Life-history traits in an evergreen Mediterranean oak respond differentially to previous experimental environments

Abstract

Living organisms respond both to current and previous environments, which can have important consequences on population dynamics. However, there is little experimental evidence based on long-term field studies of the effects of previous environments on the performance of individuals. We tested the hypothesis that trees that establish under different environmental conditions perform differently under similar post-establishment conditions. We used the slow-growing, evergreen Mediterranean oak Quercus ilex subsp. rotundifolia as target species. We analyzed the effects of previous environments, competition effects and tradeoffs among life-history traits (survival, growth, and reproduction). We enhanced seedling establishment for three years by reducing abiotic environmental harshness by means of summer irrigation and artificial shading in 12 experimental plots, while four plots remained as controls. Then these treatments were interrupted for ten years. Seedlings under ameliorated environmental conditions survived and grew faster during early establishment. During the post-management period, previous treatments 1) did not have any effect on survival, 2) experienced a slower above-ground growth, 3) decreased root biomass as indicated from reflectivity of Ground Penetration Radar, 4) increased acorn production mostly through a greater canopy volume and 5) increased acorn production effort. The trees exhibited a combination of effects related to acclimation for coping with abiotic stress and effects of intra-specific competition. In accordance with our hypothesis, tree performance overall depended on previous environmental conditions, and the response was different for different life-history traits. We recommend early management because it increased plot cover, shortened the time to attain sexual maturity and increased the amount of acorn production. Plots such as those assessed in this study may act as sources of propagules in deforested agricultural landscapes thus aiding natural establishment of new plants

Predation and aridity slow down the spread of 21-year-old planted woodland islets in restored Mediterranean farmland

“…Q. ilex is a late successional, slow-growing tree with high capacity of resprouting (Zavala et al 2000). We found that, 21 years after the start of this restoration project, the planted woodland islets have grown in volume and produce large amounts of acorns (Rey Benayas et al 2008b); however, the islets have not increased in area beyond the original planted surface of 100 m 2 . Moreover, whereas a number of holm oaks of different size have established around the islets, there is a ca.…”

Soil chemical properties in abandoned Mediterranean cropland after succession and oak reforestation

“…However, we used an experimental approach rather than a phenomenological approach to test the effects of environmental manipulation on soil properties. Our study is part of long-term research aiming to investigate the effects of environmental manipulation on ecosystem processes in relation to restoration of Mediterranean woodland (Cayuela et al, 2008;Rey Benayas et al, 2008a). In this context, we also evaluated the relevance of previous management in addition to current environmental conditions on soil chemistry of the reforested woodland.…”

Revisión y evaluación técnico-económica de los sistemas de micro - riego usados en repoblación forestal

“…Se han realizado numerosos estudios sobre la eficacia en las plantaciones de uno o varios cuidados culturales simultáneos y/o posteriores al establecimiento (Reque y Bravo 1993;Peñuelas et al, 1996;Lemieux y Delisle, 1998;Rey et al, 2002;Rey y Camacho, 2004;Rey et al, 2005;Rey et al, 2008;Badano et al, 2009;Palmerlee y Young, 2010;Kribeche et al, 2012;Pardos et al, 2015). Estos estudios muestran que los cuidados culturales reducen la mortalidad de las plantas sustancialmente y ofrecen buenos ratios beneficio/inversión (Rey y Camacho 2004;Dey et al, 2008).…”