Monitoring the health of our mountains
If pests enter the natural parks and rural areas of Malaga province, they can cause a real envionmental disaster with far-reaching consequences. For example, the nematode which affects the wood of pine trees (Bursaphelenchus xylophilus), which was detected in Europe for the first time in Portugal in 1999, is considered by the European Commissions to be a quarantine organism. If it were to be detected on just one tree in the Montes de Malaga, the whole of the woodland in a five kilometres radius would have to be felled. “That would mean that the beauty spot would no longer exist” says Franma Sánchez Callado, a technician in Ecological Balance with the Junta de Andalucía’s Environmental Department in Malaga, who is one of those in charge of monitoring the mountains and taking action where necessary to keep them in good health. “Thank goodness, the pine nematode doesn’t exist in Andalucía,” he says.
To monitor the mountain areas and take whatever action is needed to control pests, the regional government has set up a Monitoring Network for Damage to Woodlands and another to cover Biological Balance. In Malaga, the principal pests which affect wooded areas are the pine processionary caterpillars, the gypsy moths and insects that bore into pine trees. However, the most recent one, and the one causing most concern at present because of the damage it is causing, is the chestnut gall wasp.
The Junta’s Environmental Department has put special plans called PLIs (‘Planes de Lucha Integrada’) into effect to combat the first three of these. The plans aim to monitor the pests and employ different means of tackling them, depending on their location and how serious the situation is, while at the same time respecting the environment and the local fauna and preventing the apparition of resistence to insecticides. These plans were first put into effect in the 1990s and as a result the incidence of the pests in question “has reduced to a very low level,” says Franma Sánchez.
In the case of the pine processionary caterpillar, in Malaga the most badly affected areas are reforested pine woods, rough mountain woodland and areas where there are exotic species of pine trees, such as the Canary Island pine or the Monterey pine. What is extremely important is that, as these areas are popular with visitors, the pests must not affect people.
The gypsy moth is a lepidoptera which causes different types of oak tree to lose their leaves, especially in the spring, when they feed on the new shoots. Given the ecological and economic importance of cork oaks, and following serious damage to these trees in 1994 and 1995 in Los Alcornocales natural park, an integrated battle plan was set up and at present it covers about 19,300 hectares of woodland in the province.
“This is a decidedly cyclical problem so what we aim to do is control the gypsy moth population and stop it increasing,” explains Franma Sánchez. During the past decade, the area which has experienced the largest populations of gypsy moths has been the Ajibe massif (Sauceda and Majadas de Ronda).
The third integrated plan is for the insects which bore into conifers; these include a group which lives part of its vital cycle at the expense of the living tissues of trees which are weakened, damaged or broken, by penetrating their interiors. The ones which cause most damage in Andalucía are the ‘Tomicus piniperda’, ‘Orthotomicus erosus’ and ‘Ips sexdentatus’.
In Malaga, as well as the first two, there is also the ‘Cryphalus numidicus’. What is serious is that when a boring insect enters a tree, it ends up killing it, producing serious ecological damage. “At present, however, the loss of trees in the Malaga mountains is natural and only associated with forestry work. The area with the greatest incidence of this problem until 2007 was around the reservoirs in Ardales and El Chorro. Since then there have been no serious episodes,” says Franma Sánchez.
To study the condition of the forests and woodlands, the Damage Monitoring Network evaluates 10,000 trees in Andalucía a year, of which 1,600 are in Malaga.
To detect specific problems, the Environmental Department has a Forestry Health Alert Network.source surinenglish