Asner Gregory P, Hughes R Flint, Vitousek Peter M, Knapp David E, Kennedy-Bowdoin Ty, Boardman Joseph, Martin Roberta E, Eastwood Michael, Green Robert O
Department of Global Ecology, Carnegie Institution of Washington, Stanford, CA 94305, USA.
Proc Natl Acad Sci U S A. 2008 Mar 18;105(11):4519-23. doi: 10.1073/pnas.0710811105. Epub 2008 Mar 3.
Biological invasions contribute to global environmental change, but the dynamics and consequences of most invasions are difficult to assess at regional scales. We deployed an airborne remote sensing system that mapped the location and impacts of five highly invasive plant species across 221,875 ha of Hawaiian ecosystems, identifying four distinct ways that these species transform the three-dimensional (3D) structure of native rain forests. In lowland to montane forests, three invasive tree species replace native midcanopy and understory plants, whereas one understory invader excludes native species at the ground level. A fifth invasive nitrogen-fixing tree, in combination with a midcanopy alien tree, replaces native plants at all canopy levels in lowland forests. We conclude that this diverse array of alien plant species, each representing a different growth form or functional type, is changing the fundamental 3D structure of native Hawaiian rain forests. Our work also demonstrates how an airborne mapping strategy can identify and track the spread of certain invasive plant species, determine ecological consequences of their proliferation, and provide detailed geographic information to conservation and management efforts.
生物入侵加剧了全球环境变化，但大多数入侵的动态过程和后果在区域尺度上难以评估。我们部署了一个机载遥感系统，该系统绘制了夏威夷生态系统中221,875公顷范围内五种高度入侵性植物物种的位置和影响，确定了这些物种改变原生雨林三维（3D）结构的四种不同方式。在低地到山地森林中，三种入侵树种取代了原生中层林冠和林下植物，而一种林下入侵者在地面层排挤了原生物种。第五种入侵性固氮树与一种中层林冠外来树一起，在低地森林的所有林冠层取代了原生植物。我们得出结论，这种多样的外来植物物种，每种都代表不同的生长形式或功能类型，正在改变夏威夷原生雨林的基本三维结构。我们的工作还展示了机载测绘策略如何识别和追踪某些入侵植物物种的扩散，确定其扩散的生态后果，并为保护和管理工作提供详细的地理信息。
