several AIS that are current priorities for many states, the management practices that are used to 
address these species, and the role that climate change may play in the introduction, 
establishment, and spread of these species. 
A comparison of available information in the scientific literature with the 
recommendations of Section 2 reveals that more scientific, multi-stressor, long-term studies are 
necessary to understand more fully the interaction between climate change and invasive species 
and more species-specific information are needed for improved resource management. 
Section 3 outlines the information needs and research gaps in our understanding of the 
interactions between climate change and invasive species; Section 4 concludes with a discussion 
of management needs for research and information to manage AIS better in the context of a 
changing climate; the appendices focus on additional information about AIS management and an 
assessment of climate-change implications for AIS management plans. 
1.2. GLOBAL CHANGE 
Human activities have immense impact on the global environment, and these impacts will 
continue if current trends persist (IPCC, 2007; MEA, 2005; Vitousek et al., 1997a). Human- 
induced changes are currently the primary drivers of ecosystem changes (Vitousek et al., 1997b). 
Global drivers of ecosystem change can include both direct drivers (e.g., climate change, nutrient 
pollution, land conversion that changes habitats, overexploitation, and invasive species) and 
indirect drivers (e.g., demographic, economic, sociopolitical, scientific, technological, cultural, 
and religious) (Nelson, 2005). Invasive species also follow direct changes, such as invasive 
species that exploit recently disturbed habitats (Didham et al., 2005). Of the direct drivers, the 
terrestrial environment has been most affected by land conversion to other uses, often to 
agricultural use (Nelson, 2005). Overexploitation of fishing resources, pollution, and climate 
change are examples of major drivers of change in marine ecosystems (Hughes et al., 2003; 
Nelson, 2005). Primary drivers of change for freshwater ecosystems include modifications and 
use of watersheds, human contamination of water resources, altered hydrology, and invasive 
species (Vitousek, 1994; Nelson, 2005). Many assessments have recognized climate change as a 
major driver of change that will play an increasingly important role in the coming decades 
(IPCC, 2007). 
Global change as defined by the U.S. Global Change Research Act of 1990 (GCRA), 
global change “means changes in the global environment (including alterations in climate, land 
productivity, oceans or other water resources, atmospheric chemistry, and ecological systems) 
that may alter the capacity of the Earth to sustain life” (Public Law, 101-606 §2[3]). In enacting 
this law, Congress made the following findings, among others: 
1-2 
