Table 1 Information on the studied tree species and cultivars

Carpinus betulus ‘Fastigiata’

6/2

Species native to Central, Eastern, and Southern Europe to Western Asia; the cultivar ‘Fastigiata’ was introduced by the German arborist Hermann Hesse in pre-1893.

(4) 5

Crataegus monogyna ‘Stricta’

3

Species native to Europe, Northwestern Africa, and Western Asia; the cultivar ‘Stricta’ was introduced by Ronald’s nursery, Brentford, England, in 1838.

4

Ginkgo biloba

2

Species native to Southern China; planted as seed-propagated nursery stock from Sweden.

4

Malus baccata ‘Columnaris’ + Malus baccata ‘Pyramidalis’

6/3

Species native to Northern China, Sakhalin, Korea; the cultivar ‘Columnaris’ was introduced by the Arnold Arboretum, USA, in 1940; the trees shipped with the incorrect cultivar name ‘Pyramidalis’ are assumed to represent the cultivar ‘Street Parade,’ introduced in the Netherlands in 1982.

3

Pterocarya fraxinifolia

3

Species native to Caucasus and Iran; propagated by seed from a selected Swedish E provenance.

(5) 6

Quercus palustris

3

Species native to Eastern USA; planted as seed-propagated Swedish nursery stock.

4

Sorbus aucuparia

6/3

Species native to Middle and Northern Europe, Siberia, and Western Asia; planted as a vegetatively propagated, columnar clone originating from Southern Finland.

3