Search Results (46)

Quillaja saponaria Molina, a tree species endemic to central Chile, is critical to the pharmaceutical and biotechnology industries due to its triterpenic saponins, which exhibit potent immunostimulant, antiviral, and surfactant activities. However, the natural regeneration of the species is limited by low seed germination rates, and increasing pressure on natural populations in the sclerophyllous Mediterranean forest where the species lives, caused by various factors. The objective of this study was to develop an efficient micropropagation protocol for five Q. saponaria ecotypes using nodal explants. This protocol is designed to support species conservation, facilitate large-scale reforestation, and ensure the sustainable production of its bioactive metabolites. Explants were cultured on Murashige and Skoog (MS) medium, and the establishment, multiplication, and rooting stages were systematically optimized using various growth regulator combinations. The resulting protocol demonstrated high efficiency across all stages. Surface sterilization with 1% sodium hypochlorite achieved an explant survival rate of 84.73%. The most effective shoot multiplication was obtained on MS medium supplemented with 4.44 μM 6-benzylaminopurine (BAP), yielding a proliferation rate of 4.04 and an average shoot length of 8.01 cm. For rooting, a high success rate (92.85%) was achieved by treating microshoots with 984.06 μM indole-3-butyric acid (IBA) prior to an ex vitro transfer to a peat:perlite:vermiculite mixture (1:1:1 v/v/v). Acclimatized plantlets showed a consistent survival rate between 84.28% and 87.16%. Crucially, the five ecotypes demonstrated no statistically significant differences in their responses throughout the protocol. This validates the method’s broad applicability for large-scale production and reforestation initiatives. Full article

Porlieria chilensis Johnst. (guayacán), an endemic Chilean species native to the sclerophyllous forests, is experiencing a significant population decline. Typically growing as a shrub or small tree on sunny slopes and rocky soils, its populations have been severely impacted by overexploitation and habitat degradation, leading to its classification as Vulnerable (VU). Mature, well-developed individuals have become increasingly rare, now mostly replaced by shrubby regrowth. This study presents the first reported in vitro propagation method for P. chilensis, aimed at establishing a protocol for its mass propagation. A 92.0% survival rate was achieved for nodal segments cultured on Murashige and Skoog (MS) medium after surface disinfection with 1.5% sodium hypochlorite for 15 min. Shoot elongation was successfully stimulated by supplementing the medium with 8.88 μM of 6-benzylaminopurine (BAP), resulting in an average shoot length of 6.9 cm. For ex vitro rooting, plants were transferred to 200 mL containers filled with a 2:1 (v/v) peat/perlite substrate. High rooting rates were obtained (87.5% and 93.1%) when treated with 1968 μM and 1476 μM of indole-3-butyric acid (IBA), respectively. Moreover, 89.8% of the plants survived acclimatization under controlled conditions. These results highlight the strong potential of in vitro propagation as an effective strategy for the conservation and restoration of P. chilensis populations. Full article

Recalcitrant species are highly sensitive to drought and climate stress, posing urgent challenges for their conservation. Propagation for ex situ management and habitat restoration depends on adequate fruit handling, yet postharvest protocols remain insufficiently examined to support practical implementation. Cryptocarya alba, a dominant tree of the Chilean Mediterranean biome, reflects this gap. Despite its ecological relevance and central role in forest planning, the biological basis of its recalcitrant behavior has yet to be fully elucidated, constraining informed decision-making on its propagation. Accordingly, this study examined the progressive breakdown of fruit integrity under two contrasting storage conditions—refrigeration (5 °C) and room temperature (20 °C)—over 150 days, using a multiscale approach combining physical measurements, histology, and scanning electron microscopy. Fruit weight, moisture, pericarp thickness, and cotyledon starch exhibited a significant linear decline over time. The rate was consistently higher at room temperature—except for starch, which showed no quantitative differences across treatments, though the severity of granule alterations was greater. Overall evidence indicates a close association among these variables, suggesting that desiccation and metabolism-driven degradation result in the structural collapse of C. alba fruits. These findings highlight the need to integrate environmental conditions alongside complementary strategies targeted at physiological regulation, guiding the development of robust, science-based handling protocols to support the species’ conservation. Full article

