Currently, spruce, pine, oak and beech account for 73% of the area of forests in Germany, with the species having different regional focuses:

Spruce grows mainly at higher altitudes in the foothills of the Alps ...

Spruce occupies the largest area of the forest floor, followed by pine. This is followed by the deciduous trees beech and oak.

The Lower Saxony government programme "Long-term ecological forest development in the state forests" (LÖWE) of 1991 makes recommendations as to which tree species should be grown where.

Great importance is attached to spruce as a commercial tree species, but it is recommended that it should always be cultivated in mixed stands. In the coastal area of the north-west German lowlands, spruce is not sustainable due to the change in climatic conditions (storm and summer drought).

Sources:

https://bmel-statistik.de/fileadmin/SITE_MASTER/content/Holz-und_Forstwirtschaft/Bundeswaldinventur3.pdf

State Forests, N. (2018). LÖWE programme - 15 years of long-term ecological forest development. Lower Saxony State Forests, Braunschweig. https://bmel-statistik.de/fileadmin/SITE_MASTER/content/Holz-und_Forstwirtschaft/Bundeswaldinventur3.pdf