Predatory interactions involving large carnivores and their ungulate prey are increasingly recognized as important in structuring terrestrial communities, but such interactions have seldom been studied in the temperate Neotropics. Here, the large carnivore guild is limited to a single species, the puma Puma concolor, native prey populations have been drastically reduced and lagomorphs and ungulates have been introduced. We examined puma dietary patterns under varying abundances of native camelid prey -guanacos and vicu˜nas -in protected areas of northwestern Argentina. We collected puma feces from seven protected areas, and sampled each area for the relative abundance of camelids using on-foot strip and vehicle transects. In one area, where longitudinal studies have been conducted, we examined the remains of vicu˜nas and guanacos for evidence of puma predation in [2004][2005][2006]. We compared our results with a study conducted in 1978-1983, and contrasted the frequency of carcasses showing signs of puma predation with estimates of camelid abundance. Across sites, we observed a positive and significant relationship between camelid consumption by pumas and camelid abundance, with pumas about nine times more likely to consume camelids where the latter were most abundant. The temporal variation in predation rates on camelids differed by species. Guanacos, which did not change in abundance between periods, showed a slight decrease (1.5 times) in the relative frequencies of individuals killed by pumas. Conversely, vicu˜nas increased in abundance by a factor of $7 between periods, coinciding with an c. 3.4 times increase in individuals showing evidence of puma predation. Some protected areas of northwestern Argentina are conserving the trophic interaction between pumas and native camelid prey. This interaction may be the basis of the far-reaching community effects described for analogous systems on other continents. It also has implications for the possible recovery of or reintroduction of camelids to areas with high puma densities, where predation losses can be expected to be high, and possibly prohibitive.

Smallanthus (Asteraceae, Millerieae), the “yacón” genus, comprises 23 species ranging from southeastern United States to central Argentina, with the greatest diversity in Peru and Mexico. Species of Smallanthus are herbs, shrubs or small trees with tuberous roots, opposite, trinerved or triplinerved leaves, paleate receptacle, ray corollas externally hairy at the base, pappus lacking, and marginal cypselae partially embraced by the inner phyllaries of the involucre. As a result of this revision: Smallanthus araucariophilus and S. riograndesis are considered synonyms of S. macroscyphus; lectotypes are designated for nine names; and the geographical distribution of S. latisquamus, S. lundelli, S. riparius, and S. siegesbeckia is extended. A comprehensive key to the species and detailed descriptions, geographical distribution, phenology, illustrations and distribution maps are provided for all taxa.

Lophopappus (Asteraceae, Nassauvieae) comprises five species endemic to South America. The genus is defined by its shrubby habit with unarmed branches, actinodromous or acrodromous leaf venation, solitary or few capitula at the apex of the branches with bilabiate and/or tubular-funnelform corollas, dorsally papillose style branches, and apically plumose pappus bristles. Leaf anatomy, cypsela trichomes, and pappus morphology are examined here for the first time in this genus. Lophopappus cuneatus is corroborated as a distinct species, L. berberidifolius is established as a synonym of L. tarapacanus, and a lectotype is designated for L. foliosus. A comprehensive key to the species and detailed descriptions, geographical distribution, phenology, illustrations and distribution maps are provided for all taxa.

The elaboration of a comprehensive database about the distribution of the South American genus Nassauvia has allowed investigate its conservation biogeography. The combined use of historical (Dispersal Vicariance Analysis) and ecological (UPGMA) biogeographical approaches has led to detecting past, present and future critical areas in the evolution and persistence of the genus. According to the size of distribution areas, number of locations, environmental niche models, and predicted shifts of these spatial characteristics following the Intergovernmental Panel on Climate Change forecasts for the next decade, it has been possible to award the level of global and national risk for all species of the genus and assign their corresponding IUCN categories. Severe gaps in legal and in situ conservation policies have been detected within the region, making it urgent the adoption of measures aimed at preventing the extinction of the most endangered species. We identify a future dramatic loss of Nassauvia species in the Andes and conversely a species increase in Patagonia. Patagonia has emerged as the cradle of the genus and could be its refuge in the future according the predictions targeted by climate change. Communicated by Daniel Sanchez Mata. This article belongs to the Topical Collection: Biodiversity Conservation and Reserves.

Se establece la sinonimia entre las especies Chaptalia graminifolia, C. mandonii, C.piloselloides y C. runcinata, bajo el nombre de C. piloselloides. Se presenta una re-descripción de C.piloselloides con ilustración y mapa de distribución de la especie y una clave actualizada de las especies argentinas de Chaptalia.