Forest in the city city in the forest How planning principles in - - PowerPoint PPT Presentation

Forest in the city – city in the forest

How planning principles in forestry could be applied to urban trees in cities

Astrid Hamm, Consultant Urban Forestry, Arboriculture and Urban Greening 'Citybranchings', Ravensburg Germany www.citybranchings.com

In forestry, a change of attitude over the past decades has successfully lead to more sustainable methods. Foresters had to accept that mixed forests with a wide diversity of species, structure, and age are more sustainable than monocultures! Therefore, todays forests are fit to successfully face the challenges of an increasing range of tasks! The situation is different for urban trees not part of a forest, such as street and avenue trees, or individual trees in urban parks and gardens. This presentation outlines current problems and presents some ideas how a change of strategy towards a more sustainable urban forest in the urban landscape could meet future challenges and ensure urban human wellbeing.

With over 600 000 km of roads, Germany has one of the densest road networks in the world

• 74 ha of land are built up and sealed every day
• extensive loss of habitat for plants and animals
• loss of biodiversity currently at its highest in Germany
• since 2002 the German Federal government has promised to

develop a biotop network system of at least 10% of land in Germany

• only 6,9 % have been implemented so far
• road and traffic authorities claim street trees are responsible for

most fatal traffic accidents

• urban trees - especially street trees – have a bad image
• a recent survey showed that only 19 % of Germans consider

environmental issues as important

Urban trees seem to get less attention, as they – at first sight – don't provide economic profit.

Current problems for individual standing trees in the urban environment

Severe physical damages Pests and diseases Inadequate pruning = lopping Tip dieback and stress growth No protection against construction works, pollution, soil compaction

AVERAGE LIFESPAN OF STREET TREES IN GERMANY: 19 YEARS!

In spite of extensive research and technical advances, urban trees do not get adequate treatment to enable their long-term survival.

Many old trees along country roads are removed and not replaced

Forestry: aims at close to nature practices, including stable, species-rich and high-performance mixed forests

• street trees are still planted as monocultures
• tree species are limited to only few
• use of one species only per street

Why not using forestry principles for urban forests?

• different tree species per street
• e.g. street tree selection based on forest types
• if possible, including shrubs and understorey plants
• different age = different size
• no straight lines – alternate plantings -

VISUAL VARIETY

Species variety: more than one tree species

Are street trees outdated – a concept of the past?

Do we need different concepts for the future?

Small urban woodlands, for example using vacant blocks of land in residential and industrial areas

Broad medians with pedestrian and bycycle lanes enframed by woodland nature strips

Graphics: Alan Simpson

Green islands between noise and pollution:

recreational AND wildlife habitat

Green refuge in city centre next to a 4-lane main road

Broad nature strip with mixed forest plantings, footpath and bycycle lane behind

Suburban train station

Nuremberg Germany

Motorway with under- neath pedestrian passage and overhead crossing Business/ residential area behind nature strip to the right

Graphics: Alan Simpson

Road construction design minimising defragmentation

• f forest habitat

We have to find better solutions to enable urban forests to survive. Politicians and decision makers as well as the urban public have to take responsibility for OUR habitat.

50 SHADES

• f

GREEN

Thank you for your attention! AGAINST THE MONOTONY OF URBAN AGAINST THE MONOTONY OF URBAN GREYNESS GREYNESS