While the negative effects of infrequent, high-intensity fire on soil fungal abundance are well-understood, it remains unclear how the short-term history of frequent, low-intensity fire in fire-dependent ecosystems impacts abundance, and whether this history governs any abundance declines. We used prescribed fire to experimentally alter the short-term fire history of patches within a fire-frequented old-growth pine savanna over a 3 y period. We then quantified fungal abundance before and after the final fire using phospholipid fatty acid (PLFA) assays and Droplet Digital™ PCR (ddPCR). Short-term fire history largely did not affect total fungal abundance nor pre-to post-fire abundance shifts. While producing similar conclusions, PLFA and ddPCR data were not correlated. In addition to piloting a new method to quantify soil fungal abundance, our findings indicate that, within fire-frequented pine savannas, recurrent fires do not consistently decrease total fungal abundance, and abundance changes are not contingent upon short-term fire history. This suggests that many fungi in fire-dependent ecosystems are fire-tolerant.

尽管不难理解高强度火灾对土壤真菌丰度的负面影响，但目前尚不清楚依赖火的生态系统中频繁，低强度火灾的短期历史如何影响丰度，以及这种历史是否支配着任何丰度下降。我们使用规定的火力，在3年的时间里，通过实验改变了经常着火的老松树热带稀树草原中斑块的短期着火历史。然后，我们使用磷脂脂肪酸（PLFA）测定法和Droplet Digital™PCR（ddPCR）定量了最后一道火之前和之后的真菌丰度。短期火灾史在很大程度上并未影响真菌的总丰度，也未影响火灾前至火灾后的丰度变化。尽管得出相似的结论，但PLFA和ddPCR数据没有相关性。除了试行量化土壤真菌丰度的新方法外，我们的发现表明，在火灾频发的松树大草原中，反复发生的火灾并不能持续降低真菌的总丰度，而且丰度的变化也不取决于短期的火灾史。这表明依赖火的生态系统中的许多真菌具有耐火性。