TY - GEN A1 - Garcia de la Riva, Enrique A1 - Prieto, Iván A1 - Marañón, Teodoro A1 - Pérez-Ramos, Ignacio Manuel A1 - Olmo, Manuel A1 - Villar, Rafael T1 - Root economics spectrum and construction costs in Mediterranean woody plants: the role of symbiotic associations and the environment T2 - Journal of Ecology N2 - 1. Many studies have quantified the functional variation of fine root traits to un-derstand the overarching trade-off between maximizing resource acquisition or conservation (root economics spectrum [RES]). However, we know remarkably less on how plant strategies along the RES are actually constrained by the amount of photosynthates required to construct roots (i.e. construction costs, CC) or how below- ground interactions with symbiotic organisms modify root trait patterns and their relationships with CC.2. Our main aim was to quantify CC of fine roots (<2 mm) and their underlying compo-nents (carbon, minerals and organic nitrogen concentrations) in 60 Mediterranean woody species with contrasting symbiotic association types (ectomycorrhizas, ar-buscular and ericoid mycorrhizas and N-fixing bacteria). We examined (a) whether the covariation among fine root traits along the RES was related to the intrinsic cost of producing roots and whether this relationship was dependent on the type of root symbiosis; (b) whether the relationship of each CC component with the RES was dependent on the type of root symbiosis and (c) whether soil water and nutrient availability determined differences in CC across sites.3. According to the RES hypothesis, fine root traits showed a main covariation trend (acquisition vs. conservation), defined by the first PCA axis, which also segregated species by their two main contrasting symbiotic types (arbuscular and ectomycor-rhizal). We found a positive relationship between root CC and the RES (i.e. PCA axis 1) and, interestingly, slopes differed among symbiotic types, in response to the different role of each specific CC component. In addition, independently of symbiotic type, root CC decreased linearly with soil nutrient availability and quad-ratically with plant water availability.4. Synthesis. Our study demonstrates that woody plants display different functional strategies in their root CC, related with their position on the RES, and that CC differ among symbiotic groups. The influence of the root CC components across species varied among symbiotic associations, pointing to a trade-off between structural and metabolic compounds. Root CC were also strongly modulated by soil resource availability (nutrients and water). This study highlights that root CC are fundamental to better understand below- ground resource-use strategies. KW - below-ground strategies KW - functional traits KW - mycorrhiza KW - resource gradient KW - rhizobium KW - root carbon KW - soil nutrient KW - specific root length Y1 - 2021 UR - https://opus4.kobv.de/opus4-UBICO/frontdoor/index/index/docId/28144 SN - 1365-2745 VL - 109 IS - 4 SP - 1873 EP - 1885 ER -