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Impacts of fire severity and cattle grazing on early plant dynamics in old-growth Araucaria-Nothofagus forests

Forest Ecosystems 2019年第4期6卷 298-311页

作者： Paola Arroyo-Vargas Andres Fuentes-Ramírez Bart Muys Aníbal Pauchard Laboratorio de Biometría Departamento de Ciencias ForestalesUniversidad de La FronteraCasilla 54-DTemucoChile Programa de Magíster en Manejo de recursos naturales Facultad de Ciencias Agropecuarias y ForestalesUniversidad de La FronteraCasilla 54-DTemucoChile Butamallin Research Center for Global Change Universidad de La FronteraTemucoChile Instituto de ecología y Biodiversidad(IEB) SantiagoChile department of Earth and Environmental Sciences University of LeuvenCelestijnenlaan 200EBox 24113001 LeuvenBelgium Laboratorio de Invasiones Biológicas(LIB) Facultad de Ciencias ForestalesUniversidad de ConcepciónCasilla 160-CConcepciónChile.

Background: Fire has historically shaped the dynamics of Araucaria araucana-Nothofagus pumilio forests in the Andean region of South America. Nevertheless, human disturbances and stronger drought events have resulted in increased occurrence and severity of wildfires. Regardless of their conservation relevance, the initial response to fire of Araucaria-Nothofagus forests has not been well documented. Through this research we tested the hypothesis that plant composition of Araucaria-Nothofagus forest after fire will initially differ in its recovery depending on fire severity, but over time, plant similarity will increase among areas with different levels of fire severity. The study was carried out in old-growth Araucaria-Nothofagus forests in south-central Chile(38°S) that were burned in 2015. We studied vegetation response to three levels of fire severity(low(LS), moderate(MS) and high(HS) severity), also including an adjacent unburned forest(UN), which were assessed one, two and three years after fire. We also evaluated the impact of cattle on plant recovery after fire. We measured species richness, abundance, plant diversity and origin of all vascular plant ***: Species richness and plant abundance responded differently to fire severity. Time-since-fire had a significant effect on plant richness and abundance. Plant composition within LS areas was similar to UN areas, but MS and HS areas were significantly less diverse compared to UN and LS. In absence of other major disturbances, similarity in plant composition tended to increase over time across the different levels of fire severity, becoming more similar to UN. We also found a synergetic effect of cattle and fire on species richness. This interaction promotes the establishment of nonnative species and limits the recovery of native species following ***: Fire severity had a significant impact on the plant community of old-growth Araucaria-Nothofagus forests,especially in areas of high fir

关键词： Fire severity gradient Wildfire Post-fire plant recovery Cattle exclusion Synergistic effects of disturbances Araucaria araucana Nothofagus pumilio

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Grazing Pressure and Plant Functional Types in Puna Highlands,Northwestern Argentina

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Phyton-International Journal of Experimental Botany 2024年第5期93卷 1067-1080页

作者： Quiroga Mendiola Mariana Tálamo Andrés IPAF NOA—INTA(National Institute for Agricultural Technology) Posta de HornillosJujuy4622Argentina Facultad de Ciencias naturales Universidad Nacional de SaltaSalta4400Argentina Instituto de Bio y Geociencias del NOA(IBIGEO) UNSa-CONICET.Laboratorio de Ecología Aplicada a la Conservación(LEAC)Facultad de Ciencias NaturalesUniversidad Nacional de SaltaSalta4400Argentina Maestría en Gestión Ambiental Escuela de NegociosUniversidad Católica de Salta(UCASAL)Salta4400Argentina

The Puna grasslands support grazing systems that produce meat and wool in multi-species herds,especially from llama(Lama glama)and ***,it is yet unknown whether grazing pressure can modify grassland structure and Plant Functional Types diversity and cover in Puna *** analyzed the relationship between grazing pressure and Plant Functional Types by comparing transects located near stockyards(high grazing pressure)and far from them(low pressure)and by evaluating the relationship between the Plant Functional Types cover to a Grazing Pressure Index(GPI).This index incorporates the heterogeneity of traditional pastoral *** two ecological sites(Ciénego and Tolar),we sampled paired transects(near-far).Plots near and far from corrals were similar in all the variables measured except for plots in Tolar,which tend to have higher total cover,possibly due to fecal fertilization near ***,we recorded an increase in total cover and grass cover at higher GPI in Ciénego,while in Tolar we found lower values of total cover and herbaceous dicotyledonous cover at intermediate intensities of *** only negative relationship found was the cover of clonal and non-clonal shrubs,possibly explained by the greater use of these shrubs as firewood near *** summary,our study does not show important changes in Plant Functional Types as a function of grazing pressure in the studied grasslands probably because grazing pressure is diluted or diminished when livestock rotates in different areas and grazing durations ***,the long grazing history with which the Puna has evolved could also contribute to the co-structuration between native vegetation and livestock farming.

