I had noticed these contributions while reviewing inconsistent tagging of ways and nodes as natural=tree and wood, and I commented on a small sample of these changesets (e.g.). Before me LSkalayo from Kaart had already intervened, and the result is roads with very many trees. maybe someone else wants to check.
The names assigned to these natural=wood nodes are in the form <sequential-ref>, <description>, and descriptions are one or more of ‘cultivo’, ‘cesped’, ‘flores’, ‘otro’, or ‘nada’. Some sequential numbers show typing errors, like the sequence 2145, 2146, 247, 2148 … as if they never reviewed their own work.
I would guess it’s flower beds, possibly empty and left as bare ground (nada), or just grass (césped), or possibly guerrilla gardening (cultivo). It’s a pity that we don’t manage to get in contact with the individuals nor the organization behind them. As organization, I would guess some public local institution.