Nieves Dyonishia J, Reich Peter B, Stefanski Artur, Bermudez Raimundo, Beidler Katilyn V, Kennedy Peter G
Department of Ecology, Evolution and Behavior, University of Minnesota, St. Paul, MN, USA.
Department of Forest Resources, University of Minnesota, St. Paul, MN, USA.
Mycorrhiza. 2024 Nov;34(5-6):403-416. doi: 10.1007/s00572-024-01169-1. Epub 2024 Oct 9.
Understanding the responses of ectomycorrhizal (ECM) fungi and their tree hosts to warming and reduced soil water availability under realistic future climate scenarios is essential, yet few studies have investigated how combined global change stressors impact ECM fungal community richness and composition as well as host performance. In this study, we leveraged a long-term factorial warming (ambient, + 1.7 ºC, + 3.2 ºC) and rainfall reduction (ambient, 30% reduced rainfall) experiment in northern Minnesota, USA to investigate the responses of two congeneric hosts with varying drought tolerances and their associated ECM fungal communities to a gradient of soil moisture induced by a combination of warming and rainfall reduction. Soil drying had host-specific effects; the less drought tolerant Pinus strobus had decreased stem growth and lower ECM fungal community richness (fewer ECM fungal Operational Taxonomic Units, OTUs), while the more drought tolerant Pinus banksiana experienced no decline in stem growth but had an altered ECM fungal community composition under drier, warmer soils. Taken together, the results of this study suggest that the combined effects of warming and decreased precipitation will largely be additive in terms of their impact on host performance and ECM fungal community richness, but that drier and warmer soil conditions may also differentially impact specific ECM fungal genera independently of host performance.
了解外生菌根（ECM）真菌及其树木宿主在现实未来气候情景下对变暖和土壤水分可用性降低的反应至关重要，但很少有研究调查全球变化压力源的综合作用如何影响ECM真菌群落丰富度和组成以及宿主表现。在本研究中，我们利用美国明尼苏达州北部的一项长期因子升温（环境温度、+1.7℃、+3.2℃）和降雨减少（环境降雨、降雨减少30%）实验，来研究两种具有不同耐旱性的同属宿主及其相关的ECM真菌群落对由升温和降雨减少组合导致的土壤湿度梯度的反应。土壤干燥具有宿主特异性影响；耐旱性较差的美国白松茎生长下降，ECM真菌群落丰富度较低（ECM真菌操作分类单元较少），而耐旱性较强的班克松在更干燥、温暖的土壤条件下茎生长没有下降，但ECM真菌群落组成发生了变化。综合来看，本研究结果表明，变暖和降水减少的综合影响在对宿主表现和ECM真菌群落丰富度的影响方面在很大程度上是累加的，但更干燥和温暖的土壤条件也可能独立于宿主表现而对特定的ECM真菌属产生不同影响。
