Many tree diseases that are common throughout Germany also occur in Monchengladbach. Spruces and Douglas firs in the urban area suffer from bark beetle infestation. The fungus species "the false white stem cup" causes ash shoot dieback. Other deciduous trees are suffering from fungi such as the fire-crust fungus or the giant or lacquer porus.
The bark beetle
The bark beetle loves spruces to eat.
The pest occurs throughout Germany. Spruces and Douglas firs are eaten up – also in Monchengladbach. It does not stop at private gardens, forests, parks or cemeteries. Two species currently exist in this area: the box elder and the copper engraver.
Infested trees such as those in the Hardt or Wickrath forests must be felled as quickly as possible before the larvae develop into beetles, fly out and cause new damage. It is easy to determine whether the conifer in your home garden is infested with the bark beetle: Simply remove a piece of bark and look to see if there are the typical circular boron holes underneath.
There are several reasons that promote bark beetle growth. In Monchengladbach, hurricane "Friederike" in January, storm "Eberhard" in March 2019 and the dry summers were the main contributors in 2018. The violent storms have brought down many trees.
This in turn leads to perfect breeding conditions for the bark beetles due to the tree trunks and branches lying on the ground. The long dry season in the summers. The persistently high temperatures have done the rest. While healthy trees that are sufficiently supplied with water can defend themselves against the bark beetle through the formation of resin, this is not the case with undersupplied conifers.
The "False white stem cup"
A fungus called "false white stem cup" is responsible for ash shoot dieback.
This refers to a type of fungus responsible for ash shoot dieback. The "false white stem cup" comes from East Asia and occurs throughout Europe. The fungus destroys entire forest stands every year. This tree disease has also been affecting ash trees in Monchengladbach since around 2005. For example, at Rheydt Castle, in the Volksgarten, in Hoppbruch/Trietenbroich and in the Donk.
The leaves are attacked first. The "False White Stem Beetle" then migrates via the stem into the branches, which subsequently die off. Affected ash trees can be recognized by their so-called secondary crown – a fight for survival for ash trees, in which they usually lose out to the fungus.
According to mags tree inspectors, affected ash trees are best distinguished from healthy trees by their foliage during the summer months. "Finding, marking, promoting!"The forest protection management of Wald und Forst NRW recommends action.
For Monchengladbach, this means that resistant ash trees in infested forest areas are particularly well cared for. Thus, intact mother ash trees ensure immune offspring. Affected trees must, however, be felled.
The burnt crust fungus
The blight fungus visually lives up to its name.
Its name does not bode well. This is how the blight fungus endangers the stability and breakage of trees in particular. Due to its inconspicuous fruiting body, it is considered by mags tree inspectors to be one of the dangers that are invisible to the layman. The fire-crust fungus occurs worldwide. Affects both forests and city trees.
Old beech and poplar trees are most frequently affected by this pest in Monchengladbach. For example at the house Horst or in the Elschenbruch. Because trees infected with the blight fungus pose a danger to people, such hazardous trees must be felled for reasons of road safety obligations. The same is true for trees that are Giant or Lackporling are diseased. These fungi also affect the stand-. Breakage safety of trees massively.
The sooty bark disease
A black-sooty fungal coating on the bark can be an indication of sooty bark disease.
The disease, which is widespread in many regions, occurs mainly after long dry periods or high temperatures. The sooty bark disease can be recognized by a black-sooty fungal coating on the bark.
This tree disease first causes the leaves of individual branches to wither, and within a very short time the entire tree dies. Affected trees can lose branches. In addition, the stability of the trees is no longer given. Sooty bark disease can also cause allergic reactions in humans.
The most recent example of this tree disease are the maples in the city forest. Sycamore trees suffering from sooty bark disease have been noticed along the Rheydt garbage hill. Because the fungus endangers people and trees, several hundred trees had to be felled.
Reforestation with beech, oak, red oak and cherry followed by mags.
Why we do not use pesticides against pests
For one thing, besides pests, beneficial insects also live on trees. So other insects that live in symbiosis with the trees. They would also die if treated with pesticides, which is not justifiable.
On the other hand, tree pests such as the bark beetle are important food sources for woodpeckers as well as songbirds, on which the animals depend. Working with pesticides here would be fatal.
Compensatory planting and reforestation
In many places in the city, new forest areas are being created through reforestation – as here in the Hardter Forest. In 2021, more than 300 new street trees were planted. In the forest about 54.000 trees (seedlings) are reforested.Reforest 000 trees (seedlings). Nature also supports the forest with the natural seeding of young trees.
Due to the so-called natural regeneration, thousands of young trees grow up naturally in the forests every year. This is how natural young growths develop in Monchengladbach, too. These are integrated into our forest stands through stand maintenance activities by mags.