Effect of the host tree genotype and the fire recurrence on fungal communities in Mediterranean pine forests

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología. Fecha de lectura:10-03-2017Esta tesis tiene embargado el acceso al texto completo hasta el 10-03-201

Carbon redistribution by erosion processes in an intensively disturbed catchment

29 Pags.- 6 Tabls.- 6 Figs. This article belongs to a special issue of Catena titled "Geoecology in Mediterranean mountain areas. Tribute to Professor José María García Ruiz". The definitive version is available at: http://www.sciencedirect.com/science/journal/03418162Understanding how organic carbon (OC) moves with sediments along the fluvial system is crucial to determining catchment scale carbon budgets and helps the proper management of fragile ecosystems. Especially challenging is the analysis of OC dynamics during fluvial transport in heterogeneous, fragile, and disturbed environments with ephemeral and intense hydrological pulses, typical of Mediterranean conditions. This paper explores the catchment scale OC redistribution by lateral flows in extreme Mediterranean environmental conditions, from a geomorphological perspective. The study area is a catchment (Cárcavo) in SE Spain with a semiarid climate, erodible lithologies, and shallow soils, which is highly disturbed by agricultural terraces, land levelling, reforestation, and construction of check-dams. To increase our understanding of catchment scale OC redistribution induced by erosion, we studied in detail the subcatchments of eight check-dams distributed along the catchments main channel. We determined 137Cs, physicochemical characteristics, and the OC pools of the catchment soils and sediments deposited behind each check-dam, performed spatial analysis of catchment properties and buffer areas around the check-dams, and carried out geomorphological analysis of the slope-channel connections. The soils showed very low total organic carbon (TOC) values, oscillating between 15.2 and 4.4 g kg− 1 for forest and agricultural soils, respectively. Sediments mobilized by erosion were poor in TOC (6.6 ± 0.7 g kg– 1) compared to the eroded (forest) soils, and the redistribution of OC through the catchment, especially of the mineral associated organic carbon (MAC) pool, showed the same pattern as clay particles and 137Cs. The TOC erosion rates estimated for the Cárcavo watershed are relatively low (0.031 ± 0.03 Mg ha− 1 y− 1) but similar to those reported for subhumid Mediterranean catchments that are less fragile and more conducive to plant growth. The TOC erosion/total erosion ratio was lower (0.06%) than other estimates, although the average OC concentration of the sediments was higher than that of the agricultural soils of the catchment, underlining the problem of maintaining sustainable soil OC contents. The OC in deposited sediments came not only from surface erosion processes, but also from deeper soil or sediment layers mobilized by concentrated erosion processes. Sediment richer in OC came from the surface soil of vegetated (reforested) areas close and well connected to the channels. Subcatchments dominated by laminar erosion processes showed a TOC erosion/total erosion ratio that was two times higher than that of subcatchments dominated by concentrated flow erosion processes. The lithology, soils, and geomorphology exert a more important control on OC redistribution than land use and vegetation cover in this geomorphologically very active catchment.This work was financially supported by the projects ADAPT (CGL2013-42009-R) and DISECO (CGL2014-55-405-R) from the Spanish Government, National Plan of Science; the project CAMBIO (18933/JLI/13) of the Seneca Foundation, Regional Government of Murcia (Spain); and the project SOGLO (P7/24 IAP BELSPO) from the Belgian Government. Joris de Vente was supported by a ‘Ramón y Cajal’ grant (RYC-2012-10375).Peer reviewe

Habitat fragmentation is linked to cascading effects on soil functioning and CO2 emissions in Mediterranean holm-oak-forests

We studied key mechanisms and drivers of soil functioning by analyzing soil respiration and enzymatic activity in Mediterranean holm oak forest fragments with different influence of the agricultural matrix. For this, structural equation models (SEM) were built including data on soil abiotic (moisture, temperature, organic matter, pH, nutrients), biotic (microbial biomass, bacterial and fungal richness), and tree-structure-related (basal area) as explanatory variables of soil enzymatic activity and respiration. Our results show that increased tree growth induced by forest fragmentation in scenarios of high agricultural matrix influence triggered a cascade of causal-effect relations, affecting soil functioning. On the one hand, soil enzymatic activity was strongly stimulated by the abiotic (changes in pH and microclimate) and biotic (microbial biomass) modifications of the soil environment arising from the increased tree size and subsequent soil organic matter accumulation. Soil CO2 emissions (soil respiration), which integrate releases from all the biological activity occurring in soils (autotrophic and heterotrophic components), were mainly affected by the abiotic (moisture, temperature) modifications of the soil environment caused by trees. These results, therefore, suggest that the increasing fragmentation of forests may profoundly impact the functioning of the plant-soil-microbial system, with important effects over soil CO2 emissions and nutrient cycling at the ecosystem level. Forest fragmentation is thus revealed as a key albeit neglected factor for accurate estimations of soil carbon dynamics under global change scenarios

