Ecological restoration has been proved to be an effective strategy to contrast biodiversity loss due to land use change. Among terrestrial ecosystems, dry grasslands represent biodiversity hotspot strongly threatened by soil consumption. Passive grassland restoration, based on spontaneous succession, is highly unpredictable and, in some cases, unsuitable to re-establish native communities. The use of spontaneous seeds (hay seed) and or/ commercial seed mix might contribute to boost early restoration stages by triggering native plant colonization. A crucial stage for the success of any restoration action and for determining community composition is the seeds germination. In addition, the soil seedbank of restoration sites can exert main effect on the final plant assembly, even if it is often neglected. We designed a controlled environment experiment in which commercial grassland seed-mix and spontaneous hay seeds collected in local dry grassland were sown on commercial soil (seedbank less) and agricultural soil (with seedbank) with two seed density. We hypothesized soil, seed mix type and density to interplay in determining community diversity and composition. Commercial seed provided greater species abundance and rapid containment of seedbank species. The abundance of the seedbank ruderal species greatly contributed to the total biodiversity in the case of hay seeds. The number of individuals of species not belonging to the seedbank has always been higher if commercial seed mix was sown; in the case of hay seeds this parameter was favored by agricultural soil probably due to the substrate or to positive interaction with seedbank species. The composition of functional groups (i.e. monocot vs dicot and life span) and species assembly were also influenced by the soil and seed mix type. Soil seedbank effect in determining the success of site restoration when operating seed sowing should not be overlooked, alternative management actions aimed at curb seedbank germination should be, hence, considered.
Success of native hay-seed mix for dry grassland restoration: do not neglect the role of soil seed bank
Marco Vuerich;Elisa Petrussa;Enrico Braidot;Francesco Boscutti
2022-01-01
Abstract
Ecological restoration has been proved to be an effective strategy to contrast biodiversity loss due to land use change. Among terrestrial ecosystems, dry grasslands represent biodiversity hotspot strongly threatened by soil consumption. Passive grassland restoration, based on spontaneous succession, is highly unpredictable and, in some cases, unsuitable to re-establish native communities. The use of spontaneous seeds (hay seed) and or/ commercial seed mix might contribute to boost early restoration stages by triggering native plant colonization. A crucial stage for the success of any restoration action and for determining community composition is the seeds germination. In addition, the soil seedbank of restoration sites can exert main effect on the final plant assembly, even if it is often neglected. We designed a controlled environment experiment in which commercial grassland seed-mix and spontaneous hay seeds collected in local dry grassland were sown on commercial soil (seedbank less) and agricultural soil (with seedbank) with two seed density. We hypothesized soil, seed mix type and density to interplay in determining community diversity and composition. Commercial seed provided greater species abundance and rapid containment of seedbank species. The abundance of the seedbank ruderal species greatly contributed to the total biodiversity in the case of hay seeds. The number of individuals of species not belonging to the seedbank has always been higher if commercial seed mix was sown; in the case of hay seeds this parameter was favored by agricultural soil probably due to the substrate or to positive interaction with seedbank species. The composition of functional groups (i.e. monocot vs dicot and life span) and species assembly were also influenced by the soil and seed mix type. Soil seedbank effect in determining the success of site restoration when operating seed sowing should not be overlooked, alternative management actions aimed at curb seedbank germination should be, hence, considered.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
