Department of Life Sciences, Ben-Gurion University of the Negev, POB 653, Beer Sheva, 84105, Israel.
Department of Plant & Environmental Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel.
Mycorrhiza. 2021 Mar;31(2):203-216. doi: 10.1007/s00572-020-01010-5. Epub 2021 Jan 21.
Fire effects on ecosystems range from destruction of aboveground vegetation to direct and indirect effects on belowground microorganisms. Although variation in such effects is expected to be related to fire severity, another potentially important and poorly understood factor is the effect of fire seasonality on soil microorganisms. We carried out a large-scale field experiment examining the effects of spring (early-dry season) versus autumn (late-dry- season) burns on the community composition of soil fungi in a typical Mediterranean woodland. Although the intensity and severity of our prescribed burns were largely consistent between the two burning seasons, we detected differential fire season effects on the composition of the soil fungal community, driven by changes in the saprotrophic fungal guild. The community composition of ectomycorrhizal fungi, assayed both in pine seedling bioassays and from soil sequencing, appeared to be resilient to the variation inflicted by seasonal fires. Since changes in the soil saprotrophic fungal community can directly influence carbon emission and decomposition rates, we suggest that regardless of their intensity and severity, seasonal fires may cause changes in ecosystem functioning.
火灾对生态系统的影响范围从破坏地上植被到对地下微生物的直接和间接影响。尽管这种影响的变化预计与火灾严重程度有关，但另一个潜在重要且了解甚少的因素是火灾季节性对土壤微生物的影响。我们进行了一项大规模的野外实验，研究了春季（旱季早期）与秋季（旱季晚期）燃烧对典型地中海林地土壤真菌群落组成的影响。尽管两个燃烧季节的规定燃烧强度和严重程度在很大程度上一致，但我们发现土壤真菌群落组成存在差异，这是由腐生真菌群体的变化驱动的。外生菌根真菌的群落组成，无论是在松树苗生物测定还是从土壤测序中检测到的，似乎都能抵御季节性火灾带来的变化。由于土壤腐生真菌群落的变化会直接影响碳排放量和分解速率，因此我们认为，无论季节性火灾的强度和严重程度如何，它们都可能导致生态系统功能发生变化。
