GERMINATION AND SURVIVAL OF COLORADO SPRUCE, SCOTS PINE, CARAGANA, AND SIBERIAN ELM AT FOUR SALINITY AND TWO MOISTURE LEVELS

Abstract

In a greenhouse study, salinity levels of ECe = 1, 4, 7, and 10 mmhos/cm at 25° were used to test the salinity tolerance of Colorado spruce (Picea pungens Engelm.), Scots pine (Pinus sylvestris L.), caragana (Caragana arborescens Lam.), and Siberian elm (Ulmus pumila L.) seedlings at two levels of soil moisture. Emergence, survival, plant height, and dry-matter yield were used as the response criteria.The deciduous species were more salt-tolerant than the coniferous species. In terms of survival, an ECe value of between 7 and 10 mmhos appeared to be critical for caragana and elm in a soil with a moisture content of about midway between the wilting point and field capacity. The corresponding values for spruce and pine were closer to 4 and 6 mmhos respectively. Seedling survival was markedly improved by maintaining the soil moisture level at field capacity.