等其他过程对植物种类分布的影响却鲜为人知。我们使用了位于美国加利福尼亚内华达山脉的优胜美地国家公园内整个优胜美地国家公园内561个样地的数据集，面积为0.1公顷，以确定火和气候对木本植物物种的共同影响。我们分析了气候（年度实际蒸散量[AET]，气候缺水[Deficit]）和火灾特征（所有地块的发生[BURN]，未燃烧地块的回火间隔偏离[FRID]）以及最严重的严重程度的影响火[dNBR]）对木本植物物种的分布。在至少两个样地中存在的43种物种中，在五个或更多个样地中存在38种。在这38种中 通过包括火灾发生变量（BURN），大大改善了13种（34％）分布的模型。通过包含FRID，可以显着改善10种（26％）的分布模型，通过包含dNBR，可以改善两种（5％）的分布模型。通过包含火灾变量改善分布模型的物种包括一些面积最大的木本植物。物种和生态区沿AET赤字梯度排列，从阴凉潮湿到干热。在频繁发生火灾的生态系统中，例如在北美西部大多数地区，通过包括与火灾有关的变量来改善物种分布模型。考虑到火灾情况的潜在变化，还将改进用于改变物种分布的模型。