Extinction risks and invasiveness in the British flora

植物是地球上生命的基础，提供多种生态系统服务。然而，关于灭绝风险的潜在生物学的科学研究正在零散地发展，而且主要集中在脊椎动物身上。迄今为止，IUCN红色名录为评估灭绝风险提供了最广泛使用和最知名的系统(1)。最初，它并没有打算设定保护优先级，但在实践中，它经常直接推动这一过程。该提案的PI最近的研究表明，在南非开普植物群中，灭绝和物种形成的过程是有联系的——似乎最脆弱的物种往往是最年轻的(2)。这项研究再次引发了关于如何最好地利用世界自然保护联盟红色名录的争论：事实上，年轻物种可能仅仅因为它们的种群还没有时间生长和传播而面临灭绝的高风险（2,3）。然而，也有可能一些植物物种从一开始就注定要灭绝。至关重要的是，萨沃莱宁和他的同事们发现，最脆弱的植物物种仍在以更快的速度走向灭绝，但令人惊讶的是，它们与人类的影响无关(2)。外来入侵植物的入侵是对生态系统的另一个主要威胁。事实上，全世界被列为“外来入侵物种”的物种多达50万种，每年造成的损失超过1万亿欧元(4)。到目前为止，还不可能预测引入的物种是否会成为入侵物种，也不清楚某些特征是否会促进入侵。PI最近在亚热带群岛（亚速尔群岛）的研究表明，当该地区没有密切相关的物种时，引入的植物物种很可能成为入侵物种(5)。利用系统发育信息，一些进化亲缘关系的测量被证明是入侵的可靠预测指标。此外，通过对不同地理尺度的分析，Savolainen及其同事认为，敌人的释放在亚速尔群岛的生物入侵中起着重要作用(5)。尽管就分类学、地理学和生态学而言，英国植物是迄今为止世界上最著名的植物之一，但令人震惊的是，它们灭绝风险的原因以及“外来分类群”（目前英国本土物种数量超过本土物种）的威胁尚未得到充分研究。我们将遵循PI在亚热带地区开发的方法，并以宿主现有的初步系统发育数据为基础，填补这一知识空白——旨在确定英国植物区系灭绝的相关因素和入侵的预测因素。毫无疑问，将英国和亚热带地区进行比较也将证明是相关的。

Plants are the basis of life on earth and provide multiple ecosystem services. However, scientific research on the underlying biology of extinction risks is developing piecemeal, and has mostly focused on vertebrates. To date, the IUCN Red List provides the most widely used and well-known system for assessing extinction risks (1). Initially, it was not intended to set conservation priorities, but in practice it often feeds directly into this process. Recent research by the PI of this proposal showed that the processes of extinction and speciation are linked in the Cape flora of South Africa - seemingly the most vulnerable species are often the youngest (2). This research revived debates about how best to employ IUCN Red Lists: indeed, young species may appear at high risk of extinction simply because their populations have not yet had time to grow and spread (2, 3). However, it is also possible that some plant species might be doomed to extinction from their very inception. Critically, Savolainen and co-workers found that the most vulnerable plant species are nonetheless marching towards extinction at a more rapid pace, but surprisingly, independently from human impact (2). Encroachment by invasive alien plants is another major source of threat to ecosystems. Indeed, up to half a million species are classified as 'invasive aliens' worldwide, causing costs of over 1 trillion euros per year (4). So far, it has not been possible to predict whether an introduced species will become invasive, and it is unclear whether certain traits promote invasiveness. Recent research by the PI in a subtropical archipelago (Azores) showed that introduced plant species are likely to become invasive when there are no closely related species in the area (5). Using phylogenetic information, some measures of evolutionary relatedness turned out to a reliable predictor of invasiveness. Also, using analyses at different geographic scales, Savolainen and co-workers argued that enemy release plays an important role in biological invasions in the Azores (5). Although British plants are by far some of the best-known anywhere in the world in terms of taxonomy, geography and ecology - astoundingly, the causes of their extinction risks as well as threats by 'alien taxa' (currently outnumbering native species in the UK) are understudied. Following methodologies developed by the PI in subtropical areas, and building on preliminary phylogenetic data available at the host, we will fill this knowledge gap - aiming to identify correlates of extinctions and predictors of invasions in the British flora. Undoubtedly comparisons between the UK and the subtropics will also prove pertinent.