The recency requirements (to maintain the licence) are in the published Air Crew Regulation (i.e. Implementing Rules which sit above the AMCs) at:
EUR-Lex - Official Journal - 2011 - L 311
See section:
FCL.060(b) on page 13 (for pax carrying)
FCL.140A for LAPL(A) page 17
I cannot find the equivalent to the LAPL(A) in the PPL (A) requirements in terms of recency but I recall a while ago asking this question of my EASA contact - I'll try to find the answer.
On top of that, maintenance of one's medical of course.