Abstract
The biological activities in ten soil samples, from eight rhizosphere soils of halophytic plants and two of bare soils. Al Protectorate Farasan Island, Saudi Arabia, were investigated. Respiration rates (CO2 evolution), moisture content, organic matter, soluble salts and pH were estimated.
The results showed that respiration rates fluctuated greatly in soil samples of different plant species grown under identical conditions. The greater respiration rates were correlated with the greater organic matter content and the lower salinity levels. Both, the total and active microbial biomass, were calculated, the first was concomitant to the respiration rate activities, while the other was adversely proportional to the rate of respiration.