Watching the Desertification of Portugal

Climate Breakdown and Desertification

Dried up pond (Photo: Steve Andrews)
I have been living in Portugal since late 2014 and over the years have been watching the changes in the weather and to the countryside. Every year we have had very hot weather and wildfires and droughts are becoming the new ‘normal’ here due to Climate Breakdown. It is getting worse and I feel I am watching the early stages of the desertification of Portugal.

Ponds Dry Up

Cracked mud (Photo: Steve Andrews)

I am sure that amphibians and other aquatic wildlife are having a hard time due to the lack of water. A river near where I live has run dry in the past and this year some roadside pools have already dried up and are just cracked mud. This is very unfortunate news for the small colony of Iberian Water Frogs that were breeding there. Only a month or so back there were thousands of tadpoles in these pools and Water Starwort was an aquatic plant that was growing.

Iberian Water Frog tadpoles (Photo: Steve Andrews)

Sadly the hot, dry weather has evaporated all the water before the tadpoles could complete their metamorphosis and they have all perished. I had moved some to the deeper pools but it was in vain because they dried up too.

Wildflowers

French lavender (Photo: Steve Andrews)

The wildflowers here are spectacular in spring with so many species bringing a splash of colour to the countryside. French Lavender, Candytuft, Campanula lusitanica, Silene colorata (a bright pink Catchfly), Common Poppies, Three-leafed Snowflake, Narrow-leafed Lupin, St John’s Wort, Crown Daisy, Asphodel, Toadflax, Tassel Hyacinth, Blue Hound’s Tongue, Scrambling Gromwell, and Sage-leafed Cistus are just some of the colourful plants that beautified my country walks back in April and May. It is hard to think that all these pretty flowers were growing well not long ago on ground which is now brown and tinder dry. Where even the grass has died down and the paths are dust.

Flowers in Spring (Photo: Steve Andrews)

Earlier in the year there were countless butterflies. I would expect to see Swallowtails, Red Admirals, Green Hairstreaks, Spanish Festoons, Clouded Yellows, Speckled Woods, Small Coppers, and Small Whites and would never fail to be disappointed.

Green Hairstreak (Photo: Steve Andrews)

A bit later the Meadow Browns became the most commonly seen butterfly but now there are hardly any about.  There are hardly any flowers left from which they could feed and the vegetation has died back or is conspicuously brown and shrivelled up. In the four years before this year I have never seen it so dry and so dead looking as it is now. I live in Quinta Do Conde, a town between Lisbon and Setubal, so am not in the hot south of the country. If it is like this here I dread to think what it must be like in the Algarve.

Skeleton Weed (Photo: Steve Andrews)

But not all plants are doing badly in the hot and dry conditions. Some are colonising new ground and others are adapting. The Skeleton Weed (Chondrilla juncea) is a species that is happy growing in arid places and I see more and more of the plant on waste ground where I live and even growing in cracks in paving. It is an invasive weed that has become a problem in many parts of the world and after wildfires it will rapidly colonise new ground where other vegetation has been killed.
Black Mustard, or a species of mustard that earlier in the season looks very like Black Mustard, is forming bushy clumps when it goes to seed here. They resemble tumbleweeds and can easily break off helping to distribute the plant.

Mustard clump (Photo: Steve Andrews)

Wildfires

As already mentioned, wildfires are becoming a new ‘norm’ for Portugal and can now occur all year round, due to Climate Breakdown and droughts which can now take place even in the winter. These fires, in addition to destroying farms and houses, are killing animals and people, as well as vast numbers of trees of native species. Pines and Cork Oak can regenerate if not too badly burned but when the trees are weakened and if drought continues they become very susceptible to disease. The Pine Wilt Nematode, spread by various wood-boring beetles is killing pines throughout the country. When the rains finally do arrive another problem the countryside faces is the erosion of the fertile top soil that is washed away.

The Portuguese authorities have implemented legal measures requiring landowners to take action by clearing undergrowth,  brushwood and scrub that could easily burn. Many areas where this has been done will have destroyed wildlife habitat and many dormant and active species sheltering in the vegetation. Efforts to provide safety for farmers and residents of Portugal, are surely taking a toll on the flora and fauna of the country.

Permaculture as the Solution

Desertification of Spain and Portugal

I have known about the predicted desertification of Mediterranean countries including Spain and Portugal before I came to live here. Sadly I am now watching the problem in action. I was searching online for information on desertification in Portugal and found this very detailed and excellent lecture by Doug Crouch, who describes how the system of modern farming is degrading the land further. He also proposes permaculture as the solution. He explains what has been going wrong and what can be done to reverse the ongoing growth of what he calls the “New Sahara.”

