South-central Chile Research Articles

Cenozoic Basin Evolution During Alternating Extension and Shortening in the Southern Central Andes Along the Chile-Argentina Border, 37–38°S

The south-central Chile and Argentina margin experienced a regional phase of extensional tectonics during the Oligocene–early Miocene, forming several basins across the forearc, Andean Cordillera, and retroarc regions. These basins accumulated thick successions of volcanic and sedimentary rocks. Subsequently, Neogene contractional tectonics led to the development of the current Andean Cordillera and the deposition of synorogenic clastic deposits in foreland basins. Traditionally, the Cura Mallín Formation, comprising a lower volcanic unit (CMV) and an upper sedimentary unit (CMS), has been interpreted to have formed during the Oligocene–early Miocene extensional phase. However, some studies propose deposition of the CMS in a foreland basin during the early–late Miocene. To unravel the transition from extensional to contractional tectonics in the Andes of south-central Chile and Argentina, we conducted new geochronological analyses (U-Pb, LA-ICP-MS) and integrated these results with structural, stratigraphic, and sedimentological observations in key sections within the CMS and the overlying Trapa-Trapa Formation in the Principal Cordillera along the Chile-Argentina border (37°–38°S). Our findings indicate that only the lower part of the CMS was deposited in an extensional setting, as evidenced by the presence of an inverted extensional wedge dated at ∼20 Ma. The middle-upper CMS (∼19 to 9 Ma) and contemporaneous units to the east exhibit evidence of syncontractional deformation, suggesting deposition in a foreland basin generated by shortening of the western Principal Cordillera. Around 9 Ma, uplift of the Agrio and Chos Malal fold and thrust belts, east of the Principal Cordillera, led to segmentation of the foreland basin. The Trapa Trapa Formation was deposited in a hinterland basin, with sediment sourced from the east. After ∼6.5 Ma, major contractional deformation shifted westward, resulting in intense folding of the CMS and Trapa Trapa Formation and subsequent thrusting of the western Principal Cordillera over the Central Depression. Our study suggests that deformation progressed toward the eastern foreland during the early to late Miocene and then shifted toward the western forearc during the late Miocene to Pleistocene.

Moderate-severity silvicultural methods generate better forest reorganization than other silvicultural methods in temperate rainforests four decades after implementation

Silvicultural regeneration methods promote regeneration of new tree cohorts following the harvest of mature trees and include a gradient of options from cutting all (clearcuts) or some (selection cuts) trees resulting in even- or uneven-aged forests. For forest managers and landowners, it is essential to have the best possible information on how forests reorganize following these different methods. Forest development, composition and growth are dependent on site quality and harvest type. In this study we evaluated two even-aged (clearcut (CC), seed-tree cut (STC)), one two-aged cut (extended irregular shelterwood (ISC)), one uneven-aged (single-tree selection cut (SC)), and an unmanaged control (CON), four decades after harvest implementation in old-growth Evergreen temperate rainforests above 500 m a.s.l. in the Coastal Range of south-central Chile. These forests grow on poor-quality sites due to old and shallow soil conditions and were dominated by late-successional species and a thick understory with the bamboo Chusquea machrostachya at the time of harvest implementation. Compositional and structural conditions reflected the type of harvests, with even- and two-aged methods largely similar to one another and the SC and the OG having very similar characteristics, which is likely a consequence of the very light severity of the SC. Tree species composition in even-aged harvests was dominated by shade midtolerant species of high timber value, although short-lived pioneer species of the Proteaceae family were also abundant, especially in ISC. The ISC had the greatest homogeneity in all stand variables (tree density, basal area, volume, and quadratic stand diameter), and since it was a two-layered forest, had basal areas and volumes close to the SC and OG, and a rotated-sigmoid diameter distribution (different to all other treatments). Height of the new cohort in the ISC was significantly taller than in the CC and the STC for most species’ groups, suggesting that the cut plus the residual canopy of ISC diminished the initial cover of the bamboo C. macrostachya and competition for regeneration. Only diameter growth of trees of all shade tolerances was lower in ISC, but diameter growth patterns were similar to CC and STC, with increasing growth during the first two-three decades followed by a decline. Based on these findings, we conclude that silvicultural methods of intermediate harvesting severity, especially ISC, provide the best ecological and economic option in these poor-quality sites given rapid reorganization following their implementation, while maintaining a relatively complex vertical structure, high tree species diversity, and a growing stock dominated by tree species of high timber value.

