An efficient way of guaranteeing the survival of seedlings in areas under water stress

Abstract

Afforestation and forest restoration in Mediterranean drylands frequently fail because summer drought creates a demographic bottleneck. In these water-limited ecosystems, the establishment of Quercus rotundifolia Lam., a late-successional species, is essential for rebuilding the tree layer and enabling community assembly. Ensuring early survival is critical for initiating ecosystem recovery under arid conditions. Global climate change reinforces the need to optimize resource use, particularly water, which is limiting across the Mediterranean Basin. Water scarcity reduces forest functioning and threatens ecosystem services such as carbon sequestration and productivity. The Nodriza device is a passive reservoir designed to capture precipitation and gradually deliver water to the root zone during dry periods, buffering seedlings against water stress. This study evaluates the efficiency of the Nodriza device in improving soil moisture, seedling performance and survival, and compares it with a commercial device (Groasis) in a reforestation using Quercus rotundifolia . Two field experiments with Q. rotundifolia seedlings were conducted in Mediterranean environments. Experiment A compared Nodriza with non-irrigated controls, while Experiment B compared Nodriza, Groasis and control treatments across a heterogenous soil. Soil moisture at 10–40 cm depth, microclimate, growth, and survival were monitored and linear mixed models and generalised linear models were used to analyse treatment effects. In Experiment A, Nodriza improved soil moisture at 20–40 cm depth, prolonging water availability into late summer and reducing water stress. Seedlings with the Nodriza showed greater height and basal diameter at the end of the experiment, and survival reached 87%, compared with 0% in the Control treatment. In Experiment B, Nodriza maintained higher soil moisture than Groasis and reduced internal temperatures. Nodriza seedlings showed growth and achieved 100% survival, exceeding Groasis (87%) and controls (70%). Overall, the Nodriza device improved soil-water availability, moderated microclimatic extremes and increased survival, making it a potential tool for plant restoration in Mediterranean drylands.