Our mature (25 ft high) monkey puzzle tree has recently ( 3 months ago) started developing browning on several of its lower limbs. In addition, it has started leaking sap from one area, and, to our knowledge, there was no injury to the tree anywhere. The upper part of the tree seems very healthy but we are very concerned. We do not fertilize the tree but did water it this last summer a little as it was such a dry summer here on the peninsula. Any diagnosis or suggestions on care?