How do saline soils affect trees and shrubs?
Plant root cells contain a membrane which allows water to pass through, but which prevents salt from entering. As the soil’s salt content increases, it becomes more difficult for water to pass through the membrane into the root. In addition, if salt levels get high enough they may actually dehydrate roots or cause “salt burn” by drawing water out of root cells. High levels of soluble salts also cause changes to soil structure, resulting in compacted soils that are problematic for plants. Because salts bind with soil clays, causing them to swell, compaction occurs more frequently in clayey soils than in sandy soils. Compaction causes reduction of pore spaces between soil particles, reducing water and oxygen penetration into the soil, and water drainage from the soil. As a result, water and oxygen availability to plant roots, and consequently plant growth and pest resistance, is affected. Plants vary in their ability to grow in salty soils. Plants that grow only in saline soils are calle
