Nutrient Analysis of Antarctic Plant Tissue

With rapid glacial retreat occurring in Antarctica, more and more ice-free regions are becoming available for colonization by Antarctica’s assemblage of terrestrial plants, promoting unprecedented recent rates of Antarctic-greening. Although there have been numerous studies aimed at understanding the processes and mechanisms of soil and vegetation development following glacial retreat in high latitude montane systems, we have a limited understanding of soil and vegetative development patterns with glacial retreat in Antarctica. Further, we have virtually no understanding of the mechanisms of successional vegetative processes during glacial retreat in Antarctica nor how this associated greening will impact terrestrial ecosystem function, such as how carbon moves through the system, in this rapidly changing environment. During three field seasons from 2022-2024, we conducted intensive surveys of plant-soil interactions across succession sites, and we implemented a manipulative transplant experiment, in which we moved different plant species into soil that had never had plant growth previously. We conducted this research in the South Shetland Islands, Antarctica to determine how different Antarctic plant species affect the soil in which they grow. Using samples we collected during these field seasons, we measured plant functional traits (including nutrients, water holding capacity, morphological traits and thermal traits); soil physical properties and biogeochemistry; and soil microbial and invertebrate communities. Our results suggest that taken together, nutrient- and water-based, plant functional traits demonstrate that Antarctic plants exhibit differentiated ecological strategies that can be linked to key ecosystem processes—carbon accumulation, nutrient cycling, water regulation, and microhabitat stabilization. Additionally, our experiment shows that Antarctic plant species can significantly differentially affect soil carbon in a relatively short time span. These results have important implications with respect to how species-specific effects of plants influence soil properties, including carbon cycling, during glacial retreat. Training of graduate and undergraduate researchers was a key component of our research, and students were able to present their results at international meetings.
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随着南极冰川快速消退，越来越多无冰区域可供南极陆生植物群落定植，推动近年来南极绿化速率达到前所未有的水平。尽管已有大量研究聚焦高纬度山地系统中冰川消退后的土壤与植被发育过程及机制，但我们对南极地区冰川消退背景下的土壤及植被发育模式的认知仍十分有限。此外，在这一快速变化的环境中，我们几乎尚未明确南极冰川消退过程中的植被演替机制，也不清楚此类伴随的绿化现象将如何影响陆地生态系统功能——例如碳在生态系统中的循环路径。2022至2024年的三个野外季中，我们对演替样地内的植物-土壤相互作用开展了系统性调查，并设置了控制性移栽实验：将不同植物物种移栽至此前从未有植物生长的土壤中。本研究在南极南设得兰群岛开展，旨在明确不同南极植物物种对其生长土壤的影响机制。依托本次野外季采集的样本，我们测定了多项指标：植物功能性状（包括养分、持水能力、形态性状与热性状）、土壤物理性质及生物地球化学特征，以及土壤微生物与无脊椎动物群落组成。研究结果显示，综合基于养分与水分的植物功能性状分析表明，南极植物呈现出差异化的生态策略，且这些策略与关键生态系统过程紧密相关——包括碳固存、养分循环、水分调节与微生境稳定。此外，本实验证实，南极植物物种可在相对较短的时间内对土壤碳库产生显著的差异化影响。上述结果对于理解冰川消退过程中，植物的物种特异性效应如何影响土壤性质（包括碳循环）具有重要意义。培养研究生与本科生科研人员是本研究的核心环节之一，参与学生得以在国际学术会议上展示其研究成果。