Talk Treelined roads the green infrastructure as an important part within transport infrastructure

Tree-lined roads (avenues) in European countries represent shared European landscape. They are witness of regional history and are of especially great importance for biodiversity. They are an important green infrastructure that should serve Europeans for centuries to come. Yet the future of avenues is in severe danger.

To sustain avenues it needs both, protecting existing avenues and developing new ones! Yet new or changed requirements and demands on roads and traffic safety, as well as new or modified views to the environment, have an impact on the development of avenues.

There has to be a way to meet both challenges, to increase road safety and to develop regulations and measures to protect tree-lined roads as important living landscapes within the transport infrastructure. An example is shown in Mecklenburg-Western Pomerania.

In some states of Germany avenues are highly legal protected, (particularly) so in Mecklenburg-Western Pomerania with approximately 5.200 km out of the estimated 30.000 km of existing avenues along main roads nationwide. An avenue, by our definition, is two 100 m long rows of trees, which lie opposite each other and each side has at least 3 trees.

How can this high protection be carried into effect?

1. An “Avenue Edict” valid since 1998, specifies the proportion of trees which must be replaced, quality and distances from the road kerb. Because of new nationwide regulations it had to be revised. A new edict is in force since January 2016.

2. An “Alleenfonds “is established in case there is no space to plant trees. Alternatively money can be paid into the Alleenfonds (€400.00 per tree). The idea is to cover the costs of larger-scale avenue–planting projects. This element is unique within Germany.

3. An Avenue development and protection program for the federal- and state roads with targets for the next 20 years was announced 2006 (AEP). This allows to plan the necessary steps well in advance for example for acquisition of land.

This goes together with a comprehensive inventory of street trees which was completed for federal and state roads in April 2016 and is kept up to date. An “Avenue Map” shows all avenues, the age of the trees, the density of the avenue and the tree species. Thus further potential roads selected for avenue development can be examined more closely as to their suitability. The detailed avenues map can be viewed by everyone in the Internet.

4. A Planning Guide for avenues will be written for Nature Conservation authorities and Landscape Management until 2017.

These measures worked well and explain the increase of young avenues to approximately 40% (2160 km) of all avenues from 1990 until 2014.However, the statistics also show that so many more trees were planted in the years until 2010. Since then there is an annual deficit. This is due to the fact that the roles for plantings have changed especially regarding the demanded distances between road and trees. Our aim is no less than to preserve the heritage to its full glory for the future.

Avenue, Green infrastructure, Tree-lined roads, Heritage, Road safety