Atmospheric Rivers in South-Central Chile: Zonal and Tilted Events

The extratropical west coast of South America has one of the largest frequencies of landfalling atmospheric rivers (ARs), with dozens of events per season that account for ~50% of the annual precipitation and can produce extreme rainfall events in south-central Chile. Most ARs form an acute angle with the Andes, but, in some cases, the moist stream impinges nearly perpendicular to the mountains, referred to as zonal atmospheric rivers (ZARs). Enhanced surface-based and upper-air measurements in Concepcion (36.8° S), as well as numerical simulations, were used to characterize a ZAR and a meridionally oriented AR in July 2022. They represent extremes of the broad distribution of winter storms in this region and exhibit key features that were found in a composite analysis based on larger samples of ZARs and tilted ARs. The latter is associated with an upper-level trough, broad-scale ascent, extratropical cyclone, and cold front reaching southern Chile. Instead, ZARs are associated with tropospheric-deep, strong zonal flow and a stationary front across the South Pacific, with ascent restricted upstream of the Andes. Consequently, ZARs have minimum precipitation offshore but a marked orographic precipitation enhancement and exhibit relatively warm temperatures, thus resulting in an augmented risk of hydrometeorological extreme events.

Exploring the social metabolism of urban wastewater reuse: Analysis framework and a case study in South-Central Chile

Although wastewater reuse is a vital strategy for mitigating water scarcity, its implementation is complex and faces several challenges. To effectively inform decision-makers, comprehensive evaluations are essential, considering the strategy's benefits and socio-ecological constraints in a case-specific manner. This study employs the social metabolism concept to assess the sustainability of wastewater reuse, through the joint application of the Material Flow Analysis (MFA) and Multiscale Integrated Assessment of Societal and Ecological Metabolism (MuSIASEM) tools. We analyze key aspects of wastewater reuse, including its potential as a water source, its technical challenges, and main social constraints.The results of our analysis highlight the potential of wastewater reuse to improve urban self-sufficiency, replace water in relevant economic activities at the regional level, and avoid the environmental impacts of wastewater discharge. Nevertheless, the viability of wastewater reuse is constrained by variations in wastewater flow and effluent quality. This limitation is further compounded by social barriers, which become more pronounced with increased contact with reclaimed water. Overall, the proposed framework serves as a valuable tool for evaluating wastewater reuse alternatives. It can be enriched by in-depth assessments of critical problems, providing a comprehensive approach to address the multifaceted aspects of sustainable wastewater reuse.

The transition from backarc extension to Andean growth: Insights from geochronologic, sedimentologic, and structural studies of Mesozoic and Cenozoic sedimentary and volcanic rocks in south-central Chile (36°S)

Many studies propose a significant shift in the tectonic and paleogeographic evolution of the Andes in south-central Chile and Argentina during the Late Cretaceous. It has been proposed that the preceding Jurassic-Early Cretaceous extensional regime that resulted in a low-relief volcanic arc and the backarc Neuquén basin came to an end, giving way to shortening and Andean growth from the Late Cretaceous onward. Nevertheless, there are disagreements regarding the timing and nature of this transition to Andean orogenesis. To address these issues, we conducted geochronologic (U–Pb and 40Ar/39Ar), sedimentologic, and structural studies on Mesozoic-Cenozoic sedimentary and volcanic rocks in the Río Maule area (Principal Cordillera, Chile, 36°S). From our findings and prior analyses, we propose the following tectono-stratigraphic evolution of the region. (1) Marine deposition of the Tithonian-Hauterivian Baños del Flaco Formation took place in an extensional backarc basin. (2) After a ∼ 40 Myr hiatus, fluvial deposits of the Colimapu Formation and volcanic rocks of the Plan de los Yeuques Formation accumulated during the Cenomanian-Danian. Whereas the Colimapu Formation displays evidence of syndepositional shortening, the Plan de los Yeuques Formation exhibits synextensional growth strata. Contrary to other studies, our results suggest that the Chilean part of the Principal Cordillera was largely a zone of active deposition rather than an elevated fold-thrust belt during the Late Cretaceous. We propose that sedimentation occurred within a series of relatively stable intermontane subbasins generated by shortening, followed by extension. (3) After a ∼ 20 Myr hiatus, middle Eocene to early Miocene (Lutetian-Aquitanian) accumulation of a thick succession of andesitic lavas and minor clastic sediments of the Abanico Formation occurred in an intraarc extensional basin. (4) Finally, major shortening and uplift of previously deposited Mesozoic-Cenozoic rocks took place throughout the Neogene. This phase constituted the primary contractional deformation in the Andes of south-central Chile and Argentina. In terms of the transition to early Andean deformation, we propose that structural deformation did not generate a major, regional-scale fold-thrust belt during the late Albian-Santonian. Modest extension, tectonic quiescence, or low-magnitude shortening seem to have dominated during the early to middle Cenozoic.

