The discovery of a clump of broad-leaved paper-bark trees (Melaleuca quinquenervia) in 2009 by a field ranger lead to an exciting study on this global wetland invader.
Invasions of alien species begin with the human-assisted movement of living individuals or propagules across biogeographic barriers. As a result, the contributions of specific pathways to introduction and subsequent invasion—and the changes in the importance of pathways over time—are receiving increasing attention from scientists and policymakers.
Recently there have been a series of debt crises in economies around the world, from Greece to Argentina to the U.S.A. Unfortunately we also have a global biodiversity-debt crisis. These debt crises share one important feature in common—managers need to respond to the emergency.
Many invasive species provide both benefits and costs to society and the environment. These benefits include aesthetic values, but also provide resources such as timber, fuelwood, fodder and food.
Alien species cause a number of impacts in the ecosystems they live in, ranging from hardly detectable to dramatic change. Measuring such impacts is not always straightforward. Furthermore, a wide range of methods and variables has been used to describe these impacts, making comparison between species and habitats difficult.