Person: Raggio Quílez, José
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First Name
José
Last Name
Raggio Quílez
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Farmacia
Department
Farmacología, Farmacognosia y Botánica
Area
Botánica
Identifiers
6 results
Search Results
Now showing 1 - 6 of 6
Item Recent Warming and Cooling in the Antarctic Peninsula Region has Rapid and Large Effects on Lichen Vegetation(Scientific Reports, 2017) Navarro, Francisco; Ramos, Miguel; Pablo, Miguel Angel De; Blanquer, José Manuel; Valladares, Fernando; García Sancho, Leopoldo; Pintado Valverde, Ana; Raggio Quílez, José; Green, Thomas George AllanThe Antarctic Peninsula has had a globally large increase in mean annual temperature from the 1951 to 1998 followed by a decline that still continues. The challenge is now to unveil whether these recent, complex and somewhat unexpected climatic changes are biologically relevant. We were able to do this by determining the growth of six lichen species on recently deglaciated surfaces over the last 24 years. Between 1991 and 2002, when mean summer temperature (MST) rose by 0.42 °C, five of the six species responded with increased growth. MST declined by 0.58 °C between 2002 and 2015 with most species showing a fall in growth rate and two of which showed a collapse with the loss of large individuals due to a combination of increased snow fall and longer snow cover duration. Increased precipitation can, counter-intuitively, have major negative effects when it falls as snow at cooler temperatures. The recent Antarctic cooling is having easily detectable and deleterious impacts on slow growing and highly stress-tolerant crustose lichens, which are comparable in extent and dynamics, and reverses the gains observed over the previous decades of exceptional warming.Item Photosynthetic rate and thallus size are not related in alpine yellow-green Rhizocarpon crustose lichens: Implications for lichenometry and growth(Geomorphology, 2018) Raggio Quílez, José; Green, Thomas George Allan; García Sancho, Leopoldo; Pintado Valverde, AnaLichenometry, first proposed at the beginning of the XXth century, is a technique that uses growth rates of saxicolous crustose lichens to date exposed surfaces over an age range of 500 years from present. Despite of the wide use of the methodology, it has been strongly criticized by several authors who consider that biological aspects involved in growth rates of lichens used are not sufficiently considered and that this will contribute to uncertainty in the final surface dating. The assumption, important for direct lichenometric measurements, that crustose lichens have constant growth rates through all their life span, is controversial, with some works pointing to a change in growth rate with thallus size in yellow-green Rhizocarpon sp. samples, the most widely lichens used for surface dating. This change in growth rate with size would contribute to inaccuracy in dating. In this work, we contribute to the discussion with a novel approach in which we measure several physiological parameters linked to carbon gain in 42 Rhizocarpon sp. samples of different sizes collected in the same locality. We found no significant relationship between thallus photosynthetic rate and thallus size indicating that possible growth rate variations over Rhizocarpon life span are not linked to carbon gain. The experiment performed provides a new data set to include in lichenometric modelling with the aim to obtain a better understanding of crustose lichens biology before attempting more feasible and accurate surface dating strategies. Measurements of length of activity periods and carbon allocation in Rhizocarpon are recommended to achieve future improvements in this direction.Item Relative humidity predominantly determines long‐term biocrust‐forming lichen cover in drylands under climate change(Journal of Ecology, 2020) Baldauf, Selina; Porada, Philipp; Maestre, Fernando T.; Tietjen, Britta; Raggio Quílez, José; Shurong ZhouAbstract Manipulative experiments typically show a decrease in dryland biocrust cover and altered species composition under climate change. Biocrust-forming lichens, such as the globally distributed Diploschistes diacapsis, are particularly affected and show a decrease in cover with simulated climate change. However, the underlying mechanisms are not fully understood, and long-term interacting effects of different drivers are largely unknown due to the short-term nature of the experimental studies conducted so far. We addressed this gap and successfully parameterised a process-based model for D. diacapsis to quantify how changing atmospheric CO2, temperature, rainfall amount and relative humidity affect its photosynthetic activity and cover. We also mimicked a long-term manipulative climate change experiment to understand the mechanisms underlying observed patterns in the field. The model reproduced observed experimental findings: warming reduced lichen cover, whereas less rainfall had no effect on lichen performance. This warming effect was caused by the associated decrease in relative humidity and non-rainfall water inputs, which are major water sources for biocrust-forming lichens. Warming alone, however, increased cover because higher temperatures promoted photosynthesis during early morning hours with high lichen activity. When combined, climate variables showed non-additive effects on lichen cover, and effects of increased CO2 levelled off with decreasing levels of relative humidity. Synthesis. Our results show that a decrease in relative humidity, rather than an increase in temperature, may be the key factor for the survival of