Leaves, branches and trees (trunks) are considered obstacles in the same way as rubbish bins, lampposts or flower pots, for example. If a ball or the cochonet touches an obstacle, play continues as normal. Unless, of course, the cochonet is no longer visible from the circle when standing upright. Otherwise, obstacles must be marked in advance as forbidden territory with a boundary similar to that of the playing field. This is how it is regulated in Germany. Sincerely, your referee Ps: an obstacle must be at least 25cm high.