Decoupling of soil nutrient cycles as a function of aridity in global drylands

18 páginas.- 10 figuras.- 72 referencias.- Online Content Any additional Methods, Extended Data display items and Source Data are available in the online version of the paper; references unique to these sections appear only in the online paper..- Puede conseguir el texto completo en el Portal de la producción científica de la Universidad Complutense de Madrid https://produccioncientifica.ucm.es/documentos/5ec78dc52999520a1d557660 .- o en lel respositorio institucional CONICET digital https://ri.conicet.gov.ar/bitstream/handle/11336/29204/CONICET_Digital_Nro.ead4e2ed-0da6-4041-814b-259e8f27bbf6_D.pdf?sequence=5&isAllowed=yThe biogeochemical cycles of carbon (C), nitrogen (N) and phosphorus (P) are interlinked by primary production, respiration and decomposition in terrestrial ecosystems1. It has been suggested that the C, N and P cycles could become uncoupled under rapid climate change because of the different degrees of control exerted on the supply of these elements by biological and geochemical processes1,2,3,4,5. Climatic controls on biogeochemical cycles are particularly relevant in arid, semi-arid and dry sub-humid ecosystems (drylands) because their biological activity is mainly driven by water availability6,7,8. The increase in aridity predicted for the twenty-first century in many drylands worldwide9,10,11 may therefore threaten the balance between these cycles, differentially affecting the availability of essential nutrients12,13,14. Here we evaluate how aridity affects the balance between C, N and P in soils collected from 224 dryland sites from all continents except Antarctica. We find a negative effect of aridity on the concentration of soil organic C and total N, but a positive effect on the concentration of inorganic P. Aridity is negatively related to plant cover, which may favour the dominance of physical processes such as rock weathering, a major source of P to ecosystems, over biological processes that provide more C and N, such as litter decomposition12,13,14. Our findings suggest that any predicted increase in aridity with climate change will probably reduce the concentrations of N and C in global drylands, but increase that of P. These changes would uncouple the C, N and P cycles in drylands and could negatively affect the provision of key services provided by these ecosystems.This research is supported by the European Research Council (ERC) under the European Community's Seventh Framework Programme (FP7/2007-2013)/ERC Grant agreement no. 242658 (BIOCOM), and by the Ministry of Science and Innovation of the Spanish Government, grant no. CGL2010-21381. CYTED funded networking activities (EPES, Acción 407AC0323). M.D.-B. was supported by a PhD fellowship from the Pablo de Olavide University.Peer reviewe

Study of floristics, life form and chorology of plants in Shimbar protected area (Khuzestan province)

The Shimbar or Shirin Bahar region with an area of 53000 h is located in 45 km north east of Masjed Soleyman city, Andica town and north of Shahid Abaspour dam. The area belongs to the Zagrosian district of Irano-Turanian region. In three seasons, winter, spring and summer of 2012 to 2013, herbarium specimens of the area were collected and named by the Floras of Iran and neighboring countries. In this research, 189 species belonged to 149 genera and 51 families were determined. Most of the species belonged to Asteraceae with 23, Poaceae with 19, Lamiaceae and Papilionaceae with 18, Rosaceae with 10, Apiaceae with 9 and, Brassicaceae followed by the Caryophyllaceae each with 8 species. The life forms of the species in Shimbar included 13% phanerophytes, 6% chamephytes, 25% hemicryptophytes, 15% cryptophytes and 41% therophytes. The highest precent of the species belonged to the Irano-Turanian region

Increasing aridity reduces soil microbial diversity and abundance in global drylands

