Impact of canopy and seasoning on activity of soil enzymes in some Juniper habitats of Iran

Soil enzyme analysis is a widely used technique for examining nutrient cycling processes in soil. These enzymes are sensitive to the effects of anthropogenic activities and disturbance on the soil and provide valuable assessing of the metabolic response of soil to management practices and environmental stresses. This research was performed in four juniper habitats of Iran including Layen (Khorasan province), Chaharbagh (Golestan province), Kanderagh (Ardebil province) and Chahartaghe Adaral (Chaharmahal va Bakhtiari province). Three enzymes including acid phosphatase, alkaline phosphatase and dehydrogenase were assessed by reaction with substrate and photometrical method under canopies and intercanopy in May and September 2008. Our results showed that the activities of all studied enzymes were significantly higher in soils under Junipers that represented more activity of microorganisms at this area. Soil enzyme activities showed seasonal variation with higher activity in September at both areas. It seems that the activity of microorganisms has been reduced under drought and heat duration. Our research indicates that soil enzymes may be valuable indexes for assessing soil ecosystem because of changing climatic conditions and vegetation.