Q.Lime Tree Dying
I live in Abu Dhabi, UAE. I’ve had a lime tree for 14 years. It bears fruit every year form April to July. However, limbs have been dying off for a few years now. I have cut off the dead wood but other branches then die off. It now has nothing but dead branches on top and new shoots growing around the bottom of the trunk. I don’t know what to do and gardening help is difficult to get. The climate is warm all year, daytime temp. up to 48 C in summer and down to 18 C in winter. Nighttime temps can fall to 5 C. Hope you can help.

Certified GKH Gardening Expert
Unfortunately, it sounds like your tree may be dying from old age. Trees, like people, have lifespans and lime trees live about 15 years. If you bought it as a small tree, it was probably already a few years old and is beyond its normal lifespan. (https://www.gardeningknowhow.com/ornamental/trees/tgen/what-does-a-dying-tree-look-like-signs-that-a-tree-is-dying.htm)
The shoots around the bottom are suckers. They may be true to the tree or they may be from rootstock, it depends on how the tree was cultivated. If they are true to the tree, you can remove one from the tree (with some roots attached) and start the tree over again.