Fire has had a profound impact on Australia’s landscapes and biodiversity since the late Tertiary. Indigenous (Aboriginal) people have lived in Australia for at least 65,000 years and fire is an integral part of their culture and cosmology. In 2015, an Indigenous cultural burn was undertaken by Banbai rangers at Wattleridge Indigenous Protected Area, New England Tablelands, NSW. We compared the impact of this burn on the composition, cover, abundance, and species richness of dry sclerophyll vegetation and fuel hazard, with a hazard reduction burn at nearby Warra National Park, using a Before-After-Control-Impact experimental design. Our study found that the low-severity cultural burn and moderate-severity hazard reduction burn reduced fuel loads but did not have a significant impact on the composition of the vegetation overall or the herb layer. The hazard reduction burn had a significant impact on shrub and juvenile tree (woody species) cover, while the abundance of woody species was significantly affected by both fires, with a mass germination of ‘seeder’ species, particularly after the cultural burn. The long unburnt fire regime at Wattleridge may have made the vegetation more responsive to fire than the more frequently burnt vegetation at Warra, through accumulation of seed in the seed bank, so that the patchy cultural burn had a greater impact on woody species abundance. In terms of ecological and bushfire management outcomes, this study provides evidence to support claims that Indigenous cultural burning decreases fuel loads, stimulates regeneration of shrubs and trees, and manages at a local, place-based scale. We recommend cultural burning as a key management tool across Indigenous Protected Areas and other land tenures, with its implementation monitored and adaptively managed through two-way science, to foster fire regimes that are both culturally and ecologically beneficial. This is a vital element of our resilience in the Pyrocene and a significant step toward decolonizing science and land management. Full article

In the search for safe and effective natural antioxidants, this study investigates the antioxidant and cytotoxic properties of aqueous extracts obtained from three fungi of the family Hymenochaetaceae: Inonotus sp., Fulvifomes sp., and Phylloporia boldo, all associated with endemic trees of the Chilean sclerophyll forest. Antioxidant capacity was assessed through DPPH, ABTS, and hydroxyl radical scavenging assays. Fulvifomes sp. exhibited the highest antioxidant activity across all methods, which was consistent with its elevated polyphenol content. P. boldo, on the other hand, had the highest protein concentration but comparatively lower antioxidant activity. Cytotoxicity was evaluated using the WST-1 assay in the RTgill-W1 salmonid cell line, revealing that Inonotus sp. displayed the lowest cytotoxicity at both tested concentrations, suggesting it may be suitable for bioactive applications in aquaculture. In contrast, Fulvifomes sp. and P. boldo showed significant cytotoxic effects at higher concentrations. These findings highlight the potential of Inonotus sp. as a natural antioxidant with low cytotoxicity and encourages further exploration of native forest fungi as sources of functional bioactive compounds for food, nutraceutical, or aquaculture applications. Full article

Forest ecosystems in the Mediterranean basin are significantly affected by summer wildfires. Drought, extreme temperatures, and strong winds increase the fire risk in Greece. This study explores the potential of NDVI for assessing and forecasting post-fire regeneration in burnt areas of the Peloponnese (2007) and Evros (2011). NDVI data from Landsat 7 and 9 were analyzed to identify the stages of the regeneration process and the dominant vegetation species at each stage. Comparing pre-fire and post-fire values highlighted the recovery rate, while the trendline slope indicated the regeneration rate. This combined analysis forms a methodology that allows drawing conclusions about the vegetation type that prevails after the fire. Validation was conducted using photointerpretation techniques and CORINE land cover data. The findings suggest that sclerophyllous species regenerate faster, while fir forests recover slowly and may be replaced by sclerophylls. To predict vegetation regrowth, two time series models (ARMA, VARIMA) and two machine learning-based ones (random forest, XGBoost) were tested. Their performance was evaluated by comparing the predicted and actual numerical values, calculating error metrics (RMSE, MAPE), and analyzing how the predicted patterns align with the observed ones. The results showed the overperformance of multivariate models and the need to introduce additional variables, such as soil characteristics and the effect of climate change on weather parameters, to improve predictions. Full article

