Study site and plant material
The six angiosperm species studied included Betula pendula ,Carpinus betulus , Fagus sylvatica , Liriodendron tulipifera , Prunus avium , and Quercus petraea . Samples were collected at Ulm University, Germany (48°25’20.3” N, 9°57’20.2” E). Except for L. tulipifera , all species are common, native angiosperm trees to Ulm. Various individuals of L. tulipiferawere grown at the Botanical garden of Ulm University. Most species studied were diffuse porous, except for Q. petraea , which was ring-porous. Also, C. betulus and Q. petraea were considered as species with marcescent leaves during winter, with partial marcescent leaves in F. sylvatica . The remaining three species are deciduous. We selected four to five mature trees for each species. Healthy, mature and sun-exposed branches were sampled between June and September 2019 for experiment 1 and 3, and in May 2020 for experiment 2.