Clayey soils tend to have dry to very wet moisture extremes depending on rainfall amounts. Adapting to water deficits To survive prolonged water stress, trees must be able to prevent or reduce water loss from certain tissues. Narrow or spiky leaves of conifers enable them to survive not only the droughts of hot summers but also the cold induced droughts of winter. An extreme form of dealing with water deficits is leaf drop. Some trees adapt to dry conditions by developing massive, spreading roots, or deep roots, either of which can enable the tree to absorb larger volumes of water.
Expansive roots can be a problem in confined soil volumes.
Soil compaction Soil compaction over a tree's roots, due to equipment operation, material storage, or paving, can prevent moisture from reaching roots. As a result of construction, the grade around a tree may be lowered, altering drainage patterns and making the site either wet or dry. In sandy soils increase the rate to 5 cubic yards per 1,000 square feet. Drying winds Drying winds can seriously increase the effects of drought. In coastal regions, winds carry both salt and sand, causing abrasions to leaves and stems as well as desiccation.