Understanding determinants of plant invasiveness: a case study on tree mallow Lavatera arborea

我们发现媒体非常热衷于报道我们在苏格兰对树锦葵的初步研究，部分原因是它对海雀的影响，海雀是一种受欢迎的保护图标。因此，我们选择从这个角度来介绍拟议的工作，将其作为一个有效的平台来接触人们，并随后告知他们拟议的关于植物入侵决定因素的研究。换句话说，下面的文字可以是一个典型的新闻稿发出启动研究。英国最著名的海鸟之一，海雀，正被一种入侵的快速生长的外来植物物种赶出苏格兰的一些海鸟岛屿殖民地。科学家们发现，高达3米的密集锦葵正在窒息海雀的繁殖地，并警告说，这种植物可能很快就会开始影响其他沿海繁殖鸟类，如鸬鹚，绒鸭，银鸥和管鼻雀。树锦葵，Lavatera arborea，一种原产于海岸的地中海植物，被认为是在种植在海岸花园后逃到苏格兰的野外。虽然在封闭的地方存在了几百年，但这种植物突然变得具有侵略性，接管了岛屿生态系统，从而抑制了地面繁殖的鸟类和原生植被。这种快速扩张的原因是温暖的冬天，具有讽刺意味的是，繁殖的海鸟数量增加，它们通过打洞和践踏来肥沃土壤并扰乱植被。海鸟栖息地中粪肥丰富、光秃秃的地方现在成了锦葵的栖息地，它们从这里逐渐侵入岛屿生态系统。这个问题不仅发生在苏格兰，澳大利亚和新西兰的岛屿也因为树锦葵接管而被挤出海鸟。尽管锦葵在部分非本土范围内是一个上级竞争对手，但它在英国西南部并没有入侵，它在那里度过了最后一个冰河时代，并与其他植物物种和谐相处。这种“杰基尔博士式”的行为变化似乎发生在许多植物中，只有当它们被引入新环境时才会表现出入侵性。理解为什么植物在一个地方可以入侵，而在另一个地方却不能，已经变得至关重要。一旦确定，入侵植物对本地植物和动物的负面影响以及控制它们的相关成本急剧上升，因此更好的策略是识别高风险物种并采取措施防止这种情况发生。不过，我们必须知道问题可能在哪里出现，以及如何出现，以便这些预防措施能够准确地针对性。阿伯丁大学的科学家们建议研究侵入性和非侵入性范围，而不是在桌子后面讨论问题。在苏格兰和康沃尔也将进行类似的实验，在这些实验中，似乎有利于锦葵生长的条件正在被模仿：鸟类的粪便将被添加进去，植被将像海鸟在繁殖地一样受到干扰。此外，一半的地点将受到保护，免受兔子和绵羊等食草动物的影响，因为它们对不耐放牧的树锦葵的胃口似乎也起着关键作用。在这两个地方，来自苏格兰和康沃尔的锦葵植物的生长将进行比较，以揭示苏格兰植物是否特别，或者锦葵生长的条件是否决定了它是否会真正变成入侵植物并导致生物多样性丧失。入侵植物是对全球生物多样性的主要威胁，据估计，全球每年的经济成本远远超过870亿美元。我们希望我们对这一单一植物物种的研究将给我们提供见解，帮助找到如何最好地限制入侵物种进一步传播的方法，以造福我们的自然环境。

We have found the media to be extremely keen to report on our initial studies on tree mallow in Scotland, partly because of its impact on puffins, a popular conservation icon. Hence, we have chosen to present the proposed work in this light, using it as an effective platform to reach people and subsequently inform them about the proposed study on determinants of plant invasiveness. In other words, the text below could be a typical press release send out upon initiating the study. One of Britain's best known seabirds, the puffin, is being forced out of a number of Scottish seabird island colonies by an invading fast-growing alien plant species. Scientists have discovered that dense stands of tree mallow, growing up to 3 metres tall, are choking puffin breeding sites and have warned that the plant could soon start affecting other coastal breeding birds such as cormorant, eider duck, herring gull and fulmar. Tree mallow, Lavatera arborea, an Atlantic-Mediterranean plant native to coasts, is believed to have escaped into the wild in Scotland after being planted in coastal gardens. Whilst present in confined places for several hundreds of years, the plant has suddenly become invasive, taking over island ecosystems and thereby suppressing ground breeding birds and native vegetation. The reasons for this rapid expansion are milder winters and, ironically, an increase in the number of breeding seabirds who fertilise the soil and disturb the vegetation through burrowing and trampling. Manure-rich, bare patches in seabird colonies are now the places where tree mallow establishes and from which they gradually invade island ecosystems. The problem occurs not only in Scotland, but islands in Australia and New Zealand are also having their seabirds squeezed out as tree mallow takes over. Despite being a superior competitor in parts of its non-native range, tree mallow is not invasive in the southwest of the UK, where it survided the last ice age and lives among other plant species in harmony. This 'Dr. Jekyl-style' change in behaviour seems to occur in many plants, with only their invasive character shown when introduced to new environments. Understanding why plants can be invasive in one place whilst not in another has become essential. Once established, the negative effects of invasive plants on native plants and animals, and the associated costs of operations to control them, rise steeply, so a better strategy is to identify high risk species and take measures to prevent this from happening. However, we need to know where and how the problems are likely to arise so that these preventative measures can be targeted precisely. Rather than discussing problems from behind a desk, scientists from the University of Aberdeen propose to study both invasive and non-invasive ranges. Parallel experiments will be set up in Scotland and Cornwall in which conditions that seem to favour tree mallow are being mimicked: guano from birds will be added, and the vegetation disturbed just like seabirds do in their breeding colonies. Moreover, half of the sites will be protected from grazers such as rabbits and sheep as their appetite for the grazing-intolerant tree mallow seems also to play a critical role. In both places, the growth of tree mallow plants from Scotland and Cornwall will be compared to reveal whether Scottish plants are something special, or whether the conditions under which tree mallow grows determines whether or not it will actually turn invasive and cause biodiversity loss. Invasive plants are a major threat to global biodiversity, and their economic costs are estimated to be far in excess of $87 billion U.S. per year worldwide. We hope that our research on this single plant species will give us insights that help finding ways how best to limit further spread of invasives, to the benefit of our natural environment.