Search Results (78)

Protected areas (PAs) constitute a fundamental strategy for mitigating biodiversity loss. The land–sparing approach has expanded in response to international agreements, but expansion of PAs does not guarantee conservation objectives. The objective was to assess PA effectiveness in conserving Nothofagus antarctica forests in Santa Cruz (Argentina), evaluating human impacts associated with fires, animal uses, and harvesting. The research was conducted within pure native forests in Santa Cruz, Argentina. This province encompasses 52 protected areas, representing the highest concentration of conservation units within the forested landscapes across Argentina. At least eight PAs included N. antarctica forests. Three land tenure categories were evaluated: protected areas (PAs), a buffer of 15 km from PA boundaries on private lands (BL), and private lands (PL) outside the buffer. In total, 103 stands were sampled, where 38 variables were assessed (impacts, soil, forest structure, understory, and animal use). Three indices were developed to analyze ecosystem integrity: forest structure (FI), soil (SI), and animal use (AI). PAs presented the highest FI (0.64 for PA, 0.44 for BL, and 0.30 for PL) and AI (0.60 for PA, 0.55 for BL, and 0.52 for PL), and together with buffer areas, the highest SI (0.43 for PA, 0.47 for BL, and 0.32 for PL). PAs were clearly distinct from private lands; however, sustained actions for livestock exclusion, harvest regulation, and fire management remain necessary for future sustainable planning at the landscape level. Full article

Silvopastoral systems in Patagonia (Argentina) aim to synergize forest and grassland productivity through thinning interventions in native forests of Antarctic beech (Nothofagus antarctica (G.Forst.) Oerst.), locally known as ñire, modifying ecosystem dynamics. This study aimed to determine how thinning strategies modify microclimatic conditions (air and soil temperatures, precipitation, soil water content) and modulate the intra-annual radial growth patterns in N. antarctica trees within subpolar deciduous forests of Tierra del Fuego, Argentina. We established three treatments: unmanaged mature forest (UF), thinning under crown cover influence (UC), and thinning outside crown cover influence (OC). Microclimate and radial growth were continuously monitored using high-precision dendrometers and associated data loggers during the 2021–2022 and 2023–2024 growing seasons. Data were analyzed using Generalized Linear Mixed Models and Principal Component Analysis. OC treatment consistently exhibited the highest total annual radial growth, averaging 1.44 mm yr⁻¹, which was substantially greater than the observed in both the UC (0.56 mm yr⁻¹) and UF (0.83 mm yr⁻¹) across the two seasons. An advanced growth dynamic, with cambial activity starting approximately five days earlier than in UF and UC, was detected. Air temperature was a primary positive driver of daily growth (GLMM Estimates > 0.029, p < 0.001 for all treatments), while soil water content (SWC) was significantly higher in OC (mean 25.4%) compared to UF (22.3%) and UC (15.9%). These findings showed that OC, characterized by higher soil moisture, likely facilitated the trees’ ability to capitalize on warm temperature days. This accelerates and extends the period of radial growth, offering a direct strategy to enhance productivity in these silvopastoral systems, essential for long-term forest sustainability. Full article

Nest predation is a major factor limiting avian reproductive success. It depends on factors such as bird community, land use, vegetation structure and landscape. Anthropogenic disturbances in native forests, such as logging and livestock grazing, alter forest structure and understory, potentially affecting nest predation rates. In this study, we analysed the susceptibility of open-cup nests to predation in Nothofagus antarctica forests in Tierra del Fuego (Argentina), comparing 15–50 years ago thinned—T and unthinned forests, the latter classified as open—O, closed—C or very closed—VC. We also identified nest predators through camera traps and the main variables influencing predation using a Generalized Lineal Model. Data were collected from 32 sites representing the four studied categories of canopy cover across two years (256 artificial nests per year). Artificial nest predation rates varied between year (9.4% in 2018 and 40.2% in 2022) and among forest types. In 2018, the O forests had the highest predation rate (50%, 12 in total), whereas in 2022, VC forests showed the greatest predation (38%, 39 in total). Camera traps identified three nest predators: Milvago chimango, Campephilus magellanicus and Xolmis pyrope. In 2018, canopy cover was the only variable that influenced artificial nest predation, while in 2022, tree sapling cover, patch shape, open-cup nester density and tree basal area were the most influential (in that order). We found annual variations driven by different ecological factors in N. antarctica forest of southern Patagonia. Although thinning showed no significant long-term effects on artificial nest predation on this study, more research is needed to understand the influence of low impact forest management in austral bird communities. Full article

