City of Essen cuts more trees than are replanted
According to the tree balance, more trees were recently felled along streets in Essen than were replanted. The city now wants to take countermeasures.
Photo: Andre Hirtz / FUNKE Photo Services
Essen. The tree balance sheet of the city of Essen reads positively only at first glance. But can trees replace trees? This is what lies behind the figures.
This year, the city of Essen will plant more trees on streets and on municipal green spaces than in previous years. This was explained by Melanie Ihlenfeld, head of Grun und Gruga, in an interview with the editorial team. Although the city has once again presented "a positive tree balance sheet. At second glance, however, the statistics read less encouragingly. More trees were felled than planted.
The balance is positive for the following reason: The number of trees on municipal property, i.e. along roads, in parks and in cemeteries, increased again in 2020 compared with the previous year – from 202 to 20,000.420 to 209.162. That is an increase of 6742 trees.
According to statistics, the stock of street trees has already recovered two years after "Ela"
The trend of the past years thus continues, despite climate change, despite much too hot summer months and despite hurricane "Ela" and its devastating consequences in 2014. According to the tree balance of Grun und Gruga, the stock of trees in public street space had already recovered two years after the storm event.
But: "As is well known, the devil is in the details," warns the initiative "Together for Urban Change". She already pointed out last year that the so-called natural regeneration was also included in the tree balance of Grun und Gruga. This refers to trees that are not planted but grow back naturally as the wind carries falling seeds. "A gift of nature", as "Together for Urban Change" points out.
Essen records trunks from a circumference of 20 to 25 centimeters in the tree balance sheet
These trees are included in the balance from a trunk circumference of 20 to 25 centimeters at a height of one meter, confirms Grun und Gruga. Whereby not every single tree is counted, but so-called "collectives". A single tree cadastre is still under construction. As a first step, the cadastre is to provide an overview of all street trees in the city.
The tree balance only reads positively "because it sets off tree against sapling," criticizes "Together for Urban Change" and points out that a young tree with a trunk diameter of six to eight centimeters cannot replace a tree that is up to 100 years old as a CO2 reservoir, shade giver and habitat on an equal basis.
The number of trees felled is reversing the positive balance in Essen
The tree balance is quite different if natural regeneration is not taken into account. In 2020, 3971 trees were felled along roads and on city-owned land. That was significantly more than in 2019, when the saw circled on 3234 trunks. As far as the number of trees felled is concerned, the positive balance is reversed.
Melanie Ihlenfeld doesn’t want to let this impression stand: "We only cut down diseased trees and trees that are no longer safe for traffic," emphasizes the head of Grun und Gruga. Only in exceptional cases, such as for construction work, would healthy trees also be removed.
Essen’s street trees were unable to recover sufficiently in 2021
According to Ihlenfeld, the fact that more trees were cut down in 2020 than in the previous year is evidence that Essen’s street trees have suffered considerably in recent years. Every fourth tree is weakening, it was already said in 2021 after three hot and dry summers in a row. Ihlenfeld said that the stock had not been able to recover from this in 2021, when it rained more frequently.
Back to the tree balance: According to Grun und Gruga, the declared goal is to plant a new tree for every tree that is cut down. However, the city fell well short of this goal in 2020. For 3971 felled trees were replanted just 845 trees. Already in 2019, the bottom line was about 1700 more trees cut than planted. 1506 trees were replaced, which, statistically speaking, was not even every second tree.
As a first step, the tree cadastre is to record all trees along roads according to tree species, age, height, trunk diameter and crown width. In addition, changes at the respective location are to be documented.
The data required for this are to be collected with the help of artificial intelligence. The Office of Geoinformation has launched a 2.5 million euro research project on this subject. The condition of the roads is determined, the measuring technology should also provide information about street trees.
Melanie Ihlenfeld explains this disproportion with the difficult location conditions for trees on many streets. "Sometimes one is surprised that trees could grow there at all."Grun und Gruga," he said, was working to improve conditions and provide more space for street trees.
Already in the current year 2022, significantly more trees are to be replanted, Ihlenfeld announces. "1000 new trees" have CDU and Greens in their cooperation agreement programmatically fixed.