Poplar (Populus spp.) is a high-value crop for wood and biomass production and a model organism for tree physiology and genomics. The early release, in 2006, of the complete genome sequence of P. trichocarpa was followed by a wealth of studies that significantly enriched our knowledge of complex pathways inherent to woody plants, such as lignin biosynthesis and secondary cell wall deposition. Recently, in the attempt to cope with the challenges posed by ongoing climate change, fundamental studies and breeding programs with poplar have gradually shifted their focus to address the responses to abiotic stresses, particularly drought. Taking advantage from a set of modern genomic and phenotyping tools, these studies are now shedding light on important processes, including embolism formation (the entry and expansion of air bubbles in the xylem) and repair, the impact of drought stress on biomass yield and quality, and the long-term effects of drought events. In this review, we summarize the status of the research on the molecular bases of the responses to drought in poplar. We highlight how this knowledge can be exploited to select more tolerant genotypes and how it can be translated to other tree species to improve our understanding of forest dynamics under rapidly changing environmental conditions.

Poplar is one of the most important forest trees because of its high economic value. Thanks to the fast-growing rate, easy vegetative propagation and transformation, and availability of genomic resources, poplar has been considered the model species for forest genetics, genomics, and breeding. Being a field-growing tree, poplar is exposed to environmental threats, including biotic stresses that are becoming more intense and diffused because of global warming. Current poplar farming is mainly based on monocultures of a few elite clones and the expensive and long-term conventional breeding programmes of perennial tree species cannot face current climate-change challenges. Consequently, new tools and methods are necessary to reduce the limits of traditional breeding related to the long generation time and to discover new sources of resistance. Recent advances in genomics, marker-assisted selection, genomic prediction, and genome editing offer powerful tools to efficiently exploit the Populus genetic diversity and allow enabling molecular breeding to support accurate early selection, increasing the efficiency, and reducing the time and costs of poplar breeding, that, in turn, will improve our capacity to face or prevent the emergence of new diseases or pests.

The circular economy will play an important role in the reduction of carbon emissions and poplar might be one of the winning choices according to sustainable development. As for agricultural crops, high-quality production is strictly related to genetic variability and best management practice. The main objective of this study was to analyze different stand management options to quantify differences on carbon emission and environmental impacts. Moreover, the study was focused on the assessment of differences between standard poplar management for veneer and poplar management according to sustainable production (such as the PEFC certification scheme). The system boundaries embraced fertilization (inorganic or organic), agricultural operations, machinery, and field emissions associated with poplar cultivation. The environmental impacts were quantified by a life cycle assessment (LCA) calculation using SIMAPRO software v8.0 with different databases. The primary data of poplar stands were collected during a decades-long Italian experience. A reduction of carbon emissions was observed in the stand managed with MSA clones (Case “Mezzi PEFC”), and negative emissions were observed due to organic fertilization (scenarios 7m-29 t CO₂-eq ha⁻¹ and 26M-129 t CO₂-eq ha⁻¹). In all cultivation scenarios, the environmental impacts were lower than conventional crops in the study area, such as corn. A higher impact was observed in the 26M scenario with oversized machinery for stand management. These data can also contribute to poplar stand modeling and represent a basis for future research developments in this field.

The use of oak barrel alternatives, including oak chips, oak staves and oak powder, is quite common in the production of spirits obtained from the distillation of vegetal fermented products such as grape pomace. This work explored the use of unconventional wood formats such as peeled and sliced wood. The use of poplar wood was also evaluated to verify its technological uses to produce aged spirits. To this aim, GC-MS analyses were carried out to obtain an aromatic characterisation of experimental distillates treated with these products. Moreover, the same spirits were studied for classification purposes using NMR, NIR and e-nose. A significant change in the original composition of grape pomace distillate due to sorption phenomena was observed; the intensity of this effect was greater for poplar wood. The release of aroma compounds from wood depended both on the toasting level and wood assortment. Higher levels of xylovolatiles, namely, whisky lactone, were measured in samples aged using sliced woods. Both the NIR and NMR analyses highlighted similarities among samples refined with oak tablets, differentiating them from the other wood types. Finally, E-nose seemed to be a promising alternative to spectroscopic methods both for the simplicity of sample preparation and method portability.

The authors wish to make the following corrections to their paper