Artículo de publicación ISISoil bacteria and fungi play key roles in the functioning of terrestrial ecosystems, yet our understanding of their responses to climate change lags significantly behind that of other organisms. This gap in our understanding is particularly true for drylands, which occupy similar to 41% of Earth ' s surface, because no global, systematic assessments of the joint diversity of soil bacteria and fungi have been conducted in these environments to date. Here we present results from a study conducted across 80 dryland sites from all continents, except Antarctica, to assess how changes in aridity affect the composition, abundance, and diversity of soil bacteria and fungi. The diversity and abundance of soil bacteria and fungi was reduced as aridity increased. These results were largely driven by the negative impacts of aridity on soil organic carbon content, which positively affected the abundance and diversity of both bacteria and fungi. Aridity promoted shifts in the composition of soil bacteria, with increases in the relative abundance of Chloroflexi and alpha-Proteobacteria and decreases in Acidobacteria and Verrucomicrobia. Contrary to what has been reported by previous continental and global-scale studies, soil pH was not a major driver of bacterial diversity, and fungal communities were dominated by Ascomycota. Our results fill a critical gap in our understanding of soil microbial communities in terrestrial ecosystems. They suggest that changes in aridity, such as those predicted by climate-change models, may reduce microbial abundance and diversity, a response that will likely impact the provision of key ecosystem services by global drylands.European Research Council (ERC) under European Community 242658 Spanish Ministry of Economy and Competitiveness BIOMOD Project CGL2013-44661-R Australian Research Council DP13010484 Salvador de Madariaga program of the Spanish Ministry of Education, Culture and Sports Grant PRX14/00225 Research Exchange Program of the Hawkesbury Institute for the Environment Alexander Von Humboldt Foundation Iniciativa Cientifica Milenio (MIDEPLAN) PO5-002 Comision Nacional de Investigacion Cientifica y Tecnologica PFB-2

Decoupling of soil nutrients cycles as a function of aridity in global drylands

The biogeochemical cycles of carbon (C), nitrogen (N) and phosphorus (P) are interlinked by primary production, respiration and decomposition in terrestrial ecosystems. It has been suggested that the C, N and P cycles could become uncoupled under rapid climate change because of the different degrees of control exerted on the supply of these elements by biological and geochemical processes. Climatic controls on biogeochemical cycles are particularly relevant in arid, semi-arid and dry sub-humid ecosystems (drylands) because their biological activity is mainly driven by water availability. The increase in aridity predicted for the twenty-first century in many drylands worldwide may therefore threaten the balance between these cycles, differentially affecting the availability of essential nutrients. Here we evaluate how aridity affects the balance between C, N and P in soils collected from 224 dryland sites from all continents except Antarctica. Wefind a negative effect of aridity on the concentration of soil organic C and total N, but a positive effect on the concentration of inorganic P. Aridity is negatively related to plant cover, which may favour the dominance of physical processes such as rock weathering, a major source of P to ecosystems, over biological processes that provide more C and N, such as litter decomposition1. Our findings suggest that any predicted increase in aridity with climate change will probably reduce the concentrations of N and C in global drylands, but increase that of P. These changes would uncouple the C, N and P cycles in drylands and could negatively affect the provision of key services provided by these ecosystems.Fil: Delgado Baquerizo, Manuel. Universidad Pablo de Olavide; España. Universidad Rey Juan Carlos. Departamento de Biología y Geología. Área de Biodiversidad y Conservación; EspañaFil: Maestre, Fernando T.. Universidad Pablo de Olavide; España. Universidad Rey Juan Carlos. Departamento de Biología y Geología. Área de Biodiversidad y Conservación; EspañaFil: Gallardo, Antonio. Universidad Pablo de Olavide; EspañaFil: Bowker, Matthew A.. No especifíca;Fil: Wallenstein, Matthew D.. Northern Arizona University; Estados UnidosFil: Bran, Donaldo Eduardo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina. Universidad Rey Juan Carlos. Departamento de Biología y Geología. Área de Biodiversidad y Conservación; EspañaFil: Gatica, Mario Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Hepper, Estela Noemí. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Pampa. Facultad de Agronomía; ArgentinaFil: Prina, Anibal Oscar. Universidad Nacional de La Pampa. Facultad de Agronomía; ArgentinaFil: Pucheta, Eduardo Raúl. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Huber Sannwald, Elisabeth. Instituto Potosino de Investigación Científica y Tecnológica; MéxicoFil: Jankju, Mohammad. Ferdowsi University of Mashhad; IránFil: Liu, Jushan. Northeast Normal University. Institute of Grassland Science,; ChinaFil: Mau, Rebecca L.. Northern Arizona University; Estados UnidosFil: Miriti, Maria. Ohio State University; Estados UnidosFil: Monerris, Jorge. Université du Québec a Montreal; CanadáFil: Naseri, Kamal. Ferdowsi University of Mashhad; IránFil: Noumi, Zouhaier. Université de Sfax; TúnezFil: Polo, Vicente. Universidad Rey Juan Carlos. Departamento de Biología y Geología. Área de Biodiversidad y Conservación; EspañaFil: Ramírez Collantes, David A.. International Potato Center; PerúFil: Romão, Roberto. Universidade Estadual de Feira de Santana. Departamento de Ciencias Biológica, Herbario; BrasilFil: Tighe, Matthew. University of New England; AustraliaFil: Torres, Duilio. Universidad Centroccidental ‘‘Lisandro Alvarado’’; VenezuelaFil: Torres Díaz, Cristian. Universidad del Bio Bio. Facultad de Ciencias. Departamento de Ciencias Básicas. Laboratorio de Genómica y Biodiversidad; ChileFil: Ungar, Eugene D.. The Volcani Center. Agricultural Research Organization. Institute of Plant Sciences; IsraelFil: Val, James. Office of Environment and Heritage; AustraliaFil: Wamiti, Wanyoike. National Museums of Kenya. Zoology Department; KeniaFil: Wang, Deli. Northeast Normal University. Institute of Grassland Science; ChinaFil: Zaady, Eli. Gilat Research Center; Israe

