The first place you look is in your lease to see if it addresses mainenance of the space that you rent.
If there is nothing specific about tree trimming in your lease, see if the lease obligates the parties to comply with park rules.
Then look at the park rules and see if there is anything specific about tree trimming.
If there is nothing about tree trimming in the lease or rules, then you go to the statutes.
The Indiana landlord tenant statute is here:
The statute for mobile home parks is here:
I took a quick look at both statutes and didn't find anything that would obligate the park owner to trim the trees. Spend some time and carefully read the statutes in case I missed something.
If you have tree limbs falling on your house I suggest you seriously consider spending some money to get them trimmed rather than experience the cost and aggravation of having a tree limb put a hole in your roof during a storm. Insurance doesn't cover everything.