关键词： Natural grasslands Puna herbivory ecological perturbation

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Processes involving soil CO_(2)dynamic in a sector of Chaco-Pampean plain,Argentina:An isotope geochemical approach

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Acta Geochimica 2024年第5期43卷 947-958页

作者： Sanci Romina Panarello Héctor Instituto de Geociencias Básicas Aplicadas y Ambientales de Buenos Aires(IGEBA)Facultad de Ciencias Exactas y NaturalesUniversidad de Buenos AiresCABAIntendente Güiraldes 2160Pabellón IIPiso 1C1428EGA Ciudad UniversitariaArgentina Instituto de Geocronología y Geología Isotópica(INGEIS) Facultad de Ciencias Exactas y NaturalesUniversidad de Buenos AiresCABAIntendente Güiraldes 2160Pabellón INGEISC1428EGA Ciudad UniversitariaArgentina

The magnitude and spatial variability of CO_(2)surface emissions and processes involving CO_(2)released to the atmosphere from the soils are relevant issues in the context of climate *** work evaluated CO_(2)fluxes and^(13)C/^(12)C ratio of vegetation,organic matter,and soil gases from no disturbed soils of Chaco Pampean Plain(Argentina)with different soil properties and environmental conditions(PL and PA units).Soil organic decomposition from individual layers was accompanied byδ^(13)C of total organic carbon(δ^(13)C-TOC)values more enriched to depth.δ^(13)C-TOC values in the upper soil profile~ca.0–15 cm were like the plant community of this area(~−33 to−29‰)whileδ^(13)CTOC varied stronger bellow horizon A,till~−24‰.Bothδ^(13)C-TOC and soilδ^(13)C-CO_(2)were similar(~−24 to 26‰)at deeper horizons(~50–60 cm).Toward the superficial layers,δ^(13)C-TOC andδ^(13)C-CO_(2)showed more differences(till~4‰),due influence of the diffusion *** A layer(~0–20 cm)from both PL and PA units contained the most enrichedδ^(13)C-CO_(2)values(~−15–17‰)because atmospheric CO_(2)permeated the soil air.A simple two-component mixing model between sources(atmosphericδ^(13)C-CO_(2)and soil CO_(2))confirmed that ***,CO_(2)fluxes reflected the biodegradation of C3 plants(source),diffusive transport,and CO_(2)exchange(atmosphere/soil).Soil moisture content appeared as a determining factor in the diffusion process and the magnitude of CO_(2)surface emissions(12–60 g·m^(−2)·d^(−1)).That condition was confirmed by CO_(2)diffusion coefficients estimated by air-filled porosity parameters and soil radon gradient model.

关键词： Soil CO_(2) Carbon isotopes Isotope fractionation Radon gases

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Are endophytes an important link between airborne spores and allergen exposure?

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Fungal Diversity 2013年第3期60卷 33-42页

作者： Beatriz R.Vázquez de Aldana Gerald Bills Iñigo Zabalgogeazcoa Instituto de recursos naturales y Agrobiología de Salamanca(IRNASA-CSIC) Cordel de Merinas 40-5237008 SalamancaSpain Texas Therapeutics Institute The Brown Foundation Institute for Molecular MedicineUniversity of Texas Health Science Center at Houston1825 Pressler StreetHoustonTX 77030USA

Grasses represent one of the Earth’s most common plant groups,and natural and cultivated habitats dominated by grasses cover about 40%of the land *** turn,each grass species hosts multiple fungal species which can behave as *** analysis of the endophytic taxa identified in surveys conducted in 14 grass species showed that some of the most frequent taxa on each grass were also present across several host *** taxa were Alternaria,Epicoccum,Cladosporium,Fusarium,and a few others.A similar analysis of airborne fungi surveyed at 41 different locations throughout the world showed that some of the most geographically widespread,and most locally frequent airborne fungi belonged to the same genera that are dominant endophytes in grasses(***,Alternaria,Fusarium,etc.).Therefore,airborne spores of genera that are ubiquitous in grasses are common worldwide and attain high atmospheric *** addition,spores of the above mentioned fungi are also important respiratory *** observation indicates that saprobic colonization and sporulation of non-systemic grass endophytes could become unrestrained when their host plant tissue ***,when appropriate environmental conditions favour sporulation on grass host surfaces,the natural cycle for airborne conidia initiates,and large numbers of these conidia disperse as inoculum for new endophytic ***,the cycle of endophytism may be an important link between climate,plant biology and public health.

