Either from wood logs or nuts/fruits (coconuts for instance, or logs like towercaps give), all structure trees drop some form of hydroponics product that converts into a seed that yields a micro-tree that can be grown inside a hydroponics tray and then gives a product that can be created to create a new full tree.
For instance harvest christmas tree logs, grow a micro-christmas tree from the seed and get a acorn product, now wherever you plant that raw acorn (not the seed) on a sandstone soil plot a tree sapling will be placed, consuming the tray & growing to put down a new tree that grows into a full structural tree. This can be used for making blocking tactical trees, or just for aesthetics/production.
Macro hydroponics, grow real trees, micro-christmas trees mutate into killer christmas trees, and all fruit trees can evolve into full structure trees because they were already micro-trees. etc, towercaps can evolve into a full towercap structure tree type too. Trees don't respect hydroponics rules & will drop-preset amounts & pretty much never die unless they are burnt or chopped, making them easy maintenance.
- Beach bums start planting/eating/using coconuts outside the biodome
, or people take away the pine/christmas trees from the snowbiodome, podpeople vault also get something extra to play with mutation wise.