Compositional and functional shifts in arctic fungal communities in response to experimentally increased snow depth
Compositional and functional shifts in arctic fungal communities in response to experimentally increased snow depth
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DOI：
10.1016/j.soilbio.2016.06.001
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发表时间：
2016-09
影响因子：
9.7
通讯作者：
T. Semenova;Luis N. Morgado;J. Welker;M. Walker;E. Smets;J. Geml
中科院分区：
文献类型：
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作者：
T. Semenova;Luis N. Morgado;J. Welker;M. Walker;E. Smets;J. Geml
气候变暖导致北极海的蒸发更加强烈，导致北极低地的降水增加，例如，冬季降雪量较大。更深的积雪使北极土壤保持温暖，并改变土壤属性和植被，例如，氮供应增加，灌木扩大，不耐阴地衣和苔藓减少。土壤性质和植被的变化预计会影响腐食性和植物共生真菌，但积雪深度的增加如何影响其群落组成仍然未知。在目前的工作中，我们使用DNA元条形码研究长期的实验操作的影响，积雪深度对土壤真菌群落在干燥的健康和潮湿的草丛苔原在北极阿拉斯加。我们报告了两种苔原类型中真菌群落组成的强烈变化，在大多数真菌功能性公会中观察到明显的下降，包括外生菌根，地衣化，植物致病，腐生性和brathtrote-associated物种。观察到的变化，地衣化和bratite相关的真菌与先前公布的地上变化，即减少地衣和bratite覆盖和多样性。然而，大多数观察到的趋势，包括外生菌根真菌（预计将受益于其宿主植物的扩张）的下降，表明真菌群落的变化并不完全对应于植被的变化，也不是主要由植被的变化驱动。相反，北极真菌群落似乎表现出更快的周转，这可能受到与许多生物和非生物因素，土壤养分循环和其他土壤微生物群落动态。我们强调“地下研究”在评估生态系统对气候变化的反应方面的重要性，因为微生物群落的更快周转可能适用于监测气候变化引起的早期变化。
Climate warming leads to more intensive evaporation from the Arctic sea resulting in increased precipitation in the low Arctic, e.g., higher snowfall during winter. Deeper snow keeps the arctic soils warmer and alters soil attributes and vegetation, e.g., increase in nitrogen availability, expansion of shrubs and decline in shade-intolerant lichens and bryophytes. Changes in soil properties and vegetation are expected to influence on saprotrophic and plant-symbiotic fungi, but how increased snow depth affects their community composition remain unknown. In the present work, we used DNA metabarcoding to study the effects of long-term experimental manipulations of snow depth on soil fungal communities in dry heath and moist tussock tundra in Arctic Alaska. We report strong changes in fungal community compositions in the two tundra types, with pronounced declines observed in the majority of fungal functional guilds, including ectomycorrhizal, lichenized, plant pathogenic, saprotrophic and bryophyte-associated species. The observed changes in lichenized and bryophyte-associated fungi are in agreement with previously published above-ground changes, i.e. decrease of lichen and bryophyte cover and diversity. However, the majority of observed trends, including the decline of ectomycorrhizal fungi (that were anticipated to benefit from the expansion of their host plants), suggest that changes in fungal communities do not entirely correspond to and are not primarily driven by shifts in vegetation. Instead, arctic fungal communities appear to exhibit faster turnover that may be influenced by dynamic interactions with numerous biotic and abiotic factors, e.g., soil nutrient cycling and community dynamics in other groups of soil microorganisms. We highlight the importance of “below-ground studies” in assessing ecosystem responses to climatic changes, because faster turnover of microbial communities may be applicable for monitoring early-stage alterations caused by climatic changes.