Summary• It has long been believed that plant species from the tropics have higher levels of traits associated with resistance to herbivores than do species from higher latitudes. A meta-analysis recently showed that the published literature does not support this theory. However, the idea has never been tested using data gathered with consistent methods from a wide range of latitudes.• We quantified the relationship between latitude and a broad range of chemical and physical traits across 301 species from 75 sites world-wide.• Six putative resistance traits, including tannins, the concentration of lipids (an indicator of oils, waxes and resins), and leaf toughness were greater in highlatitude species. Six traits, including cyanide production and the presence of spines, were unrelated to latitude. Only ash content (an indicator of inorganic substances such as calcium oxalates and phytoliths) and the properties of species with delayed greening were higher in the tropics.• Our results do not support the hypothesis that tropical plants have higher levels of resistance traits than do plants from higher latitudes. If anything, plants have higher resistance toward the poles. The greater resistance traits of high-latitude species might be explained by the greater cost of losing a given amount of leaf tissue in low-productivity environments.

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Livestock ranching is one of the main productive activities in arid regions of the world. Grazing produces changes in animal as well as plant communities (e.g. richness, abundance and species dominance relationships). Ants are good biological indicators due to the environmental fidelity of some of their community parameters. We described the functional structure of the ant community in the central Monte of Mendoza, Argentina, and examined the effect of grazing using richness, diversity and the functional group scheme. We used pitfall traps to sample ants at a reserve with 30-year cattle exclusion and at an adjacent ranch. Eleven of the 27 recorded species showed significant differences in their abundance and two species were absent at the ranch. While richness and diversity did not reflect these differences, functional groups did. Hot Climate Specialists were more abundant at the ranch while Cryptic Species and Generalized Myrmicinae increased at the reserve. This study supports the utility of the functional group scheme to study the effects of grazing disturbance in ant communities of arid regions.

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Mountain habitats host a large number of endemic species, which are vulnerable to climate change. We studied scorpion communities of the Central Andes in Argentina at 17 sites located in Andean and extra-Andean areas between 900 and 3400 m elevation. Using pitfall traps, we collected 254 individuals from seven species, all from the Bothriuridae family. Although we expected a decrease in richness towards the high altitude sites, we did not find a clear pattern. In turn, the lowest site was the most diverse and rich; other sites had similar richness values regardless of altitude. High-altitude sites were characterized by the presence of Orobothriurus Maury 1975 species. Orobothriurus alticola (Pocock 1899) has been found exclusively on Andean sites located above 3200 m, and O. grismadoi Ojanguren-Affilastro et al. 2009 has only been found at extra-Andean sites on Cerro Nevado. Community composition showed an association with altitude, with some species exclusive to high altitude sites and others only found at lower sites. Because of the ecological importance of scorpions in arid environments, this study provides base information that may help design conservation actions for these habitats. In particular, the presence of high-altitude specialists like Orobothriurus species seems relevant, since they may be used as bioindicator species.