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，对本土动植物造成了诸多负面影响。矢车菊是美国西部的一种有毒入侵植物，对入侵物种的研究大多是在长期入侵的基础上进行的。然而，导致入侵成功的最重要的过程和因素可能发生在入侵的早期阶段。它是一种新的侵袭性疾病，在纽约州迅速增加，这为在早期阶段研究入侵提供了难得的机会。这项研究将集中在当地小种群的斑点浮萍是如何变化的。这项研究将在长岛和阿迪朗达克公园的大量小的、孤立的斑点颠茄种群中进行。研究人员将使用对种群及其环境的测量来构建数学模型，预测斑点浮萍种群如何随着时间的推移而变化。使用关于种群大小和个体植物生长、存活和繁殖的数据，研究人员将回答三个基本问题：(1)大多数这些孤立的小种群是否以大致相同的速度增长，或者许多种群实际上增长缓慢或萎缩，只有少数成功的“头奖”种群增长非常迅速？(2)环境的哪些特性最有可能对每个地区的种群增长率负责？(3)在决定种群是否快速扩张方面，个体植物表现的哪些方面(例如种子生产和植物生存)是最重要的？这些答案还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例。这项研究将提供一些关于范围扩大的早期阶段的基本生态学问题的答案，并预测植物种群如何随着气候变化而扩大或收缩。因为入侵在早期阶段是最容易控制的，所以这项研究的结果将直接对负责预防、控制和管理入侵物种的土地管理者有用。

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.