Why are Portugal's Pines and Palms Dying?

Portugal’s Palm and Pine Trees are under attack

Dead Pine (Photo: Steve Andrews)

As you travel around in Portugal you can’t hope but notice the dead palms and dead and dying pine trees, but what is causing this disaster? It is a combination of drought, disease, and in the case of the pines, because of a tiny nematode worm and species of beetles that transport it. The pines and palms of Portugal are under attack. Let’s take a look at the two problems, starting with the pines.

Male Pine Wilt Nematode (Photo: A. Steven Munson, USDA Forest Service, Bugwood.org)

Pine trees, which are a very common tree in the forests of Portugal, are under threat from a very tiny worm known as the pine wilt nematode (Bursaphelenchus xylophilus), which causes “pine wilt,” as well as from a fungus known to science as Fusarium circinatum, which causes pitch canker disease. The worm’s name is often abbreviated to the letters PWN.

The nematode worms are spread to healthy trees by bark beetles and wood borer beetles that have become infested with the worms in a dead and decaying tree. After a tree is infected the needles become brown and the tree can die within a matter of months. The early stage of this nematode does not feed directly on the pinewood but on fungi in the decaying wood. Once the worm is in a healthy tree it feeds within the resin canals and spreads throughout the roots, trunk and branches. It reproduces rapidly in summer. It first caused terrible and noticeable tree loss in Japan in 1905, but is found in and has spread in many other parts of the world, including America, Canada, Mexico, China and Korea. In Europe it has become a problem in Portugal, and there are serious concerns that it could spread to other countries, including the UK, where it would be a threat to the Scots pine (Pinus sylvestris).

Monochamus galloprovincialis (Photo: Siga)

In Europe, the pine wilt nematode is known to be spread by the Timberman Beetle (Monochamus galloprovincialis). In Japan the epidemics have been particularly bad in hot, dry summers, and the problem appears to be spreading in drought conditions experienced in Portugal. Drought weakens the trees and they become prone to attack by beetles.

I have become alerted to the pine wood nematode by witnessing the dead and dying pines near where I live in the Quinta do Conde area. The authorities here are chopping the trees down and then cutting up the trunks in an effort to deal with this threat to the forests. The wood can be fumigated or kiln-dried to kill the worms and beetles or it can be burned or chipped.

Infected pines (Photo: Steve Andrews)

Some species of pine appear to be more resistant to attacks by PWN than others. This can be seen in forests where there are stands of dead trees and others surviving.

Red Palm Weevil

Destroyed Palm Crown (Photo: Kuchenkraut)

The threat to the palms of Portugal, and to those in many other countries around the world, is being caused by an insect known as the Red Palm Weevil (Rhynchophorus ferrugineus). The grub of this weevil eats the crown of the tree and burrows into the palm trunks making a long tunnel and killing its host as it does so. The adult insects are quite attractive and large, reaching a size of between 2 and 4cm.

Red Palm Weevil (Photo: Luigi Barraco)

The females lay their eggs on palms, especially in the crowns, and on recently pruned leaf scars and in lesions in the trunks. They can lay as many as 500 in total and an infestation of these weevil larvae will kill the host palm. After eating their fill the grubs pupate in a cocoon they weave of palm fibres and usually make in leaf litter.

The insects attack many species of palm, although a favourite for this weevil is the Canary Date Palm (Phoenix canariensis), a very popular ornamental palm that is frequently planted in gardens, parks and in city streets and squares. The Date Palm (P. dactylifera) is also a victim of this pest. Fortunately the Washingtonia palms seem to be resistant to attacks by the insect. The weevils can fly and this is how they invade new territory but they can also be transported in infested palms.

In Portugal, most of damage caused by Red Palm Weevils has taken place in the Algarve and south of the country, but over the years this insect pest has spread to other parts as well. In the heart of Lisbon you will see what’s left of palms that have been killed by the Red Palm Weevil.

In some parts of the world, including Borneo, Vietnam and Indonesia, the grubs are regarded as a delicacy, and are eaten alive or cooked. In countries, like Spain and Portugal, they are a very serious problem that are destroying ornamental palms.

There are various ways of treating infested palms, and insecticides injected into the trunk is a method that has often been used. It is possible to save palms under attack by these insects but often the damage has become to severe and a very beautiful tree will die and get removed.

Both palms and pines add to the beauty of Portugal and it would be tragic if they were lost from many parts of the country.