title: Irrigation and Maize Cultivation Erode Plant Diversity Within Crops in Mediterranean Dry Cereal Agro-Ecosystems.
abstract: The intensification of agriculture has increased production at the cost of environment and biodiversity worldwide. To increase crop yield in dry cereal systems, vast farmland areas of high conservation value are being converted into irrigation, especially in Mediterranean countries. We analyze the effect of irrigation-driven changes on the farm biota by comparing species diversity, community composition, and species traits of arable plants within crop fields from two contrasting farming systems (dry and irrigated) in Spain. We sampled plant species within 80 fields of dry wheat, irrigated wheat, and maize (only cultivated under irrigation). Wheat crops held higher landscape and per field species richness, and beta diversity than maize. Within the same type of crop, irrigated wheat hosted lower plant diversity than dry wheat at both field and landscape scales. Floristic composition differed between crop types, with higher frequencies of perennials, cosmopolitan, exotic, wind-pollinated and C4 species in maize. Our results suggest that irrigation projects, that transform large areas of dry cereal agro-ecosystems into irrigated crop systems dominated by maize, erode plant diversity. An adequate planning on the type and proportion of crops used in the irrigated agro-ecosystems is needed in order to balance agriculture production and biodiversity conservation.
authors.affiliation: Facultade de Ciencias, Universidade da Coruña, Campus da Zapateira, 15071, A Coruña, Spain. jaime.fagundez@udc.es.
authors.forename: Jaime
authors.initials: J
authors.lastname: Fagúndez
authors.affiliation: Departamento de Ecología, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
authors.forename: Pedro P
authors.initials: PP
authors.lastname: Olea
authors.affiliation: Departamento de Ecología, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Tejedo
authors.affiliation: Instituto de Investigación en Recursos Cinegéticos (IREC), CSIC-UCLM-JCCM, Ciudad Real, Spain.|Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456, Coimbra, Portugal.
authors.forename: Patricia
authors.initials: P
authors.lastname: Mateo-Tomás
authors.affiliation: Estudios y Proyectos Linea S.L., 47005, Valladolid, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Gómez
mesh_terms: D057914:Agricultural Irrigation / Q000379:methods*; D044822:Biodiversity; D018556:Crops, Agricultural / Q000254:growth & development*; D017753:Ecosystem; D019083:Mediterranean Region; D013030:Spain; D014908:Triticum / Q000254:growth & development*; D003313:Zea mays / Q000254:growth & development*
keywords: Alien species; Cereal-steppe agro-ecosystems; Farmland biodiversity; High Nature Value farming; Maize; Wheat