Hi, welcome to GoY, Araucaria araucana, {monkey puzzle tree}, tend to lose some lower branches as they get older, this is quite normal if this is a fairly mature tree, they can grow to between 50 and 80 ft high, with a spread of 20 to 30 ft, young trees will also lose some branches as they grow, again this is quite normal, Derek.

Thanks for your reply, mytreeis only about 4yrs old, so hopefully it is normal.