Finally enjoying the summer weather again: Many people are drawn to the outdoors to grill and chill out.
At the same time, the risk of forest fires is increasing in many regions.
Eberswalde / Berlin (dpa) - High temperatures, little rain: As nice as the summer weather is for people in Germany, there is a risk of fires for forests.
The forest fire risk index of the German Weather Service (DWD) showed alarming red to dark red spots for the weekend including Friday.
The index is racing towards the highest forest fire warning level, said a DWD spokesman.
The weather experts see a high level of danger in northeast Germany in particular.
The top soil layers there are too dry.
A possible fire could also get bigger quickly if the wind kept coming up.
DWD forest fire expert Christopher Böttcher sums it up like this: Air humidity, wind speed, precipitation, temperature and solar radiation are important factors.
The east of Germany is predominantly colored dark red, for all the eastern states from Mecklenburg-Western Pomerania to Berlin to Thuringia the highest warning level applies to a large extent.
In the case of Lower Saxony, Hesse, Rhineland-Palatinate and Baden-Württemberg, there were dark red spots on the hazard map on Friday.
Brandenburg is particularly badly affected by forest fires year after year, because it often does not rain, or only a little or only very locally, in the state. If the winds come from the north, Scandinavia's mountains ensure that only a dry current arrives in Brandenburg, as a DWD meteorologist explained. From the southwest, thunderstorms mostly accumulated over the low mountain range, clouds rained down, only a small amount of residual precipitation arrives in Mecklenburg-Western Pomerania and Brandenburg. The land around Berlin also suffers from sandy soils that cannot keep the rain long.
By Thursday, the state of Brandenburg had to fight more than 80 forest fires this year - and the number is rising.
More than 15 hectares of forest are affected.
Looking at the past few years, that is comparatively not much: in 2020, the Ministry of the Environment already counted more than 160 fires at that time.
But the risk increases with rising temperatures and little rain.
In other countries too, such as Bavaria, Saxony and Lower Saxony, the risk of forest fires increases every day.
Danger levels four and sometimes also five have already been declared there.
Warmth alone does not say anything about the risk, the decisive factor is the lack of moisture, explained Knut Sierk, spokesman for the state forests in Lower Saxony.
"The vast majority of forest fires are caused by negligent behavior," reported Renke Coordes, spokesman for the Sachsenforst state enterprise. It is therefore important not to smoke, grill or light campfires in these areas. Disposable grills, which are often left behind, are a particular problem. "That really is a curse," explained Sierk, "the sandwich for the hike is better than grilling the steak in the forest."
The forest fire control centers in the federal states are manned from danger level 3 and monitor the events with sensors.
In Brandenburg, for example, there are two such centers in Zossen (Teltow-Fläming) and Eberswalde (Barnim).
Within a few minutes, employees can pass on information about fires to the respective control centers in the regions.
These sensors, which locate the forest fires so precisely, were originally intended for space missions. Among other things, the system was supposed to analyze dust clouds on Mars, as the Brandenburg forest fire officer Raimund Engel reported.
According to DWD information, relaxation is currently only in sight on the weekend with increasing probability of thunderstorms.
A large-scale thunderstorm front, which will put an end to the current heat wave, is not expected until the beginning of the week and also involves storm risks.
At the Thünen Institute of Forest Ecology in Eberswalde in northeast Brandenburg, the water supply in the soil is measured.
The institute also wired some trees to record how much water flows through the trunks each day.
"It's looking pretty good here at the moment," said Tanja Sanders, Head of the Forest Ecology and Biodiversity Division at the institute.
Even the deeper roots of the pine would still have enough to drink.
The flow of sap in the beech trees has leveled off well and reaches peaks of 0.7 liters per hour.
"We had deep seepage - that has not existed for years." It looks similar in Bavaria and Thuringia, says Sanders.
Rhineland-Palatinate and North Rhine-Westphalia, on the other hand, have less water.
© dpa-infocom, dpa: 210618-99-45826 / 2
DWD hazard index
Forest fire hazard in Brandenburg
Twittering trees Thünen Institute