Budapest – Young stands of natural regenerations and plantages are especially vulnerable to various deteriorations. Forest authority regularly investigates the damage to the ongoing afforestations during the yearly confirming the existence of the investment on site. The authority takes the data down for record.
The damage survey in the afforestations applies to the damage in full, dissociating the quantitative damage from the qualitative, according to the type of the deterioration.
Quantitative damage occurs when the deterioration causes the complete extinction of the afforestation on the whole forest subcompartment or on its parts, and it can only be recovered by re-afforestation.
In case of qualitative damage the deterioration does not mean the extinction of the afforestation, but it causes growth regression, increment loss or qualitative loss.
In case of both damage types the way of deterioration can be divided according to the followings:
damage caused by natural disasters:
– drought damage,
– fire damage,
– other damage: caused by water, frost, snow or wind;
biotic damage:
– insect damage,
– game damage: damage caused by red deer, roe deer, wild boar, fallow deer, hare or other game,
– other damage: damage caused by rodents, soil defect, fungal disease or the forest manager’s fault.
We have limited possibilities of decreasing the damage caused by natural disasters, only by indirect methods. The rational choosing of forest management methods usually effectively prevents natural disasters. Mainly the plantations that follow the large-scale clear-cuts are exposed to damage, especially whether the risks are not diminished by regular tending, creating fire-belts and other ways.
In the past fifteen years the total area of qualitative and quantitative damage was significantly higher than the average on two occasions. In case of both occasions the growth of the extent of the drought damage caused the culmination. First a strong growth was observed from 1991 to 1993, which decreased to an average extent by 1996. The second growth was observed from 2001 to 2003.
The change of three other types of deteriorations is in relatively close correlation with the change of the seriousness of drought damage. The growth of the extent of the registered insect damage to the afforestations is also demonstrable after the droughty years, and after a few years it decreases to an average level. The extent of other damage behaves similarly. The extension of the hare damage in the droughty years is also demonstrable – but the correlation is less spectacular.
The fluctuation of the extension of game damage is also observable. One can notice the continuous decreasing of the very high value, from 1992 until 1999. But after 1999 the extension of registered game damage is increasing. It is also observable that the extent of qualitative game damage in hectares is significantly higher than the values of the quantitative damage. This represents well that the game damage usually does not go hand in hand with the extinction of the established forestations, but it causes significant qualitative degradation of the plants and decreased growth rate. The yearly change of the other types of damage is either even, or it changes year by year without correlation.
In 2007 the forest authority registered 184 hectares quantitative and 3070 hectares qualitative game damage to the afforestations. It is only the 2% of the nearly 165 thousand-hectare area that is obliged to be regenerated.
Deers and wild boars do the significant damage in case of quantitative damage. However, as for of the qualitative damage, deers and roe deers do the most significant damage. In the 2006/2007 breeding year deers and roe deers did 2900-hectare qualitative damage to the afforestations. Last year 48% of the total game damage was done by deers, and 46% by roe deers.
Game damage mainly occurs as qualitative damage. Chiefly the broadleaved stand is exposed to game damage. The extent of quantitative damage is the highest to the oak- and Turkey oak stands, while the qualitative damage is to the Turkey oak and beech stands. Among the fast-growing stands significant damage occurs to the locust and hybrid poplar stands.
Significant damage occurs in those counties that have large broadleaved stands. (Baranya, Bács-Kiskun, Borsod-Abaúj-Zemplén, Heves, Somogy, Veszprém counties)
Besides game damage, drought damage occurred on prominently large areas of the afforestations in the 2006/2007 breeding year. Drought caused 4480 hectares quantitative and 2790 hectares qualitative damage to the afforestations. It is more than the 20% of the total damage. This summer drought has done the 80% of the total quantitative damage. Due to this fact, large-scale re-afforestations, renewal is expected. However, only the 20% of the qualitative damage was caused by drought.
A great many wildfire and vegetation fire occurred in early spring (March, April) and in the precipitation-free periods of summer in the last years.
Wildfires emerging during the spring period are mainly caused by human carelessness, due to the burning of meadows and stubble fields. This causes damage to the broadleaved afforestations and regenerations, mainly in the Northern region of the country. Annually 35-40% of the vegetation fire emerges during this period.
This year the number of the wildfires has grown significantly due to the droughty period in July and in early August. In the forests the litter- and needle-layer completely dried out in the several precipitation-free, very hot weeks. Under these weather conditions wildfires emerged mainly because of thrown cigarette-ends, ignited camp-fires despite the prohibition and weed burning, and arson also must be taken into consideration. Summer fires caused damage chiefly to pine stands, and to elder broadleaved stands.
In 2007 firemen were called 5500 times because of vegetation fire, of which 211 times forest management areas were burning. More than 3400 hectares burnt down due to fires in forest areas. 2100 hectares of forest and 1300 hectares of forest-connected shrubland, turf and pasture burnt down. Pines made up 70% of the burnt-down forest.
Nearly in 290 cases the flames destroyed additional 980 hectares. These were not registered as forests, but they were woody, bushy areas.
The forests were burning 86 times only in July, of which 7 cases on more than 50 hectares. The biggest wildfire emerged in the Kunfehértó-Kiskunhalas region in the end of July. Due to the fire more than 1100 hectare of forest burnt down.
In 2007 240 hectares of reforestation and 80 hectares of afforestation burnt down. Quantitative damage occurred on 120 hectares, and due to this fact probably the afforestation has to be repeated.
99% percent of wildfires occur supposedly due to human carelessness or arson. The wildfires caused by natural factors are insignificant. In 2007, 40% of wildfires provably occurred due to human carelessness, and 10% due to arson. In case of nearly the half of the wildfires, the cause of the fire was unfortunately indefinable.
The majority of wildfires occurred in Bács-Kiskun, Borsod-Abaúj-Zemplén, Fejér, Heves, Somogy and Vas counties.
The insect and fungal damage was insignificant comparing to the outstanding insect damage in the last years. The causes of the insect damage is mainly the wood-beetle, the gypsy moth and – on lowlands – the cockchafers’ grubs.
As for the abiotic-origin deteriorations, frost caused considerable damage in the spring of 2007. The extent of quantitative damage was relatively low (320 hectares), but the damage caused qualitative loss was 5420 hectares. Inland waters have not caused considerable damage this year. Forest supervisors registered altogether 140 hectares of damage.
The quantity of damage caused by natural disasters and by insects is largely affected by the weather, so the value of the damage changes annually in areal breakdown.
All in all the efficiency of the forestations was deteriorated with 4-6% by the biotic and abiotic damage in the past years.