Novel species and records of Colletotrichum associated with native woody plants in south-central Chile

Novel species and records of Colletotrichum associated with native woody plants in south-central Chile

Application of Environmental and Biological Frequency Indicators to Assess the Serpula lacrymans Fungus in Wooden Dwellings

High moisture content, low ventilation levels, and changes in the hygrothermal design of wooden dwellings could generate environmental conditions favorable for developing the rot fungus Serpula lacrymans, which is known as the most destructive fungus of its kind. The purpose of this research was to develop an experimental methodology to determine the conditions of the appearance of the fungus S. lacrymans, through in situ measurement of biological and environmental frequency indicators for wooden dwellings in South Central Chile. The referential standards for the appearance of the fungus were determined based on specialized literature and measurements of dwellings with and without deterioration. The frequency indicators for the appearance of the fungus defined and studied were as follows: frequency of air temperature FATs (%), frequency of relative humidity FRMs (%), frequency of ventilation rate FVRs (%), and rot fungus spore concentrations (CFU/pp). The methodology was validated by being measured in various enclosures and spaces under the floor in wooden dwellings in the cities of Valdivia and Temuco. The results confirmed the strong relationship between environmental relative humidity frequencies, ventilation levels, and spore concentration regarding the appearance of the fungus, where the growth dynamics cannot be separately explained without a previous analysis of the variables. In general, the dwellings most affected by the presence of the fungus had the greatest moisture levels, lower ventilation levels, and greater spore concentration. This study is the basis to diagnose the phenomena of the appearance of the rot fungus in wooden dwellings in climates favorable for its development.

Spatiotemporal Variations in Biophysical Water Quality Parameters: An Integrated In Situ and Remote Sensing Analysis of an Urban Lake in Chile

This study aims to develop and implement a methodology for retrieving bio-optical parameters in a lagoon located in the Biobío region, South-Central Chile, by analyzing time series of Landsat-8 OLI satellite images. The bio-optical parameters, i.e., chlorophyll-a (Chl-a, in mg·m−3) and turbidity (in NTU) were measured in situ during a satellite overpass to minimize the impact of atmospheric distortions. To calibrate the satellite images, various atmospheric correction methods (including ACOLITE, C2RCC, iCOR, and LaSRC) were evaluated during the image preprocessing phase. Spectral signatures obtained from the scenes for each atmospheric correction method were then compared with spectral signatures acquired in situ on the water surface. In short, the ACOLITE model emerged as the best fit for the calibration process, reaching R2 values of 0.88 and 0.79 for Chl-a and turbidity, respectively. This underlies the importance of using inversion models, when processing water surfaces, to mitigate errors due to aerosols and the sun-glint effect. Subsequently, reflectance data derived from the ACOLITE model were used to establish correlations between various spectral indices and the in situ data. The empirical retrieval models (based on band combinations) yielding superior performance, with higher R2 values, were subjected to a rigorous statistical validation and optimization by applying a bootstrapping approach. From this process the green chlorophyll index (GCI) was selected as the optimal choice for constructing the Chl-a retrieval model, reaching an R2 of 0.88, while the red + NIR spectral index achieved the highest R2 value (0.79) for turbidity analysis, although in the last case, it was necessary to incorporate data from several seasons for an adequate model training. Our analysis covered a broad spectrum of dates, seasons, and years, which allowed us to search deeper into the evolution of the trophic state associated with the lake. We identified a striking eight-year period (2014–2022) characterized by a decline in Chl-a concentration in the lake, possibly attributable to governmental measures in the region for the protection and conservation of the lake. Additionally, the OLI imagery showed a spatial pattern varying from higher Chl-a values in the northern zone compared to the southern zone, probably due to the heat island effect of the northern urban areas. The results of this study suggest a positive effect of recent local regulations and serve as the basis for the creation of a modern monitoring system that enhances traditional point-based methods, offering a holistic view of the ongoing processes within the lake.

