Hamburg
In Hamburg, for the Hamburg Port Authority, a large group of Ulmus x Hollandica on the Pionierinsel were injected with Dutch Trig®. These trees are located on an Island in the Elbe River where many people gather to recreate on warm sunny days. The elms on the island form an important part of the backdrop and atmosphere on this island. These injections were done in cooperation with The Elm Office, Dr Gordon Mackenthun.
Elms, Dutch Elm Disease and the Hamburg Elm Program
An outline by dr. Gordon Mackenthun, Elm Office
Dutch Elm Disease has killed hundreds of millions of trees worldwide. This pandemic was and still is an extreme disaster and many people have given up hope that elms can be protected and saved. On closer inspection, however, it becomes clear that more elms have survived the disease than was first thought.
Many elms have indeed survived the pandemics. Examples from foreign countries - The Netherlands, Great Britain, USA and Canada - show us how the disease can be successfully managed and contained. With this background the Hamburg Elm Program was started in 2002 by the city of Hamburg and dr. Gordon Mackenthun of the Elm Office.
Objectives
Urban green spaces and their diversity will be protected and enhanced; streets, boulevards, squares and parks will stay or become more attractive; habitats for birds and small mammals will be saved and their numbers will increase; the amount of dust and particulate matter in the air will be reduced; the fixation of carbon dioxide will be improved; the temperature on hot days will be reduces by as much as 2-3° C.
Methods
There are six areas of work in the Hamburg Elm Program:
- the mapping and registration of elms;
- the monitoring the elm population for disease symptoms;
- the sanitation of diseased trees and DED sites;
- the preventative vaccination of elms using the 'Dutch Trig®' system;
- the replanting of elms;
- professional training courses and public relations work.
There is no other larger town or city in Germany which has a similarly ambitious program like the one in Hamburg. Even on a European scale, there are few regions with a functioning elm protection program.
Success
The inventory of elms has greatly advanced. Whereas there were some 500 elms in the inventory at the start of the program in 2002, Hamburg now has more than 3500 registered elms. This forms the database for a reliable overview of the city's elm population in its urban green spaces.
Full-scale monitoring of all known elms was carried out in the city both in 2006 and 2007. This year, one out of the seven city districts was found to be free of DED incidences, while the rate of occurrence was below 1% in a further three districts. The southern and eastern districts are still struggling with a higher number of infected trees. Frictionless co-operation has been established between the City authorities, the city districts and the Elm Office.
An innovative vaccination method, "Dutch Trig", was imported from the Netherlands and is now used on a regular basis. Hamburg is the first city in Germany to apply "Dutch Trig" systematically and on a grand scale.
The replanting of elms has increased tenfold over the last couple of years from 20 in 2002 to nearly 200 in 2006. One large planting following the historical park lay-out has been carried out in the central City Park using the American 'New Horizon' cultivar.
An elaborate description of the 'Hamburg Elm Program' (by dr. Gordon Mackenthun, Elm Office) can be downloaded from the download page.
