Long-term impacts of Argentine ant invasion of urban parks in Hiroshima, Japan

Abstract

Ant communities are well suited for monitoring changes in ecosystems. Although numerous studies have examined the responses of ant communities to environmental disturbance, relatively few long-term studies on ant communities have been undertaken in urban environments. We examined species richness in nine urban parks in Hiroshima, Japan, and compared the survey results with data collected at the same sites by using the same methods in 1999. In both surveys, total of 25 species was recorded: 23 species in 1999 and 20 species in 2012. Non-metric multidimensional scaling analysis revealed that the ant communities consisted of two distinct groups, which could in turn be characterized by three patterns of ant community changes in between the two groups. The first of these community change patterns was characterized by a shift within group 1, but the number of species remained constant (approx. 10 species). The second pattern was characterized by a shift within group 2, but the number of species remained low (approx. 4 species). The third pattern was characterized by a shift from group 1 to group 2 as the abundance of Linepithema humile (Mayr) increased over time. Unlike the first and second patterns, the number of ant species in communities of the third type decreased significantly. These findings suggest that L. humile has a marked effect on the species diversity of indigenous ant communities in urban environments.

Effects of Fipronil on Non-target Ants and Other Invertebrates in a Program for Eradication of the Argentine Ant, Linepithema humile

“…competition (Holway, 1999;Human & Gordon, 1996). However, although negative associations were reported between several other ant species (i.e., F. japonica and Crematogaster matsumurai) and L. humile in previous studies (Miyake et al, 2002;Park et al, 2014), no associations were observed between them in this study. The difference in results may be due in part to seasonal or temporal factors and/or small sample sizes.…”

“…Our GLM results for each ant species indicated decreases in P. punctatus and T. tsushimae abundance. The incidence of T. tsushimae was also reported to be clearly lower where L. humile had increased over time in several parks in Japan (Park et al, 2014). Two mechanisms have been proposed to explain the displacement of indigenous ant fauna by L. humile invasion: exploitative competition and interference L. humile on other invertebrate taxonomic groups are also not universal, and various studies have reported negative, positive, or no relationship.…”

Landscape effects on pollinator abundance differ among taxonomic groups

“…Although the host species have not been identified, the larvae of St. obsoleta have been reported to be myrmecophilous and live within ant nests (Artamonov, 2012; Bharti & Bharti, 2016). It has been demonstrated that ant communities change with urbanization in Japan (Iwata et al, 2005; Park et al, 2014; Yamaguchi, 2004, 2005; Yoshimura, 2009). One possibility for the decreasing abundance of St. obsoleta in urban areas may be due to a decrease in host availability as a result of urbanization (Corcos et al, 2019).…”

Diversity of corticolous myxomycetes in the last glacial refugia of Cryptomeria japonica in Japan

“…The myxomycete community (i.e., of all 19 sites collectively) was analyzed by nonmetric multidimensional scaling (NMDS; Kenkel & Orlóci 1986), which is a method to examine the community structure and produces an ordination based on a dissimilarity matrix of communities, and is often used in the ecological analysis for community structure (e.g., Takahashi & Hada 2010, Park et al 2014. NMDS was performed using PAST software, based on Bray-Curtis dissimilarities (Bray & Curtis 1957).…”