Question
QUESTION: What do our Pine Trees have?  We live in Bishop California which is in the high desert of the Sierra Mountains - Zone 8.  Some of our trees have needles turning brown with dead branches. The trees have no pine needle at the bottom of the tree but have pine needles at the top of the tree.  The browning of the needles starts at the bottom and works it's way up the tree. There are other trees in our neighborhood that look the same.

ANSWER: This is normal. Pines have two sets of needles on the tree and during the year (the time varies by species and weather conditions) the old needles will drop and the tree will have green needles near the ends of the branches. next spring a new set will grow. Sounds normal to me if you have the green needles still on the tree. There is a fungi that will speed this process up called needles cast but this disease does not harm the tree.

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QUESTION: The branches brake very easily.  They use to have some flexibility - not now.  The pine needle at the bottom of the tree are gone, the middle is al most gone and very the top of the trees have some green but mostly brown.  I think they are dying.  My pine trees across the yard are greener and have more pine needles.

Answer
Sounds like either a lack of water or the tree is infested with a bark beetle. Look for small wads of pitch on the trunk maybe up mid way to the crown. If these are present then the tree has bark beetles and should be remover and destroyed. If these are not present try watering with 1 inch of water (place a pan under the tree and turn the sprinkler on and when the pan has 1 inch of water in it stop) Do this about twice a week and see if this helps. May want to check your local phone book and If the Calif. State Forestry agency is listed i would call them and ask one of their Foresters to try and come take a look. An on the ground look is better than trying to describe the problem.