Invasion impacts on biodiversity: responses of ant communities to infestation by cat’s claw creeper vine, Macfadyena unguis-cati (Bignoniaceae) in subtropical Australia

Abstract

Ants are the dominant soil faunal group in many if not most terrestrial ecosystems, and play a key role in soil structure and function. This study documents the impacts of invasion by the exotic cat's claw creeper vine, Macfadyena unguis-cati (L.) Gentry (Bignoniaceae) on surface-situated (epigaeic) and subterranean (hypogaeic) ant communities in subtropical SE Queensland Australia where it is a major environmental weed of riparian areas, rainforest communities and remnant natural vegetation, smothering standing vegetation and causing canopy collapse. Soil ants were sampled in infested and uninfested areas at eight sites spanning both riparian and non-riparian habitats in subtropical SE Queensland. Patterns of ant species composition and functional grouping in response to patch invasion status, landscape type and habitat stratum were investigated using ANOVA and non-metric multidimensional scaling ordination. The epigaeic and subterranean strata supported markedly different ant assemblages, and ant communities also differed between riparian and non-riparian habitats. However, M. unguis-cati invasion had a surprisingly limited impact. There was a tendency for ant abundance and species richness to be lower in infested patches, and overall species composition was different between infested and uninfested patches, but these differences were relatively small, and did not occur consistently across sites. There were changes in functional group composition that conformed to known functional group responses to environmental change, but these were similarly limited and inconsistent across sites. Our study has shown that ant communities are surprisingly resilient to invasion by M. unguis-cati, and serves as a warning against making assumptions about invasion impacts based on visual appearances.

Coordination and plasticity in leaf anatomical traits of invasive and native vine species

“…Anredera cordifolia has no native equivalent family member in Australia; observations and previous ecophysiological work has shown some degree of similarity between these two species (see Osunkoya et al, 2010b for details). The growth habit of the six study species, including the extent of infestations and impact of the invasive species on ecosystem properties have been fully reported by Osunkoya et al (2009, 2010a, 2010b, 2011) and Perrett et al (2012).…”

Effects of the non-native amphibian species Discoglossus pictus on the recipient amphibian community: niche overlap, competition and community organization

“…The effects of invasions by non-native species are often complex, which makes their impact on a recipient community difficult to predict (Williamson 1999;Ficetola et al 2007;Osunkoya et al 2011). Several ecological interactions between non-native and native species may be involved, and their effects may be apparent to a greater or lesser degree (Kiesecker et al 2001;Blaustein and Kiesecker 2002;Kats and Ferrer 2003).…”

Germination Biology and Occurrence of Polyembryony in Two Forms of Cats Claw Creeper Vine, <i>Dolichandra unguis-cati</i> (Bignoniaceae): Implications for Its Invasiveness and Management

“…It also creates thick mats on forest floors that smother low vegetation and hamper seedling recruitment [24]. This growth pattern transforms natural habitats into monospecific stands, resulting in loss of floral biodiversity and changes in soil biota and chemistry [29] [30]. D. unguis-cati regenerates sexually, through the production of numerous papery seeds, and asexually (vegetatively) by production of subterranean tubers [24] [31].…”