Quotation from the statute:
"The planting must be carried out on the property where the trees were removed. In individual cases, the replacement planting may be carried out on another property within the scope of this statute."
And something else, especially the last sentence is interesting:
"The assessment of the requirement for replacement planting is based on the value of the removed tree stock, taking into account the purpose of protection. The value of a protected tree and the resulting and required replacement plantings are derived from the criteria and provisions defined in Annex 1 to this statute. Unreasonable hardships in historically overgrown properties must be taken into account."
Hedges are also possible:
"In exceptional cases, the planting of hedges and shrubs can also be considered as replacement planting. The hedges should have the following minimum dimensions: Length: at least 5 meters Width: at least 0.5 meters Height: at least 1 meter (future, permanent growth height) An exceptional case usually only exists if the planting of trees is not reasonable due to the size of the property and already existing protected trees."