with pawlonias in Alicante, in Pontevedra Betula pendulum and in Las Palmas de Gran Canaria Laurus Nobilis. These are just a few of the studies carried out in different parts of the region to measure the carbon absorption capacity of certain plant species. Because not all of them have the same capacity to stabilize emissions, and moreover, some should be avoided in urban areas. Although most trees reduce air pollution, some species contribute to bad ozone formation.in a deadly combination of isoprene released by organic compounds with polluting gases from traffic and solar radiation. Therefore, in the context of global warming, ideal is to program in detail what you want to plant in city gardens. for an environmental improvement while reducing fossil fuels or opting for much more sustainable mobility.
Biologist Vicent Calatayud Lorente from the Mediterranean Center for Environmental Studies (CEAM) has been collecting data for months to prepare a roadmap for tackling climate change. Among the most recommended trees for areas with high environmental pollution, jacaranda (mimosifolia), linden (Tila platyphyllos) or mulberry (white mulberry). In contrast, false acacia (Robinia locust), ornamental and very abundant in most Spanish parks, it is one of the most isoprene emitters.
Canary palm tree (Phoenix), is abundant on all islands because it tolerates the proximity of the sea and sandy soils, being one of the least suitable in residential areas with a lot of motorized traffic. If you can choose, Calatayud recommends the date palm (phoenix dactylifera).
Species to Avoid
On the other hand, Washingtonia, like poplar, is not one of the most recommended (population), found in large areas in many Chinese gardens.
TOAs for n eucalyptus (eucalyptus globulusIt should also be avoided because of its emissions (which cause many problems in the Galician forests).. Its effects have disastrous consequences, as the composition of its leaves makes the soil poisonous, waterproof, dry and compact. In Asturias, new plantations are not permitted on lands not already occupied by this aggressive exotic invader native to Australia and New Guinea, given the consequences for biodiversity.
Best with elm, plum, pear and apple trees
It will also prevent the formation of pollutants such as elm trees, ornamental plums, pears and apple trees. Other conifers, such as pines and cypresses, have intermediate emissions, but they have the advantage of removing pollutants in the winter, as they have leaves all year.
The University of Alicante, meanwhile, is among its latest projects to analyze the level of CO2 a Pawlonias plantation can sequester. It is located next to the Cemex cement factory. It is a species that can hold ten times more carbon. The plot now covers eight hectares and has a total of 3,200 specimens. Its large leaves can capture 21.7 kilos of carbon dioxide a day and convert it to six kilos of oxygen. However, it is considered an exotic invader today, as it originally came from China.
The University of Oviedo has also developed mathematical models to determine how much carbon dioxide the most common species can absorb. In the forests of Asturias and Galicia. The study compiles formulas for the ten most common species in the northwest of the peninsula, such as chestnut (castania sativa), Celtiberian birch (betula feathers), beech and three species of oak.
The device, which Calatayud uses in various parts of the city of Valencia but can be exported to any point, then captures the leaves’ volatile organic compounds in a small tube and then measures their reaction, which is already in the laboratory. polluting gases of transport. The investigation was slowed by the restrictions of the pandemic as specimens had to be collected in city gardens, but new momentum is now expected.
In addition to cleaning the air, trees provide valuable environmental services by regulating temperature. From here The European Union’s new Forest Strategy envisions planting 3,000 million trees by 2030. Of course, taking into account the conditions of each region, betting on local varieties, more resilient and prepared for scenarios of water stress or more extreme environmental conditions. Urban and urban areas are a priority due to greater environmental pollution. If the plan is successful, within ten years 10% of Europe’s surface should be firmly protected against 3%.
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Report
Biologist Vicent Calatayud from the Mediterranean Center for Environmental Studies:
“Brussels wants to make cities greener, but it needs to be well planned”
The Mediterranean Center for Environmental Studies has spent twenty-five years researching extreme weather events such as heat waves and heavy rains, as well as climate change mitigation and adaptation. But also about air pollution and its effects in urban, rural and industrial settings. Biologist Vicent Calatayud is now studying the interaction between polluting gases from traffic and isoprene emitted by the flora.
“Europe suggests it in its climate change adaptation strategy to make cities greener, but we should also look at trees that emit less,” he says. “Obviously I wouldn’t remove any of the existing ones because trees are useful but I would make good plans. “Looking to the future and considering this new information,” he says.
“The services they provide to us are indisputable, because they regulate the temperature and can reduce the temperature by one to three degrees compared to other residential areas in big cities,” Calatayud recalls. Despite this, he states several times: we shouldn’t entrust everything to the role of carbon collectors, “but we should reduce gas emissions from vehicles.”
“Plants and trees in a mountain area are not a problem per se, the problem only occurs when you have a combination of volatile organic compounds with high levels of nitrogen oxides and this is when tropospheric ozone is formed.”
Wide variety of volatile
The researcher recalls that plants emit a wide variety of Volatile Organic Compounds (VOCs). “Some of these protect the photosynthesis of leaves against heat. Others are emitted by flowers to attract pollinators, and also by fruits, whose fragrance will help animals distinguish ripe from immature. In addition, they represent a defense mechanism against insect pests: Plants stressed by attacks by certain insects increase the emission of certain VOCs to attract other insects that will attack that pest,” he notes.
Calatayud explains that we need to continue to bet on these types of studies that will “allow progress in building more sustainable cities.” shadow bananas (platanus hispanica), for example, are large emitters.