Fungal communities inhabiting leaves are key players in ecosystem processes but remain largely unexplored in Southern Hemisphere temperate forests. We characterized the foliar mycobiota of Nothofagus pumilio, a dominant deciduous tree in Patagonian forests, using ITS1 metabarcoding across seasons and tree health conditions. We detected 426 fungal taxa, including a 40-Amplicon Sequence Variant (ASV) core mycobiome persisting year-round. Fungal richness and biomass increased significantly in autumn, coinciding with leaf senescence, and community composition shifted markedly between seasons. Spring leaves were enriched in pathogens and basidiomycetous yeasts, while autumn leaves hosted more saprotrophs, ascomycetous yeasts, and lichen-associated fungi. Tree health had limited influence on overall community structure, but symptomatic trees showed higher ASV richness and specific indicator taxa, including the pathogen Trichosporiella multisporum and members of the Taphrinaceae and Saccotheciaceae families. Despite taxonomic turnover, ecological guilds remained relatively stable, suggesting functional redundancy. These findings reveal a seasonal successional trajectory in the foliar mycobiota of N. pumilio, from early-colonizing endophytes in spring to diverse decomposer assemblages in autumn. This study provides the first high-throughput insight into the structure and dynamics of foliar fungal communities in Southern Hemisphere temperate forests, offering a baseline for understanding microbial roles in forest health and resilience. Full article

This study investigates how small logs from native trees, which fail to meet standard sawing criteria, can be utilized to enhance their value by producing solid wood for direct use or remanufacture rather than being relegated to biomass or fuelwood. We analyzed a sample of 177 small, discarded logs from native species from second-growth forests of Nothofagus in the Ñuble Region, Chile. The logs were scored after a qualitative and quantitative assessment for small logs, as designed in this study, and processed using a flexible sawing pattern to optimize wood recovery based on random lengths, widths, and thicknesses. Log dimensions varied, with lengths from 31 to 156.2 cm, small end diameters from 11.5 to 25.6 cm, and volumes between 0.001 and 0.092 m³. Key defects in logs included knots (95%), curvature (79%), and checks (46%), among others. A key result is the obtained general yield value of 36%, a considerable value for small-diameter, low-quality logs. The highest sawing yields were achieved with Nothofagus dombeyi (Mirb.) Oerst (42%), Geviuna avellana Molina and Persea lingue Miers ex Bertero Nees (39%), and Nothofagus obliqua (Mirb.) Oerst (34%). The quality of the boards correlates positively with the quality of the logs, and the yields with the log size and quality. The yield achieved in boards coming from such low-quality logs shows a promising possibility of improvement for this kind of process. Further development of the grading process and automation of the sawmill process could be future research steps. Full article

The pre-courtship behavior of Proholopterus chilensis on Nothofagus obliqua trees was recorded for the first time, documenting a putative female “calling” behavior and the consequent male “oriented search,” enabling the description of behavioral units, sequences, frequencies, and degrees of stereotypy. Post-resting activity in both sexes began with walking and grooming during the first hour of the scotophase, following a period of daytime inactivity. Subsequently, females extended their ovipositor both horizontally and vertically, alternating between contact with the tree substrate and, simultaneously, walking the surface (=putative calling behavior), while males became active, extending their antennae perpendicularly to the longitudinal body axis. In response to the putative call, males exhibited oriented flight and hasty walking that followed the trajectory and direction previously taken by females on the substrate, ultimately leading to their location. Statistical analysis of behavioral sequences and the stereotypy index indicated that both behaviors were non-random and partially stereotyped. These findings are consistent with previous chemical analyses of female aerations and terminalia performed by our research group, which identified semiochemicals likely functioning as long-range sex pheromones guiding males to the vicinity of the female’s tree, as well as potential trail pheromones facilitating close-range localization. This dual signaling system seems necessary to the high mobility displayed by females during calling behavior, characterized by frequent and extended bidirectional vertical walks along the trunk, which may enhance signal dispersal and/or reduce predation risk. If confirmed, this would represent a novel sexual encounter mechanism within Cerambycidae. Full article

