Root system of Quercus suber L. seedlings in response to herbaceous competition and different watering and fertilisation regimes

Abstract

Different management practices are commonly applied to increase pasture yield of Mediterranean open woodlands, but the consequences of increasing competition for soil resources with these practices on tree recruitment are still unknown. In a greenhouse study, belowground competition of Quercus suber L. seedlings growing together with natural (Oak NP ) or improved pasture (Oak IP ) was evaluated, and their root systems compared with those of seedlings growing in bare soil (Oak BS ). Two watering levels and two regimes of P 2 O 5 fertilisation were also tested. Because of competition, the Oak IP seedlings had their fine root mass density, coarse root length, and shoot mass reduced by up to 40, 36, and 39%, respectively, when compared to Oak NP seedlings. Oak NP and Oak BS seedlings showed similar average root density parameters and shoot mass values, indicating that Q. suber seedlings growing with natural pasture is a low competitive system. High availability of water and phosphorus did not mitigate the strength of competition between herbaceous plants and oak seedlings, and favoured the pasture to the detriment of the trees. Our findings suggest that P 2 O 5 fertilisation and irrigation practices performed to improve herbaceous productivity will negatively influence recruitment of Q. suber seedlings.

Growth and physiological responses of Quercus brantii seedlings inoculated with Biscogniauxia mediterranea and Obolarina persica under drought stress

“…This strategy underlines the importance of root development to explore a larger volume of soil, as reported in other species of oaks (Cubera, Moreno, Solla, & Madeira, 2012). On the other hand, no significant changes were made in root biomass under different treatments.…”

“…It seems that the seedlings used their limited reserves of carbon to develop roots. This strategy underlines the importance of root development to explore a larger volume of soil, as reported in other species of oaks (Cubera, Moreno, Solla, & Madeira, 2012).…”

Early response ofQuercus roburseedlings to soil compaction following germination

“…According to Jones et al (1997), early emergence can lead to higher survival and biomass accumulation, as well as provide a competitive advantage compared with seedlings that emerge later. Other researchers (Cubera et al, 2012;Gordon, Welker, Menke, & Rice, 1989;Rey-Benayas, Navarro, Espigare, Nicolau, & Zavala, 2005) have shown that, in the Mediterranean climate, summer drought is the main factor limiting water availability, and competition for soil water by herbaceous plants is an additional cause of water limitation for oak seedlings. ORCID Barbara Mariotti http://orcid.org/0000-0003-3779-2104…”

Facilitation of holm oak recruitment through two contrasted shrubs species in Mediterranean grazed woodlands

“…In addition, increased pasture growth could reinforce competition for soil resources, with negative consequences for young seedlings (Cubera et al. ). In contrast, Cistus arrests pasture growth (Rivest et al.…”

“…The positive effect of Retama on the production of pasture understorey (Pugnaire et al 1996;Rodríguez-Echeverría & Pérez-Fernández 2003;Armas et al 2011;Rivest et al 2011) suggests that this shrub could attract herbivores and thus may lead to higher losses through browsers once seedlings are established. In addition, increased pasture growth could reinforce competition for soil resources, with negative consequences for young seedlings (Cubera et al 2012). In contrast, Cistus arrests pasture growth (Rivest et al 2011) and herbivores may be attracted to a lesser extent.…”