Marcello De Vitis

Introduction: Seed dormancy regulates germination timing to improve seedling survival. Many temperate species produce physiologically dormant seeds, requiring winter conditions (i.e. moist‐cold stratification) to overcome dormancy. Exposing seeds to suboptimal stratification lengths for restoration may alter genetic diversity and/or stratification requirements in offspring. Objectives: We investigate how the moist‐cold stratification length seeds are exposed to impacts on germination in offspring and whether variation in seed dormancy is under genetic and/or environmental control, with implications for producing and using germplasm for restoration. Methods: For one population of each of three Viola species, we created two F0 subpopulations using short versus long moist‐cold stratification. Resulting plants were grown in a common environment for two generations, with germination proportion and rate quantified under short, long, and no moist‐cold stratification treatments. We also assessed the proportion of variation in germination explained by genotype and the interaction between genotype and environment. Results: Moist‐cold stratification length significantly impacted germination in all study species, but transgenerational effects were limited: germination proportion was greater in one species but only when F0 and F1 seeds were exposed to shorter stratification, while germination rate was two to three times slower in another species, but varied by subpopulation. Between 10 and 22% of variation in germination was explained by genotype and its interaction with the environment. Conclusions: The length of moist‐cold stratification seeds with physiological dormancy is exposed to in production may alter how restored populations perform. Species producing seeds with deeper dormancy may be more likely to be impacted.

Primula palinuri , an endangered plant species strictly confined to the coastal limestone cliffs of southern Italy, represents a key Mediterranean endemic threatened by habitat loss and environmental stressors. This study investigated the effects of temperature, salinity, water stress, and burial depth on its seed germination. Germination was favoured by cool temperatures, with an optimum at 15 °C. Rates significantly declined at both 5 °C and 25 °C. Increasing salinity markedly inhibited germination, confirming the species’ sensitivity to salt stress. Water stress experiments demonstrated that P. palinuri requires high soil moisture for successful germination, with total inhibition under moderate (- 0.4 MPa) to severe drought conditions (- 1.5 MPa). Burial depth negatively affected seedling emergence, likely due to the small seed size and light-dependency. These results underline the species’ narrow ecological requirements, emphasising the need for careful habitat selection in conservation actions, favouring moist, shady, and salt-protected microsites with shallow seed placement.

Conservation translocations are becoming common conservation practice, so there is an increasing need to understand the drivers of plant translocation performance through reviews of cases at global and regional levels. The establishment of the Italian Database of Plant Translocation (IDPlanT) provides the opportunity to review the techniques used in 186 plant translocation cases performed in the last 50 years in the heart of the Mediterranean Biodiversity Hotspot. We described techniques and information available in IDPlanT and used these data to identify drivers of translocation outcomes. We tested the effect of 15 variables on survival of translocated propagules as of the last monitoring date with binomial logistic mixed‐effect models. Eleven variables significantly affected survival of transplants: life form, site protection, material source, number of source populations, propagation methods, propagule life stage, planting methods, habitat suitability assessment, site preparation, aftercare, and costs. The integration of vegetation studies in the selection of suitable planting sites significantly increased the success of translocation efforts. Although posttranslocation watering had a generally positive effect on translocation outcome, other aftercare techniques did not always increase transplant survival. Finally, we found that how funds were spent appeared to be more important than the actual amount spent. Plant translocations in Italy and in the Mediterranean area should account for the complexity of speciation, gene flow, and plant migrations that has led to local adaptations and has important implications for the choice and constitution of source material.

Plant production practices can influence the genetic diversity of cultivated plant materials and, ultimately, their potential to adapt to a reintroduction site. A common step in the plant production process is the application of seed pretreatment to alleviate physiological seed dormancy and successfully germinate seeds. In production settings, the seeds that germinate more rapidly may be favored in order to fill plant quotas. In this study, we investigated how the application of cold‐moist stratification treatments with different durations can lead to differences in the genetic diversity of the propagated plant materials. Specifically, we exposed seeds of three Viola species to two different cold stratification durations, and then we analyzed the genetic diversity of the resulting subpopulations through double‐digestion restriction site‐associated sequencing (ddRADseq). Our results show that, in two out of three species, utilizing a short stratification period will decrease the genetic diversity of neutral and expressed loci, likely due to the imposition of a genetic bottleneck and artificial selection. We conclude that, in some species, the use of minimal stratification practices in production may jeopardize the adaptive potential and long‐term persistence of reintroduced populations and suggest that practitioners carefully consider the evolutionary implications of their production protocols. We highlight the need to consider the germination ecology of target species when selecting the length of dormancy‐breaking pretreatments.

The U.N. Decade on Ecosystem Restoration aims to accelerate actions to prevent, halt, and reverse the degradation of ecosystems, and re-establish ecosystem functioning and species diversity. The practice of ecological restoration has made great progress in recent decades, as has recognition of the importance of species diversity to maintaining the long-term stability and functioning of restored ecosystems. Restorations may also focus on specific species to fulfill needed functions, such as supporting dependent wildlife or mitigating extinction risk. Yet even in the most carefully planned and managed restoration, target species may fail to germinate, establish, or persist. To support the successful reintroduction of ecologically and culturally important plant species with an emphasis on temperate grasslands, we developed a tool to diagnose common causes of missing species, focusing on four major categories of filters, or factors: genetic, biotic, abiotic, and planning & land management. Through a review of the scientific literature, we propose a series of diagnostic tests to identify potential causes of failure to restore target species, and treatments that could improve future outcomes. This practical diagnostic tool is meant to strengthen collaboration between restoration practitioners and researchers on diagnosing and treating causes of missing species in order to effectively restore them.

IDPlanT is the Italian Database of Plant Translocation, an initiative of the Nature Conservation Working Group of the Italian Botanical Society. IDPlanT currently includes 185 plant translocations. The establishment of a national database on plant translocation is a key step forward in data sharing and techniques improvement in this field of plant conservation.

Effective seed storage after sourcing (harvesting or purchasing) is critical to restoration practitioners and native seed producers, as it is key to maintaining seed viability. Inadequate seed storage can lead to a waste of both natural and economic resources when seeds of poor quality are sown. When working with native species with unknown storage behavior, general assumptions can be made based on studies on related species, and standard practices may be applied with caution; however, an investigation should be conducted to understand if specific storage requirements are needed and for how long seeds can be stored before they lose significant viability. In this paper of the Special Issue Standards for Native Seeds in Ecological Restoration, we provide an overview of the key concepts in seed storage and the steps to take for effective storage of native seeds for restoration use.