Examinando por Autor "Hevia, Andrea"
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Ítem A multi-proxy framework to detect insect defoliations in tree rings: a case study on pine processionary(Frontiers, 2023) Camarero, Jesús J.; Colangelo, M.; Rita, A.; Hevia, Andrea; Pizarro, M.; Voltas, JordiAssessing and reconstructing the impacts of defoliation caused by insect herbivores on tree growth, carbon budget and water use, and differentiating these impacts from other stresses and disturbances such as droughts requires multi-proxy approaches. Here we present a methodological framework to pinpoint the impacts of pine processionary moth (Thaumetopoea pityocampa), a major winter-feeding defoliator, on tree cover (remote-sensing indices), radial growth and wood features (anatomy, density, lignin/carbohydrate ratio of cell walls, d13C and d18O of wood cellulose) of drought-prone pine (Pinus nigra) forests in north-eastern Spain. We compared host defoliated (D) and coexisting non-defoliated (ND) pines along with non-host oaks (Quercus faginea) following a strong insect outbreak occurring in 2016 at two climatically contrasting sites (cool-wet Huesca and warm-dry Teruel). Changes in tree-ring width and wood density were analyzed and their responses to climate variables (including a drought index) were compared between D and ND trees. The Normalized Difference Infrared Index showed reductions due to the outbreak of –47.3% and –55.6% in Huesca and Teruel, respectively. The D pines showed: a strong drop in growth (–96.3% on average), a reduction in tracheid lumen diameter (–35.0%) and lower lignin/carbohydrate ratios of tracheid cell-walls. Both pines and oaks showed synchronous growth reductions during dry years. In the wet Huesca site, lower wood d13C values and a stronger coupling between d13C and d18O were observed in D as compared with ND pines. In the dry Teruel site, the minimum wood density of ND pines responded more negatively to spring drought than that of D pines. We argue that multi-proxy assessments that combine several variables have the potential to improve our ability to pinpoint and reconstruct insect outbreaks using tree-ring data.Ítem Climate variability of the southern Amazon inferred by a multi-proxy tree-ring approach using Cedrela fissilis Vell.(Elsevier, 2023-05-01) Ortega-Rodríguez, Daigard Ricardo; Sánchez-Salguero, Raúl; Hevia, Andrea; Granato-Souza, Daniela; Cintra, Bruno B.L.; Hornink, Bruna; Andreu-Hayles, Laia; Assis-Pereira, Gabriel; Roig, Fidel Alejandro; Tomazello-Filho, MarioThe analysis of climate variability and development of reconstructions based on tree-ring records in tropical forests have been increasing in recent decades. In the Amazon region, ring width and stable isotope long-term chronologies have been used for climatic studies, however little is known about the potential of wood traits such as density and chemical concentrations. In this study, we used well-dated rings of Cedrela fissilis Vell. from the drought-prone southern Amazon basin to assess the potential of using inter-annual variations of annually-resolved ring width, wood density, stable oxygen isotope (δ18OTR) measured in tree-ring cellulose and concentration of Sulfur (STR) and Calcium (CaTR) in xylem cells to study climate variability. During wet years, Cedrela fissilis produced wider and denser rings with higher CaTR and lower STR, as well as depleted δ18OTR values. During dry years, a wider range of responses was observed in growth, density and STR, while lower CaTR and enriched δ18OTR values were found. The annual centennial chronologies spanning from 1835 to 2018 showed good calibration skills for reconstructing local precipitation, evapotranspiration (P-PET), Amazon-wide rainfall, as well as climate modes related to sea surface temperature (SST) anomalies such as El Niño South Oscillation (ENSO), Tropical Northern Atlantic (TNA), and the Western Hemisphere Warm Pool (WHWP) oscillations. CaTR explained 42 % of the variance of local precipitation (1975–2018), RW explained 30 % of the P-PET variance (1975–2018), while δ18OTR explained 60 % and 57 % of the variance of Amazon rainfall (1960–2018) and El Niño 3.4 (1920–2018), respectively. Our results show that a multi-proxy tropical tree-ring approach can be used for high-reliable reconstructions of climate variability over Amazon basin at inter-annual and multidecadal time scales.