Fire severity as a key determinant of aboveground and belowground biological community recovery in managed even-aged boreal forests

Changes in fire regime of boreal forests in response to climate warming are expected to impact postfire recovery. However, quantitative data on how managed forests sustain and recover from recent fire disturbance are limited.Two years after a large wildfire in managed even-aged boreal forests in Sweden, we investigated how recovery of aboveground and belowground communities, that is, understory vegetation and soil microbial and faunal communities, responded to variation in the severity of soil (i.e., consumption of soil organic matter) and canopy fires (i.e., tree mortality).While fire overall enhanced diversity of understory vegetation through colonization of fire adapted plant species, it reduced the abundance and diversity of soil biota. We observed contrasting effects of tree- and soil-related fire severity on survival and recovery of understory vegetation and soil biological communities. Severe fires that killed overstory Pinus sylvestris promoted a successional stage dominated by the mosses Ceratodon purpureus and Polytrichum juniperinum, but reduced regeneration of tree seedlings and disfavored the ericaceous dwarf-shrub Vaccinium vitis-idaea and the grass Deschampsia flexuosa. Moreover, high tree mortality from fire reduced fungal biomass and changed fungal community composition, in particular that of ectomycorrhizal fungi, and reduced the fungivorous soil Oribatida. In contrast, soil-related fire severity had little impact on vegetation composition, fungal communities, and soil animals. Bacterial communities responded to both tree- and soil-related fire severity.Synthesis: Our results 2 years postfire suggest that a change in fire regime from a historically low-severity ground fire regime, with fires that mainly burns into the soil organic layer, to a stand-replacing fire regime with a high degree of tree mortality, as may be expected with climate change, is likely to impact the short-term recovery of stand structure and above- and belowground species composition of even-aged P. sylvestris boreal forests

Complex effects of habitat fragmentation on plant‐soil microbial interactions in Mediterranean Holmoak forests

Póster presentado en el 1st Global Soil Biodiversity Conference (2-5 December 2014 - Dijon, France)The adverse effects of habitat fragmentation on biodiversity have been widely explored; however, little research has been conducted to understand its effects on ecosystem functioning. Effects of forest fragmentation are tightly linked to the surrounding matrix in terms of nutrient inputs and spatial constraints, leading to complex edge effects. Soil ecosystem processes related to carbon cycling are particularly important since soils are the largest carbon pool in terrestrial ecosystems, and habitat fragmentation affects their sink capacity and their vulnerability to global change. Soil organic matter (SOM) decomposition is affected directly by the canopy cover. Thus, the effects of an agricultural matrix could be overridden by the direct effects of canopy rather than by habitat fragmentation itself. In order to evaluate which key factors could be driving SOM decomposition in fragmented landscapes, we analyzed potential enzymatic activities (β-glucosidase, chitinase and phosphatase acid) and field soil respiration in fragmented Mediterranean Holm oak forests. We evaluated if the impact of fragmentation on soil microbial functioning could be explained through its effect on microhabitat characteristics by using structural equation models. Variables measured included biotic (microbial biomass), abiotic (soil moisture, temperature, organic matter, pH, nutrients) and tree structural (stem diameter, canopy projection, leaf area index) characteristics. Tree effects on soil functioning (enzymatic activities) were potentiated by the influence of the agricultural matrix. As expected, trees created a microenvironment where the increment of SOM modified the pH, increasing soil moisture and decreasing temperature, rising the amount of microbial biomass and, therefore, improving the functioning of soil microbial community. Agricultural matrix influence on SOM decomposition was mainly indirect, through its positive effect on tree size. Mediterranean fragmented forests with high influence of agricultural matrix could increase SOM decomposition rates, decreasing soil carbon sink capacity.Peer reviewe

A global experiment on motivating social distancing during the COVID-19 pandemic

Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e., a controlling message) compared with no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared with the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing. Controlled motivation was associated with more defiance and less long-term behavioral intention to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges

75 años como referente de la investigación agraria y medioambiental española en condiciones de clima mediterráneo [Sitio Web]

