Recently planted trees are likely to have troubles getting enough water. That is because their root system has very likely been cut off quite considerably when they were taken out of their previous habitat. The root systems of trees are incredibly complex structures, that often live in symbiosis with funghi mycelia and in interaction with the soil around them. Therefore, when a tree gets dug out and moved to a different spot, it takes away a lot that constitutes its livelihood. Plants adapt to and grow into their environment, they are not used to moving. So it is likely that a recently moved tree would be maladapted to the new environment, that it would be missing large parts of its root system, and therefore not be able to draw enough water.
What happens to a tree when they don't receive enough water?
Leaves would curl up and become papery. They might still be green (if they dried recently) or otherwise brown (if it's been longer). Beech leaves turn yellow in autumn, but that's a gradual process that is not really caused by a lack of water, so I don't think that they'd turn yellow in your scenario.
Tree trunks are solid structures that have layers of special cells (called xylem) that transport water up through the trunk. The tree's xylem is a layer inside of the trunk that doesn't directly influence the bark. Tree bark is cracked in some species of trees, and more smooth in others (e.g. beech trees), but lack of water would probably not influence that.
How to save the trees
Your trees have been planted there recently. Are they tall trees, or very young ones? Young trees would probably benefit from getting watered more frequently.
For mature trees that have acclimated to drier conditions, she says you should only need to give it a soak once a month, depending on the soil and type of tree.
Check out this link, it might have some helpful further information.