Do exotic pine plantations favour the spread of invasive herbivorous mammals in Patagonia? MARÍA-VICTORIA LANTSCHNER, 1 * VERÓNICA RUSCH 1 AND JOHN P. HAYES 2 1 Grupo de Ecología Forestal, INTA EEA Bariloche, CC 277, 8400 Bariloche, Río Negro, Argentina (Email: mvlantschner@bariloche.inta.gov.ar); and 2 Department of Wildlife Ecology and Conservation, University of Florida, Gainesville 32611, Florida, USA Abstract Changes in land use patterns and vegetation can trigger ecological change in occupancy and commu- nity composition. Among the potential ecological consequences of land use change is altered susceptibility to occupancy by invasive species. We investigated the responses of three introduced mammals (red deer, Cervus elaphus; wild boar, Sus scrofa; and European hare, Lepus europaeus) to replacement of native vegetation by exotic pine plantations in the Patagonian forest-steppe ecotone using camera-trap surveys (8633 trap-days).We used logistic regression models to relate species presence with habitat variables at stand and landscape scales. Red deer and wild boar used pine plantations significantly more frequently than native vegetation. In contrast, occurrence of European hares did not differ between pine plantations and native vegetation, although hares were recorded more frequently in firebreaks than in plantations or native vegetation. Presence of red deer and wild boar was positively associated with cover of pine plantations at the landscape scale, and negatively associated with mid-storey cover and diversity at the stand scale. European hares preferred sites with low arboreal and mid-storey cover. Our results suggest that pine plantations promote increased abundances of invasive species whose original distributions are associated with woodlands (red deer and wild boar), and could act as source or pathways for invasive species to new areas. Key words: Cervus elaphus, invasion, land use change, Lepus europaeus, Sus scrofa. INTRODUCTION Transformation of landscapes by humans may facili- tate the spread of invasive species, by changing the spatial and temporal distribution of resources (Sakai et al. 2001; With 2002). In general the replacement of native vegetation by exotic conifer plantations, results in an impoverished flora and fauna (Hartley 2002; Brockerhoff et al. 2008); however, some species, including some invasives, can benefit from the habitat provided in these altered habitats (Allen et al. 1995; Odgen et al. 1997). Moreover, synergy among non- indigenous species could facilitate invasions and increase the likelihood of survival and occurrence and magnitude of ecological impact, as predicted under the invasional meltdown hypothesis (Simberloff & Von Holle 1999). Exotic forest plantations often have been found to favour invasion of exotic species, including plants (Allen et al. 1995; Chiarucci & De Dominicis 1995; Odgen et al. 1997; Hobbs et al. 2003; Ito et al. 2004; Paritsis & Aizen 2008), arthropods (Neuman 1979; Bonham et al. 2002; Pawson et al. 2008), birds (Clout & Gaze 1984; Lindenmayer et al. 2002), and mammals (Barnett et al. 1977; Lindenmayer et al. 1999). The increased abundance of exotic species in exotic forest plantations may result from increased disturbance, changes in light and soil conditions, changes in land management, and increased availability of certain resources (Bremer & Farley 2010). In Argentinean Patagonia, exotic fast-growing plan- tations have been established since the 1970s in the forest-steppe ecotone, strongly promoted by the state (Schlichter & Laclau 1998). There are approximately 80 000 ha of planted forests, mainly Pinus ponderosa, and to a lesser degree, Pseudotsuga menziesii and Pinus contora (Loguercio & Deccechis 2006; CFI- FUNDFAEP 2009). A few herbivorous mammal species also were introduced into Patagonia during the late 1800s and early 1900s, mainly for hunting (Grigera & Rapoport 1983; Jaksic et al. 2002). The most widespread species are European hare (Lepus europaeus), red deer (Cervus elaphus), and wild boar (Sus scrofa). While these species benefit local econo- mies (Novaro & Walker 2005), they may affect native ecosystems in several ways (Vázquez 2002). Through browsing, grazing and trampling, these species have altered floristic composition and stand structure in Andean rain forests and xeric woodlands (Veblen et al. 1992; Vázquez 2002).These introduced herbivores are also suggested to affect native herbivores through *Corresponding author. Accepted for publication April 2012. Austral Ecology (2012) ••, ••–•• © 2012 The Authors doi:10.1111/j.1442-9993.2012.02411.x Austral Ecology © 2012 Ecological Society of Australia