Plant Species Richness and Ecosystem Multifunctionality in Global Drylands

Acknowledgments: The long-term data on the demography and foraging ecology of wandering albatrosses at Possession Island, Crozet Islands, were supported by the French Polar Institute IPEV (program no. 109 to H.W.), with additional funding from the Prince Albert II de Monaco Foundation. The study is a contribution to the Program ANR Biodiversité 2005-11 REMIGE. We acknowledge the modeling groups, the Program for Climate Model Diagnosis and Intercomparison (PCMDI), and the World Climate Research Programme’s (WCRP’s) Working Group on Coupled Modeling (WGCM) for their roles in making available the WCRP CMIP-3 multimodel data set. Support for data and model selection was provided by S. Jenouvrier. We thank the many field workers involved in the Crozet long-term monitoring since 1966 and in tracking programs since 1989, and D. Besson for help with the management of the demographic database. M.L. was funded by a postdoctoral contract of the Spanish Ministry of Education and Science (Ref. EX2007-1148) and Marie Curie Individual Fellowship (PIEF-GA-2008-220063). We are grateful to L. Riotte-Lambert for help with data analysis and C. Barbraud, C. A. Bost, Y. Cherel, and S. Jenouvrier for comments on the manuscript.Experiments suggest that biodiversity enhances the ability of ecosystems to maintain multiple functions, such as carbon storage, productivity, and the buildup of nutrient pools (multifunctionality). However, the relationship between biodiversity and multifunctionality has never been assessed globally in natural ecosystems. We report here on a global empirical study relating plant species richness and abiotic factors to multifunctionality in drylands, which collectively cover 41% of Earth’s land surface and support over 38% of the human population. Multifunctionality was positively and significantly related to species richness. The best-fitting models accounted for over 55% of the variation in multifunctionality and always included species richness as a predictor variable. Our results suggest that the preservation of plant biodiversity is crucial to buffer negative effects of climate change and desertification in drylands.Depto. de Biodiversidad, Ecología y EvoluciónFac. de Ciencias BiológicasTRUEpu

Plant Species Richness and Ecosystem Multifunctionality in Global Drylands

Experiments suggest that biodiversity enhances the ability of ecosystems to maintain multiple functions, such as carbon storage, productivity, and the buildup of nutrient pools (multifunctionality). However, the relationship between biodiversity and multifunctionality has never been assessed globally in natural ecosystems. We report here on a global empirical study relating plant species richness and abiotic factors to multifunctionality in drylands, which collectively cover 41% of Earth's land surface and support over 38% of the human population. Multifunctionality was positively and significantly related to species richness. The best-fitting models accounted for over 55% of the variation in multifunctionality and always included species richness as a predictor variable. Our results suggest that the preservation of plant biodiversity is crucial to buffer negative effects of climate change and desertification in drylands

