The effect of heavy metal pollution and presence of Lycopodium annotinum on soil enzyme activity

 

Chem. Met. Alloys 4 (2011) 38-45

 

Anna ŚLIWIŃSKA-WYRZYCHOWSKA, Aleksandra NADGÓRSKA-SOCHA

 

A better understanding of the role of the activity of soil enzymes in the ecosystem will potentially provide a unique opportunity for an integrated biological assessment of soils due to their crucial role in several soil biological activities, their ease of measurement, and their rapid response to changes in soil management practices. 5 study plots with and 5 study plots without occurrence of Lycopodium annotinum, exposed to diverse imission of heavy metals, were chosen for the investigation. The aim of the research was: To estimate the soil pollution by heavy metals; To check the relation between the activity of selected soil enzymes (dehydrogenase, acid and alkaline phosphatases, urease) and heavy metals (Zn, Cd, Pb) in the soil; To estimate the enzyme activity in soils at places of occurrence of Lycopodium annotinum and at places where Lycopodium annotinum does not occur. The soil pollution index after HNO3 and CaCl2 extraction was the highest for the investigated Żurada stand. When the metal contents in the acid-extracted fraction and potentially bioavailable fraction of soils from more polluted stands (Chrząstowice, Kolbark, Żurada) were compared to those from cleaner stands (Zrębice, Sokole Góry), higher amounts of metals were found only in the soil of the Żurada stand. For all of the investigated stands the heavy metal contents were lower in the potentially bioavailable fraction than after acid extraction. The highest content among the three analysed elements was found for lead in the acid-extracted fraction. However, a very high (a few hundred times) decrease of the content in the potentially bioavailable fraction (CaCl2-extracted) was noticed for this element. We did not observe any reduction of the activity of the investigated enzymes in the soil of the most polluted stand. We did also not observe tendencies to a decrease or increase of the enzyme activity of the soil from the study plots with occurrence of Lycopode, in comparison with the places where Lycopode does not occur. The soil pH was higher at the places of occurrence of Lycopode.

 

 

Average acid phosphatase activity in surface soil samples of the investigated study plots with standard deviation. The different letters denote significant differences between the data for each examined enzyme activity (p<0.05).

 

Keywords

Club moss / Pollution index / Zinc / Lead / Cadmium / Urease / Dehydrogenase / Phosphathase