Every year, the newspaper El Mundo-Diario de Castilla y León celebrates the Innovadores Awards, whose nominations include the projects and initiatives that throughout the year have merited an article in the pages of this supplement, which is a showcase for innovation.
The work carried out within the RESINLAB operational group was the subject of one of these articles (El laboratorio forestal para los resineros, published on 2 May) and the ‘holder’ of this award went to Cesefor, in its role as coordinator of this innovation project.
Within the framework of this initiative, focused on the territories of Castilla y León, Castilla-La Mancha and Extremadura, the jury valued the experimental work in which new resin extraction techniques were tested and the forest mass was studied to ensure the sustainability of extraction in the face of the challenge of climate change.
Cesefor engineer Aída Rodríguez, a doctor in Forestry Engineering and coordinator of this work, told El Mundo that the researchers carried out field work in which they placed sensors in the pines to measure the plant’s physiological variables, growth, sap flow, resin pressure and climatic variables such as temperature and humidity.
The plants chosen were selected according to the following premises: pines resined by the traditional method and a stand representative of the whole forest stand. The study was carried out during the 2022 resin production campaign. “In the end, what we have studied is what happens in the trees when you extract resin depending on the climate”, explains Aída Rodríguez.
Among the conclusions of the trials, Rodríguez stresses that the data obtained from the pines revealed that at certain levels of water stress (lack of rain and water in the soil) the plants begin to suffer in terms of growth and resin pressure.
A sensor measured fluid buoyancy in real time, which made it possible to estimate the production of each plant. The researchers corroborated a positive relationship between rainfall and soil moisture with resin pressure inside the tree. “In very long, very hot and very dry summers, pine trees have problems producing resin,” explains the researcher, and furthermore, when the variations related to temperature were analysed, it was observed that the flow and viscosity of the resin were directly related to it, “the higher the temperature, the more resin flow is normal,” explains Aída Rodríguez.
Those responsible for this project consider it necessary to continue with these tests during more resin production seasons and also to do so in other traditional resin production areas, such as Segovia, or in areas with potential such as the Levante or Andalusia. Rodriguez suggests the need to collect more data to be able to create tools and make useful predictions for managers.
Another line of research within the GORESINLAB project involved testing resin extraction methods to study productivity. To this end, tests were carried out in which the traditional extraction method of hand picking was compared with a method using a drill.
The team chose this second mechanised model because, a priori, it offered a series of advantages: on the one hand, the resin collector saved time in debarking and nailing the pines, and the collection is done in a closed bag, so the result is cleaner than the open jars used in the work with picks, so perhaps a higher quality resin could be obtained.
Seven forest plots were selected for the field work, located in different locations, taking into account plant species and climatic conditions. The work was carried out during two campaigns on about 3000 trees.
The results showed that in all the plots the production was lower when the mechanised method was used than when it was done with traditional picks, although with large differences, in some locations the reduction in production was 50% and in others it was 30%, and in some there were even slight increases. The researchers are committed to continuing with this line of study in order to obtain more studies on resin extraction methods.
The director of Cesefor, Pablo Sabin, announces that the centre will continue with its research work in this sector, seeking to improve extraction methods and also the logistics of harvesting. “It is very important to look for new processes to make the work less arduous,” he says. The manager explains that Cesefor is not only working on research, which is an important pillar, but is also exploring other avenues such as positioning the resource in international markets, seeking a brand of Iberian resin to achieve a competitive and profitable product.