The necrosis of fir trees in the Parnitha National Park has resulted in a gradual deterioration of the forest. Firs on the southern and eastern slopes often grow in shallow and rocky soils and it is here that the necrosis is more widespread, particularly on the outer limits of the forest. But in several places, where some decades ago there were fir trees (at heights of 800-1,000 meters), there are now stands of Aleppo pine, which is more drought-resistant. In the 1960s the problem was dealt with by removing the dead trees. Repeated efforts were made to remove all of them, in order to reduce the population of insects that kill the trees by eating the bark, but the problem was not resolved. It is not feasible to try and remove the dead trees from Parnitha at this time. Even if we tried to cut down and remove 250,000 trees from the forest, we might cause even greater damage to the vegetation, and it has been shown in practice that these bark-eating insects cannot be controlled in this way. A large section of the fir forest, particularly on the eastern, southern southeastern and southwestern slopes, is at the limits of the fir’s xerothermic range. The fir population is declining and one solution could be reforestation with more xerothermic species, such as the Aleppo pine. Also useful would be the black pine, which grows at high altitudes. During the 1950s, the black pine was used to reforest several areas of the mountain, and has developed well. The fir can regenerate underneath stands of black pine. (1) Panayiotis Tsopelas is a researcher at the Institute of Mediterranean Forest Ecosystems at the National Foundation for Agricultural Research (ETHIAGE).