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Nothofagus alessandrii, categorized as Endangered on the IUCN Red List, is an endemic, deciduous tree species of the coastal range of central Chile. We assessed the effects of fire severity, invasion by the exotic fire-prone Pinus radiata, and land-cover composition and configuration of the landscape on the resilience of fragments of N. alessandrii after a mega-fire in 2017. We used remote sensing data to estimate land-use classes and cover, fire severity and invasion cover of P. radiata. We monitored forest composition and structure and post-fire responses of N. alessandrii forests in situ for 2 years after the mega-fire. In the coastal Maule region wildfires have been favoured by intense drought and widespread exotic pine plantations, increasing the ability of fire-adapted invasive species to colonize native forest remnants. Over 85% of N. alessandrii forests were moderately or severely burnt. The propagation and severity of fire was probably amplified by the exotic pines located along the edges of, or inside, the N. alessandrii fragments and the highly flammable pine plantations surrounding these fragments (> 60% of land use is pine plantations). Pinus radiata, a fire-adapted pioneer species, showed strong post-fire recruitment within the N. alessandrii fragments, especially those severely burnt. Positive feedback between climate change (i.e. droughts and heat waves), wildfires and pine invasions is driving N. alessandrii forests into an undesirable and probably irreversible state (i.e. a landscape trap). A large-scale restoration programme to design a diverse and less flammable landscape is needed to avoid the loss of these highly threatened forest ecosystems.

Achieving a local understanding of fire regimes requires high-resolution, systematic and dynamic databases. High-quality information can help to transform evidence into decision-making in the context of rapidly changing landscapes, particularly considering that geographical and temporal patterns of fire regimes and their trends vary locally over time. Global fire scar products at low spatial resolutions are available, but high-resolution wildfire data, especially for developing countries, are still lacking. Taking advantage of the Google Earth Engine (GEE) big-data analysis platform, we developed a flexible workflow to reconstruct individual burned areas and derive fire severity estimates for all reported fires. We tested our approach for historical wildfires in Chile. The result is the Landscape Fire Scars Database, a detailed and dynamic database that reconstructs 8153 fires scars, representing 66.6 % of the country's officially recorded fires between 1985 and 2018. For each fire event, the database contains the following information: (i) the Landsat mosaic of pre- and post-fire images; (ii) the fire scar in binary format; (iii) the remotely sensed estimated fire indexes (the normalized burned ratio, NBR, and the relative delta normalized burn ratio, RdNBR); and two vector files indicating (iv) the fire scar perimeter and (v) the fire scar severity reclassification, respectively. The Landscape Fire Scars Database for Chile and GEE script (JavaScript) are publicly available. The framework developed for the database can be applied anywhere in the world, with the only requirement being its adaptation to local factors such as data availability, fire regimes, land cover or land cover dynamics, vegetation recovery, and cloud cover. The Landscape Fire Scars Database for Chile is publicly available in https://doi.org/10.1594/PANGAEA.941127 (Miranda et al., 2022).

The forest of Araucaria araucana (“pewen” in Mapuche language), with its associated species of the genus Nothofagus, is unique from an evolutionary, biological and sociocultural point of view. Due to the interdependence and interrelation with the Mapuche-Pewenche people, it is considered a biocultural ecosystem. This work is a comprehensive binational review of current scientific information applicable to its management and conservation. The scientific community contributed with significant advances in the knowledge of: a) the interrelationships within and significance of this biocultural ecosystem; b) the regional genetic diversity; c) the fire regimen, its main drivers, its role in forest dynamics, and the recovery capacity of biodiversity in the face of different burn severities; d) the ecological role of seed production and its unusual interactions with granivorous fauna and cavity nesters; e) the decline and death of the canopy, due to environmental stress and the emergence of new pewen pathogens; f) the consequences of the invasion of pines and exotic mammals that alter the biological interactions and the original ecological processes, and g) the effects of cattle ranching and overexploitation of firewood and pine nuts on ecological integrity and biodiversity. This knowledge is considered essential to strengthen policies and strategies for protection, conservation, and management of this ecosystem, which is endemic, rare, regionally threatened, and globally declared endangered. Considering the identified problems, it is imperative to achieve social empowerment of the Mapuche-Pehuenche people, intercultural respect, and enforcing public policies for the conservation and sustainable use of these forests., El bosque de Araucaria araucana (“pewén” en lengua Mapuche), con sus especies asociadas del género Nothofagus, es singular desde el punto de vista evolutivo, biológico y sociocultural. Por la interdependencia con el pueblo Mapuche-Pewenche, se lo considera un ecosistema biocultural. Este trabajo es una revisión integral binacional de información científica actualizada aplicable a su gestión y conservación. La comunidad científica avanzó significativamente en el conocimiento de: a) la interrelación y significancia del ecosistema biocultural; b) la diversidad genética regional; c) el régimen de incendios, sus factores determinantes, su rol en el bosque y la capacidad de recuperación de la biodiversidad frente a distintas severidades de quema; d) el rol ecológico de la producción de semillas y sus interacciones con la fauna granívora y nidificadora de cavidades; e) el decaimiento y muerte del dosel debido al estrés ambiental y al surgimiento de nuevos patógenos del pewén; f) las consecuencias de la invasión de pinos y de mamíferos exóticos que alteran las interacciones biológicas y los procesos ecológicos originales y; g) los efectos de la ganadería y la sobreexplotación de leña y piñones sobre la integridad ecológica y la biodiversidad. Este conocimiento se considera fundamental para fortalecer políticas y estrategias de protección, conservación y gestión de este ecosistema endémico, escaso, amenazado regional y globalmente declarado en peligro. Frente a las problemáticas identificadas, es imperioso lograr el empoderamiento social del pueblo Mapuche-Pehuenche, el respeto intercultural y la efectivización de las políticas públicas para la conservación y uso sustentable de este ecosistema biocultural.