Landscapes can be selectively used by different carnivore species, leading to habitat specialization, which acts as a limiting resource for maintaining healthy populations. Between 1 March 2021 and 31 March 2022, we set up 30 camera traps in three different landscapes of central Chile: (a) Mediterranean coastal sclerophyllous forest (SF), (b) Mediterranean coastal thorn forest (TF), and (c) exotic monoculture tree plantations (MP), with a total capture effort of 10,046 camera-days (3098 TF, 3446 MP, and 3502 SF). We described the daily activity patterns for each native carnivore species recorded in each landscape, based on the density of independent records per hour of the day. We assessed the overlap between the activity patterns of each carnivore species in the different macrohabitats based on their coefficient of overlapping (Δ). We identified 9120 carnivore records, corresponding to 3888 independent events: 3140 for Lycalopex fox species, 276 for guiña Leopardus guigna, 434 for skunk Conepatus chinga, and 38 for the lesser grison Galictis cuja. Our study revealed differences of activity patterns with high to medium overlap, among landscape types for C. chinga and Lycalopex spp.—for skunk, between native forests and exotic monoculture tree plantations, and for foxes, among all landscape types. The carnivore community of the highly anthropized central Chile is mostly composed of habitat generalists and habitat specialists with high adaptability to landscape fragmentation, which has been crucial for their long-term survival. Full article

Peumus boldus Mol. (boldo) is a Chilean endemic tree species, characteristic of the region’s sclerophyllous forests. Increasing demand for its leaves and bark, valued for their antioxidant properties, has contributed to declining populations of this species in its natural habitat. This decline is further exacerbated by low natural germination rates and anthropogenic pressures. To support conservation efforts, efficient mass propagation protocols are needed. This study pioneered the use of temporary immersion systems (TIS) for the in vitro propagation of boldo, successfully developing a novel mass propagation protocol. To optimize the in vitro propagation of boldo shoots using the temporary immersion system (TIS), various immersion durations were tested. While a 3 min immersion resulted in a high proliferation rate (10.8), it also induced shoot vitrification, a detrimental physiological disorder. However, reducing the immersion duration to 2 min successfully prevented vitrification while still achieving a satisfactory multiplication rate of 7.2. The shoots reached an average length of 6.1 to 6.4 cm with 6-benzylaminopurine (4.44 μM). Ex vitro rooting was achieved in 75.4% of shoots treated with 1476 μM indole-3-butyric acid (IBA) across all tested substrates. The plantlets subsequently acclimatized with a survival rate between 77.1% and 83.3%. Full article

The Parque Nacional La Campana (PNLC) was recently recognized for its high soil surface microbial richness. Here, we explored the microbial community structure in soil profiles from contrasting facing slopes where sclerophyllous forest (SF) and xerophytic shrubland (XS) develop. Soil physicochemical conditions (dry density, pH, and organic matter C and N isotopic soil signatures) were determined at three depths (5, 10, and 15 cm depths). Amplicon sequencing (16S rRNA and ITS1-5F) and specific quantification (qPCR bacteria, archaea and ammonia-oxidizing archaea, fungi) were used to profile the microbial community. Our results indicate that opposite slopes, with different vegetation types and soil conditions studied potentially explained the spatial variability of the microbial community composition, especially between sites than through soil depth. Discriminative taxa were observed to vary between sites, such as, C. nitrososphaera (ammonia-oxidizing archaea) and Sphingomonas, and bacteria associated with Actinobacteria and Bacteroidetes were predominant in SF and XS, respectively. Fungi affiliated with Humicola and Preussia were more abundant in SF, while Cladosporium and Alternaria were in XS. Higher ASV richness was observed in SF compared to XS, for both prokaryotes and fungi. Furthermore, SF showed a higher number of shared ASVs, while XS showed a decrease in unique ASVs in deeper soil layers. In XS, the genus DA101 (Verrucomicrobia) increases with soil depth, reaching higher levels in SF, while Kaistobacter shows the opposite trend. PNLC soils were a reservoir of redundant microbial functions related to biogeochemical cycles, including symbiotic and phytopathogenic fungi. In conclusion, as with the predominant vegetation, the structure and potential function of microbial life in soil profiles were associated with the contrasting the effect of facing slopes as toposequence effects. Full article

