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Author: Espinoza, Sergio E. ×

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  • Artículo de revista
    Long-Term Effects of Copper Mine Tailings on Surrounding Soils and Sclerophyllous Vegetation in Central Chile
    This study analyzed the nutrients and metals concentrations of the surrounding soils and sclerophyllous vegetation of a tailing at the CODELCO–El Teniente copper mine in Central Chile. The content of metal, macro-, and micronutrients were analyzed in the soils outward from the tailing till 60-m distance at depths of 30, 60, and 90 cm, and in the foliage and stems of the native vegetation associated to the tailing. At plant level, we measured height, diameter, level of damage, and physiological attributes. Cu, Ni, Cr, and As were higher in the tailing, whereas soil Mn and Fe were higher at 60 m from the tailing. Soil K was higher at 30-cm depth, whereas Na was higher at 90-cm depth. Foliar Cu was higher in Acacia caven (40.5 mg kg−1), whereas the levels of Cu and Zn in stems were higher in Quillaja saponaria (6.5 mg kg−1 for Cu and 13.1 mg kg−1 for Zn). As the values of water potential and quantum efficiency of the photosystem II averaged − 1.1 MPa and 0.73, respectively, these two species exhibited no physiological stress. Only Q. saponaria tended to increase the level of damage at higher distances from the tailing. A. caven and Q. saponaria exhibited foliar contents of Cu and Fe considered toxic (Cu from 18.5 to 40.5 and Fe from 298 to 407 mg kg−1); however, both species were able to prosper at the limit of the tailing.
    Espinoza, Sergio E.-Quiroz Marchant, Iván-Magni Díaz, Carlos-Yañez, Marco A.-Martínez, Eduardo E.
    2022
  • Artículo de revista
    The recruitment of the recalcitrant-seeded Cryptocarya alba (Mol.) Looser, established via direct seeding is mainly affected by the seed source and forest cover
    Natural regeneration of recalcitrant-seeded tree species is strongly limited in Mediterraneantype climate zones due to increasing droughts imposed by climate change. Direct seeding can be a low-cost alternative to seedling establishment, but there is still limited information for some species. This study aimed to assess the effects of the seed source and forest cover on the germination and survival of the endemic Cryptocarya alba Mol. established through direct seeding. Three habitat types differing in forest cover were identified within the natural park Reserva Natural Altos de Cantillana, Metropolitan Region, Chile. The forest cover corresponded to open (canopy density <25%), semidense (canopy density around 50%), and dense forest (canopy density >75%). All forest cover had C. alba as one of the dominant species. At each habitat type, 38 families from four seed sources (Cuesta La Dormida (CD), Antumapu (AN), Cantillana (CA, local seed source) and Cayumanque (CY)) were directly seeded. Germination (Germin) and survival (Surv) were evaluated weekly during one growing season. There were significant differences between seed sources in Germin and Surv, with means values varying from 7.8% to 37% for Germin and 0% to 20% for Surv. The local seed source CA had the highest values in both traits. A significant variation was also observed between families within seed sources only for Germin. The dense forest cover had the highest Germin (22%) and Surv (55%) results compared to the other forest cover types, which was partially associated with differences in soil moisture, temperature, and bulk density. Due to the most frequent droughts in these Mediterranean-type climate zones, the use of local seeds on dense forest cover is recommended for the direct seeding of the species in the initial recruitment.
    Magni, Carlos R.-Saavedra, Nicole-Espinoza, Sergio E.-Yañez, Marco A.-Quiroz Marchant, Iván-Faúndez, Angela F.-Grez M., Iván-Martínez, Eduardo E.
    Región Metropolitana de Santiago
    2022
  • Artículo de revista
    Provenance causes variation on early growth and survival and sun protection on physiological responses of the vulnerable Nothofagus glauca (Phil.) Krasser in a common garden in Central Chile
    We assessed outplanting performance of N. glauca in two trials. In Trial 1, provenances from Pre- Andean (Linares, Longaví) and Coastal (Curanipe, Empedrado) origins were planted in a common garden under two sun protection treatments (i.e., black mesh shelter, and kaolin at 6% concentration), and a control treatment at full sun. In Trial 2, a local provenance was established under two site preparation treatments (i.e., old subsoiling from 4 years ago versus no-subsoiling). Growth, survival, gas exchange, and Chlorophyll fluorescence parameters were measured one year after outplanting. In Trial 1 survival was similar among treatments but larger seedlings were found under kaolin and in the local provenance Empedrado. The provenances varied by sun protection treatment in survival, and the Pre Andean provenance Linares tended to show the lowest survival at full sun. At the leaf-level physiology, provenances responded similarly in gas exchange and fluorescence parameters. In the sun protection treatments seedlings under kaolin increased stomatal conductance and electron transport, but decreased photosynthesis, water use efficiency, and efficiency of PSII. Provenances also varied by treatment in physiology. The Empedrado provenance exhibited the highest transpiration and stomatal conductance under kaolin whereas the Pre Andean provenance of Longaví showed the lowest photosynthesis and efficiency of PSII in the kaolin treatment. In Trial 2, root collar diameter, intercellular CO2 and water use efficiency were higher in the old-subsoiling treatment. As a potential adaptation tool, seed sources from Pre Andean origins can be established in Coastal origins with no detriments on seedling survival.
    Quiroz Marchant, Iván-Espinoza, Sergio E.-Yañez, Marco A.-Magni Díaz, Carlos-Martínez, Eduardo E.-Gutiérrez Caro, Braulio-Faúndez, Angela F.-Vaswani, Suraj A.
    Región del Maule
    2022