the lichen D. diacapsis under climate change and that effects of increased CO2 levels might be offset by a reduction in non-rainfall water inputs in the future. Because of a global trend towards warmer and drier air and the widespread global distribution of D. diacapsis, this will affect lichen-dominated dryland biocrust communities and their role in regulating ecosystem functions worldwide.Item High nitrogen contribution by Gunnera magellanica and nitrogen transfer by mycorrhizas drive an extraordinarily fast primary succession in sub‐Antarctic Chile(New Phytologist, 2019) Benavent González, Alberto; Raggio Quílez, José; Villagra, Johana ; Pintado Valverde, Ana; Blanquer, José Manuel ; Rozzi, Ricardo ; Green, Thomas George Allan; García Sancho, LeopoldoChronosequences at the forefront of retreating glaciers provide information about colonization rates of bare surfaces. In the northern hemisphere, forest development can take centuries, with rates often limited by low nutrient availability. By contrast, in front of the retreating Pia Glacier (Tierra del Fuego, Chile), a Nothofagus forest is in place after only 34 yr of development, while total soil nitrogen (N) increased from near zero to 1.5%, suggesting a strong input of this nutrient. We measured N-fixation rates, carbon fluxes, leaf N and phosphorus contents and leaf δ15N in the dominant plants, including the herb Gunnera magellanica, which is endosymbiotically associated with a cyanobacterium, in order to investigate the role of N-fixing and mycorrhizal symbionts in N-budgets during successional transition. G. magellanica presented some of the highest nitrogenase activities yet reported (potential maximal contribution of 300 kg N ha−1 yr−1). Foliar δ15N results support the framework of a highly efficient N-uptake and transfer system based on mycorrhizas, with c. 80% of N taken up by the mycorrhizas potentially transferred to the host plant. Our results suggest the symbiosis of G. magellanica with cyanobacteria, and trees and shrubs with mycorrhizas, to be the key processes driving this rapid successioncyanobacteriaItem Warming reduces the cover, richness and evenness of lichen‐dominated biocrusts but promotes moss growth: insights from an 8 yr experiment(New Phytologist, 2018) Ladrón de Guevara, Mónica; Gozalo, Beatriz; Lafuente, Angela; Prieto, María; Maestre, Fernando T.; Raggio Quílez, JoséSummary Despite the important role that biocrust communities play in maintaining ecosystem structure and functioning in drylands world-wide, few studies have evaluated how climate change will affect them. Using data from an 8-yr-old manipulative field experiment located in central Spain, we evaluated how warming, rainfall exclusion and their combination affected the dynamics of biocrust communities in areas that initially had low (< 20%, LIBC plots) and high (> 50%, HIBC plots) biocrust cover. Warming reduced the richness (35 ± 6%), diversity (25 ± 8%) and cover (82 ± 5%) of biocrusts in HIBC plots. The presence and abundance of mosses increased with warming through time in these plots, although their growth rate was much lower than the rate of lichen death, resulting in a net loss of biocrust cover. On average, warming caused a decrease in the abundance (64 ± 7%) and presence (38 ± 24%) of species in the HIBC plots. Over time, lichens and mosses colonized the LIBC plots, but this process was hampered by warming in the case of lichens. The observed reductions in the cover and diversity of lichen-dominated biocrusts with warming will lessen the capacity of drylands such as that studied here to sequester atmospheric CO2 and to provide other key ecosystem services associated to these communities.Item Continuous chlorophyll fluorescence, gas exchange and microclimate monitoring in a natural soil crust habitat in Tabernas badlands, Almería, Spain: progressing towards a model to understand productivity(Biodiversity and Conservation, 2014) Vivas, M.; Büdel, B.; Colesie, C.; Weber, B.; Schroeter, B.; Lázaro, R.; Raggio Quílez, José; Pintado Valverde, Ana; García Sancho, Leopoldo; Green, Thomas George AllanThe Soil Crust International project aims to better understand the functioning of biological soil crust environments (BSC) in Europe in order to understand the importance of these ecosystems.The final objective of this project is to inform and streng then protection strategies for these types of habitats in the frame of the European Union. To achieve this, four different soil crust regions have been chosen in Europe following latitudinal and altitudinal gradients .The work presented here is based on the simultaneous monitoring of gas exchange, chlorophyll fluorescence and microclimate of the most abundant BSC in one of these four locations, the Tabernas badlands, Almeria, SE Spain, one of thedriest regions in Europe. The five BSC types monitored are dominated by the lichen species Squamarina cartilaginea, Diploschistes diacapsis, Toninia albilabra and Psora decipiens, and by the moss Didymodon rigidulus.We aim to understand the conditions in which the BSC are metabolically active in order to get a better knowledge about the contribution of the BSC to the carbon budge tof the ecosystem. Our first results after nearly1 year of chlorophyll fluorescence and microclimatic monitoring linked to gas exchange data during typical activity days obtained in the field suggest similar physiological performance between the different BSC types studied. BSC were active under suboptimal conditions, and activity duration was not different whether measured by chlorophyll a fluorescence or CO2 gas exchange, a relationship that will be the basis of a productivity model.