Evaluation of climate-change impacts on the temporal and spatial behaviour of drought in South-Central Chile

ABSTRACT Chile is particularly vulnerable to climate change due to its geomorphology, ecological wealth and economic dependence on water resources, and has been facing a severe drought since 2010. The objective of this work is to propose a methodology able to project and evaluate changes in the magnitude, duration and frequency of meteorological and hydrological droughts, as a decision-making tool to support adaptation to climate change. Four basins were assessed using different downscaled General Circulation Models (GCM) and the Soil & Water Assessment Tool (SWAT) model. Results were evaluated using Standardized Precipitation Index (SPI) and Standardized Streamflow Index (SSFI) comparing drought events over two periods of time. An increase in magnitude and duration of meteorological droughts is projected, especially in the Andes Mountain range. Regarding hydrological drought, greater increases in magnitude and duration are projected for the Itata River Basin. In both types of droughts, an increase in frequency is expected.

Can the Firmness, Weight, and Size of Blueberry Fruit Be Enhanced through the Application of Low Amounts of Calcium to the Soil?

The firmness, weight, and size of blueberries are vital for commercial success of this crop. Fertilization is a key agronomic management practice that affects fruit quality, where calcium (Ca) plays a critical role. This study aimed to assess the impact of low levels of soil-dosed Ca in carboxylic acid form on fruit size, weight, firmness, and residual soil fertility. The study focused on two varieties of blueberries, Duke and Legacy, over two consecutive growing seasons on three commercial farms located in south-central Chile. This study consisted of five treatments, ranging from 0 to 4.0 kg Ca per hectare. The highest firmness values observed for Duke were between 164 and 186 g mm-1, with size values ranging from 15.7 to 16.9 mm, and weight observations ranging from 1.60 to 1.76 g. On the other hand, Legacy showed firmness values between 163 and 173 g mm-1, with size values ranging from 16.2 to 17.2 mm, and weight observations ranging from 2.01 to 2.40 g. The application of low Ca rates to the soil did not impact the size, weight, or firmness of 'Duke' and 'Legacy' blueberries. There was a positive correlation between the Ca soil application and the concentration of exchangeable Ca.

Three Biannual Rotations Cycles with Residue Incorporation Affect Wheat Production and Chemical Soil Properties.

There are few reports of crop rotations with high residue incorporation in terms of their effects on indicator crop yields and soil properties, so this study evaluated the effect of two medium-term biannual rotations on wheat yield development and soil chemical properties after six years of rotation. The experiment was conducted with two biannual rotations (canola-wheat and bean-wheat) and four residue incorporation levels (0%, 50%, 100%, and 200%) in an Andisol in south central Chile. Wheat grain yield and residue production were evaluated during each biannual cycle during three cycles of crop rotation, and soil chemical properties were evaluated at final evaluation. The use of beans as a wheat preculture partially improved grain yield in 7.3%. The chemical properties of the soil showed an increase in pH (0.08 units), organic matter content (15 g kg-1), and concentrations of P (2.8 mg kg-1), S (7.4 mg kg-1), and Al (0.03 cmol+ kg-1) after canola cultivation, while after bean cultivation there was an increase in the available N concentration (3.7 mg kg-1). The use of increasing doses of residue allowed for an increase in the soil pH and decrease in the exchangeable Al concentration. The continuous incorporation of the residues produced within the biannual rotations evaluated in this volcanic soil did contribute to improving some chemical properties of the soil without affecting wheat crop yield.

