Department of Biology, Fort Lewis College, Durango, Colorado, USA.
School of Forestry, Northern Arizona University, Flagstaff, Arizona, USA.
Glob Chang Biol. 2022 Nov;28(21):6280-6292. doi: 10.1111/gcb.16369. Epub 2022 Aug 29.
Climate change is altering temperature and precipitation, resulting in widespread plant mortality and shifts in plant distributions. Plants growing in soil types with low water holding capacity may experience intensified effects of reduced water availability as a result of climate change. Furthermore, complex biotic interactions between plants and soil organisms may mitigate or exacerbate the effects of climate change. This 3-year field experiment observed the performance of Bouteloua gracilis ecotypes that were transplanted across an environmental gradient with either sympatric soil from the seed source location or allopatric soil from the location that plants were transplanted into. We also inoculated plants with either sympatric or allopatric soil biotic communities to test: (1) how changes in climate alone influence plant growth, (2) how soil types interact with climate to influence plant growth, and (3) the role of soil biota in mitigating plant migration to novel environments. As expected, plants moved to cooler-wetter sites exhibited enhanced growth; however, plants moved to warmer-drier sites responded variably depending on the provenance of their soil and inoculum. Soil and inoculum provenance had little influence on the performance of plants moved to cooler-wetter sites, but at warmer-drier sites they were important predictors of plant biomass, seed set, and specific leaf area. Specifically, transplants inoculated with their sympatric soil biota and grown in their sympatric soil were as large as or larger than reference plants grown at the seed source locations; however, individuals inoculated with allopatric soil biota were smaller than reference site individuals at warmer, drier sites. These findings demonstrate complicated plant responses to various aspects of environmental novelty where communities of soil organisms may help ameliorate stress. The belowground microbiome of plants should be considered to predict the responses of vegetation more accurately to climate change.
气候变化正在改变温度和降水，导致广泛的植物死亡和植物分布的变化。生长在保水能力低的土壤类型中的植物可能会因气候变化而经历更严重的水分供应减少的影响。此外，植物和土壤生物之间复杂的生物相互作用可能会减轻或加剧气候变化的影响。这项为期 3 年的野外实验观察了横跨环境梯度的 Bouteloua gracilis 生态型的表现，这些生态型是用来自种子源位置的同域土壤或植物被移植到的位置的异域土壤进行移植的。我们还将植物接种同域或异域土壤生物群落，以测试：（1）仅气候变化如何影响植物生长，（2）土壤类型如何与气候相互作用影响植物生长，以及（3）土壤生物群落在缓解植物向新环境迁移中的作用。正如预期的那样，移到更凉爽、更潮湿的地点的植物表现出更强的生长；然而，移到更温暖、更干燥的地点的植物的反应则因土壤和接种物的来源而异。土壤和接种物的来源对移到更凉爽、更潮湿的地点的植物的表现几乎没有影响，但在更温暖、更干燥的地点，它们是植物生物量、种子产量和比叶面积的重要预测因子。具体而言，用同域土壤生物群接种并在同域土壤中生长的移植物与在种子源位置生长的参考植物一样大或更大；然而，在温暖、干燥的地点，用异域土壤生物群接种的个体比参考地点的个体小。这些发现表明，植物对环境新奇的各个方面的反应复杂，土壤生物群落可能有助于缓解压力。应该考虑植物的地下微生物组，以更准确地预测植被对气候变化的反应。
