Microbial contribution to post-fire tundra ecosystem recovery over the 21st century
Microbial contribution to post-fire tundra ecosystem recovery over the 21st century
复制标题
21世纪微生物对火灾后冻土带生态系统恢复的贡献
DOI：
10.1038/s43247-022-00356-2
复制
发表时间：
2022-02-11
影响因子：
7.9
通讯作者：
Riley, William J.
中科院分区：
文献类型：
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作者：
Bouskill, Nicholas J.;Mekonnen, Zelalem;Riley, William J.
苔原生态系统经历了火灾的频率增加，这一趋势预计将持续整个21（st）世纪。火灾后恢复的基础是驱动营养循环的微生物功能群之间的复杂相互作用。在这里，我们使用一个机械模型来证明加速氮循环后火驱动的生态位空间和微生物竞争动力学的变化。我们发现，在火灾后的第一个5年，快速增长的细菌异养菌殖民化以前被缓慢增长的腐食性真菌占据的土壤区域。细菌异养生物矿化有机物质，释放养分到土壤中。这种途径的重量超过了新的氮源，并促进了植物生产力的恢复。我们在这里广泛地表明，虽然在陆地生态系统模型中考虑与碳和养分循环相关的不同微生物代谢仍然很少见，但在考虑干扰后生态系统恢复速度和百年时间尺度上对土壤养分循环的反馈时，它们很重要。大规模苔原火灾后，细菌定殖于先前由生长较慢的真菌占据的土壤区域并通过有机物质降解增强氮循环，根据阿拉斯加Anaktuvuk河苔原火灾的机械模型。
Tundra ecosystems have experienced an increased frequency of fire, and this trend is predicted to continue throughout the 21(st) Century. Post-fire recovery is underpinned by complex interactions between microbial functional groups that drive nutrient cycling. Here we use a mechanistic model to demonstrate an acceleration of the nitrogen cycle post-fire driven by changes in niche space and microbial competitive dynamics. We show that over the first 5-years post-fire, fast-growing bacterial heterotrophs colonize regions of the soil previously occupied by slower-growing saprotrophic fungi. The bacterial heterotrophs mineralize organic matter, releasing nutrients into the soil. This pathway outweighs new sources of nitrogen and facilitates the recovery of plant productivity. We broadly show here that while consideration of distinct microbial metabolisms related to carbon and nutrient cycling remains rare in terrestrial ecosystem models, they are important when considering the rate of ecosystem recovery post-disturbance and the feedback to soil nutrient cycles on centennial timescales.Following large tundra fires, bacteria colonize soil regions previously occupied by slower-growing fungi and enhance nitrogen cycling through organic matter degradation, according to a mechanistic model of the Anaktuvuk River tundra fire in Alaska.