Although treeline ecotones are significant components of vulnerable mountain ecosystems and key indicators of climate change, treelines of the Southern Hemisphere remain largely outside of research focus. In this study, we investigate, for the first time, the current and future distribution of the treeline species Nothofagus pumilio in the Southern Andes using a Species Distribution Modelling approach. The lack of modelling studies in this region can be contributed to missing occurrence data for the species. In a preliminary study, both point and raster data were generated using a novel Instagram ground truthing approach and remote sensing. Here we tested the performance of the two datasets: a typical binary species dataset consisting of occurrence points and pseudo-absence points and a continuous dataset where species occurrence was determined by supervised classification. We used a Random Forest (RF) classification and a RF regression approach. RF is applicable for both datasets, has a very good performance, handles multicollinearity and remains largely interpretable. We used bioclimatic variables from CHELSA as predictors. The two models differ in terms of variable importance and spatial prediction. While a temperature variable is the most important variable in the RF classification, the RF regression model was mainly modelled by precipitation variables. Heat deficiency is the most important limiting factor for tree growth at treelines. It is evident, however, that water availability and drought stress will play an increasingly important role for the future competitiveness of treeline species and their distribution. Modelling with binary presence–absence point data in the RF classification model led to an overprediction of the potential distribution of the species in summit regions and in glacier areas, while the RF regression model, trained with continuous raster data, led to a spatial prediction with small-scale details. The time-consuming and costly acquisition of complex species information should be accepted in order to provide better predictions and insights into the potential current and future distribution of a species. Full article

This study explores how integrating design processes into the native timber industry of southern Chile, specifically in the Araucanía and Los Ríos regions, can improve the value chain and promote sustainability. Chile’s native wood sector is constrained by fragmented value chains, underutilised small-diameter logs and limited market confidence. These challenges jeopardise forest sustainability and rural livelihoods, underscoring the imperative to find innovative solutions to reinvigorate the sector. A market gap analysis revealed critical limitations in the current industry, including low supply, limited demand, and weak technological development, especially in producing value-added wood products. The research identified over 417,000 hectares of second-growth roble (Nothofagus obliqua)-raulí (Nothofagus alpina)-coigüe (Nothofagus dombeyi) forests suitable for sustainable management. Interviews with woodworking SMEs showed that 66% already use native timber, yet 46% of the projected volume remains underutilised due to the prevalence of short and thin logs. In response to these challenges, the study developed innovative prototypes such as interior claddings and lattices made from smaller, underutilised logs. These designs were evaluated and validated for use in residential and public buildings, demonstrating their potential to meet new market demands while promoting resource efficiency. The results show that, whilst there is a clear need for better infrastructure, workforce training, and commercial planning to support product adoption, design-driven innovation offers a promising path forward enhancing the industry’s competitiveness. Demonstrating how design-led integration can transform under-used native timber into high-value products, simultaneously driving sustainable forest stewardship and local economic growth. Full article

Native forests provide forage for grazing animals. We investigated whether native and exotic vegetation promotes the potential animal load (PAL, ind ha⁻¹ yr⁻¹) for cattle (Bos taurus, ~700 kg) and sheep (Ovis aries, ~60 kg) in contrasting native forest types and canopy cover (closed, semi-open, open). This study was conducted in Chilean Patagonia (−44° to −49° SL). Vegetation cover (%) and growth habit data (trees, shrubs, forbs, graminoids, ferns, lianas, lichens, and bryophytes) were collected from 374 plots (>5 ha) in different environments: coihue (Nothofagus dombeyi, CO), lenga (N. pumilio, LE), mixed Nothofagus forests (MI), ñirre (N. antarctica, ÑI), evergreen forest (SV), and open land (OL). We combine this data with literature and laboratory analyses (e.g., crude protein, %) to develop PAL values for seasons. Data sampling was evaluated using descriptive analyses and uni- and multi-variate analyses (ANOVA, MCA, GLM). Results showed that closed forests had more native species (~56.6%) compared to open forests (~33.3%), while OL had higher cover of exotic species (~68.6%). LE presented the highest native species cover (~58.0%) and ÑI presented the highest exotic species cover (~53.0%). Closed forests had fewer exotic species than semi-open and open forests, which supported higher cover of native plants (p < 0.01). Forbs were the dominant growth habit in closed forests, while graminoids were dominant in OL (~45.8%). Multivariate analyses showed that LE and CO were associated with lower PAL values, explaining 91.2% variance. GLMs showed that the PAL increased in ÑI and the spring season, with forbs and graminoids having positive effects and shrubs and trees having negative effects (r² = 0.57–0.67). Our analyses also showed that exotic species dominated environment types with a high PAL, particularly during spring and summer, when cover increased. This indicates a trade-off between forage production in forests with exotic plants. Full article

