• Granada, the third most polluted city in Spain, has lost 75% of its poplar groves in the last 20 years, a volume of trees that at the beginning of the 21st century was capable of absorbing CO2 from almost 400,000 vehicles.

• The project, with the participation of the University and the Provincial Council, offers an ecological solution to the pollution in the Belt and boosts the economic development of the rural environment with the creation of a wood industry in great demand.

The LIFE Wood for Future/Madera para el Futuro project, which has just obtained funding from the European Union’s LIFE Program [LIFE 20 CCA/ES/001656], has proposed to Granada’s institutions to collaborate in a shock plan to recover the poplar groves of the Vega as an effective instrument in the fight against air pollution in the Metropolitan Area of Granada. Poplars, a fast-growing species, absorb a large amount of CO2 and polluting gases from urban traffic and create a cooler and more humid microclimate.

The University of Granada and the Provincial Council, partners of the project together with the Confederation of Forestry Organizations of Spain, the University of Santiago de Compostela and the spinoff 3edata, thus respond to the recent commitment between the Andalusian Government, the City Council of Granada and 28 municipalities of the Belt to improve air quality and reduce air pollution. For this reason, they ask the Andalusian Government for a strong support to this crop that combines environmental and economic benefits, in line with the support that the populiculturists of Castilla y León, La Rioja and Navarra receive from their autonomous governments.

Granada is the third city in Spain with the worst air quality, only behind Madrid and Barcelona, but without having the population or the industrial development of those large conurbations. Eighty percent of air pollution comes from road traffic, and the climate and orography exacerbate the concentration of gases that are harmful to human health and contribute to global warming.

Researchers and technicians of LIFE Wood for the Future believe that the recovery of poplar groves that dotted the Vega de Granada just a few years ago, along with measures in favor of sustainable mobility, could radically reverse this situation.

Due to the rapid growth of this species – the ‘Populus’ can reach a height of about 20 meters in ten years – poplar trees have a great capacity to sequester CO2 from the atmosphere and act as effective ‘green lungs’. In 2002, the province of Granada had 12,000 hectares that consumed the CO2 emissions of 384,000 vehicles (85% of the entire province); today, the 3,000 hectares are capable of absorbing the emissions of 21% of the province’s traffic.

In addition, poplars absorb various polluting gases, filtering particles from the air and trapping them in the leaves and bark, and their forests behave as natural vaporizers, as they increase the humidity of the air and lower the temperature by 3 to 6 degrees in summer.

There are indications that the drastic reduction of this crop in the Vega in recent years is related to the increase in atmospheric pollution. The Diputación de Granada manages two EDUSI (Strategy for Sustainable and Integrated Urban Development), financed by Feder funds, which are trying to confirm this impression with scientific data. Currently, a mobile unit is taking measurements in areas with poplar groves and in areas where these have disappeared to compare the results associated with the main parameters of atmospheric pollution (nitrogen dioxide, sulfur dioxide, carbon monoxide, ozone and suspended particles), as well as temperature and relative humidity.

The poplar groves are also excellent filtering agents for water pollution. In the Vega de Granada they have traditionally been irrigated with poorly treated urban wastewater, which recharges the aquifers, improves soil fertility and prevents flooding. Finally, poplar trees help to prevent soil erosion and attract a large biodiversity.

The LIFE Wood for the Future project will involve a significant investment over four years – 55% contributed by the European Union and the rest by the Spanish partners – which will be devoted to the promotion of a union of poplar growers – to whom certified seedlings and care will be provided -, the promotion of a wood processing industry and research into new materials for sustainable construction in the laboratories of the universities of Granada and Santiago de Compostela. In addition, the restoration of riverbanks with poplars and other native species in riverbeds of the Vega de Granada is planned.

Antolino Gallego, professor of Applied Physics at the Escuela Técnica Superior de Ingeniería de la Edificación and coordinator of the project, explains that the decline of poplar cultivation in Granada in the last two decades has been due to its loss of profitability, since the wood is mainly used for the manufacture of fruit and vegetable crates.

Improving the quality of the wood through the selection of the most suitable varieties and better care of the crops – felling and irrigation – would make it possible to revalue the raw material: given that EU legislation requires the carbon footprint in the construction sector to be reduced to almost zero, laminated and cross-laminated poplar wood elements for beams and panels are in growing demand in Europe.