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

Ochoa-Hueso, Raúl; Eldridge, David J.; Delgado-Baquerizo, Manuel; Soliveres, Santiago; Bowker, Matthew A.; Gross, Nicolas; Le Bagousse-Pinguet, Yoann; Quero, José L.; García-Gómez, Miguel; Valencia, Enrique; Arredondo, Tulio; Beinticinco, Laura; Bran, Donaldo; Cea, Alex; Coaguila, Daniel; Dougill, Andrew J.; Espinosa, Carlos I.; Gaitán, Juan; Guuroh, Reginald T.; Guzman, Elizabeth; ... (2018). Soil fungal abundance and plant functional traits drive fertile island formation in global drylands. Journal of Ecology, 106(1), pp. 242-253. Wiley-Blackwell 10.1111/1365-2745.12871

[img] Text
2018_JEcol_106_242.pdf - Published Version
Restricted to registered users only
Available under License Publisher holds Copyright.

Download (1MB) | Request a copy

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.

Item Type:

Journal Article (Original Article)


08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS)
08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS) > Biodiversity

UniBE Contributor:

Soliveres, Santiago


500 Science > 580 Plants (Botany)








Peter Alfred von Ballmoos-Haas

Date Deposited:

07 Feb 2018 12:26

Last Modified:

05 Dec 2022 15:09

Publisher DOI:


Uncontrolled Keywords:

aridity; drylands; fertile islands; fungal abundance; multiple threshold approach; plant functional traits; relative interaction index; soil properties




Actions (login required)

Edit item Edit item
Provide Feedback