Longer and hotter summers speed up widespread death of pine trees in Malaga

Longer and hotter summers are making the damaging effects of climate change, lack of soil nutrition, insects, worms and fungi worse on the pine trees of Malaga province. This phenomenon of drought stress on local forests is becoming ever more evident and in Malaga city, among other places, work is going on to try to save the situation.

“It is a worrying picture,” says botanist and climate change professor at the University of Malaga, Enrique Salvo. The issue is there to be seen everywhere from town parks to wide forested areas all over the province including the Costa del Sol. Summer is lingering on with temperatures over 30C on some days this week. Thousands of trees are already dead.

“This illness is really speeding up. It is affecting the upper layer of the soil,” Salvo says. “Soils have really suffered from an excess of ultraviolet rays and are becoming desertified.” This expert is calling for a rapid response, which includes planting fast-growing alternative species and removing the dead trees, which can become fuel for fires and attract insects and fungi.

“Pine trees were widely planted in the 1970s thanks to the availability of very cheap labour. The pines played a key ecological role: they provided shade, improved soil fertility and helped the natural regeneration of cork oak and holm oak forests,” Salvo explains.

“We are studying parts of the world with a very similar climate to Malaga, and forecasting ahead. In North Africa, there are species that can be planted. For example, there is the Cartagena cypress, which has thrived in areas on the edge of deserts in Morocco, Algeria and Tunisia.

“It is very important that we don’t lose the soil, because, historically, we know how our forests behaved with the phylloxera virus,” he says, referring to the added risk of flooding.

The professor also mentions the carob tree as a good plant to consider and says that they are also studying other species that could be grown in public nurseries to be ready when needed.

“In the Montes de Málaga natural park ... we have never seen so many ‘witches’ brooms’ deformities at the top of the holm oaks and cork oaks,” Salvo explains.

Drought stress in trees has been happening in Malaga city and the province since the summer of 2021. The outlook is bleak for landmarks well-known for their pine trees, such as the Gibralfaro hill dominating the centre of Malaga.

Malaga city council is stepping up the removal of sick pines and carrying out thinning. Access is banned in some cordoned-off parts. Some of the areas of this city park, especially those facing south, have large brown patches that are eating away at the green mass. Larger pines are the first to suffer as they need more water. Smaller ones fare better. The effort, both physical and financial, is enormous.

The picture is similar in other hills in the city. Malaga city council’s sustainability department has contracted experts from the University of Cordoba to carry out a study and signed an agreement with the provincial authority to speed up the contracting of the specialist skills needed. This clean-up is only the first phase. The next step, according to city councillor Penélope Gómez, is to plant “species more adapted to the Mediterranean climate”.

The study from Cordoba university concluded that the main drivers of pine forest decline are irregular and decreasing rainfall, rising temperatures and increasingly longer warm periods. Added to that is competition between species due to the scarcity of water resources.

In addition, wood boring insects take advantage of the reduced defences of the affected pines to infest them. The disease is even spreading to other species.

“The summer has been very hard and it is likely to have intensified the damage,” says Cordoba University professor of forestry engineering Ángel Lora, adding that good forest management will give results, but not very quickly.

“It is not easy. Very drastic forestry management measures need to be taken,” he warns.