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An analysis was made of the correspondence between species diversity and chromosome number (CN) diversity across 13 Protected Wild Areas (PWA) in the Araucanía Region of southern Chile, encompassing 84 plant species with available cytogenetic data. Our aim was to establish whether higher species diversity within a PWA entails higher CN variation as based on the index of chromosome number heterogeneity (ICNH). The CN data were extracted from databases for Chilean plants, and the ICNH for the flora of each PWA was calculated. Results showed that in nine PWA the species diversity clearly correlates with CN diversity. However, four PWA do not fit this trend. The percentage of species with CN data varied between 9.6% and 24.5% among PWA, with 11 PWA presenting percentages higher than 11%. A 27.3% of the Chilean vascular plant species with available cytogenetic data were studied here for the 13 PWA. The results obtained by studying one part of the flora with available CN data suggest that the PWA could be an important reservoir of genetic diversity at a chromosome level, thus justifying the protective role of the PWA as biodiversity conservation sites. RESUMEN Se realizó un análisis de la correspondencia entre la diversidad de especies y la diversidad de números cromosómicos (CN) en 13 Áreas Silvestres Protegidas (PWA) en la Región de La Araucanía en el sur de Chile, incluyendo 84 especies de plantas con datos citogenéticos disponibles. El objetivo fue establecer si una mayor diversidad de especies dentro de un PWA implica una mayor diversidad en CN expresado en base al Índice de Heterogeneidad Cromosómica (ICNH). Los CN de cada especie se extrajeron de bases de datos para plantas chilenas y se calculó el ICNH para la flora de cada PWA. Los resultados mostraron que en nueve PWA la diversidad de especies se correlaciona claramente con la diversidad de CN. Sin embargo, cuatro PWA no se ajustan a esta tendencia. El porcentaje de especies con datos de CN varió entre 9,6% y 24,5% entre PWA, con 11 PWA presentando porcentajes superiores al 11%. Un 27,3% de las especies de plantas vasculares chilenas con datos citogenéticos disponibles fueron estudiadas para las 13 PWA. Los resultados obtenidos al estudiar parte de la flora sugieren que las PWA serían un reservorio importante de diversidad genética a nivel cromosómico como se muestra aquí, justificando así el papel protector de las PWA como sitios de conservación de la biodiversidad.

QUESTIONS: Fire is a key factor influencing Araucaria araucana forests, but the impact of fire severity on the understorey vegetation is not well understood. In this study we seek to answer the following questions: (a) how do initial plant diversity, composition and spatial distribution of the understorey vegetation change in response to different levels of fire severity; and (b) does the abundance of dominant tree species exhibit different patterns across a fire severity gradient shortly after fire? LOCATION: Old‐growth Araucaria araucana–Nothofagus pumilio forests in the Andes of south‐central Chile (38° S, 71° W) burned in 2015. METHODS: We evaluated the post‐fire plant regeneration across a fire severity gradient ranging from unburned forests to areas of high fire severity. One year after fire (in February 2016), we measured woody and herbaceous species richness, abundance, height, origin (native vs exotic species), life forms and the spatial pattern of plant recovery. RESULTS: Plant species richness and abundance were significantly higher within the unburned forest and low fire severity areas one year after fire, compared to areas of high and moderate fire severity. Overall, nearly 50% of the species present in the unburned forest were not found in areas of high severity, including the tree Nothofagus pumilio. Rapid vegetative resprouting of pioneer species such as Chusquea culeou resulted in an aggregated spatial distribution of plants after fire. CONCLUSIONS: Plant diversity and the abundance of Araucaria araucana and Nothofagus pumilio were reduced in areas of high fire severity one year after fire. Exotic species were more abundant within areas of low severity, being likely mediated by cattle browsing. Our research makes clear the potential changes in forest composition and structure if dominant tree species are not capable of recovering after fire. We recommend the exclusion of cattle within fire‐affected areas and planting Nothofagus pumilio in areas of high fire severity.

