Effects of Vegetation Cover, Presence of a Native Ant Species, and Human Disturbance on Colonization by Argentine Ants

Abstract

The spread of non-native invasive species is affected by human activity, vegetation cover, weather, and interaction with native species. We analyzed data from a 17-year study of the distribution of the non-native Argentine ant (Linepithema humile) and the native winter ant (Prenolepis imparis) in a preserve in northern California (U.S.A.). We conducted logistic regressions and used model selection to determine whether the following variables were associated with changes in the distribution of each species: presence of conspecifics at neighboring sites, distance to development (e.g., roads, buildings, and landscaped areas), proportion of vegetation cover taller than 0.75 m, elevation, distance to water, presence of both species at a site, temperature, and rainfall. Argentine ants colonized unoccupied sites from neighboring sites, but the probability of appearance and persistence decreased as distance to development, vegetation cover, and elevation increased. Winter ants appeared and persisted in sites with relatively high vegetation cover (i.e., highly shaded sites). Presence of the 2 species was negatively associated in sites with high vegetation cover (more winter ants) and sites near development (more Argentine ants). Probability of colonization of Argentine ants decreased where winter ants were most persistent. At sites near development within the preserve, abundant Argentine ant populations may be excluding winter ants. The high abundance of Argentine ants at these sites may be due to immigration from suburban areas outside the preserve, which are high-quality habitat for Argentine ants. In the interior of the preserve, distance from development, low-quality habitat, and interaction with winter ants may in combination exclude Argentine ants. Interactions among the variables we examined were associated with low probabilities of Argentine ant colonization in the preserve.

Climate Change May Boost the Invasion of the Asian Needle Ant

“…For example, appropriate soil moisture levels can be an important requirement for nest location of ants. Also important is the effect of disturbance regimes, because invasive ants are frequently associated with disturbed habitats [76], [77]. However, it should be noted that P. chinensis has been found to invade intact forests [36].…”

Estimating colonization and invasion risk maps for Linepithema humile, in Japan

“…Annual minimum temperature, annual total precipitation, altitude, and flow accumulation were selected as colonization-related variables. Temperature and precipitation were shown to be effective variables in previous studies of ant species, including L. humile (e.g., DiGirolamo and Fox, 2006;Menke et al, 2007;Ward, 2007;Fitzgerald and Gordon, 2012). Minimum temperature was the most effective variable for predicting the occurrence of L. humile (Menke et al, 2007;Menke et al, 2009), and total precipitation was often used as the representative variable of precipitation for SDM studies of L. humile (Roura-Pascual et al, 2004;Ward, 2007;Menke et al, 2009).…”

Habitat association and coexistence of endemic and introduced ant species in the Galápagos Islands

“…Disturbance is known to have a structuring effect on insular ant communities (Hoffmann & Andersen, 2003;Berman et al, 2013), sometimes obscuring the effects of other factors such as island size (Rizali et al, 2010). Disturbance can also facilitate the colonisation by dominant ants (Gibb & Hochuli, 2003;Fitzgerald & Gordon, 2012). Many studies show that ant communities are also influenced by a variety of other factors such as elevation, both in arid and humid ecosystems (McCoy, 1990;Sanders et al, 2003b), and vegetation cover (Achury et al, 2012).…”