Food habits of Rufous-legged Owl in a protected area of south-central Chile affected by mixed wildfire

Abstract The diet of Rufous-legged Owl, Strix rufipes, a small raptor present in an Andean protected area, is described here. During the fall of 2017, 44 pellets were collected in the study area, being subsequently analyzed. The occurrence of small mammal prey items in pellets was compared with capture frequencies with live-trapping through Sherman traps. Regarding occurrence frequencies in the diet, arthropods were the most frequent (49.34%), followed by mammals (39.31%), birds (7.86%) and reptiles (3.37%). However, in terms of biomass, mammals had the highest biomass contribution. The observed frequency of consumed preys showed a random pattern, according to the captures of small mammals obtained with Sherman traps. The role of wildfire in the composition of prey in the observed trophic spectrum of these forest owls is also discussed.

Using a time-dynamic food web model to compare predation and fishing mortality in Pleuroncodes monodon (Galatheidae: Crustaceae) and other benthic and demersal resource species off central Chile

The stock biomass of the carrot prawn (Pleuroncodes monodon) in the south-central area of Chile (33º–39°S) has decreased progressively in the last 12 years. The depletion and lack of recovery of carrot prawn and other fish and crustacean stocks has been attributed mostly to fishing mortality (F). Predation can be also an important factor for the dynamics of marine species, especially those that are important prey in the ecosystem, like the carrot prawn and other demersal crustaceans. However, predation mortality (M2) has been less studied and quantified in Chile and elsewhere. Therefore, it is important to estimate and compare predation (M2) and fishing (F) mortality to understand their individual and combined effects on the dynamics of fishing stocks. In this study, we analyzed the biomass changes of carrot prawn and other components of the marine food web in south-central Chile from 1992 to 2018. For this, we built a food web model that was later fit to time series of observed biomass and catch data, using observed fishing mortality as forcing factor. We used the Ecopath with Ecosim software as modeling platform. This model provided M2 and F series for carrot prawn and other demersal crustaceans, which were compared to evaluate their relative contribution to total mortality (Z) from 1992 to 2018. The quantitative model considered 29 functional groups, from primary producers to top predators, and the following fishing fleets operating in the study area: artisanal and industrial purse seine fleets, artisanal and industrial hake trawling fleet and demersal prawn trawling fleet. The results indicated that M2 was the main component of Z in adults and juveniles carrot prawns, with Chilean hake as the main predator in both cases. M2 was responsible for 84 % and 86 % of Z of adults and juveniles of carrot prawns, respectively. M2 was also greater than F in yellow prawns (Cervimunida johni), whose main predator was big eye flounder (Hippoglossina macrops). In contrast, F was greater than M2 for the nylon shrimp (Heterocarpus reedi). We conclude that the stock dynamics of the carrot and yellow prawns has been strongly influenced in recent decades by the predation by Chilean hake on pre-recruits of carrot prawn as prey and bigeye flounder on yellow prawn as prey. We recommend that M2 should be considered both in evaluating the past dynamics of these stocks used to establish their status and in future projections used to establish biologically acceptable catch.

First report of a member of the family Mermithidae parasitizing the sandhopper Orchestoidea tuberculata (Amphipoda, Talitridae) in Chile

Specimens of the sandhopper Orchestoidea tuberculata (Amphipoda; Talitridae) collected from sandy beaches in south-central Chile, were found to be parasitized by juvenile mermithids, constituting the first record of a mermithid infecting a marine amphipod in Chile. A morphological description of juveniles is provided. Sequence analyses based on mitochondrial COI and nuclear 18S rDNA of the mermithids showed extremely low genetic variation. Phylogenetic analyses indicate that the mermithid is more closely related to Hexamermis agrotis, which parasitize Coleoptera, than to Thaumamermis zealandica, which parasitizes New Zealand confamilial talitrid amphipods.

