|Author:||Marcar, N. ; Morris, J.|
|Book Group Author:||NA|
Trees are planted in saline landscapes for environmental and economic benefit. The amount and concentration of salt to which tree roots may be exposed in saline soils varies with location of trees in the landscape, salt load in the soil regolith, management practices (e.g. how saline water irrigation is applied and opportunities for leaching by rainfall), the extent of lateral subsurface flow of water, and the degree to which saline soil water and groundwater are used by trees. Tree growth is progressively decreased at higher soil and groundwater salinities. The extent of this reduction is dependent on the tolerance of different species to salinity and associated stresses, such as waterlogging. There are good opportunities for producing genetically-improved planting stock with enhanced productivity in saline soils. The use of improved germplasm, coupled with appropriate establishment techniques and management practices, is required to sustain adequate plantation productivity on saline soils. Saline watertables are more likely to be lowered by planting trees in discharge areas if trees are planted at an appropriate scale and can reduce recharge and/or use groundwater directly. In addition, groundwater salinity (electrical conductivity) should be less than 5-10 dS m-1 and depth less than about 5 metres. Opportunities to lower the watertable beneath a plantation will be greater if lateral flows from surrounding areas to the plantation are relatively small. However, if the aim is to maximize the use of groundwater by trees for improved tree growth and environmental outcomes, then lateral flow from the surroundings would be an advantage.
electrical conductivity, forest plantations, geneticimprovement, groundwater, growth, saline soils, salt tolerance, soilsalinity, soil types, soil water, subsurface layers, water table, wateruse efficiency, waterlogging, Plant Breeding and Genetics (FF020), PlantWater Relations (FF062), Environmental Tolerance of Plants (FF900), SoilChemistry and Mineralogy (JJ200), Soil Physics (JJ300), Forests andForest Trees (Biology and Ecology) (KK100)