Relationship between Root Biomass and Soil Organic Carbon: Case Study of Arid Shrub Lands of Semnan Province

Abstract

This study analyzed the relationship between the vertical distribution of root biomass and soil organic carbon (SOC)<br />content in the arid shrub lands of Semnan province in Iran. Three sites were selected based on differences in canopy cover<br />of Artemisia sieberi (5%, 10% and 15%). Average density of shrubs, root biomass and SOC were determined at different<br />depths (0-20, 20-40, 40-60, 60-80 cm) in 20 quadrats at each site and are expressed on a per ha basis. Simple equations<br />were used to calculate the relationship between SOC and root biomass for each site. Statistical analyses were conducted<br />using ANOVA. The results showed that the root biomass and the SOC content generally decreased as soil depth increased.<br />There was an acceptable relationship between root biomass and SOC at all sites. The proportion of SOC in the soil was<br />found to be positively related to the vertical distribution of root biomass; 75% of total root biomass was found at 0-25 cm,<br />while this same soil layer contained 48% of SOC.