Context Panicum coloratum is a relatively undomesticated small-seeded warm-season forage grass. Seed shattering, an extended reproductive period and non-synchronic seed maturation limit harvested seed yields. Low seed quantity and quality hinder pasture establishment and discourage its use. Aims To assess whether seed yield potential could be improved by breeding, we sought to measure variability in traits related to seed production including phenotypic plasticity in response to environmental cues, and estimated narrow-sense heritability, prospective genetic gain after selection and co-heritabilities in seed yield components. Methods Seed retention (SR), number of panicles (PN), seed number per panicle (SN) and seed weight (SW) were measured in plants growing in the field. Clonal replicates of 13 genotypes were assessed in 2007 and 2010 and half-sib families derived from these genotypes were measured in 2010. Key results Phenotypic variability among genotypes was related to genetic factors for all measured variables. Two broad groups of accessions showing differences in SR were studied. Phenotypic plasticity in SR differed among genotypes and was negatively related to levels of SR, implying that stable high-SR genotypes could be selected in a breeding program. Maximum narrow-sense heritabilities were 0.89 and 0.41 for SN and SR, respectively, with estimated gains after selection around 30%. The best results were achieved if selecting for SR at 3–5 weeks after anthesis. Low genetic correlations and extremely low co-heritabilities between other characters and seed yield components discourage the possibility of indirect selection. Conclusion Moderate increases in seed production potential may be achieved after selection for SN, SW and SR in P. coloratum var. makarikariense. Implications Improvements in SR and other seed yield components would facilitate harvest, increase yield and consequently increase profitability to growers and stimulate pasture adoption by farmers.

This file contains eight supplementary figures depicting the experiments validated in different cell lines and cohorts, as well as the results supportive to the main text.

Resistance to cancer treatment can be driven by epigenetic reprogramming of specific transcriptomes in favor of the refractory phenotypes. Here we discover that tamoxifen resistance in breast cancer is driven by a regulatory axis consisting of a master transcription factor, its cofactor, and an epigenetic regulator. The oncogenic histone methyltransferase EZH2 conferred tamoxifen resistance by silencing the expression of the estrogen receptor α (ERα) cofactor GREB1. In clinical specimens, induction of DNA methylation of a particular CpG-enriched region at the GREB1 promoter negatively correlated with GREB1 levels and cell sensitivity to endocrine agents. GREB1 also ensured proper cellular reactions to different ligands by recruiting distinct sets of ERα cofactors to cis-regulatory elements, which explains the contradictory biological effects of GREB1 on breast cancer cell growth in response to estrogen or antiestrogen. In refractory cells, EZH2-dependent repression of GREB1 triggered chromatin reallocation of ERα coregulators, converting the antiestrogen into an agonist. In clinical specimens from patients receiving adjuvant tamoxifen treatment, expression levels of EZH2 and GREB1 were correlated negatively, and taken together better predicted patient responses to endocrine therapy. Overall, our work suggests a new strategy to overcome endocrine resistance in metastatic breast cancer by targeting a particular epigenetic program.Significance: This study suggests a new strategy to overcome endocrine resistance in metastatic breast cancer by targeting a particular epigenetic program defined within. Cancer Res; 78(3); 671–84. ©2017 AACR.

This file contains the supplementary information including materials and methods, primer sequences, clinicopathological characteristics of patient samples and supplemental figures legends.

Forest disturbances influence Fitzroya cupressoides forest structure and carbon stocks at multiple spatial and temporal scales. Natural disturbances such as landslides and volcanism affect and give rise to the mostly pristine Fitzroya stands present in the Andean cordillera. On the other hand, mostly human-caused fires and logging have been the main processes shaping the structure of Fitzroya stands in the Coastal range and of Fitzroya small remnants in the Central depression. The main goal of this study was to assess the carbon stocks and accumulation rates of Fitzroya forest stands according to their development stage under different disturbance regimes and environmental conditions given by the three physiographic units where the species grows (Coastal range, Central depression, and Andean range). The site selection included an age sequence of stands, known as a chronosequence approach. We identified Fitzroya post-disturbance stands in three different stages of development: young forest stage (mean stand age of the main cohort ≤ 200 years old), mature forest stage (200–800 years old), and old growth forest stage (800–1,500 years old). The following biomass components were considered: living standing trees, dead standing trees (snags), and logs from dead trees laying on the ground (coarse woody debris). Old-growth Fitzroya forests reached a mean total carbon stock (standing live trees, snags, and coarse woody debris) of 507, 279, and 331 Mg C ha−1 in the Andean and Coastal ranges, and Central depression, respectively. Fitzroya cupressoides contributes, in average, more than 80% to the total carbon stock in the Andean and Coastal ranges, and 63% in the Central depression. The remainder corresponds mainly to Nothofagus spp. The high carbon stocks in old-growth stands in the Andean range are explained by Fitzroya longevity, larger size, wood decay resistance, and the low recurrence of volcanic events. Carbon accumulation rates differ between the forests in the three physiographic units (Central depression>Andean range>Coastal range), mainly due to the different growth rates and environmental conditions present in each unit. In the context of climate change, conserving old-growth stands with large biomass and carbon stocks and restoring Fitzroya forests should be recognized as a key contribution toward national and global goals to mitigate global warming.