Restoring oak forests through direct seeding or planting: Protocol for a continental-scale experiment

Abstract

The choice of revegetating via direct seeding or planting nursery-grown seedlings influences the potential stresses suffered by seedlings such as herbivory and drought. The outcome of the balance between both revegetation methods may ultimately depend on how species identity and traits such as seed and seedling size interact with environmental conditions. To test this, we will conduct a continental-scale experiment consisting of one mini-experiment replicated by multiple participants across Europe. Each participant will establish a site with seeded and planted individuals of one or more native, locally growing oak (Quercus) species; the selection of this genus aims to favour continental-scale participation and to allow testing the response of a widely distributed genus of broad ecological and economic relevance. At each site, participants will follow the present protocol for seed collection, seeding in the field, nursery cultivation, outplanting, protection against herbivores, site maintenance, and measurement of seedling performance and environmental variables. Each measurement on each species at each site will produce one effect size; the data will be analysed through mixed-effects meta-analysis. With this approach we will assess the main effect of revegetation method, species, plant functional traits, and the potential effect of site-specific effect moderators. Overall, we will provide a continental-scale estimate on the seeding vs. planting dilemma and analyse to what extent the differences in environmental conditions across sites, seed size, functional traits, and the phylogenetic relatedness of species can account for the differences in the effect of revegetation method on seedling performance across study sites and species.

Spicing up oak forest restoration: a preliminary report of the protective use of chili peppers in direct seeding of acorns

“…A common practice during oak forest restoration is the introduction of nursery-grown seedlings (Dorji et al 2020;Leverkus et al 2021). Direct seed sowing is an alternative technique to reduce the cost of oak introduction practices and favor extensive practices (Leverkus et al 2015(Leverkus et al , 2021Löf et al 2019).…”

“…A common practice during oak forest restoration is the introduction of nursery-grown seedlings (Dorji et al 2020;Leverkus et al 2021). Direct seed sowing is an alternative technique to reduce the cost of oak introduction practices and favor extensive practices (Leverkus et al 2015(Leverkus et al , 2021Löf et al 2019). However, acorn predation is widely documented as the most important filter for the feasibility of direct seeding as a restoration strategy (Blythe et al 2015;Löf et al 2019;Villalobos et al 2023).…”

Slow Release of GA3 Hormone from Polymer Coating Overcomes Seed Dormancy and Improves Germination

“…The restoration of native systems is commonly performed by revegetating landscapes through direct seeding efforts or planting nursery-grown seedlings. Direct seeding is the most common method for restoring native vegetation across large areas [ 5 , 6 , 7 ]. Yet, this technique commonly has low success rates, which leaves sites with low biodiversity, or it can result in complete seeding failure [ 8 , 9 ].…”

Досвід Штучного Лісовідновлення Дубових Насаджень Різними Методами Та Видами Садивного Матеріалу В Південно-Східному Лісостепу України

“…Це питання є надзвичайно актуальним і для європейських країн, особливо в тих, де дубові насадження займають великі площі [21]. Зокрема, колектив учених із низки європейських країн [9] вивчив успішність відновлення дубових лісів різними методами та видами садивного матеріалу -висіванням жолудів і садінням сіянців, в межах всього європейського континенту.…”