First assessment following a field inspection in the area by WWF Greece and the Mediterranean Institute for Nature and Anthropos (MedINA).
The wildfire in Trapezitsa, Konitsa is yet another incident in a series of significant fires that have occurred in recent years in the mountainous forests of Northern Greece. Similar fires have been recorded in many areas in the past years (e.g. Orvilos, Pangaio, Menoikio, Pieria Mountains, Valia Kalda). The occurrence of wildfires in these ecosystems is not something new; it is often linked to intense lightning activity and, as the ignition points are mainly located in steep and inaccessible areas, they can remain active for many days, slowly burning low vegetation and dead woody or leafy debris on the ground.
During the last days of the fire in Trapezitsa, and while it had by then been brought under partial control, scientists from WWF Greece and the Mediterranean Institute for Nature and Anthropos (MedINA), together with members of the Konitsa Mountaineering Club, carried out a joint field inspection in the area, with the aim of an initial assessment of the extent and the manner in which the forest ecosystem was affected. Combining field observations with satellite imagery, the fire is estimated to have affected an area of approximately 1,000 hectares.
However, the picture is not uniform. Over most of the area, the fire moved mainly along the surface, burning surface vegetation and dead woody or leafy debris on the ground. Fuel management works carried out this year around Konitsa by the competent forestry office appeared to have made a positive contribution to the course of the fire. However, from the combination of mapping and on-site observations, it appears that in approximately 100 hectares the fire reached the tree crowns, i.e. the upper part of the trees. This is mainly the area that needs to be monitored more closely with regard to its post-fire development.
Surface fire & Crown fire
Wildfires that occur in mountainous forests often start or move for long periods as surface fires: that is, the fire burns mainly grasses, shrubs, pine needles, leaves, branches and other dead organic matter near the ground, without necessarily spreading to the tree crowns. When their intensity remains low or moderate, both fauna and most mature trees can survive. Under these conditions, fire can even function positively for the ecosystem, recycling nutrients, creating small gaps in the vegetation and contributing to the creation of a more heterogeneous forest landscape. The outcome, however, always depends on the severity, duration and frequency of the fire, as well as on the type of vegetation affected.
The alarming element is when these fires change character. Under conditions of severe drought, high temperature, strong wind or large accumulation of fuel, such a fire that initially moves along the surface can climb into the tree crowns and develop into a crown fire. In this case, the consequences are far more serious, particularly in mountainous cold-tolerant conifers which, unlike other species, do not possess effective mechanisms for natural post-fire recovery. The natural regeneration of these species after a crown fire depends to a great extent on the unburned trees that remain around or within the burned area and can function as seed sources.
Photos: © Aris Giannoukos / MedINA
Recovery potential for several areas, the special case of the Bosnian pine and the emphasis that must be placed on natural regeneration
The first conclusions from the field inspection and satellite analysis are relatively optimistic for a large part of the affected area. In most areas where tree crowns were affected, the burned surfaces are neither large nor uniform, so as to speak of an image of complete destruction. On the contrary, around and between them, quite a few unburned trees and islets of living vegetation have remained, which will contribute positively to the course of recovery.
For this reason, over most of the 100 hectares where tree crowns were burned, emphasis should be placed on monitoring and assisting natural regeneration and not on immediate reforestation. Reforestation in many of these areas is, moreover, judged to be almost impossible due to the slopes and the general topographic relief.
The first months will also play a crucial role. Provided there are no intense rainfall events, which could cause significant erosion, the appearance of the first vegetation is expected relatively soon. This will contribute to the retention and protection of the soil, gradually creating the conditions for the establishment of new trees that will come from the seeds of neighbouring unburned trees. To avoid erosion, an immediate investigation of the area by the Forest Service is necessary in order to assess the risk and implement targeted mild anti-erosion interventions, where deemed necessary. Particularly in the steep ravines and along certain streams on the slopes facing the town of Konitsa, narrower zones of more intensely burned vegetation and more exposed soil appear, where the construction of a limited number of log dams should be examined as a priority, also for the protection of Konitsa.
Finally, the field inspection showed that the ridge of Trapezitsa causes greater concern. There, mainly mature individuals of white or Bosnian pine (Pinus heldreichii) grow, a characteristic mountain conifer that in our country is found at the high altitudes of Northern Pindos and other mountains of Northern Greece. It is a species of exceptional ecological importance and great longevity. On the ridge of Trapezitsa, the fire affected with high severity parts of the mature Bosnian pine forest, while not enough unburned mature trees appear to have remained to ensure the natural dispersal of seeds that would contribute to the recovery of the forest in the future. This does not mean that reforestation should begin immediately. It does mean, however, that this specific zone needs systematic and long-term monitoring of natural regeneration and that targeted plantings will probably be needed.
Mountain fires did not appear suddenly. The case of Trapezitsa, however, confirms that the conditions under which fires occur at high altitudes have now changed. As a result, they acquire greater intensity, climb more frequently to the upper part of the trees and affect ecosystems that were historically less exposed. This new reality should also concern us with regard to how we plan the management of these particular ecosystems, aiming to protect them from such fires.
Photos: © Aris Giannoukos / MedINA