Mainz citadel moat

The Mainz Citadel Ditch (2016)

Mainz Citadel Ditch is the common name for the protected landscape component on the grounds of the Mainz Citadel , located in the inner city area, with a size of around 8 hectares. The city of Mainz designated the area as a protected landscape component in 1986 for nature conservation reasons . Its exact designation in the ordinance reads: Green space of the citadel complex with moat area .

Area description

The protected landscape component includes the citadel moat on the southern side of the fortress. Then there are the walls standing there and other areas within the citadel that border the protected walls and the southern citadel moat.

"The flora and fauna that developed over decades on parts of the citadel are of inestimable value today," the city of Mainz assesses the area. Investigations revealed 447 animal and plant species, 66 of which are on the "Red List"; Examples are brown long-eared bat, wall lizard, long-horned beetle, dwarf deer beetle, yew and flaky mullein. The walls are of "nationwide importance" because over 170 species of stinging voices (wild bees, digger wasps) live in their cavities. In addition, these walls with a total area of 19,000 square meters are among the "most important moss biotopes in the country". In addition to the biodiversity, undisturbed habitats have been created in the protected part of the landscape for centuries, which offer special "genetic reservoirs" of the species represented there that are worth protecting. In addition, the protected area represents a "green lung" for the inner city, "which is cut off from fresh air corridors."

Protection purpose

"The protection purpose is the preservation of a very structurally rich, anthropogenic area with its remarkable wall joint biotopes, the preservation of the flora and fauna there (including Red List species ), ensuring the efficiency of the natural balance (improvement of the urban microclimate ) as well as the revitalization, structure and maintenance of the townscape. "

pads

According to the legal ordinance of 1986, all measures that run counter to the protective purpose are prohibited, including a. the use of biocides, the damage to wild plants, any disturbance of animals (dogs must be kept on leash), the erection of new structures, etc. The fact that the protected area is located in the historically significant citadel complex of Mainz, which is a listed building, takes into account the statutory ordinance such as follows: "During the work, care must be taken that the crack and joint structure necessary for the flora and fauna is preserved as far as possible".

controversy

Occasionally there is talk of a "battle between monument protection and nature protection" in relation to the Mainz Citadel, the masonry of which has clearly lost its stability over the centuries in the entire complex. "Without a doubt, this is primarily due to the age of the building." However, it is also undisputed that roots of trees penetrated the previously damaged masonry, which increased the damage. The association Initiative Zitadelle Mainz eV (IZM) complains: "The citadel is falling into disrepair despite monument protection"; the Naturschutzbund Deutschland Mainz und Umgebung eV (NABU) would like to receive the "green gem in the city" and points out that vegetation z. T. also protected walls from weathering.

Between 2006 and 2008, an "ecological wall renovation" test was carried out on a sub-segment of the wall in a pilot project funded by the DBU . In 2015, NABU took over the maintenance of some areas in the citadel moat from the city. In February 2017, the Mainz Environment and Construction Department heads, together with NABU and IZM, announced an agreement on how monument protection and nature conservation should be brought together: 128 trees of the 2550 trees in the complex are to be felled that endanger the walls. To compensate for this, new plantings are planned on a sports field, which at the time still existed on the site of the citadel ditch. The most important measure is the laying of paths with the aim of creating a place of retreat for animals and plants that is undisturbed by walkers. Minimum distances from trees to walls are observed.

photos

The romantic entrance to the Mainz citadel moat seen from the inside. It was closed in mid-2016 due to poor road safety.
More than 2500 trees form a small primeval forest in the citadel, in the middle of the city of Mainz.
The walls are home to Stechimmen habitats and moss biotopes of national importance.
Rare lichens and mosses can be found on the walls, such as B. the round-leaved Schnabeldeckelmoos.
Herbaceous plants like the Gundermann do not damage the historic walls and make the complex an unusual habitat.
In Mainz Citadel ditch 44 different bird species have been proven - here a blackcap.
Rare wall lizards live in the walls of the old citadel. You are strictly protected.
Rare insects can be found, such as the hornet hover fly, which is on warning lists because of its endangerment .
The many butterflies in the area, such as the sensitive blue buckthorn, are a good indicator of the ecological quality of the area.
In spring, bluebells grow on the historic walls without causing any damage.
The NABU Mainz and the surrounding area has taken over the care of some areas in the shadow of the historic wall systems of the city of Mainz.
Blackberries repeatedly require maintenance measures. At the same time, however, the plants are the basis of life for diverse insect life.
Sports field in the citadel ditch, which is to be renatured and replanted with trees to compensate for planned tree felling (2016).
Former sports ground in the citadel moat, which was renatured at the beginning of 2018 to compensate for trees that were felled because they endangered the masonry.
The renovation of the historic walls will take years. (2019)