Comparative Study between Silvopastoral and Agroforest Systems on Soil Quality in a Disturbed Native Forest of South-Central Chile

Agroforestry systems (AFSs) have gained recognition as a land use strategy to address food security and climate change. They involve intentionally cultivating trees alongside crops and/or animals. AFSs cover approximately 5% of the global forest area and promote sustainable soil conservation, including soil organic carbon (C) sequestration (CSEQ). In some areas of Chile, AFSs are used to preserve the ecological value of native forests. This study evaluates the effects of two AFSs, namely, an agroforest for fodder production (AGROFRST) and Silvopastoral (SPS), within a degraded native forest (Nothofagus obliqua sp.). The evaluation focuses on their impact on CSEQ capacity and soil quality (SQ), using soil quality indexes (SQIs) derived from 30 soil quality indicators (SINDs) related to physical, chemical, and microbiological properties at two depths (0–5 and 5–20 cm). The results for the total depth analyzed (0–20 cm) indicate an average CSEQ of 6.88 and 4.83 Mg C yr−1 and a global SQI of 37.8% and 31.0% for AGROFRST and SPS, respectively. Among the thirteen SINDs that demonstrated significant differences (p < 0.05), five were associated with the considered depths (P+, Ca2+, S, ECEC, and AlSAT), three differed between AGROFRST and SPS (BD, NH4+, NO3−), while SOC, K+, and Mg2+ varied across all conditions (e.g., combinations of systems and depths), and β-GLU and NMIN differed in a single condition. However, almost all 30 SINDs analyzed showed higher values at the 0–5 cm depth, indicating the positive effects of soil organic matter (SOM)/SOC additions. Significant interactions (Pearson’s correlation) revealed that SOC correlated with most SINDs (e.g., N, NH4+, P+, K+, Ca2+, Mg2+, S, ECEC, NMIN). These findings suggest that both AGROFRST and SPS systems have similar capabilities in restoring the ecological value of native Nothofagus forests while providing conditions for productive and complementary use. This sustainable option offers opportunities for cattle production alongside ecological restoration efforts and provides a possible strategy to generate public policies related to the ecosystem services of agroforestry systems.

Teline monspessulana Can Harm the Chilean Native Tree Nothofagus obliqua: Effects on Germination and Initial Growth.

Teline monspessulana is highly invasive in several countries around the world. This species pressurizes and displaces several native and endemic tree species in south-central Chile such as Nothofagus obliqua, the native species of greatest timber interest. We determined the effects induced by allelochemical stress of T. monspessulana on N. obliqua germination and initial growth. Germination was evaluated under in vitro conditions and in natural substrate obtained from sites inhabited by N. obliqua and from nearby areas invaded by T. monspessulana. Controls irrigated with tap water and treatments with aqueous extracts of aerial organs of the invasive species were used. Morphometric and morphological variables were evaluated, and the composition of alkaloids and phenols from the plant organs used for the aqueous extracts was determined. The substrates were also chemically characterized. Allelochemicals synthesized by T. monspessulana caused germination and growth inhibition and tissue-level alterations, as well as leaf and root damage in N. obliqua seedlings. In the aerial organs of T. monspessulana, the quinolizidine alkaloids aphylline, caulophylline, anagyrine, and sophocarpine were mainly detected. In addition, 21 phenolic compounds were identified, including gallic acid, vanillic acid, chlorogenic acid, p-coumaric acid, and quercetin. The phytotoxic potential of T. monspessulana can compromise the natural multiplication of N. obliqua and its survival from its first phenological stages. This interdisciplinary study model facilitated the clarification of the plant-plant relationship mediated by allelochemicals. The model can be replicated to investigate other interspecific interactions between invasive and native species.

