Biological invasions and the spatial ecology of genes

入侵物种是被引入其自然分布区以外的地区，随后扩散并占据原生栖息地的动植物。 由于它们是生物多样性的主要威胁，也会大大降低农业生产力，因此每年花费数十亿美元来对抗入侵者。 然而，我们不能成功地击退入侵者，直到我们有一个更好的理解是什么使一些引进的物种入侵，而其他人保持稳定。 考虑到这一目标，我将重点放在普通芦苇（芦苇）上，这是一个以芦苇床而闻名的物种，它形成于世界各地的淡水地点，包括北美和欧洲。 在这两个大陆，本土芦苇种群已经稳定了数千年，但这一切都改变了北美世纪前，当一个欧洲株的共同芦苇被引入。 这种菌株现在在北美具有入侵性，在那里种群迅速蔓延，并接管了河口，湖泊，池塘，溪流和其他栖息地，这些栖息地以前是各种物种的家园。 入侵芦苇现在是一个严重的问题，它们已被确定为加拿大自然栖息地中最具破坏性的植物之一。

Invasive species are plants and animals that are introduced to regions outside their natural range, and subsequently spread out and dominate native habitats. Because they are a major threat to biodiversity, and can also greatly reduce agricultural productivity, billions of dollars are spent each year fighting invaders. However, we cannot successfully repel invaders until we have a better understanding of just what makes some introduced species invasive while others remain stable. With this goal in mind, I am concentrating on the common reed (Phragmites australis), a species that is well known for the reed beds that it forms in freshwater sites round the world including North America and Europe. In both continents, native reed populations have been stable for thousands of years, but this all changed in North America more than a century ago when a European strain of the common reed was introduced. This strain is now invasive in North America, where populations are spreading rapidly and taking over estuaries, lakes, ponds, streams, and other habitats that were previously home to a wide range of species. Invasive reeds are now such a problem that they have been identified as one of the most destructive plants in Canadian natural habitats.