Abstract

Invasive alien species are among the most significant conservation threats for Antarctica, and the South Orkney Islands are highly exposed to this threat because of their location and intensity of human activity. The alien flowering plant species Poa annua is known to occur at several locations in the Antarctic Peninsula and the South Shetland Islands. Here we report the first occurrence record of P. annua observed in the natural environment on Signy Island, South Orkney Islands. This archipelago is distant from previous records of the species in Antarctica (> 1500 km), and at local scale also distant (c. 2 km) from the main concentration of human activity close to the research station on the island. During the austral summer 2017/2018 we recorded one clump of P. annua on the island, and eradicated all individuals as well as removing the associated soil. No reproductive structures were apparent on the plants, and the soil did not contain a seed bank. Molecular analyses using available sequence data in GenBank confirmed the taxonomic species identification and, at a global scale identified six different haplotypes, confirming that the Signy Island material belongs to a distinct lineage within the species. Given Signy’s northern and relatively mild location in the maritime Antarctic, likely closer to the natural climatic and environmental niche of P. annua, the island may be at high risk of invasion, meaning that monitoring and biosecurity efforts need to be enhanced and extended well beyond the immediate vicinity of the research station area.

中文翻译：

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在南极洲建立和根除外来植物物种：Signy岛的Poa annua

摘要

外来入侵物种是对南极洲最重要的保护威胁，而南奥克尼群岛由于其位置和人类活动的强度而受到高度威胁。已知外来开花植物物种Poa annua分布在南极半岛和南设得兰群岛的多个位置。在这里，我们报告在南奥克尼群岛西尼岛的自然环境中观察到的P. annua的首次出现记录。该群岛与南极洲以前的记录（> 1500 km）相距甚远，在局部范围内，也距岛上研究站附近的人类活动的主要集中点相距（约2 km）。在2017/2018南方夏季期间，我们记录了一团P. annua在岛上，消灭所有个体并清除相关土壤。在植物上没有明显的生殖结构，并且土壤没有种子库。使用GenBank中可用序列数据进行的分子分析证实了分类学物种的鉴定，并在全球范围内鉴定出六种不同的单倍型，从而证实了Signy Island物质属于该物种内的独特谱系。考虑到Signy在海洋南极的北部和相对温和的位置，可能更接近P. annua的自然气候和环境生态位，该岛可能处于高度入侵的风险，这意味着需要加强监测和生物安全工作并将其扩展到远远超过研究站区域附近。