LIFE CONDITIONS AND STRESS FOR URBAN TREES, EXAMPLE OF BRUSSELS CITY

A study on the causes of death in the trees growing in the Brussels metropolitan area began in 1973.

Street tree survival or death is the result of a complex action of hostile environment, including:

• climatic conditions e.g. the heat island and draught stress,

• moisture deficiencies (frequent and intensive) and excesses,

• soil conditions : disruption and compaction, pH variations, gas injury with anaerobic conditions for the roots,

• nutrient imbalance (presence of toxic elements, deicing salts, heavy metals, etc…),

• vandalism.

Air pollution, e.g. the high concentration of ozone, and the increase of CO₂ concentration in the air, which generate important stress for the trees.

A larger choice of selected resistant trees, better planting and maintenance techniques could be promoted as a first remedial action.

Our investigations carried out in Brussels area and in different Belgian towns show how complex the ecological and technical factors are in urban forest.

International Symposium on Urban Tree Health

R.A. Impens

Urban trees, stress, climate, soil, nutrient imbalance, air pollution

https://doi.org/10.17660/ActaHortic.1999.496.37