关键词： Grasses Airborne spores Endophytes Cladosporium Alternaria Fusarium Epicoccum

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The marine Jurassic of Argentina： a biostratigraphic framework

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Episodes 2008年第3期31卷 326-335页

作者： Alberto C. Riccardi Facultad de Cieneias naturales y Museo Universidad Nacional de La Plata Paseo del Bosque s/n 1900 La Plata Argentina

In Argentina the best and most complete marine Juras- sic succession is exposed between 32° and 39° S, along a N-S belt roughly coincident with the border with Chile. Here all stages, except the Kimmeridgian, are represented by marine facies. Ammonites have provided a biostratigraphic framework to date and correlate lithostratigraphic units and sequences, to reconstruct the history of the marine fill, and allow the development of other palaeontological and geological studies. Recent studies on the systematics and/or biostratigra- phy of Andean ammonites have provided the basis for the presentation of a summary of the 45 ammonite zones of the Jurassic of west-central Argentina and to stress its significance in reconstructing the palaeogeographic evolution of that region.

关键词：侏罗纪海洋阿根廷生物地层学

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Exocytosis,endocytosis and recycling of secretory vesicles in neuroendocrine cells,and its regulation by cortical actin

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BIOCELL 2022年第8期46卷 1867-1873页

作者： ANA M.CÁRdeNAS I.GALLO FERNANDO D.MARENGO Centro Interdisciplinario de Neurociencia de Valparaíso Facultad de CienciasUniversidad de ValparaísoValparaíso2360102Chile Instituto de Fisiología Biología Molecular y NeurocienciasCONICET.Departamento de Fisiología y Biología Molecular y CelularFacultad de Ciencias Exactas y naturales Universidad de Buenos AiresBuenos Aires1428Argentina

The cortical actin network is a mesh of filaments distributed beneath the plasmalemma that dynamically reacts in response to *** dynamic network of cortical filaments,together with motor myosin partners,adjusts the plasmalemma tension,organizes membrane protein microdomains,remodels the cell surface and drives vesicle motion in order to fine-tune exocytosis,endocytosis and recycling of secretory *** this review,we discuss how these mechanisms work in secretory cells.

关键词： Cortical actin Neuroendocrine cell Chromaffin cell Exocytosis Endocytosis

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An overview of plant-autochthonous microorganisms and fermented vegetable foods

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Food Science and Human Wellness 2020年第2期9卷 112-123页

作者： Sebastian Torres Hernan Veron Luciana Contreras Maria I.Isla Instituto de Bioprospeccion y Fisiologia Vegetal(INBIOFIV)–CONICET TucumanArgentina Facultad de Ciencias naturales e IML Universidad Nacional de TucumanTucumanArgentina

Fermented plant-based foods and beverages constitute foods of high nutritional and functional value with appreciated health beneficial *** represent a natural and sustainable alternative to counteract the large wastage of vegetables and fruits due to their short shelf ***,the use of controlled fermentation process using autochthonous microorganisms adapted to their vegetable matrix is preferred instead of traditionally spontaneous fermentation to designing fermented vegetable foods with the desirable sensory,technological,nutritional and functional *** review summarizes the autochthonous microorganisms selected as starters for the successful fermentation of vegetables and *** main beneficial properties of autochthonous starters and fermented vegetable products with a focus on human health are revised.

关键词： Plant-autochthonous Microorganisms Fermented vegetable foods Functional foods Lactic acid bacteria Probiotics Probiotic

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Historical fluxes of metal and metalloids in an aquatic ecosystem affected by land-use change and mining activities in northwestern Mexico

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International Journal of Sediment Research 2023年第5期38卷 724-738页

作者： Ochoa-Contreras Roberto Jara-Marini Martín Enrique Ruiz-Fernández Ana Carolina Sanchez-Cabeza Joan Albert Meza-Figueroa Diana Pérez-Bernal Libia Hascibe Posgrado en Ciencias Centro de Investigación en Alimentación y Desarrollo Unidad Hermosillo 2. Centro de Investigación en Alimentación y Desarrollo Unidad Hermosillo Unidad Acad emica Mazatlán Instituto de Ciencias del Mar y Limnología Universidad Nacional Autónoma de M exico departamento de Geología División de Ciencias Exactas y Naturales Universidad de Sonora Rosales y Encinas