1 .pdf con imagen de acceso al “website”, su url y los créditos relacionados con su creación y diseño.-- Créditos: Organización, Estación Experimental de Aula Dei (EEAD-CSIC); Dirección, Jesús Val Falcón; Coordinación, Ana Álvarez-Fernandez, Jorge Álvaro-Fuentes, Ernesto Igartua; Contenido, Anunciación Abadía, Javier Abadía, Carlos Albiñana, Miguel Alfonso, Arancha Arbeloa, Raúl Arbués, Isabel Armillas, Manuel Becana, Santiago Beguería, Carmen Castañeda, Ana Castillo, José Cavero, Bruno Contreras, Azahara Díaz, Edgar García, Elena García, Juan Manuel Gascuñana, Leticia Gaspar, Yolanda Gogorcena, Juan Herrero, Victoria Lafuente, María Victoria López, Juan Antonio Marín, José Martínez, José Carlos Martínez-Giménez, Ana Pilar Mata, Manuel Matamoros, Pierre Mignard, María Ángeles Moreno, Paula Murillo, Ana Navas, Antonio Pérez, Rafael Picorel, María Pilar Vallés, Irene Villar, Inmaculada Yruela, Nery Zapata, Isabel Zarazaga; Diseño y programación: DigitalWorks (Juanjo Ascaso y Asun Dieste); Vídeo, Delegación del CSIC en Aragón (Sara Gutiérrez y Yolanda Hernáiz); Fotografía, Archivo EEAD-CSIC, Anunciación Abadía, Jorge Álvaro-Fuentes, Arancha Arbeloa, Juanjo Ascaso, Santiago Beguería, Elena García, Ernesto Igartua, Ignasi Iglesias, José Manuel Lasa, José Carlos Martínez-Giménez, Pierre Mignard, María Ángeles Moreno, Rubén Sancho, Kosana Suvocarev, María Pilar Vallés, Nery Zapata."Sitio web" de nueva creación y conmemorativo del 75 Aniversario de la EEAD-CSIC que contiene: 1) Foto esférica de su personal en activo; 2) Recopilación de sus hitos históricos más destacados, en orden cronológico; 3) Un vídeo con participación de su personal y muestra de algunas de sus instalaciones; 4) Un mapa con la distribución geográfica de los egresado del Instituto; 5) Algunas fotos, destacando las tomadas a su personal en las celebraciones del 25 y 50 Aniversarios de la EEAD-CSIC.Presentado durante la "Jornada. 75 Aniversario EEAD-CSIC (Zaragoza, Patio de la Infanta. 30 octubre 2019)".Financiación: CSIC, Vicepresidencia Adjunta de Organización y Cultura Científica.N

A multi-country test of brief reappraisal interventions on emotions during the COVID-19 pandemic.

The COVID-19 pandemic has increased negative emotions and decreased positive emotions globally. Left unchecked, these emotional changes might have a wide array of adverse impacts. To reduce negative emotions and increase positive emotions, we tested the effectiveness of reappraisal, an emotion-regulation strategy that modifies how one thinks about a situation. Participants from 87 countries and regions (n = 21,644) were randomly assigned to one of two brief reappraisal interventions (reconstrual or repurposing) or one of two control conditions (active or passive). Results revealed that both reappraisal interventions (vesus both control conditions) consistently reduced negative emotions and increased positive emotions across different measures. Reconstrual and repurposing interventions had similar effects. Importantly, planned exploratory analyses indicated that reappraisal interventions did not reduce intentions to practice preventive health behaviours. The findings demonstrate the viability of creating scalable, low-cost interventions for use around the world

Crown-fire severity is more important than ground-fire severity in determining soil fungal community development in the boreal forest

Wildfire shapes the structure, dynamic and functioning of boreal forests. With predicted warmer and drier summers, increased incidence and intensity of crown-fires may affect plant-soil interactions with consequences for post-fire fertility and forest productivity.We assessed how severity of crown- and ground-fire in boreal pine forests affected post-fire responses of soil fungal communities and their associated enzyme activities, and how variation in fire severity interacts with salvage (post-fire) logging in impacting soil fungi.Crown fire-induced tree mortality had a stronger impact on fungal biomass and community composition than did ground-fire-induced loss of soil organic matter. Severe crown-fire led to replacement of ectomycorrhizal- and litter-associated fungi by stress-tolerant ascomycetes. Elevated activities of hydrolytic enzymes in burned areas were correlated with root-associated ascomycetes and moulds, suggesting opportunistic exploitation of labile organic substrates. Fire did not, however, increase the abundance of more potent basidiomycete decomposers in the organic layer, nor did it enhance organic matter oxidation by fungal peroxidases, indicating that the potential for major post-fire losses of carbon due to stimulated decomposition is limited. Rather, peroxidase activity was low in burned areas, likely reflecting the absence of ectomycorrhizal fungi. Post-fire salvage logging induced larger shifts in fungal communities in areas with low crown-fire severity.Synthesis. Historically, boreal pine forests have been shaped by low-severity ground-fires. Our study highlights a risk that increasing occurrence of high-severity crown-fire as climate warms will have detrimental effects on mycorrhizal-mediated functions that are pivotal for maintaining organic matter turnover, soil fertility and forest resilience