Despite the growing recognition of sustainability in forest management, comprehensive multi-criteria evaluations of silvicultural practices remain scarce, particularly in Patagonia. In this study, we applied a multi-criteria decision analysis to evaluate the sustainability of different strip-cutting intensities in secondary Nothofagus antarctica forests in Northern Patagonia, Argentina. The performance of four management alternatives was assessed: no cutting, low cutting intensity, medium cutting intensity, and high cutting intensity. These alternatives were evaluated across 11 indicators of nature’s contributions to people. Indicator values were estimated from previous research across three contrasting sites, complemented by expert surveys to estimate weights and target values for each indicator. The results indicate that the key indicators included those associated with firewood harvesting, fire and invasions prevention, and timber species plantation performance. Medium cutting intensity consistently emerged as the most sustainable option across all sites, models, and scenarios. In contrast, no cutting performed poorly across most sites, models, and scenarios. These findings underscore the importance of integrating diverse ecological and socioeconomic indicators into forest management planning. The promotion of medium cutting intensity has the potential to enhance sustainability in N. antarctica forests, thereby contributing to the development of resilient and multifunctional landscapes in Northern Patagonia. Full article

Agroforestry contributes to slowing deforestation, favoring ecosystem regeneration and improving land use sustainability. This study evaluated the impact of silvopastoral systems on soil recovery and their capacity to sequester and stabilize carbon (C) and nitrogen (N) in degraded soils of a native Nothofagus obliqua forest in Ranchillo Alto (37°04′52″ S, 71°39′14″ W), Ñuble Region, Chile. Three open (Op), semi-open (SOp), and semi-closed (SC) silvopastoral systems were analyzed and compared with a control (Ctr) without silvopastoral management across four soil depths (0–10, 10–20, 20–30, 30–60 cm). Physical, chemical, and biological analyses were performed, along with soil physical organic matter (SOM) fractionation. The highest C levels were found in the 0–10 cm depth (13.9, 11.8, 11.5, and 8.5% for Op > SC > SOp and Ctr, respectively). Despite its higher degradation, Op presented the highest levels of C, N, and non-oxidizable C (Cnox), possibly due to pyrogenic carbon from old potato burns. Furthermore, the same trend was observed for mineral associated organic matter (MAOM) fraction and C stocks in all silvopastoral systems compared to the control. These results underline the potential of silvopastoral practices to improve soil quality and increase long-term carbon sequestration, contributing to sustainable soil restoration strategies. Full article

Cattle grazing and selective logging alter the functioning of an ecosystem, but their impacts on forest regeneration, particularly in relation to forest successional stages, are yet poorly understood. This study examined how these activities affect the regeneration of Nothofagus antarctica (ñire or ñirre) and N. pumilio (lenga) pure forests in Patagonia and whether these effects vary between old-growth and secondary forests. We assessed seedlings by origin (sexual, asexual) and height classes (<0.3 m, 0.3–0.6 m, >0.6 m) across 88 plots (25 × 20 m). Selective logging intensity was measured via the basal area of tree stumps, and cattle grazing pressure via dung counts. Forest regeneration, as predicted by human disturbances, forest successional stage, and tree density (parent trees), was modeled using generalized linear models. For N. antarctica, regeneration was exclusively asexual and showed a positive influence for selective logging and cattle, but negative with both interacting. In contrast, the most recent regeneration (R1) was predominantly influenced by the density of parent trees and successional stage. Conversely, N. pumilio regeneration, entirely sexual, was unaffected by cattle grazing, relying instead on parent tree density, logging intensity, and successional stage. These findings highlight the species-specific dynamics of regeneration under anthropogenic pressures. Understanding the interactions between natural and human disturbances is critical for conserving Nothofagus forests. Our results provide a basis for targeted restoration efforts and policies to mitigate degradation and promote ecosystem resilience. Full article