Ítem Environmental forensics evaluation of residual soybean sludge using trees of Brazilian savannah(Elsevier B.V., 2023-12-20) Roquette, J.G.; Ortega-Rodriguez, D. R.; Portal-Cahuana, L.A.; de Almeida Lobo, F.; Hevia, Andrea; Sánchez-Salguero, Raúl; Wallace Pereira de Carvalho, H.; Tomazello-Filho, M.Truck and train are the primary transport means for soybean shipments to national or international markets from Brazil. Substantial amounts of grain residues are dispersed throughout the transport and may accumulate in various places by the runoff. The objective of this study was to evaluate the contamination and mortality of Brazilian savannah trees due to the accumulation of soybean runoff that comes from a grain storage yard. Xylem samples were collected from 28 dead trees in a forest where residues severely polluted the natural environment. Increment cores at breast height were also taken from 25 living trees for control procedure. All samples were analyzed by X-ray densitometry and microfluorescence (XRF) techniques. No differences were observed in the xylem densitometry profile from bark to pith between dead and living trees, indicating that the stagnation in cell production and tree growth occurred drastically after the accumulation of soybean residual sludge, which was confirmed by temporal analysis of satellite images. Significantly higher S, P, Ca and Fe concentrations were observed close to the bark in dead trees. The roots of dead trees accumulated higher amounts of Al, Si, S, Ca and Mn. Higher K, Ca and Si concentrations and lower Mn concentrations were observed in trees closer to the polluted area, and it indicates the need for soil remediation. However, As, Pb and Cd, markers of fertilizers and pesticides in soybean production, were not detected by the analyses performed. It is likely that the residual soybean sludge and its fermentation process during the rainy season (tree - growing season) have generated toxic concentrations of inorganic constituents, that together with warmer soil conditions caused the death of many trees. This study provides tools for the assessment of the environmental impact of soybean production through a novel protocol for monitoring the physical and chemical patterns of tree growth using rapid microscopic scale Xray techniques.Ítem Long- and short-term impacts of climate and dry-season on wood traits of Cedrela fissilis Vell. in southern Brazilian Amazon(Elsevier B.V., 2023-04-15) Ortega-Rodríguez, Daigard Ricardo; Sánchez-Salguero, Raúl; Hevia, Andrea; Granato-Souza, Daniela; Assis-Pereira, Gabriel; Roig, Fidel Alejandro; Tomazello-Filho, MarioDuring the last two decades the tropical Amazon forests have been impacted by frequent and severe droughts. However, little is known about the impacts of these extreme events on wood traits. In this study, we quantified long- and short-term impacts on growth and wood density response and resilience strategies under extreme droughts, analyzing the wood trait trends and correlations with climate variables (temperature, precipitation, and the SPEI drought index). Then, we simulated tree-ring formation and its responses to soil moisture using the process-based VS-Lite growth model. Our results showed how climate anomalies and dry spells increased since 1990s in the southern Amazon region and have affected the growth and wood density of C. fisillis. Ring width, latewood width and minimum wood density experienced the highest sensitivity to drought. C. fissilis showed wider (narrower) and more (less) dense rings during wetter (drier) years, respectively, suggesting that the species undergoes functional plasticity in the formation of its wood in order to adapt to dry conditions. Changes in water limitations during the dry season modify growth thresholds and long-term resilience, leading to decrease growth and increase wood density, enhancing the vulnerability of C. fissilis to projected climate warming scenarios. The short-term resilience is evidenced more in wood density than in the ring width, indicating the species’ ability to adapt to short drought periods. This study is a first attempt to evidence the characteristics of the annual growth rings of C. fissilis trees in relation to climate sensitivity and resilience to drought, based on long-term data from the seasonal moist tropical forest of the Amazon.