Europe’s walnut woods get the productive forest therapy
Europe has vast forests and most are part of associated industries that need to be competitive to survive in a globalised world. WOODnat(opens in new window) researchers have modified procedures all along the walnut value chain, from young plants to already dried timber, to nurture European forests for productive landscape.
From stumps to mushrooms
“Thanks to the project, it has been possible to test better walnut plants, more profitable forestry models, innovative tools for managing both the logs and the timber, and new final products,” outlines Elias Cueto, head of the coordinating company, Seistag Innovación(opens in new window). Improved performance of the walnut plant for timber production started with selection of walnut clones with superior qualities. Lifelong research by Ricardo Licea, head of the Biotechnology Department at consortium member Bosques Naturales, Spain, has bred a fast-growing walnut plant with high survival rates and straight logs with high-quality timber. Thanks to the collaboration with Industrial Plants(opens in new window) from Bulgaria, production of this new super walnut tree has moved outside the lab. “After all, growing the actual tree takes production closer to the market,” Cueto emphasises. Collaboration with CREA(opens in new window), an Italian public research body and also part of the consortium, proved the feasibility of combining fast- and slow-growing species. “This improves profit from the plantation due to intermediate returns,” Cueto explains. Stump removal after harvesting of trees is expensive and unsustainable. Spanish partner company ECM Ingeniería Ambiental developed a biological process that produces edible mushrooms on the degrading stump.
Changing the colour of naturally pale walnut
Regarding technical tools, two Spanish companies have achieved results. An app provides information and brings transparency to the forest business, and solutions were developed by Asimov Efficiency for handling timber and veneer. The project has also enabled innovative manufacturing procedures to overcome the specific challenges of the European walnut. One restriction is the small diameter of logs; to overcome this limitation, WOODnat developed boards of mixed species. Naturally rather pale in colour, walnut wood normally commands less in the market, darker being associated with hardwoods like mahogany. In addition to the traditional technique of vaporising, WOODnat partners have developed two methods for darkening timber: using chemical dye and digital printing. A recent publication(opens in new window) in Annals of Silvicultural Research (ASR) describes the process involving digital printing. The darkening procedure can also be seen on video(opens in new window).
The future walnut forest
“Research at the cutting edge of available knowledge was possible thanks to the support provided by CREA and also thanks to the fact that walnut is a species with much added value.” Cueto envisages the next step should be to extend these methodologies to other species, with lower prices but much bigger impact on the European economy and landscape. A special issue of ASR anticipated soon will be dedicated to the main topics of the WOODnat project: plant production, forest models, mushroom cultivation and timber transformation. “This is also a tribute to Gaetano Castro and his family, a CREA researcher who contributed to the project despite illness which finally caused his death at the end of 2019,” concludes Cueto.
