Collaborative research: Demographic heterogeneity at landscape scales in an emergent invasive species, Centaurea stoebe, in New York State

外来入侵物种造成了巨大的经济损失，并对本地动植物产生了许多负面影响。斑点矢车菊，Centaurea stoebe，在美国西部被列为有害的入侵植物。然而，负责成功入侵的最重要的过程和因素可能发生在入侵的早期阶段。它是新的入侵和迅速增加，在纽约州，提供了一个难得的机会，研究入侵的早期阶段。这项研究将重点关注当地的小种群斑点矢车菊是如何变化的。这项研究将在长岛和阿迪朗达克公园对大量的小的、孤立的斑点矢车菊种群进行。研究人员将使用对种群及其环境的测量来构建数学模型，预测斑点矢车菊种群如何随时间变化。利用种群规模和个体植物生长、存活和繁殖的数据，研究人员将解决三个基本问题：（1）这些小的、孤立的斑点矢车菊种群中的大多数是以大约相同的速度增长的，还是许多种群实际上增长缓慢或萎缩，只有少数成功？头奖？人口增长非常迅速？(2)环境的哪些特性最有可能导致每个区域的人口增长率？(3)在决定种群是否快速扩张时，单株植物表现的哪些方面（例如，种子生产与植物存活）最重要？这些答案也将帮助科学家了解和预测其他入侵的进展。入侵是一个物种扩展到一个新的地理范围的特殊情况。这项研究将为一些关于范围扩张早期阶段的基本生态学问题提供答案，并预测植物种群如何随着气候变化而扩张或收缩。由于入侵在早期阶段最容易控制，因此本研究的结果将直接有助于负责预防，控制和管理入侵物种的土地管理人员。

Invasive non-native species create large economic losses and have many negative effects on native plants and animals. Spotted knapweed, Centaurea stoebe, is classified as a noxious invasive plant in the western U.S. Most studies of invasive species have been carried out on long-established invasions. However, the most important processes and factors responsible for successful invasions may occur during the early stages of an invasion. It is newly invasive and increasing rapidly in New York State, providing a rare opportunity to study an invasion in the early stages. This study will focus on how local, small populations of spotted knapweed are changing. The study will be conducted for a large number of small, isolated populations of spotted knapweed on Long Island and in Adirondack Park. The researchers will use measurements on the populations and their environments to construct mathematical models predicting how spotted knapweed populations may change over time. Using data on population sizes and on individual plant growth, survival and reproduction, the investigators will address three basic questions: (1) Are most of these small, isolated populations of spotted knapweed increasing at about the same rate, or are many populations actually growing slowly or shrinking, with just a few successful ?jackpot? populations growing very rapidly? (2) What properties of the environment are most likely to be responsible for population growth rates in each region? (3) What aspects of individual plant performance (for example, seed production vs. plant survival) are most important in determining whether a population is expanding quickly or not? These answers will also help scientists to understand and predict the progress of other invasions.Invasions are a special case of the expansion of a species into a new geographic range. This study will provide answers to some fundamental ecological questions about the early stages of range expansion, and also to predict how plant populations expand or contract as climates change. Because invasions are easiest to control in the early stages, the results of this study will be directly useful to land managers responsible for preventing, controlling, and managing invasive species.