FW-I-6: Forest fire risk and forest fires

The picture shows a road leading along the edge of a forest. Flames shoot up from the forest and large clouds of smoke rise into the sky. Click to enlarge
With climate change, the risk of forest fires may increase.
Source: Photograph: © Butch / stock.adobe.com

2019 Monitoring Report on the German Strategy for Adaptation to Climate Change

Table of Contents


FW-I-6: Forest fire risk and forest fires

Between 1991 and 2017 the areas affected by forest fires declined significantly. Weather-related forest fire risks have remained mostly the same during that period whereas in some areas they have been increasing. The situation in the dry and hot years of 2018 and 2019 is not reflected in the illustration.

Two lines show the development of the forest fire area in hectares and the mean number of reporting days of the hazard classes (FWI 4 + 5) at stations in areas with very high to medium forest fire hazard.
FW-I-6: Forest fire risk and forest fires

Two lines show the development of the forest fire area in hectares and the mean number of reporting days of the hazard classes (FWI 4 + 5) at stations in areas with very high to medium forest fire hazard. The time series on forest fire area from 1991 to 2017 shows slightly higher values again in individual years after a clear decline from very high numbers after the fall of communism to the beginning of the millennium. The result is a slightly increasing quadratic trend. The mean number of reporting days shows very clear annual fluctuations and a quadratically decreasing trend between 1977 and 2017.

Source: Bundesanstalt für Landwirtschaft und Ernährung (forest fire statistics Germany); DWD (regionalised Canadian FWI)

Higher risk of forest fires

Compared to damage in terms of windblown, wind-broken or pest-infested timber, damage caused by forest fires has so far played a secondary role in most regions of Germany. Brandenburg and in regions such as Mecklenburg-Vorpommern, Saxony, Saxony-Anhalt and Lower Saxony are characterised by a more continental climate. These regions are among the traditional areas of pine cultivation. In summer they are often subject to extended dry periods thus putting them at greater risk of forest fires which is therefore a very serious risk factor in those regions.

Forest fires can be caused by a number of different factors. Major triggers are above all negligent actions and arson. Whether the first ignition leads to a forest fire depends essentially on the amount of dry, flammable material available on site and therefore on weather and stand structure. Whether the fire is able to spread depends on wind speeds, fire monitoring and fire fighting capacities. Apart from the weather, all the other causal factors usually change gradually. However, when there are abrupt changes as e.g. in 2003 which witnessed frequent and some extensive forest fires, these can usually be attributed to extreme weather conditions with intense drought in the spring, summer and autumn months as well as extreme heat.

According to Federal statistics, the number of forest fires and the size of forests affected in Germany declined significantly between 1991 and 2017. The fact that the size of the burn area has declined to a greater extent than the number of fires indicates that there have been improvements in recognising incipient forest fires at an early stage and in containing them successfully. It is true to say that, with financial assistance from the EU, the Federal Länder have in recent years indeed invested considerably in forest fire prevention and in improving the infrastructure required for early recognition of and fighting of forest fires. For example, in the eastern Länder which are particularly at risk from forest fires and in the east of Lower Saxony, which is also at risk of forest fires, the old fire watch towers were replaced by digital and remote controlled optical sensors which facilitate the immediate communication of alerts to forest fire alert centres. Furthermore, traditional precautionary measures such as the installation of wound strips and water abstraction points were driven forward, and improvements were made regarding public information. While the latter is of importance in respect of negligent actions, it also furthers the willingness of forest visitors to alert the fire brigade as soon as they spot a fire (usually by using their own mobile) thus facilitating rapid interventions.

In connection with climate change there are ongoing discussions about the increased risk of forest fires in view of the fact that the critical months are becoming warmer and drier. The weather-related forest fire risk is expressed by means of an index value. The higher the value on the 5-level scale, the higher the risk of forest fires. Over recent years, the time series for the number of days on which high index values were reported at levels 4 and 5 is showing values that are rising significantly.

In the 1990s forest fire prevention and fire fighting in the eastern Federal Länder underwent reorganisation which led to advanced and well functioning structures. As a result, there was a distinct decline in records of damage from forest fires during the time period under observation. In the dry years of 2003, 2006, 2015 and 2016 it is possible to see that there was a higher risk of forest fires as well as a more extensive area affected by forest fires. Records for the moist year of 2017, with a nationwide area of 395 hectares affected by forest fires, clearly show a below-average incidence compared to the multiannual mean. In contrast, 2018 was an extremely dry year. In Brandenburg alone, 491 forest fires devastated approximately 1,664 hectares of forest; nationwide stands in an area of 2,349 hectares were lost. Firefighting efforts were hampered to some extent by any ordnance remaining in the ground from past wartimes. In the light of this knowledge, concepts are required for precautionary and proactive forest fire protection including the targeted removal of any ordnance so that firefighting can be carried out unhindered.

As weather conditions become hotter and drier, the challenges posed by forest fire prevention and firefighting are likely to increase rather than diminish. The continuous improvement of systems has therefore become a permanent task.



BS-I-1: Person hours required for dealing with damage from weather-related incidents



Precautionary measures against forest fires (as per the individual Länder’s legislation pertaining to forests).