The following diagram represents model construction and the elements that go into the predictive distribution models. For a more in-depth explanation of the model process, see Ibanez et al. 2009*.

Variables used and definitions of terms:

Presence/absence data - species-specific location data collected by IPANE volunteers

Climate (both New England and Japan, the native range) - landscape-level climate variables were developed from WorldClim version 1.4 (www.worldclim.org)

• Minimum temperature of the coldest month
• Maximum temperature of the warmest month
• Annual precipitation
• Precipitation seasonality
• Precipitation of the warmest quarter

Land use characteristics - Six terrestrial cover classes developed from NOAA Land Cover Analysis

• Developed
• Mixed and deciduous forests
• Evergreen forests
• Crops
• Scrub and shrubland
• Pastures and grasslands

Habitat - IPANE-collected data on canopy closure and habitat type

Colonization probability - Since a species may not have arrived at a location, but can grow there, the colonization probability estimates how likely an area is to be colonized given the species' presence in the surrounding landscape.

Site suitability - the probability that a species can grow in a given location based on the climate, habitat, and land use variables.

Potential distribution - a probability map of the areas of New England where the species is likely to be found.

*Ibáñez, I., J. A. Silander, A. Wilson, N. LaFleur, N. Tanaka and I. Tsuyama. 2009. Multi-variate forecasts of potential distribution of invasive plant species. Ecological Applications, In press.