697 Connecting landscape structure and patterns in body size distributions Ana I. Borthagaray, Matías Arim and Pablo A. Marquet A. I. Borthagaray (borthagaray@gmail.com), M. Arim and P. A. Marquet, Center for Advanced Studies in Ecology and Biodiversity (CASEB) and Depto de Ecología, Facultad de Ciencias Biológicas, Pontificia Univ. Católica de Chile, Casilla 114-D, Santiago CP 6513677, Chile. AIB and PAM also at: Inst. de Ecología y Biodiversidad (IEB), Casilla 653, Santiago, Chile. MA also at: Depto de Ecología y Evolución, Facultad de Ciencias, Centro Universitario Regional Este (CURE), Univ. de la República Uruguay, Iguá 4225 Piso 9 Sur, Montevideo, Uruguay and Santa Fe Inst., 1399 Hyde Park Road, Santa Fe, NM 87501, USA. Understanding the interaction between community structure and landscape structure represents a pressing theoretical challenge of great applied importance considering the increasing structural modifcation of ecosystems through habitat loss and fragmentation. Dispersal ability and energetic demands coupled to body size determine the landscape structure experienced by an organism, which could essentially be fragmented for small individuals but continuous for large ones. Although discontinuities in species assemblages have been predicted and detected, no explicit association between habitat structure and body size distributions has been demonstrated. In this contribution, we propose that body size structure in local communities should refect such diferent perceptions of landscape structure. To this end, we explore this association in a simple metacommunity located in the Atacama Desert, in northern Chile. Using graph theory we found that species of diferent size and trophic position (carnivores and herbivores) perceive the landscape at contrasting spatial scales. In each community (n  31) we determined the observed and the expected body size distributions – in a random sample from the metacommunity of 18 727 individuals –, which allowed us to identify the body sizes at which an overrepresentation or underrepresentation of individuals occur. Such aggregations and discontinuities in body sizes were related, for carni- vores, to patch location within the landscape, and to the internal banded vegetation pattern within patches for herbivores. Our study shows, for the frst time, an empirical connection between the spatial distribution of communities, their local attributes, and the existence and locations of discontinuities and aggregations in body size distributions. Landscape structure has been recognized as of great impor- tance for understanding population dynamics (Levins 1969, Hanski 1999) and community structure (MacArthur and Wilson 1967, Hubbell 2001, Holyoak et al. 2005). Te movement of individuals between patches connects local communities to the whole metacommunity, determining species incidence and communities’ diversity. In this con- text, two key components of landscape structure that could afect the dispersal of individuals and their persistence in the metacommunity are confguration and geometry (Turner et al. 2001). Confguration refers to the spatial arrangement of patches accounting for their position in relation to the dis- persal of individuals through the whole network of patches. Te relevance of this attribute in metacommunities has recently been highlighted (Urban and Keitt 2001, Economo and Keitt 2008, 2010, Minor et al. 2009). On the other hand, patch geometry refers to attributes of patches such as area, perimeter, and heterogeneity, which are known to afect community attributes such as species diversity (Ricklefs and Schluter 1993, Rozenweig 1995, Morin 1999). Interestingly, recent advances in community ecology have highlighted a main role of individual dispersal fow at the local and metacommunity scale as a determinant of patterns of distribution and abundance of species (Hubbell 2001, Keddy and Weiher 2004, Estrada and Bodin 2008, Economo and Keitt 2008, 2010). It should be noted that these theories draw attention to the role of landscape confguration, in an ecological theory essentially focused on geometric attributes. Te landscape structure experienced by one individual is essentially determined by its body size (McCann et al. 2005). Te body size of a given organism determines the maximum distance it can travel, at which speed, and the maximum time between meals (Peters 1983, McNab 2002, Brown et al. 2004). In addition, larger animals could occupy upper trophic positions (Arim et al. 2007, 2010). Carnivores of rel- ative big size have large energetic demands (McNab 2002). However, within a single patch the low efciency in resource transfer between trophic links determines a reduction in available energy, making movement between patches a req- uisite for the organism’s persistence (McCann et al. 2005, Arim et al. 2010). Tese biological attributes tied to body size have a deep efect on the perception of landscape con- fguration, which could essentially be disconnected for small Oikos 121: 697–710, 2012 doi: 10.1111/j.1600-0706.2011.19548.x © 2011 Te Authors. Oikos © 2011 Nordic Society Oikos Subject Editor: Stefano Allesina. Accepted 2 August 2011