Human impacts and aridity differentially alter soil N availability in drylands worldwide

[Aims]: Climate and human impacts are changing the nitrogen (N) inputs and losses in terrestrial ecosystems. However, it is largely unknown how these two major drivers of global change will simultaneously influence the N cycle in drylands, the largest terrestrial biome on the planet. We conducted a global observational study to evaluate how aridity and human impacts, together with biotic and abiotic factors, affect key soil variables of the N cycle.[Location]: Two hundred and twenty-four dryland sites from all continents except Antarctica widely differing in their environmental conditions and human influence.[Methods]: Using a standardized field survey, we measured aridity, human impacts (i.e. proxies of land uses and air pollution), key biophysical variables (i.e. soil pH and texture and total plant cover) and six important variables related to N cycling in soils: total N, organic N, ammonium, nitrate, dissolved organic:inorganic N and N mineralization rates. We used structural equation modelling to assess the direct and indirect effects of aridity, human impacts and key biophysical variables on the N cycle.[Results]: Human impacts increased the concentration of total N, while aridity reduced it. The effects of aridity and human impacts on the N cycle were spatially disconnected, which may favour scarcity of N in the most arid areas and promote its accumulation in the least arid areas.[Main conclusions]: We found that increasing aridity and anthropogenic pressure are spatially disconnected in drylands. This implies that while places with low aridity and high human impact accumulate N, most arid sites with the lowest human impacts lose N. Our analyses also provide evidence that both increasing aridity and human impacts may enhance the relative dominance of inorganic N in dryland soils, having a negative impact on key functions and services provided by these ecosystems.This research is supported by the European Research Council (ERC) under the European Community's Seventh Framework Programme (FP7/2007‐2013)/ERC grant agreement no. 242658 (BIOCOM), and by the Ministry of Science and Innovation of the Spanish Government, grant no. CGL2010‐21381. CYTED funded networking activities (EPES, Acción 407AC0323). S.G. was funded by CONICYT/FONDAP/15110009.Peer Reviewe

Decoupling of soil nutrient cycles as a function of aridity in global drylands

The biogeochemical cycles of carbon (C), nitrogen (N) and phosphorus (P) are interlinked by primary production, respiration and decomposition in terrestrial ecosystems1. It has been suggested that the C, N and P cycles could become uncoupled under rapid climate change because of the different degrees of control exerted on the supply of these elements by biological and geochemical processes1–5. Climatic controls on biogeochemical cycles are particularly relevant in arid, semi-arid and dry sub-humid ecosystems (drylands) because their biological activity is mainly driven by water availability6–8. The increase in aridity predicted for the twenty-first century in many drylands worldwide9–11 may therefore threaten the balance between these cycles, differentially affecting the availability of essential nutrients12–14. Here we evaluate how aridity affects the balance between C, N and P in soils collected from 224 dryland sites from all continents except Antarctica. Wefind a negative effect of aridity on the concentration of soil organic C and total N, but a positive effect on the concentration of inorganic P. Aridity is negatively related to plant cover, which may favour the dominance of physical processes such as rock weathering, a major source of P to ecosystems, over biological processes that provide more C and N, such as litter decomposition12–14. Our findings suggest that any predicted increase in aridity with climate change will probably reduce the concentrations of N and C in global drylands, but increase that of P. These changes would uncouple the C, N and P cycles in drylands and could negatively affect the provision of key services provided by these ecosystems.Consejo Europeo de Investigación. 7º Programa Marco de InvestigaciónMinisterio de Ciencia e Innovación (MCIN)CYTEDUniversidad Pablo de OlavideDepto. de Biodiversidad, Ecología y EvoluciónFac. de Ciencias BiológicasTRUEpu