Global change and plant–pollinator communities in Mediterranean biomes

AbstractAimOccurring in five distinct global regions, Mediterranean‐type ecosystems (MTEs) include both centres of agricultural production and hotspots of extratropical biodiversity – particularly for plants and bees. Considerable research has addressed the persistence of highly diverse biological communities within MTEs, despite their typically long histories of anthropogenic and natural disturbance. However, important questions remain, especially regarding the limits of ecological resilience in the face of accelerating environmental change. Here, we explore current knowledge regarding the effects of disturbance on MTE plant–pollinator communities.LocationMediterranean Basin, California, Cape Province in South Africa, Central Chile and Southern South‐Western Australia.Taxa StudiedFlowering plants and pollinators (insects, birds and mammals).MethodsWe reviewed the available literature about MTE plant–pollinator communities via a systematic search that yielded 234 case studies. We analysed this dataset to quantify research efforts across regions and taxonomic groups, the proportion of surveys addressing ecological interactions (i.e. rather than only taxonomic diversity) and the availability of work addressing community responses to specific stressors (viz. climate change, landscape alteration, fire, farming, grazing, urbanization and species introductions).ResultsCurrent knowledge on MTE plant–pollinator communities is dominated by work from the northern Mediterranean Basin, while the Southern Hemisphere and California are markedly understudied by comparison. Taxonomic coverage is similarly uneven, with 58% of studies focusing only on a single pollinator group. Furthermore, less than half of the surveys address ecological networks. Finally, despite some pioneering work addressing fire, climate and species introductions, only 13% focus on the impact of stressors on interaction networks.OutlookBased on our findings, we identify a need for coordinated international research efforts focusing on (i) community‐level studies, observational and experimental, (ii) ecological networks, (iii) functional traits mediating post‐disturbance recovery and (iv) impacts of combined/synergistic stressors. Progress in these areas will facilitate predictions about the long‐term impacts of global change on MTE plant–pollinator communities.

Motherhood, disability, and rurality: descolonising practices and knowledge via the Las Quiscas case in Chile

ABSTRACT Women with disabilities face a series of obstacles while exercising their motherhood. Despite the inter-disciplinary studies which have been undertaken on this topic, the ‘modern/colonial/Western/urban’ comprehension of these studies is incomplete and often lacks contextuality. The aim of this study is thus to investigate the life trajectory of a woman with a visual disability, regarding her motherhood process in a rural area of south-central Chile. We used in-depth interviews and photographic records, together with epistemic support from Disability studies, Motherhood studies, Rurality studies, and Descolonial studies. The results provided three categories of analysis: impeding access to dignified motherhood; legal incapacitation: stripping motherhood due to disability; and dehumanisation and loneliness: waiting as a resistance strategy for a conscious motherhood. The conclusions show that exercising motherhood for a woman with disability living in rurality is a trench where the boldest have subverted the precariousness of life. Furthermore, descolonising strategies translate into waiting and passivity as practices which question the colonial comprehension of time.

Social capital and landscape: effects of monoculture forest plantations on small producers in the Mediterranean dryland of south-central Chile

ABSTRACT This research focuses on the socio-ecological context of small farmers in the Mediterranean dryland region of south-central Chile or Secano Interior. This area has been characterised by a long history of natural resource exploitation, especially soil and native vegetation, and the arrival and rapid expansion of monoculture forest plantations resulting in serious environmental degradation issues. Using a mixed methods approach including social network surveys, semi-structured interviews, and geospatial data, this article compares social capital indicators and socio-ecological interactions for rural households with different levels of encroachment due to forest plantations. The research objective is to contrast diverse socio-environmental scenarios with different levels of dispersion and proximity to forest plantations. Findings on local egocentric networks propose clues about the social effects of traditional agriculture loss, rural depopulation and other socio-economic and ecological issues which respondents associated with the introduction and expansion of monoculture plantations in the region.

Evolution of Infective Endocarditis Profiles in South-Central Chile: A Four-Decade Analysis of Surgical Patients

To describe the changes observed in operated patients with infective endocarditis (IE) in the south-central region of Chile during the last four decades. Case series study. The target population was patients diagnosed with IE and indication for valve surgery between 1983 and 2020 from a Chilean public hospital. The universe (n = 306) was divided into four groups according to the period of valve surgery. Sociodemographic and clinical variables between these groups were compared using the Kruskal-Wallis and Chi-square tests for independence. Cumulative survivals were calculated and compared using the Gehan-Breslow-Wilcoxon test. Age at diagnosis (p < 0.001), frequency of comorbidities (p < 0.001), clinical presentation compatible with acute kidney injury (p < 0.001), independent mitral valve involvement (p < 0.001), positivity of microbiological cultures (p < 0.012) and cumulative survival (p = 0,015) increased. The delay from symptom onset to diagnosis (p = 0.003), clinical presentation compatible with heart failure (p < 0.001), independent involvement of the aortic valve (p < 0.001), and surgical indication for large vegetation (p < 0.001) decreased. The IE profile of patients seen in a public hospital in the south-central region of Chile has undergone significant changes during the last four decades.