Poland's forests are among Europe's most threatened, on account of the constant and simultaneous impact of many factors capable of encouraging unfavourable phenomena - and of bringing about negative changes - in the state of health of forests. The periodically intensified occurrence of even one of this list of factors (mass outbreaks of insect pests, drought, fire or epiphytoses) may lead to consequent catastrophic threats on local or even regional scales. It has great influence on limiting biodiversity of ecosystems. Therefore Polish foresters have a duty to preseve and remove effects of threat to protect ecosystems by impoverishion.
P We can distinguish three basic groups of stressful factors: antropological factors, lived and unlived factors. P To those first we can enclose poisoning the air for example greenhouse gases, exhaust gases and municipal wastes. What is more poisoning of water and soil has great influence on forest's condition. Another threat fire of forest are mostly provided by humans. Sometimes bad forest economy especially conventional planting and giving nurturing up leads to serious harms.P Let' s turn our attention to lived factors such as insects, fungi and structure of forests. We can say pour variety of species in most of polish forests conducive to degeneracy effects. P What is more unlived factors like weather anomaly like worm winters, late ground frosts, very hot summers, floods, a lot of snow and hoarfrost, huragans are important and have great impact on polish forests. An extra task is humidity of soil, low level of ground water what provide to decrease of productivity of natural habitat.
P One of the most dangerous disaster which take place in polish forests is fire. Therefore we would like to concentrate on this subject. Polish forests are among Central Europe one of the most flammable. This reflects the high proportion of the country's area falling within forest habitats. Stand age is also one of major significance. Forests up to 40 years old burn best, and these currently account for more than 30% of State forests area. 2003 brought more than twice as many registered fires on State Forests land as 2002 . There were 8209 fires, with some 4182 ha being burnt . Avarage area of fire( 0.51 ha) was in 2003 about 60% bigger than previous year but still less than in other forests, which don't belong to state forests (2.5 ha). 46% of all forest fires took place in state forests among 2003 (in 2002 it took about 37%). P The most frequent causes of forest fires in 2003 were: setting fire (39%) carelessness of adults (19%). the reason of fire wasn't established in 22% . The number of fire which starts in agricultural areas and reach forest is high and took 15% of all. Another important cause of fire is uncontroled grass burning. P Sometimes paradoxally even volunteer firefighters set fire to have profits, because their payments depend on number of fire, that they extinquished. Maybe if rate of unenployment wasn't so high this reason won't be so serious but unfortunately this situation appeares especially in poor regions. Even empty bottles leaved in forest can gather sunbeam and cause little fire which often spread very fast. Forestry is prepared for fighting with such dangerous calamities. P
Essential role in fire extinquishing take volunteers live next to grounds under treat. They are acomodated in williges and are able not only to recognise the place of fire but also to reach it and start extinquishing. Unfortunately equipment of those units is often poor and obsolate. Some forestry districts which are rated first or second category of threat among, have their own, good equiped, fire station with especially designed tools like fire-extinquishers, plough, buldozers and many more. Recently they recaived well prepared four weel drive cars with high pressure pumps . P Moreover state forests organise special air recognising system based on flying units, which also take part in extinquishing. They use helicopters mi 2, pzł sokół , and m 18 dromader airplane. P
I mentioned that airplanes are a part of system which has a duty to recognise the place of fire. P The system is based on the net of look out towers which have radio communication with them selfes and with forestry districts. Valid role take making fire belts which prevent spreading fire. Another task is information activity among citizens and forestry workers. P What is more planting decideous species has big influence to improve biodiversity and, what is connected , decreasing of fire threat.
Unfortunately sometimes all those means don't work good enough. P
One of the biggest fire in recent time in Poland took place in Potrzebowice forestry district. Everything started the 10 of august 1992 afternoon. The temperature that summer was innormaly high and humidity of forest duff extremely low. Throu the forest next to notec river there is situated important railroud connected Poznań and Szczecin. One of the trains had unfitted breaks what caused sparkling. The fire started to spread rapidly because of strong wind. Beside immediet fire detection and extinquishing action losses were enormous. Over 5 thousend of ha fullvalued pine forest have been burned. Losses came to 25 milion of dollars. P
Fire is one of factors, threatened biodiversity of forestry ecosystems. The duty of Foresters is counteracting by harmful influence of factors, which dewastate reach resources of Polish nature. P Considering the fact that forest is covering most of polish territory and forestry economy is important part of polish national economy the role of foresters is not to overestimate. P Moreover the character of polish forests becomes more and more natural and in this task we should do our best. P