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

MANUEL DELGADO-BAQUERIZO; FERNANDO T. MAESTRE; ANTONIO GALLARDO; MATTHEW A. BOWKER; MATTHEW D. WALLENSTEIN; JOSÉ L. QUERO; VICTORIA OCHOA; BEATRIZ GOZALO; MIGUEL GARCÍA-GÓMEZ; SANTIAGO SOLIVERES; PABLO GARCÍA-PALACIOS; MIGUEL BERDUGO; ENRIQUE VALENCIA; CRISTINA ESCOLAR; TULIO ARREDONDO; CLAUDIA BARRAZA-CEPEDA; DONALDO BRAN; JOSÉ A. CARREIRA; MOHAMED CHAIEB; ABEL C. CONCEIÇÃO; MCHICH DERAK; DAVID J. ELDRIDGE; ADRIÁN ESCUDERO; CARLOS I. ESPINOSA; JUAN GAITÁN; M. GABRIEL GATICA; SUSANA GÓMEZ-GONZÁLEZ; ELIZABETH GUZMAN; JULIO R. GUTIÉRREZ; ADRIANA FLORENTINO; ESTELA HEPPER; ROSA M. HERNÁNDEZ; ELISABETH HUBER-SANNWALD; MOHAMMAD JANKJU; JUSHAN LIU; REBECCA L. MAU; MARIA MIRITI; JORGE MONERRIS; KAMAL NASERI; ZOUHAIER NOUMI; VICENTE POLO; ANÍBAL PRINA; EDUARDO PUCHETA; ELIZABETH RAMÍREZ; DAVID A. RAMÍREZ-COLLANTES; ROBERTO ROMÃO; MATTHEW TIGHE; DUILIO TORRES; CRISTIAN TORRES-DÍAZ; EUGENE D. UNGAR ; JAMES VAL; WANYOIKE WAMITI; DELI WANG; ELI ZAADY

NATURE

NATURE PUBLISHING GROUP

Lugar: Londres; Año: 2013 vol. 502 p. 672 - 676

0028-0836

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.