Wildfires and drought stressors can significantly limit forest recovery in Mediterranean-type ecosystems. Since 2010, the region of central Chile has experienced a prolonged Mega Drought, which intensified into a Hyper Drought in 2019, characterized by record-low precipitation and high temperatures, further constraining forest recovery. This study evaluates short-term (5-year) post-fire vegetation recovery across drought gradients in two types of evergreen sclerophyllous forests and a thorny forest and shrubland, analyzing Landsat time series (1987–2022) from 42 wildfires. Using the LandTrendr algorithm, we assessed post-fire forest recovery based on NDVI changes between pre-fire values and subsequent years. The results reveal significant differences in recovery across drought gradients during the Hyper Drought period, among the three forest types studied. The xeric forest, dominated by Quillaja saponaria and Lithrea caustica, showed significant interaction effects between levels of drought and fire severity, while the thorny forest and shrubland displayed no significant interaction effects. The mesic forest, dominated by Cryptocarya alba and Peumus boldus, exhibited additional significant differences in recovery between the Hyper Drought and Mega Drought periods, along with significant interaction effects. These findings underscore the critical role of prolonged, severe drought in shaping forest recovery dynamics and highlight the need to understand these patterns to improve future forest resilience under increasingly arid conditions. Full article

The Pinus halepensis (Aleppo pine) forests prevailing in the western part of the Mediterranean Basin are amongst the most severely affected by fire due to their inherent flammability. Our understanding of the environmental factors driving post-fire community dynamics is currently limited by the lack of time-series data at temporal scales. In this present study, we analyzed a chronosequence of Greek Aleppo pine forests spanning a post-fire period of 65 years. Our goal is to explore the role of post-fire age, altitude, exposure, slope level, parent-rock material, rock cover, and cover of evergreen sclerophyllous shrubs (maquis) on plant assemblage diversity (species richness and Menhinick’s diversity index) and composition. Post-fire age had a significant effect on taxonomic distinctness and community turnover but not on species richness. Taxonomic distinctness increased with post-fire age due to a higher prevalence of the families Fabaceae, Asteraceae, and Poaceae during the early post-fire period. Maquis cover was significantly associated with Menhinick’s diversity index, taxonomic distinctness, and community turnover. Exposure and slope influenced only Menhinick’s diversity index. The turnover in species composition was primarily driven by the geographical proximity of the forests and secondarily by post-fire age and the maquis cover. This highlights the importance of the initial floristic composition in the process of autosuccession after a fire in Mediterranean-climate ecosystems. Full article

Leaf functional traits (LFTs) have become a popular topic in ecological research in recent years. Here, we measured eight LFTs, namely leaf area (LA), specific leaf area (SLA), leaf thickness (LT), leaf dry matter content (LDMC), leaf carbon content (LCC), leaf nitrogen content (LNC), leaf phosphorus content (LPC), and leaf potassium content (LKC), in six typical vegetation communities (sclerophyllous evergreen broad-leaved forests, temperate evergreen coniferous forests, cold-temperate evergreen coniferous forests, alpine deciduous broad-leaved shrubs, alpine meadows, and alpine scree sparse vegetation) in the Chayu River Basin, southeastern Qinghai-Tibet Plateau. Our aim was to explore their relationships with evolutionary history and environmental factors by combining the RLQ and the fourth-corner method, and the method of testing phylogenetic signal. The results showed that (i) there were significant differences in the eight LFTs among the six vegetation communities; (ii) the K values of the eight LFTs were less than 1; and (iii) except for LCC, all other LFTs were more sensitive to environmental changes. Among these traits, LA was the most affected by the environmental factors, followed by LNC. It showed that the LFTs in the study were minimally influenced by phylogenetic development but significantly by environmental changes. This study further verified the ecological adaptability of plants to changes in environmental factors and provides a scientific basis for predicting the distribution and diffusion direction of plants under global change conditions. Full article