Se caracterizó ecosistemas de referencia de acuerdo a su composición florística en dos áreas con evidentes signos de degradación; predio Pumillahue, ubicado en la comuna de Panguipulli, Región de Los Ríos y Reserva Nacional China Muerta, ubicada en la comuna de Melipeuco, Región de La Araucanía. Para tal efecto se estableció un numero variable de parcelas donde se identificó a todas las especies de plantas vasculares, se calculó su riqueza y abundancia y se realizó un análisis de ordenamiento con el fin de conocer la distribución de las áreas muestrales de acuerdo a su composición florística.

Studies on cytogenetic diversity within the Alstroemeriaceae family along its intercontinental distribution are scarce when comparing species of their four genera. This study aimed at exploring the cytogenetic diversity of the family along their geographical distribution, including species that inhabit Oceania and South America. Using quantitative and qualitative methods, we analysed 50 species of the four genera (24% of the species of the family), comparing cytogenetic characters such as chromosome number, karyotype morphology and asymmetry, location of chromosome satellites, total haploid length, meiotic behaviour, C and FISH banding, and DNA C-values. We concur with other authors in that generic delimitation based on chromosome number is clear among Alstroemeria (2n = 16) and Bomarea (2n = 18), both belonging to Alstroemerioideae. Moreover, these two genera have different chromosome numbers compared to those of Luzuriaga and Drymophila (both 2n = 20) belonging to Luzuriagoideae. The above observations were also supported by the phylogeny reconstructed here. In addition, analyses on karyotype morphology and asymmetry have determined gradual differences in nuclear architecture among genera and species. We concluded that the cytogenetic diversity described within Alstroemeriaceae is concentrated mainly in South America, which is to be expected given the higher species diversity that has been described for that continent. Although the presence of three chromosome numbers within Alstroemeriaceae has no relation with their wide geographical distribution in two continents, an appreciable variation was observed in karyotype morphology and asymmetry, total haploid length and cytomolecular features when the species were compared along their geographical range.

To test the hitherto generally-accepted hypothesis that most aquatic macrophytes have broad world distributions, we investigated the global distribution, diversity and endemism patterns of 3457 macrophyte species that occur in permanent, temporary or ephemeral inland freshwater and brackish waterbodies worldwide. At a resolution of 10 × 10° latitude x longitude, most macrophyte species were found to have narrow global distributions: 78% have ranges (measured using an approach broadly following the IUCN-defined concept “extent of occurrence”) that individually occupy T: 625 species/gridcell, 350 of them Neotropical endemics). In contrast, the Sahara/Arabian Deserts, and some Arctic areas, have the lowest macrophyte α-diversity (ST 5-fold difference between the most species-rich (Neotropics) and species-poor (Palaearctic) ecozones. Our findings strongly support the assertion that small-ranged species constitute most of Earth's species diversity.

Impacts of fragmentation on floristic composition of swamp forests in south-central Chile. The swamp forests of south-central Chile have been greatly altered by the fragmentation of the landscape, which is mainly derived from anthropogenic activities. Despite their high ecological and conservation value for the biodiversity, these ecosystems have been scarcely studied. The main goal of this study was to evaluate the richness of vascular plants in different fragments of swamp forests in the Araucania region (38° S, Chile). A total of 11 fragments were studied, in which edge and core zones were defined. Floristic transects were established, and we recorded and identified all species of vascular plants. Differences in the floristic composition between the edge and the core zones were determined, and we performed a GLM to model the response of species richness according to the area of the fragments and the geographical origin of the plants. A total of 123 species of plants were found across all fragments, of which 76 were native and 47 were non-native species. The floristic composition differs significantly between edge and core zones, and the GLM revealed that species richness is influenced by the area of the fragments and the geographical origin of the plants. Our study concludes that the size of the fragments, as well as by the characteristics of the surrounding matrix are fundamental variables that influence the floristic composition of swamp forests in south-central Chile.