Plant's gypsum affinity shapes responses to specific edaphic constraints without limiting responses to other general constraints

Aims Harsh edaphic environments harbor species with different soil affinities. Plant's responses to specific edaphic constraints may be compromised against re- sponses to prevalent stresses shared with other semi- arid environments. We expect that species with high edaphic affinity may show traits to overcome harsh soil properties, while species with low affinity may respond to environmental constraints shared with arid environments. Methods We quantified the edaphic affinity of 12 plant species co-occurring in gypsum outcrops and measured traits related to plant responses to specific gypsum con- straints (rooting and water uptake depth, foliar accumu- lation of Ca, S and Mg), and traits related to common constraints of arid environments (water use efficiency, macronutrients foliar content). Results Plants in gypsum outcrops differed in their strategies to face edaphic limitations. A phylogenetic informed PCA segregated species based on their foliar Ca and S accumulation and greater water uptake depths, associated with plant responses to specific gypsum lim- itations. Species' gypsum affinity explained this segre- gation, but traits related to water or nutrient use efficien- cy did not contribute substantially to this axis. Conclusions Plant's specializations to respond to spe- cific edaphic constraints of gypsum soils do not limit their ability to deal with other non-specific environmen- tal constraintsThe author thanks the Yesaires team, es- pecially to Daniel A. Rodríguez Ginart, for making the fieldwork of quantification of species gypsum affinity possible. We thank Dr. Sara Palacio (IPE) and two anonymous reviewers for their helpful revisions and comments on the manuscript. RSM was supported by the Ministry of Science and Innovations (FPU grant FPU17/00629). JPF was supported by Grupo de Referencia H09_20R (Aragón regional government, Spain). Financial support was provided by the Valencian Regional Government (GV/2016/ 187) and the Spanish Ministry of Science, Innovation and Univer- sities (RTI2018-099672-J-I00; CGL2013-48753-R co-funded by FEDER)