Watershed and fire severity are stronger determinants of soil chemistry and microbiomes than within-watershed woody encroachment in a tallgrass prairie system
Watershed and fire severity are stronger determinants of soil chemistry and microbiomes than within-watershed woody encroachment in a tallgrass prairie system
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与高草草原系统中流域内的木质侵占相比，流域和火灾严重程度是土壤化学和微生物组的更强决定因素
DOI：
10.1093/femsec/fiab154
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发表时间：
2021
影响因子：
4.2
通讯作者：
Jumpponen, Ari
中科院分区：
文献类型：
--
作者：
Mino, Laura;Kolp, Matthew R.;Fox, Sam;Reazin, Chris;Zeglin, Lydia;Jumpponen, Ari
火灾可以通过改变非生物和生物条件来影响陆地生态系统。短的火灾间隔使草原和社区能够适应频繁的、低严重程度的火灾。灌木入侵后，较长的火灾间隔积累燃料，可以增加火灾的严重性。这种斑块状分布的生物质在燃烧-热解多样性中产生了燃烧严重程度的马赛克。提供了一个预定的燃烧的分水岭保护免受火灾27年，我们调查的影响，木质侵蚀和烧伤的严重程度对土壤化学和土壤中栖息的细菌和真菌。我们比较了火灾前和火灾后的土壤内，灌木侵蚀流域和土壤在相邻的，每年烧毁和非侵蚀流域。有机质和营养物质积累在防火流域，但响应较少的侵犯流域内的木本入侵。生物可利用的氮和磷和真菌和细菌群落对高严重度的烧伤，无论侵占。低严重性火灾对土壤养分的影响不同，增加细菌，但减少真菌的多样性和木质侵蚀的影响范围内的侵蚀流域是最小的。在防火流域的高严重度烧伤导致了一种新的土壤系统状态，不同于非侵入和侵入的土壤系统。我们的结论是，严重的火灾可能会打开草地恢复的机会，操纵土壤化学和微生物群落灌木侵占的栖息地。
Fire can impact terrestrial ecosystems by changing abiotic and biotic conditions. Short fire intervals maintain grasslands and communities adapted to frequent, low-severity fires. Shrub encroachment that follows longer fire intervals accumulates fuel and can increase fire severity. This patchily distributed biomass creates mosaics of burn severities in the landscape—pyrodiversity. Afforded by a scheduled burn of a watershed protected from fires for 27 years, we investigated effects of woody encroachment and burn severity on soil chemistry and soil-inhabiting bacteria and fungi. We compared soils before and after fire within the fire-protected, shrub-encroached watershed and soils in an adjacent, annually burned and non-encroached watershed. Organic matter and nutrients accumulated in the fire-protected watershed but responded less to woody encroachment within the encroached watershed. Bioavailable nitrogen and phosphorus and fungal and bacterial communities responded to high-severity burn regardless of encroachment. Low-severity fire effects on soil nutrients differed, increased bacterial but decreased fungal diversity and effects of woody encroachment within the encroached watershed were minimal. High-severity burns in the fire-protected watershed led to a novel soil system state distinct from non-encroached and encroached soil systems. We conclude that severe fires may open grassland restoration opportunities to manipulate soil chemistry and microbial communities in shrub-encroached habitats.