The success of using active restoration in Mediterranean-type climate zones mostly depends on an appropriate matching of plant species and specific management prescriptions upon establishment. In this study, we assessed the early growth and short-term physiological acclimation of seven common species found in the sclerophyllous forests in central Chile to water restriction and shading. We established a nursery experiment that included three treatments (T0: sun-exposed and water-restricted, T1: sun-exposed and fully irrigated, and T2: shaded and fully irrigated) and seven tree species differing in their shade and drought tolerance (Quillaja saponaria Molina, Aristotelia chilensis (Mol.) Stuntz, Peumus boldus Molina, Lithraea caustica (Mol.) Hook. and Arn, Luma apiculata (DC.) Burret, Colliguaja odorifera Molina, and Escallonia pulverulenta (Ruiz and Prav.) Pers). We measured the increment in seedling height and different leaf morpho-physiological traits during two months in the dry season. Based on the measured traits, none of the species took advantage of the higher water availability in T1 relative to T0, but most of the species responded to the shade in T2, regardless of their shade or drought tolerance. Height increments due to shade varied from 0% in P. boldus to 203% in L. apiculata. Overall, all the species responded similarly to the treatments in specific leaf area, chlorophyll content index, photosynthetic rate, stomatal conductance, and intrinsic water use efficiency. This suggests that the species exhibited similar acclimation patterns of these parameters to shade and drought, even regarding the variation in midday xylem water potential found in the water-restricted treatment T0 (from −1.5 MPa in P. boldus to −3.1 MPa in E. pulverulenta). In this study, shading had a higher positive effect on the seedling performance of sclerophyllous species than watering, which at operational level highlights the need for investing in tree shelters when using these species in restoration programs. Full article

Parque Nacional La Campana (PNLC) is recognized worldwide for its flora and fauna, rather than for its microbial richness. Our goal was to characterize the structure and composition of microbial communities (bacteria, archaea and fungi) and their relationship with the plant communities typical of PNLC, such as sclerophyllous forest, xerophytic shrubland, hygrophilous forest and dry sclerophyllous forest, distributed along topoclimatic variables, namely, exposure, elevation and slope. The plant ecosystems, the physical and chemical properties of organic matter and the soil microbial composition were characterized by massive sequencing (iTag-16S rRNA, V4 and ITS1-5F) from the DNA extracted from the soil surface (5 cm, n = 16). A contribution of environmental variables, particularly related to each location, is observed. Proteobacteria (35.43%), Actinobacteria (32.86%), Acidobacteria (10.07%), Ascomycota (76.11%) and Basidiomycota (15.62%) were the dominant phyla. The beta diversity (~80% in its axes) indicates that bacteria and archaea are linked to their plant categories, where the xerophytic shrub stands out with the most particular microbial community. More specifically, Crenarchaeote, Humicola and Mortierella were dominant in the sclerophyllous forest; Chloroflexi, Cyanobacteria and Alternaria in the xerophytic shrubland; Solicoccozyma in the dry sclerophyllous forest; and Cladophialophora in the hygrophilous forest. In conclusion, the structure and composition of the microbial consortia is characteristic of PNLC’s vegetation, related to its topoclimatic variables, which suggests a strong association within the soil microbiome. Full article

Agroforestry has a long history of evolution in Europe and has been especially selected under the unfavorable socioeconomic and environmental conditions of the Mediterranean region. The recent changes in social-ecological conditions have increased the interest in the contribution of agroforestry to the mitigation of forthcoming challenges. Thus, the present study aimed to analyze the socioeconomic and ecological suitability of agricultural lands for preserving, restoring, and establishing agroforestry practices in Europe. We classified different agroforestry systems based on the LUCAS database, finding that most agroforestry in Europe is in areas associated with older human populations of varying densities and employment levels at lower altitudes, gentler slopes, moderate annual mean temperature and precipitation, and in medium textured soils with limited organic carbon content. Focusing on the prevalent agroforestry system of silvopasture, the majority of which is found in three Mediterranean ecoregions of mainly sclerophyllous forests, the most important factors for the occurrence of this system were subsoil available water content (Aegean), land cover (Adriatic), and topsoil available water content (Iberian). The suitable area for silvopasture according to MaxEnt was 32%, 30%, and 22% of the Aegean, Adriatic, and Iberian ecoregion’s area, respectively. Such mapping of agroforestry suitability can help policymakers to undertake adaptive management for the implementation of agroforestry-based solutions to address ecosystem restoration, food insecurity, and rapid environmental changes and threats. Full article