Street tree
A street tree is a tree that stands on an inner-city or out-of-town street. As a rule, these are deciduous trees of the same species that stand at regular intervals on one or both sides of the street.
A street tree shades the roadway, absorbs noise and pollutants to a certain extent through its leaves , absorbs carbon dioxide and supplies oxygen , lowers the temperature of the street air through evaporation on hot days and contributes to the improvement of the townscape with its lush greenery . Outside of built-up areas there are trees on the avenue and trees on the edge of forests.
Ideal street trees are characterized by their high tolerance to pollutants, have deep roots, have a robust bark and produce little dead wood . Typical street trees are linden , horse chestnuts , ginkgo and, in warmer areas, especially plane trees . Occasionally, Norway and sycamore maple , white and rowan berries , and hazel trees are used. Red thorn or hawthorn is often chosen as a small and decorative species . Tree nurseries also offer a large number of exotic varieties, which are selected according to characteristics such as slender habit; so among other things types of cherry trees and maples .
City trees are burdened by various factors:
- compacted and sealed soils absorb little rainwater , so that most of it flows away; gas exchange is stopped and too little oxygen reaches the roots.
- By disposing of the leaves in autumn and a lack of humus layer , hardly any nutrients are added to the substrate
- Pollutant input from car traffic, road salt in winter, dog feces and urine
- Injuries to the bark from collision damage and construction work
- increased temperatures in summer due to the heating of floor coverings and facades in the sun
For normal-growing street trees, a root space of around 12 cubic meters is filled with a special substrate when new avenues are built . Some cities and municipalities specify minimum plant sizes for their street trees. In order to prevent the soil from being compacted by vehicles in the immediate vicinity of the trunk, this area is often protected from being driven on by bollards or the like. Alternatively, the tree grate can also be protected by horizontally lying cast iron grids, which transfer the loads introduced onto a reinforced concrete frame. A drainage pipe is often installed in the planting pit so that one end of the pipe protrudes from the ground near the trunk, so that the irrigation water can be brought in more easily in dry summers and the root area is aerated.
Due to global warming, more heat and dry periods with cold winters can be expected in the future. In some urban locations, tree species such as linden, maple, plane and chestnut are already suffering damage from drought, frost and the pests and tree diseases that they bring about.
It therefore increased tree species from Southeast Europe ( hackberry , hop hornbeam , flowering ash , silver linden ), Asia ( Perlschnurbaum , zelkova , ironwood tree , magnolia ) and America ( Honeylocust ) and selected varieties and hybrids of native tree species (eg. As Quercus frainetto 'Trump' , Quercus x hispanica 'Wageningen', Tilia tomentosa 'Brabant', Ulmus 'Lobel').
When selecting new street trees to be planted, not only their robustness and weather resistance against the changing climatic conditions must be considered. The size of the root space required, the shape and expected size of the tree, the duration or type of leaf shedding (with regard to the effort required to clean the street), whether the respective species could pose a risk for allergy sufferers or whether the tree species tends to break green branches is also relevant such as willows or poplars. The clearance profile also plays a major role along roads. It is at least 4.50 meters high for roadways and 2.20 meters along sidewalks.
literature
- Kurt Garcke-Wittgendorf: The fruit tree as a street tree: Instructions for planting and caring for fruit trees on streets, public transport routes and in large companies, as well as for assessing orchards. Frankfurt a. O. 1901
- Verein deutscher Gartenkünstler (Ed.): General rules for the planting and maintenance of trees in cities, together with a list of the tree species that can be used for street planting. Berlin 1901
- Otto Hübner: The street tree in the city and in the country, its planting and care as well as the necessary measures to protect it. Parey, Berlin 1914
- Alfred Hoffmann: The street tree in the big city with special consideration of the Berlin conditions . Berlin 1954
- Hans-Georg Brod (Ed.): Road tree damage. Landsberg / Lech: ecomed publishing company, 1991
- Josef Rüegg: The street tree in the street space is a concept for the green planning of streets and their surroundings in the urban area of Ingolstadt. Ingolstadt 1995
Individual evidence
- ↑ Trees at the edge of forests on public roads are subject to the same traffic safety obligations as road trees. See H. Frese: "Summary of part of the judgment of the OLG Hamm of March 30, 2007 (13 U 62/06)". In: Natur in NRW 2/2007 p. 31 ( PDF ( Memento of the original from March 10, 2012 in the Internet Archive ) Info: The archive link has been inserted automatically and not yet checked. Please check the original and archive link according to the instructions and then remove it Note. )
- ↑ Urban Trees Working Group: Archived Copy ( Memento of the original from July 5, 2010 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ^ A b Andreas Hussak: Green space maintenance and tree management. In: COMMUNAL. Austrian Association of Municipalities, January 26, 2018, accessed December 20, 2018 .
- ↑ New plantings in the City Official Gazette No. 046 of the City of Mainz from October 25, 2013, p. 2 ff. (635 kB)
- ↑ Urban tree species in climate change - “Urban Green 2021” project Archived copy ( memento of the original from June 21, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
