During the 7th century the power of the Eastern Roman (Byzantine) Empire was challenged by the Sassanids of Persia, who invaded Egypt in 616. They were expelled again in 628, but soon after, in 642, the country fell to the Arabs, who brought with them a new religion, Islam, and began a new chapter of Egyptian history.
the bark protcts the zylem and the phloem fron infection.bark is like our skin and if we cut off some of it and didnt keep it clean it would become infected.you could shave off a couple of inches and a tree may live depending on its age but if its a sapling and about 3 to 5 inches in diameter it would die eventually.
Trees expand from a thin layer under the bark called the cambium. THis lays down tissue all year but the cells vary in size depending on the seasons, hence the annual growth rings seen when cutting a tree. Trees expand from a thin layer under the bark called the cambium.