Background Report "Green Branch Break at Ommersheimer Pond" – Supplemented Version

Image caption: Barrier at the Ommersheimer Weiher after several branch breakages. Entering the closed-off area is life-threatening. Photos: Stefan Eins, Municipality of Mandelbachtal. +++ Important info about the closure at Ommersheimer Weiher The medieval market can take place as planned. The gastronomy, the mini-golf course, the pedal boat basin, and the circular path around the pond remain accessible. Only an area under the poplars behind the Gangelbrunnen at the eastern edge of the site is closed. Branch breakages may occur there. The municipal maintenance team is working to eliminate the hazard. Please observe the barriers and do not enter the closed-off area. +++ Closures at Ommersheimer Weiher: Danger from green branch breakage Mandelbachtal, June 24, 2026 As the municipality of Mandelbachtal already announced on social media, areas of the Gangelbrunnen recreational facility at Ommersheimer Weiher had to be closed at short notice due to the danger of green branch breakage. Municipal employees and tree inspector Olaf John are currently working to mitigate the danger at Ommersheimer Weiher and to secure the affected areas. "Even during work on site, spontaneous branch breakages continue to occur," reports Olaf John. "First, you hear a crack, immediately followed by the branch crashing to the ground." The affected poplars are fully leafed and appear outwardly inconspicuous. At the same time, branch breakage occurs from the crowns. Especially in the afternoons, the probability of breakage is highest. Green branch breakage – also called spontaneous or summer breakage – refers to the sudden breaking off of healthy, fully leafed branches. The problem mainly occurs during prolonged heat and dry periods as well as during complete calm wind conditions. The calm wind makes the phenomenon difficult to understand for many people. Unlike storms or thunderstorms, there is often no visible external trigger. The affected trees appear healthy, with green and dense crowns. Nevertheless, heavy branches can unexpectedly break off. Especially in parks and recreational facilities like at Ommersheimer Weiher, green branch breakage poses a particular hazard. There are various explanatory approaches regarding the causes. Heat stress, dry stress, and the high load on wide-spreading crown branches are among those discussed. Despite many observations, it is still not conclusively clarified why seemingly healthy branches suddenly fail. Research therefore assumes an interplay of various factors. With the increasingly longer heat and dry periods of recent years, the topic is coming more into focus for experts. Particularly affected are trees with large crowns and widely spreading branches. Such branches act like long levers and are subject to high loads. At Ommersheimer Weiher, the poplar stands of the facility are especially affected. Even on outwardly healthy trees, heavy branches can suddenly break off without any visible warning and fall to the ground. The danger is not limited to the park area at Ommersheimer Weiher. It can occur wherever large deciduous trees stand – for example in forests, cemeteries, along roads, in residential areas, or recreational facilities. The hazard can only be predicted to a limited extent. No visible external damage can be detected on the affected branches prior to breakage. Neither rot nor other signs of pre-damage are found at the break points. Regular tree inspections also cannot guarantee complete safety. The municipality asks to observe the barriers and notices on site. Until the securing work is completed, the affected areas of the recreational facility remain closed. Key information about the closure at Ommersheimer Weiher Closed: Rear part of the facility at Gangelbrunnen (paths and areas under poplars). Hazard: Acute life danger due to unforeseeable, spontaneous branch breakage. Open: Gastronomy, mini-golf course, pedal boat basin, and circular path around the pond remain accessible.