The word for tree in Chabacano is pono. This word possibly comes from the Tagalog puno which means the same thing. Mauro in the comments section below, comments though that it may come from Ilonggo which also uses the word puno.
I recently have found out, that this word also exists in the Chavacano de Ternate. Now, because the Chavacano de Ternate is known to have existed before the Chabacano de Zamboanga, I believe that this word may come from the Chavacano de Ternate.
Although the Spanish word arbol also exists in the Chabacano de Zamboanga, it is not used anymore by today’s youth. Most young people wouldn’t probably even know the meaning of the word arbol. Both the words arbol and pono exist in the Chavacano de Ternate.
Here are some examples of how the word pono is used in Chabacano.
Chabacano: Cosa clase de pono ese?
English: What kind of a tree is that?
Chabacano: Pono de mangga ba ese?
English: Is that a mango tree?
Chabacano: Necesita kita siembra mas mucho pono.
English: We need to plant more trees.