Freshwater reservoirs are essential owing because of their ecological, economic, and social *** are particularly vulnerable to contamination, as of metal and metalloids, derived from anthropogenic activities like mining. The temporal variations in trace element concentrations(arsenic(As),mercury(Hg), chromium(Cr), copper(Cu), nickel(Ni), lead(Pb), and zinc(Zn)), enrichment, fluxes, and possible sources were evaluated by studying two sediment cores from the La Angostura(ANG) Reservoir(northwest Mexico), using210Pb geochronology. The enrichment factors showed from null to minor enrichment for most elements, but moderate to severe enrichment of mercury(Hg). Most trace element concentrations had a detrital origin, and notable Hg concentration increases since the past decade were associated with severe drought periods, likely resulting from wildfires. The observed sediment concentrations of As and Hg can cause adverse effects on biota in the ecosystem since they are above the probable effect level(PEL). development of strategies for metal attenuation in this reservoir is recommended and metals should be controlled until specific ecotoxicological studies are performed.

关键词： Aquatic ecosystems 210Pb geochronology Mining activities Metals Metalloids Enrichment factors

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Screening chloroplast regions in Calophyllum brasiliense (Calophyllaceae) for suitability for population genetic analyses

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Journal of Forestry Research 2018年第4期29卷 978-985页

作者： Cecilia B. Percuoco Lucas G. Gimenez Liliana N. Talavera Stefani Jorge V. Crisci Carina F. Argüelles Laboratorio GIGA Instituto de Biologia Subtropical Nodo Posadas Universidad Nacional de Misiones (UNaM) Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) Jujuy 1745 N3300NFK Posadas Misiones Argentina Catedra de Genetica Molecular Facultad de Ciencias Exactas Quimicas y Naturales (FCEQyN) Universidad Nacional de Misiones (UNaM) Felix de Azara 1552 N3300LQH Posadas Misiones Argentina Laboratorio de Sistematica y Biologia Evolutiva (LASBE) Facultad de Ciencias naturales y Museo (FCNyM) Universidad Nacional de La Plata-(UNLP) Avenida 122 y 60 1900 La Plata Buenos Aires Argentina

The uniparental inheritance and conserved structure of the chloroplast genome among many angiosperms makes it suitable for constructing gene lineages and inferring population histories based on these relationships. However, the analysis of a single chloroplast region to solve population issues has not yielded the desired amount of variability due to the low mutation rate. Therefore, it is necessary to screen and carefully analyze chloroplast intergenic or intronic regions to select the most appropriate for studying the genetic variability in the chloroplast genome of a particular taxon. In this context, the aim of this work was to characterize 8 regions in Calophyllum brasiliense using 11 selected primer pairs and to evaluate their usefulness for phylogeographic analysis. Intergenic spacers petA-psbJ, petG-trnP and rp132-trnL and the trnL intron demonstrated potentially informative sites. The combination of these 4 regions will allow the analysis of genetic population structure and the integration of historical aspects to inform strategies for conserving C. brasiliense, especially for highly impacted populations and those at risk of local extinction.

关键词： cpDNA cpSSRs Noncoding regions

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Ecofriendly E-Nose Based in PLA and Only 0.3 wt%of CNTs

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Journal of Renewable Materials 2019年第4期7卷 355-363页

作者： Laura Ribba Jonathan Cimadoro Silvia Goyanes Universidad de Buenos Aires Facultad de Ciencias Exactas y NaturalesDepartamento de FísicaLaboratorio de Polímeros y Materiales Compuestos(LP&MC)Instituto de Física de Buenos Aires(IFIBA-CONICET)Ciudad Universitaria(1428)Ciudad Autónoma de Buenos AiresArgentina

In this work,conductive polymer nanocomposites were developed based on a biodegradable and biobased polymer(poly(lactic acid)),with the incorporation of only 0.3 wt%of carbon nanotubes(CNTs)to be used as volatile solvent *** correct dispersion of the nanofiller was achieved thanks to a CNT non-covalent modification with an azo-dye(disperse orange 3)which allowed to reach the percolation for electric conduction in values as low as 0.3 wt%.The chemo-resistive properties of the developed sensors were investigated by exposure to organic vapors(ethanol,tetrahydrofuran and toluene)and water vapor,showing good *** addition,considering the manipulation to which the sensor will be exposed,wear resistance was characterized,finding that the incorporation of CNTs produced an increase in more than a 50%.

关键词： Poly(lactic acid) carbon nanotubes sensor CPC organic solvent vapor DO3

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