Chile holds ~50% of temperate forests in the Southern Hemisphere, thus constituting a genetic–ecological heritage. However, intense anthropogenic pressures have been inducing distinct forest structural-regeneration patterns. Accordingly, we evaluated 22 soil properties at 0–5 and 5–20 cm depths in two protected sites, with similar perturbation records but contrasting post-disturbance regeneration stages: long-term secondary forest (~50 y) (SEC_FORST) (dominated by Chusquea sp.-understory) and a short-term forest after disturbance (~5 y) (FAD_IST) within a Nothofagus spp. forest to determine the potential of these soils to promote nutrient availability, water cycling, soil organic carbon (SOC) sequestration (CO₂→SOC), and microbiome. Results detected 93 correlations (r ≥ 0.80); however, no significant differences (p < 0.05) in physical or chemical properties, except for infiltration velocity (+27.97%), penetration resistance (−23%), SOC (+5.64%), and % Al saturation (+5.64%) relative to SEC_FORST, and a consistent trend of suitable values 0–5 > 5–20 cm were estimated. The SOC→CO₂ capacity reached 4.2 ± 0.5 (FAD_IST) and 2.7 ± 0.2 Mg C y⁻¹ (SEC_FORST) and only microbial abundance shifts were observed. These findings provide relevant insights on belowground resilience, evidenced by similar ecosystem services provision capacities over time, which may be influenced progressively by opportunistic Chusquea sp. Full article

Variable retention harvesting (VRH) was designed for timber purposes and biodiversity conservation in natural forests. This system was globally tested, but few studies are related to soil microbial components. The objective was to evaluate different retention types (aggregated and dispersed retention) considering different years-after-harvesting (6, 9, 16 YAH) on soil microbial community attributes compared with unmanaged primary forests (PF) in Nothofagus pumilio forests of Tierra del Fuego (Argentina). This study also evaluated the influence of climate, soil, and understory vegetation. Results showed that aggregated retention increased microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), and soil basal respiration (SBR) compared to dispersed retention, but with similar values than PF. However, harvested areas decreased MBC/MBN values compared with PF. The results showed an overall decrease in microbial biomass and activity in 9 YAH stands, with a positive recovery at 16 YAH. Soil pH, mean annual temperature, and understory vegetation cover showed a positive relationship with MBC, MBN, and SBR. The recovery after 16 YAH reached to different microbial communities. Therefore, the maintenance of retention components in managed stands for longer periods is needed. The results highlight some advantages of VRH as a tool for conservation of forest-dwelling soil microorganisms, including microbial biomass and activity. Full article

Pilgerodendron uviferum is an endemic Cupressaceae of Patagonia (Argentina) that is restricted to a small group of individual trees, growing in isolated populations (relicts) along its distribution. The main objective was to evaluate the habitat, forest structure, leaf traits, leaf nutrient reabsorption and growth of four relicts (area between 0.3 and 0.86 ha) in the Santa Cruz province (Argentina) to improve the available information for forest conservation purposes. Principal components analysis was conducted to determine the separation between relict populations based on their ecological characteristics (individual and habitat levels). We found contrasting environmental and forest structure conditions among the four studied relicts. For example, two relicts associated with Nothofagus antarctica showed higher values of P. uviferum tree density, DBH and dominant height at the stand level. Alongside that, these relicts presented a higher sapling density (1950–3167 ind ha⁻¹) and understory plant diversity compared to pure P. uviferum relicts growing near the ecotone with the steppe grassland. Specific leaf area, carbon and nutrient concentrations in P. univerum leaves varied depending on the relict conditions and tree age of the individuals. The mean nutrient resorption efficiency varied according to relicts and particular nutrients, ranging from 18.1% to 49.5% for Ca and P, respectively. The diameter growth of the dominant P. univerum trees ranged from 0.33 to 0.46 mm yr⁻¹, indicating that the species follows a stress-tolerant strategy. The information of this work may assist in the conservation of marginal P. uviferum forest communities spatially disconnected with continuous forests, growing in relicts. Full article