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As Sus scrofa is an invasive species in South America, it may have a significant impact on biodiversity. Evaluating this threat requires reliable data, and population density can serve as a critical measure. However, such data is currently lacking for the southern Andes region. To address this gap, we monitored wild boar density in the Villarrica National Park, located in the Andes of south-central Chile. This study area is notable not only for its challenging climatic conditions but also for its endangered Araucaria araucana forest, which provides abundant food resources during autumn seed fall. The density calculated for the entire study period was 1.4 individuals/km 2 , with no significant variation between cold and warm seasons. The encounter rate showed strongly monthly variations. Given that this represents the first density estimate for wild boar in this region, our findings emphasize the need for continued monitoring, particularly due to the potential threat to the ecosystem and the already endangered Araucaria forest., Competing Interests: The authors declare there are no competing interests., (©2025 Skewes et al.)

In fragile ecosystems, the introduction of exotic species could alter some ecological processes. The Austral parakeet ( Enicognathus ferrugineous ) shows close ecological and evolutionary relationships with the Andean Araucaria ( Araucaria araucana ), so any alteration in these interactions may have negative consequences for both partners and for ecosystem functioning and structure. We conducted extensive roadside surveys to estimate the abundance of parakeets in the northern Patagonian Andes over 4 years and recorded the food plants consumed by foraging flocks. The use of native habitats and humanized areas like villages and farms was influenced by the Araucaria seed crop. In masting years, the large seed crop allowed a massive use of this resource during the non-breeding season, and even during the breeding season. The exploitation of exotic plants was minor in the masting year, but became predominant in non-masting years, especially during the non-breeding season. This feeding switch towards exotic plants primarily arose because the low Araucaria seed crop in non-masting years is entirely consumed just after production by domestic and wild exotic mammals living in Araucaria forests year-round, thus forcing the displacement of parakeets towards anthropic habitats to exploit exotic plants. Given the degradation of the remaining Andean Araucaria forests due to the impact of exotic mammals on the ecological interaction between Araucaria and Austral parakeets, ambitious programs to exclude or reduce the density of these alien mammals, including livestock, are warranted., Competing Interests: All authors declare no competing interests., (© 2022 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)

The extent of the Pleistocene glaciations in the Patagonian Channel region (southwesternmost South America) and their impact on the vegetation there are largely unknown. Whether the regional flora was wiped out completely (tabula rasa) or survived in ice-free pockets (in situ survival) is still an open question. The molecular imprint of either scenario should still be visible in extant populations. Therefore, DNA sequence data of Oreobolus obtusangulus Gaudich. (Cyperaceae) were analysed. This species is an abundant constituent of Patagonian cushion peat bogs, one of the Patagonian Channel region's major vegetation types. Three hundred and eighty-four individuals from 48 populations were sequenced for two chloroplast (ycf3-psaA and trnQ UUG -psbK intergenic spacers) and 14 nuclear loci containing simple sequence repeats (SSRs; microsatellites). Phylogenetic reconstructions and the geographic distribution of genetic diversity revealed that the species was split into three main lineages whose general distributions comprise three separate major regions, that is, south-central Chile, Fuego-Patagonia and the East Patagonian Andes, which probably constitute glacial refugia. Postglacial migration fronts formed a suture zone with high levels of genetic diversity in the Northwest Patagonian Andes, where remnants of a supposedly ancestral lineage were also found to be locally restricted to a single population (Huinay). The heavily glaciated Patagonian Channels were likely recolonized from the northwest, and partly from the south. Although the westernmost Patagonian Channel population (Estero Bachem) harboured private SSR alleles (singletons) and showed slightly elevated genetic diversity, it remained unclear whether this population actually survived in situ. This study helps fill a major gap in reconstructing the Pleistocene vegetation history of West and Andean Patagonia., (© 2017 John Wiley & Sons Ltd.)