Temperate Forests Of Southern South America Research Articles

Immature stages, phenology, distribution and host plants of the Andean Moon Moth Cercophana frauenfeldii Felder, 1862 (Lepidoptera: Saturniidae)

Abstract Cercophana frauenfeldii Felder (Lepidoptera: Saturniidae), also known as the “Andean Moon Moth”, is a Neotropical species native to continental Chile whose larvae feed on species of the families Gomortegaceae, Laureaceae and Winteraceae. We describe and document C. frauenfeldii immature stages, namely, egg, its four larval instars, and chaetotaxy of the last instar, pupa and cocoon for the first time. In terms of its phenology, we extend its larval activity, originally described to occur between November and mid-December, to June until the end of January. We report the adult flight period depends on the species’ distributional range following two well-differentiated patterns: February to mid-April in Central-North Chile and April to June in Central-South Chile. Furthermore, we provide a unified view of its current distributional range and host plants (including the endangered tree Gomortega keule) through bibliographic data, field observations and laboratory rearing. Finally, we discuss aspects of the species’ conservation as part of the unique ecosystems found in the temperate forests of southern South-America.

Are small abandoned plantations a threat for protected areas in Andean forests? The potential invasion of non-native cultivated species

Abandoned farms with small fruit plantations of the non-native species Prunus cerasus and Malus domestica are common in protected areas of the temperate forests of southern South America (TFSA), in Patagonia. Our aims were to determine whether an invasion of P. cerasus and M. domestica might be starting in protected areas, and whether either native or alien animal species are involved in the dispersal process. We evaluated sapling and seed spread, adult tree distribution in three habitats, and seed dispersal vectors of P. cerasus and M. domestica in “Los Alerces” National Park (Argentina). We sampled mature trees, saplings and seeds of P. cerasus and M. domesticain in two plots located next to plantations. Adult trees and mammal faeces also were searched for on roads, hiking trails, deforested areas, plots and transects opened by us. We monitored fruiting trees with cameras and we caught birds to obtain faeces. Saplings of P. cerasus were abundant and their locations were not related to adult locations, but saplings of M. domestica were rare. Ninety-two percent of P. cerasus adult trees were found in successional forest, whereas 99% of M. domestica trees were in deforested areas. Faeces of native foxes contained high number of intact seeds of both plant species studied, but we did not find any in the bird faeces. Our results indicates that P. cerasus has been invading natural habitats in protected areas of TFSA, and that foxes can be the major dispersal vectors. Further, successional forest is the most invasible habitat.

Do animal–plant interactions influence the spatial distribution of Aristotelia chilensis shrubs in temperate forests of southern South America?

Seed dispersal constrains the environmental heterogeneity to which a plant species is exposed through its life. Behavior of seed dispersers and seed predators could be influenced by food availability and vegetation cover. Consequently, recruitment probabilities are heterogeneous in space and time, and “regeneration windows” may appear. Aristotelia chilensis is the most abundant fleshy-fruited shrub in the temperate forest of southern South America (TFSA). TFSA exhibits an environmental patchiness that could influence fruit abundance and animal behavior. Our objective was to determine the regeneration windows of A. chilensis, and to detect how forest structure and animal behavior could affect the spatial distribution of this species. We characterized forest structure in two plots that included mature forest, young forest, and open areas. We assessed the spatio-temporal distribution of A. chilensis fruits and studied fruit removal by animals. Also, we experimentally evaluated germination and post-dispersal seed predation. We developed a conceptual model to relate A. chilensis recruitment with forest successional stages. The fruiting individuals of this shrub were mostly located in fire-opened areas or forest gaps, and the seed rain generated by the migratory bird Elaenia albiceps was denser in these areas. In contrast, seed predation by rodents was higher in closed, young forest areas. A. chilensis recruitment follows a nucleation dynamic around fruiting females. Concerning forest succession, A. chilensis recruitment was higher near re-sprouting females in open areas, and lowest in young forests, where fruiting process was hindered by light constraints. When forests mature, new nucleation processes start around females surviving in gaps. We conclude that areas opened by disturbances provide a regeneration window for A. chilensis shrubs.

Do leaf margins of the temperate forest flora of southern South America reflect a warmer past?

ABSTRACTAim Our aims were: (1) to characterize the linear relationship between the proportion of woody dicotyledonous species with entire‐margined leaves (E) and mean annual temperature (MAT) from a southern temperate flora that still harbours many lineages that originated under warmer climates; (2) to compare this relationship with those developed from floras of different regions of the world; and (3) to contrast temperature predictions based on leaf margins of the native southern flora versus the naturalized alien flora, mostly of boreal origin.Location The temperate forest of southern South America (TFSA).Methods At each 1° latitudinal band, we estimated E based on species latitudinal ranges and MAT from both an isotherm map and a global temperature grid. We also calculated E from five local floras located between 40 and 43° S, and from the naturalized alien flora of Nahuel Huapi National Park in southern Argentina.Results We found a close relationship between E and MAT for the TFSA. Equations developed from floras of the Northern Hemisphere overestimated extant temperatures of this biome by 6–10 °C at both geographical and local spatial scales. On the other hand, MAT predictions from leaf margins of the alien flora were similar to the actual MAT. A published regression between E and MAT from tropical South America was remarkably similar to the one we estimated from the TFSA. This tropical equation predicted accurately the temperatures observed for this temperate biome based on leaf margins of the native flora.Main conclusions Despite massive plant extinction due to environmental cooling and biogeographical isolation during the Tertiary, leaf‐margin analysis reveals that the flora of the TFSA still reflects its original development under the warmer conditions of western Gondwana and its past connections with low‐latitude forest floras of tropical South America.