Campaign to plant city trees

The goal of every urban arboriculturalist is to have safe, healthy and beautiful trees that enable urban residents to enjoy all of their positive aspects. Trees in towns cool the air, intercept solar radiation, filter and clean the air, absorb noise, produce oxygen, can serve as a screen in front of unsightly views, reduce wind speed and so on.

Urban trees grow in exceptionally unforgiving growing conditions. Factors restricting the growth of urban trees include compacted surfaces, lack of oxygen in water and the air, air and ground pollution, numerous illnesses and damage, as well as frequent mechanical damage to their roots, trunks and crowns. For reasons associated with the factors listed above, trees in towns have a shorter lifespan than those which live in the natural environment such as a forest.

 

More than 33,000 trees grow in public places in Ljubljana, and together with the trees on functional land there are, according to our assessments, twice as many trees again in the City of Ljubljana. More than half of all trees are less than 10 metres tall. As larger trees are the ones that contribute most to improving the city climate and cleaning the air as well as simultaneously performing all of their positive functions, the City of Ljubljana has started to invest in a green city fund aimed at planting large numbers of trees.

The City of Ljubljana plans to plant 440 trees this spring and the same number again this autumn.

 

Requirements for successful planting

The plants must be assured suitable growing conditions: enough space (in and above the ground), sufficient suitable substrata, the inflow of water containing dissolved powdered salt must be prevented, the plants must be watered in droughts, fertilised as necessary, protected from mechanical damage to the trunk and roots, and the habitat must be protected from external pressures (vehicles, walkers, fly tipping and so on).

 

Causes of decline and thinning of city trees

The causes of decline and thinning of city trees are in most cases unsuitable growing conditions, decline due to mechanical damage, as well as factors of natural chance such as drought.

Unsuitable growing conditions:

  • a lack of growing space and nourished substrata
  • ground pollution with powdered salts
  • compacted and water-impenetrable ground (lack of oxygen and water for the tree) (illegal parking) 

Mechanical damage:

  • crowns (unsuitable care in the past – removal of too great a share of the crown, inappropriate removal of branches that were too big, breakage due to heavy snow, vandalism and so on)
  • trunk (vandalism, vehicle impact, damage due to building machinery and so on)
  • roots (vandalism, vehicle impact, carelessness in building works and so on),
  • root systems (construction excavations or other work around the root systems)

 

Removal of larger trees

Removal of larger trees is solely done in Ljubljana due to the danger of the tree or larger branches falling. Damaged trees have no place in the sense of assuring safe, healthy and beautiful trees so they are removed and replaced with new ones. The most frequent causes of the removal of trees are root damage, damage to the trunk or larger branches, decrease in vitality, crown thinning and so on.

 

Meeting of European
Capitals'Mayors

7. - 9. May 2008

 

500th anniversary of birth Primož Trubar
Ljubljana from A to Z
Weather Forecast
Slovenien Presidency of EU
Vision of Ljubljana in 2025