I can't seem to attach a picture because it's too large but I have a multi trunk pepper tree that has been beautiful for years. All of a sudden I'm noticing the tops of the branches on the right side is dying. The rest of the tree looks beautiful. It's only dying at the top. It's beautiful on the trunk and the bottom because I have a lot to New Growth shoots coming from the bottom of the trunk. It looks like it's dying from the top down on these branches which is all off of one of the trunks. What could be causing this? I live in Gilbert Arizona and it's been really warm here in the 80s to 90s so it's not because of cold.
If you mean a Schinus variety (usually commonly called pepper tree), how old is it? 30 years is considered a long life span for these trees - they are not particularly long lived, so it might just be its simply old.
Otherwise, die back in parts might be indicative of a problem of some sort at the root, if the dying part has no other evidence of a problem, such as insect infestation or obvious infection with fungal disease. Inspect the tree thoroughly, examining backs of leaves and woody parts for any signs of infection or infestation or fungal growth such as shelf or bracket fungus. You will need to remove the dead parts if they're completely dead, if possible.