. Author manuscript; available in PMC: 2022 Sep 6.

Published in final edited form as: Manag Biol Invasion. 2020 Jul 23;11(3):607–632. doi: 10.3391/mbi.2020.11.3.17

Table 2.

“Future invaders” risk weighting factors applied to each re-scaled spatial surrogate value and used to derive invasion risk index scores based on future predicted patterns of invasion (per Davidson et al. 2017). The risk weighting factors were calculated as the proportion of species in each taxonomic group that is predicted to arrive by the specified pathway(s). When more than one pathway is indicated, the risk weighting factor is the sum of all pathways combined.

Spatial surrogates	Davidson et al. 2017 pathways	All taxa	Fish	Inverts	Plants
U.S. Population (2013)	Unauthorized intentional release (INT) Escape from recreational culture (ESC)	0.67	0.57	0.14	0.98
Shipping vessel trips to port (2004–2013)	Shipping (SH)	0.31	0.33	0.74	0.09
Marina size (# of boat slips)	Hitchhiking/Fouling (HF)	0.59	0.33	0.40	0.84
Boat launch size (# of parking spaces)	Hitchhiking/Fouling (HF)	0.59	0.33	0.40	0.84
Ponds	Unauthorized Intentional release (INT) Escape from recreational culture (ESC) Escape from commercial culture (COMM)	0.74	0.67	0.14	1.08
Canals	Dispersal (D)	0.44	0.43	0.34	0.49