Browsing by Author "Fajardo, Alex"

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    Drivers of woody dominance across global drylands
    (American Association for the Advancement of Science, 2024-10-11) Biancari, Lucio; Aguiar, Martín R.; Eldridge, David J.; Oñatibia, Gastón R.; Le Bagousse-Pinguet, Yoann; Saiz, Hugo; Gross, Nicolas; Austin, Amy T.; Ochoa, Victoria; Gozalo, Beatriz; Asensio, Sergio; Guirado, Emilio; Valencia, Enrique; Berdugo, Miguel; Plaza, César; Martínez-Valderrama, Jaime; Mendoza, Betty J.; García-Gómez, Miguel; Abedi, Mehdi; Ahumada, Rodrigo J.; Alcántara, Julio M.; Amghar, Fateh; Anadón, José D.; Aramayo, Valeria; Arredondo, Tulio; Bader, Maaike Y.; Bahalkeh, Khadijeh; Ben Salem, Farah; Blaum, Niels; Boldgiv, Bazartseren; Bowker, Matthew; Branquinho, Cristina; Bu, Chongfeng; Byambatsogt, Batbold; Calvo, Dianela A.; Castillo Monroy, Andrea P.; Castro, Helena; Castro-Quezada, Patricio; Chibani, Roukaya; Conceição, Abel A.; Currier, Courtney M.; Donoso, David A.; Dougill, Andrew; Ejtehadi, Hamid; Espinosa, Carlos I.; Fajardo, Alex; Farzam, Mohammad; Ferrante, Daniela; Fraser, Lauchlan H.; Gaitán, Juan J.; Gherardi, Laureano A.; Gusmán-Montalván, Elizabeth; Hernández-Hernández, Rosa M.; Hölzel, Norbert; Huber-Sannwald, Elisabeth; Hughes, Frederic M.; Jadán, Oswaldo; Jeltsch, Florian; Jentsch, Anke; Ju, Mengchen; Kaseke, Kudzai F.; Kindermann, Liana; Köbel, Melanie; le Roux, Peter C.; Liancourt, Pierre; Linstädter, Anja; Liu, Jushan; Louw, Michelle A.; Maggs-Kölling, Gillian; Malam Issa, Oumarou; Marais, Eugene; Margerie, Pierre; Messeder, João Vitor S.; Mora, Juan P.; Moreno, Gerardo; Munson, Seth M.; Oliva, Gabriel; Pueyo, Yolanda; Quiroga, R. Emiliano; Reed, Sasha C.; Rey, Pedro J.; Rodríguez, Alexandra; Rodríguez, Laura B.; Rolo, Víctor; Ruppert, Jan C.; Sala, Osvaldo; Salah, Ayman; Stavi, Ilan; Stephens, Colton R. A.; Swemmer, Anthony M.; Teixido, Alberto L.; Thomas, Andrew D.; Throop, Heather L.; Tielbörger, Katja; Travers, Samantha K.; van den Brink, Liesbeth; Wagner, Viktoria; Wamiti, Wanyoike; Wang, Deli; Wang, Lixin; Wolff, Peter; Yahdjian, Laura; Zaady, Eli; Maestre, Fernando T.; Earth and Environmental Sciences, School of Science
    Increases in the abundance of woody species have been reported to affect the provisioning of ecosystem services in drylands worldwide. However, it is virtually unknown how multiple biotic and abiotic drivers, such as climate, grazing, and fire, interact to determine woody dominance across global drylands. We conducted a standardized field survey in 304 plots across 25 countries to assess how climatic features, soil properties, grazing, and fire affect woody dominance in dryland rangelands. Precipitation, temperature, and grazing were key determinants of tree and shrub dominance. The effects of grazing were determined not solely by grazing pressure but also by the dominant livestock species. Interactions between soil, climate, and grazing and differences in responses to these factors between trees and shrubs were key to understanding changes in woody dominance. Our findings suggest that projected changes in climate and grazing pressure may increase woody dominance in drylands, altering their structure and functioning.
