Influence of provenance origin on the early performance of two sclerophyllous Mediterranean species established in burned drylands

Abstract

Forest restoration have had limited success due to intense and prolonged droughts in Mediterranean-type ecosystems. In this context, knowledge of growth and physiology in seedlings of different provenances can be useful in the selection of appropriate seed sources for restoration. In this study we investigated variations in survival, growth, and leaf-level physiology of five provenances of Quillaja saponaria Mol. and five provenances of Cryptocarya alba Mol. originated from coastal and Pre Andean sites exhibiting latitudinal-related climate differences in central Chile. Seedlings were grown in a nursery on 600 mL pots for 18 months and then planted in a dryland site severely damaged by fire. One year after establishment, we measured survival, growth, and leaf-level physiology. We also analyzed the relationship between outplanting survival with seedling characteristics prior to planting, and the relationship between growth and survival with physiological traits and with climate variables. Growth and survival were similar among provenances of Q. saponaria and C. alba, with the exception of differing heights observed within the provenance of Q. saponaria. Initial root collar diameter of Q. saponaria was observed to be positively correlated to outplanting survival. With the exception of photosynthesis in Q. saponaria, all provenances of both species differed in the leaf-level physiological traits. Those provenances originating from interior dryland sites exhibited lower stomatal conductance and used water more efficiently. The opposite was true for provenances coming from coastal sites. In outplanting sites with Mediterranean-type climates that have been damage by severe fire, selections based on larger diameter seedlings, especially for Q. saponaria and from interior and pre-Andean provenances, will likely improve outplanting success.