Most of us are not familiar with trees that grow in the Netherlands. Try your local Agricultural/Horticultural authorities or Universities' Ag/Hort websites. A good tree identification book like the Audubon(for us) tree guide or Peterson's(also for us) tree guide will help.
Type of bark(smooth, scaly,furrowed, etc.) , structure of the tree(limb attitude and branching), leaf shape and characteristics(smooth margin or toothed, shape, texture, color etc.) and habitat(wet or dry location) all help with the ID process.
If you were planning on harvesting the tree in the pics follow the rules for harvesting and prepping the tree trunk and the following staves. After the wood has seasoned do a bend test with a small piece. Make a test bow making it longer and a bit wider than you normally would. If that works you can tweek the design by slightly shortening and/or narrow the width. If it works out being good bow wood you'll already have extra staves to work with. If not use it for firewood, tomato stakes or whatever you can think of.
Good luck and keep us posted with your progress.
