Impact of soil compaction on root system of Caucasian aldar (Aluns subcotdata C. A. Mey.) seedlings

Soil compaction, as one of the causes of stress, has a negative impact on plant growth. The aim of this study was to evaluate the effect of soil compaction on root system of Caucasian alder (Aluns subcotdata C. A. Mey.) seedlings in controlled condition. After sowing of alder seeds in plastic pots in loamy or clay-loamy soils with constant moisture regimes, the reaction of seeds were evaluated under six levels of soil compaction. Collar diameter, length, biomass, and allocation ratio of root system were measured and calculated. According to the results, the studied parameters decreased significantly by increasing soil bulk density and their trend were downward quadratic, except ratio of lateral root length to main root length. Thirty six percent decrease in the mean of lateral root length, 31% decrease in the mean of main root length, 37% reduction in the mean diameter of main root and 27% fell down in the mean value of root dry biomass was recorded in treatments with different levels of soil compaction in compare to the control treatment. In general, results indicate that compaction tension has negative effect on the characteristics in the root system of Caucasian alder seedlings.