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    Grazing and ecosystem service delivery in global drylands
    (American Association for the Advancement of Science, 2022-11-24) Maestre, Fernando T.; Bagousse-Pinguet, Yoann Le; Delgado-Baquerizo, Manuel; Eldridge , David J.; Saiz, Hugo; Berdugo, Miguel; Gozalo, Beatriz; Ochoa, Victoria; Guirado, Emilio; García-Gómez, Miguel; Valencia, Enrique; Gaitán, Juan J.; Asensio, Sergio; Mendoza, Betty J.; Plaza, César; Díaz-Martínez, Paloma; Rey, Ana; Hu, Hang-Wei; He, Ji-Zheng; Wang, Jun-Tao; Lehmann, Anika; Rillig, Matthias C.; Cesarz, Simone; Esenhauer, Nico; Martínez-Valderrama, Jaime; Moreno-Jiménez, Eduardo; Sala, Osvaldo; Abedi, Mehdi; Ahmadian, Negar; Alados, Concepción L.; Aramayo, Valeria; Amghar, Fateh; Arredondo, Tulio; Ahumada, Rodrigo J.; Bahalkeh, Khadijeh; Ben Salem , Farah; Blaum, Niels; Boldgiv, Bazartseren; Bowker, Matthew A.; Bran, Donaldo; Bu, Chongfeng; Canessa, Rafaella; Castillo-Monroy, Andrea P.; Castro, Helena; Castro, Ignacio; Castro-Quezada, Patricio; Chibani, Roukaya; Conceição , Abel A.; Currier, Courtney M.; Darrouzet-Nardi, Anthony; Deák, Balázs; Donoso, David A.; Dougill, Andrew J.; Durán, Jorge; Erdenetsetseg, Batdelger; Espinosa, Carlos I.; Fajardo, Alex; Farzam, Mohammad; Ferrante, Daniela; Frank, Anke S. K.; Fraser, Lauchlan H.; Gherardi, Laureano A.; Greenville, Aaron C.; Guerra, Carlos A.; Gusmán-Montalvan, Elizabeth; Hernández-Hernández, Rosa M.; Hölzel, Norbert; Huber-Sannwald, Elisabeth; Hughes, Frederic M.; Jadán-Maza, Oswaldo; Jeltsch, Florian; Jentsch, Anke; Kaseke, Kudzai F.; Köbel, Melanie; Koopman, Jessica E.; Leder, Cintia V.; Linstädter, Anja; Le Roux, Peter C.; Li, Xinkai; Liancourt, Pierre; Liu, Jushan; Louw, Michelle A.; Maggs-Kölling, Gillian; Makhalanyane, Thulani P.; Malam Issa, Oumarou; Manzaneda, Antonio J.; Marais, Eugene; Mora, Juan P.; Moreno, Gerardo; Munson, Seth M.; Nunes, Alice; Oliva, Gabriel; Oñatibia, Gastón R.; Peter, Guadalupe; Pivari, Marco O. D.; Pueyo , Yolanda; Quiroga, R. Emiliano; Rahmanian, Soroor; Reed, Sasha C.; Rey, Pedro J.; Richard, Benoit; Rodríguez, Alexandra; Rolo, Víctor; Rubalcaba, Juan G.; Ruppert, Jan C.; Salah, Ayman; Schuchardt, Max A.; Spann, Sedona; Stavi, Ilan; Stephens, Colton R. A.; Swemmer, Anthony M.; Teixido, Alberto L.; Thomas , Andrew D.; Throop, Heather L.; Tielbörger, Katja; Travers, Samantha; Val, James; Valkó, Orsolya; Van Den Brink , Liesbeth; Ayuso, Sergio Valesco; Velbert, Frederike; Wamiti, Wanyoike; Wang, Deli; Wang, Lixin; Wardel, Glenda M.; Yahdjian, Laura; Zaady, Eli; Zhang, Yuanming; Zhou, Xiaobing; Singh, Brajesh K.; Gross, Nicolas; Earth and Environmental Sciences, School of Science
    Grazing represents the most extensive use of land worldwide. Yet its impacts on ecosystem services remain uncertain because pervasive interactions between grazing pressure, climate, soil properties, and biodiversity may occur but have never been addressed simultaneously. Using a standardized survey at 98 sites across six continents, we show that interactions between grazing pressure, climate, soil, and biodiversity are critical to explain the delivery of fundamental ecosystem services across drylands worldwide. Increasing grazing pressure reduced ecosystem service delivery in warmer and species-poor drylands, whereas positive effects of grazing were observed in colder and species-rich areas. Considering interactions between grazing and local abiotic and biotic factors is key for understanding the fate of dryland ecosystems under climate change and increasing human pressure.
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    Isotopic evidence for oligotrophication of terrestrial ecosystems
    (Nature, 2018) Craine, Joseph; Elmore, Andrew J.; Wang, Lixin; Aranibar, Julieta; Bauters, Marijn; Boeckx, Pascal; Crowley, Brooke E.; Dawes, Melissa A.; Delzon, Sylvain; Fajardo, Alex; Fang, Yunting; Fujiyoshi, Lei; Gray, Alan; Guerrieri, Rossella; Gundale, Michael J.; Hawke, David J.; Hietz, Peter; Jonard, Mathieu; Kearsley, Elizabeth; Kenzo, Tanaka; Makarov, Mikhail; Marañón-Jiménez, Sara; McGlynn, Terrence P.; McNeil, Brenden E.; Mosher, Stella G.; Nelson, David M.; Peri, Pablo L.; Roggy, Jean Christophe; Sanders-DeMott, Rebecca; Song, Minghua; Szpak, Paul; Templer, Pamela H.; Van der Colff, Dewidine; Werner, Christiane; Xu, Xingliang; Yang, Yang; Yu, Guirui; Zmudczyńska-Skarbek, Katarzyna; Earth Sciences, School of Science
    Human societies depend on an Earth system that operates within a constrained range of nutrient availability, yet the recent trajectory of terrestrial nitrogen (N) availability is uncertain. Examining patterns of foliar N concentrations and isotope ratios (δ15N) from more than 43,000 samples acquired over 37 years, here we show that foliar N concentration declined by 9% and foliar δ15N declined by 0.6–1.6‰. Examining patterns across different climate spaces, foliar δ15N declined across the entire range of mean annual temperature and mean annual precipitation tested. These results suggest declines in N supply relative to plant demand at the global scale. In all, there are now multiple lines of evidence of declining N availability in many unfertilized terrestrial ecosystems, including declines in δ15N of tree rings and leaves from herbarium samples over the past 75–150 years. These patterns are consistent with the proposed consequences of elevated atmospheric carbon dioxide and longer growing seasons. These declines will limit future terrestrial carbon uptake and increase nutritional stress for herbivores.