Soil fungal abundance and plant functional traits drive fertile island formation in global drylands

TY - JOUR

T1 - Soil fungal abundance and plant functional traits drive fertile island formation in global drylands

AU - Ochoa-Hueso, Raúl

AU - Eldridge, David J.

AU - Delgado-Baquerizo, Manuel

AU - Soliveres, Santiago

AU - Bowker, Matthew A.

AU - Gross, Nicolas

AU - Le Bagousse-Pinguet, Yoann

AU - Quero, José L.

AU - García-Gómez, Miguel

AU - Valencia, Enrique

AU - Arredondo, Tulio

AU - Beinticinco, Laura

AU - Bran, Donaldo

AU - Cea, Alex

AU - Coaguila, Daniel

AU - Dougill, Andrew J.

AU - Espinosa, Carlos I.

AU - Gaitán, Juan

AU - Guuroh, Reginald T.

AU - Guzman, Elizabeth

AU - Gutiérrez, Julio R.

AU - Hernández, Rosa M.

AU - Huber-Sannwald, Elisabeth

AU - Jeffries, Thomas

AU - Linstädter, Anja

AU - Mau, Rebecca L.

AU - Monerris, Jorge

AU - Prina, Aníbal

AU - Pucheta, Eduardo

AU - Stavi, Ilan

AU - Thomas, Andrew D.

AU - Zaady, Eli

AU - Singh, Brajesh K.

AU - Maestre, Fernando T.

N1 - Funding Information: We thank M. D. Puche, V. Ochoa, B. Gozalo and D. Encinar for their help with the laboratory analyses and data management. 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), by the Spanish Ministry of Economy and Competitiveness (BIOMOD, project CGL2013-44661-R) and by the Australian Research Council (project DP13010484). F.T.M. also acknowledges support from the ERC grant agreement 647038 (BIODESERT). J.R.G. thanks CONICYT/ FONDECYT 1160026. Y.L.B.P. was supported by a Marie Sklodowska-Curie Actions Individual Fellowship (MSCA-IF) within the European Programme Horizon 2020 (DRYFUN Project 656035). N.G. was supported by the AgreenSkills+ fellowship programme which has received funding from the EU’s Seventh Framework Programme under grant agreement no. FP7-609398 (AgreenSkills+ contract). R.O.H. is supported by a Juan de la Cierva Fellowship (IJCI-2014-21252) of the Spanish Ministry of Economy and Competitiveness. Funding Information: Australian Research Council, Grant/Award Number: DP13010484; Spanish Ministry of Economy and Competitiveness, Grant/Award Number: CGL2013-44661-R; European Research Council, Grant/Award Number: 242658; European Research Council (ERC), Grant/Award Number: 647038 Publisher Copyright: © 2017 The Authors. Journal of Ecology © 2017 British Ecological Society

PY - 2018/1/1

Y1 - 2018/1/1

N2 - Dryland vegetation is characterized by discrete plant patches that accumulate and capture soil resources under their canopies. These “fertile islands” are major drivers of dryland ecosystem structure and functioning, yet we lack an integrated understanding of the factors controlling their magnitude and variability at the global scale. We conducted a standardized field survey across 236 drylands from five continents. At each site, we measured the composition, diversity and cover of perennial plants. Fertile island effects were estimated at each site by comparing composite soil samples obtained under the canopy of the dominant plants and in open areas devoid of perennial vegetation. For each sample, we measured 15 soil variables (functions) associated with carbon, nitrogen and phosphorus cycling and used the relative interaction index to quantify the magnitude of the fertile island effect for each function. In 80 sites, we also measured fungal and bacterial abundance (quantitative PCR) and diversity (Illumina MiSeq). The most fertile islands, i.e. those where a higher number of functions were simultaneously enhanced, were found at lower elevation sites with greater soil pH values and sand content under semiarid climates, particularly at locations where the presence of tall woody species with a low-specific leaf area increased fungal abundance beneath plant canopies, the main direct biotic controller of the fertile island effect in the drylands studied. Positive effects of fungal abundance were particularly associated with greater nutrient contents and microbial activity (soil extracellular enzymes) under plant canopies. Synthesis. Our results show that the formation of fertile islands in global drylands largely depends on: (1) local climatic, topographic and edaphic characteristics, (2) the structure and traits of local plant communities and (3) soil microbial communities. Our study also has broad implications for the management and restoration of dryland ecosystems worldwide, where woody plants are commonly used as nurse plants to enhance the establishment and survival of beneficiary species. Finally, our results suggest that forecasted increases in aridity may enhance the formation of fertile islands in drylands worldwide.

AB - Dryland vegetation is characterized by discrete plant patches that accumulate and capture soil resources under their canopies. These “fertile islands” are major drivers of dryland ecosystem structure and functioning, yet we lack an integrated understanding of the factors controlling their magnitude and variability at the global scale. We conducted a standardized field survey across 236 drylands from five continents. At each site, we measured the composition, diversity and cover of perennial plants. Fertile island effects were estimated at each site by comparing composite soil samples obtained under the canopy of the dominant plants and in open areas devoid of perennial vegetation. For each sample, we measured 15 soil variables (functions) associated with carbon, nitrogen and phosphorus cycling and used the relative interaction index to quantify the magnitude of the fertile island effect for each function. In 80 sites, we also measured fungal and bacterial abundance (quantitative PCR) and diversity (Illumina MiSeq). The most fertile islands, i.e. those where a higher number of functions were simultaneously enhanced, were found at lower elevation sites with greater soil pH values and sand content under semiarid climates, particularly at locations where the presence of tall woody species with a low-specific leaf area increased fungal abundance beneath plant canopies, the main direct biotic controller of the fertile island effect in the drylands studied. Positive effects of fungal abundance were particularly associated with greater nutrient contents and microbial activity (soil extracellular enzymes) under plant canopies. Synthesis. Our results show that the formation of fertile islands in global drylands largely depends on: (1) local climatic, topographic and edaphic characteristics, (2) the structure and traits of local plant communities and (3) soil microbial communities. Our study also has broad implications for the management and restoration of dryland ecosystems worldwide, where woody plants are commonly used as nurse plants to enhance the establishment and survival of beneficiary species. Finally, our results suggest that forecasted increases in aridity may enhance the formation of fertile islands in drylands worldwide.

KW - aridity

KW - drylands

KW - fertile islands

KW - fungal abundance

KW - multiple threshold approach

KW - plant functional traits

KW - relative interaction index

KW - soil properties

UR - http://www.scopus.com/inward/record.url?scp=85032191896&partnerID=8YFLogxK

U2 - 10.1111/1365-2745.12871

DO - 10.1111/1365-2745.12871

M3 - Article

AN - SCOPUS:85032191896

SN - 0022-0477

VL - 106

SP - 242

EP - 253

JO - Journal of ecology

JF - Journal of ecology

IS - 1

ER -