Invasion speed is affected by geographical variation in the strength of Allee effects.
Allee effects can play a critical role in slowing or preventing the establishment of low density founder populations of non-indigenous species. Similarly, the spread of established invaders into new habitats can be influenced by the degree to which small founder populations ahead of the invasion front are suppressed through Allee effects. We develop an approach to use empirical data on the gypsy moth, a non-indigenous invader in North America, to quantify the Allee threshold across geographical regions, and we report that the strength of the Allee effect is subject to spatial and temporal variability. Moreover, we present what is to our knowledge the first empirical evidence that geographical regions with higher Allee thresholds are associated with slower speeds of invasion.
Tobin
Patrick C
PC
United States Department of Agriculture, Forest Service, Northern Research Station, 180 Canfield Street, Morgantown, WV 26505, USA. ptobin@fs.fed.us
Whitmire
Stefanie L
SL
Johnson
Derek M
DM
Bjørnstad
Ottar N
ON
Liebhold
Andrew M
AM
D000818:Animals; D003247:Conservation of Natural Resources; D005843:Geography; D008962:Models, Theoretical; D009036:Moths; D009656:North America; D010571:Pest Control; D011157:Population Dynamics