Tree species identity influences the vertical distribution of labile and recalcitrant carbon in a temperate deciduous forest soil

In terrestrial environments, soil organic matter (SOM) is the largest organic carbon (C) pool. The quantity and quality of organic carbon in soils can be affected by vegetation through influencing the inputs and outputs of SOM. We examined how storage and quality of C in SOM were affected by vegetation under grass cover or single and a polyculture plot of Betula pendula, Alnus glutinosa and Fagus sylvatica. An acid hydrolysis approach was used to quantify three SOM fractions differing in biodegradability. Tree species identity and stand composition had no significant effect on the total amount of C stored in different SOM fractions to a depth of one meter. However, when examining individual SOM fractions in the upper layers of the soil profile, significantly more C was stored in the putatively more labile fractions 1 and 2 under F. sylvatica and A. glutinosa, respectively. In deeper soil layers, the highest storage of recalcitrant organic C was found under the tree polyculture. The vertical distribution of these three soil organic C pools was compared to C inputs via decomposed leaf litter. Our data indicated that in the tree species polyculture, combining litter inputs of multiple species can have a positive impact on the accumulation of acid resistant recalcitrant C in deep soil layers in 4 years. This C fraction has the greatest potential for long-term sequestratio

Detection of Uranium Contamination in Acacia Cell Sap by Capillary Zone Electrophoresis (CZE) Technique

The study was carried out to detect uranium level in the cell sap of acacia plant cells, for this purpose callus cultures of Acacia albida was used as well as plants. Cell saps from both callus and plant leaf were taken using Micro capillary syringe and detected using Capillary zone electrophoresis technique. It was shown that using citrate buffer of 3.0pH help in detecting uranium accumulated in the cells. Prospective calculation for the level of uranium uptake showed that 1.64mM is the level of uranium in the leaf cells that had been grown on soil with addition of 500 mg.kg-1 uranyl nitrate for 3 months, while for callus which grown on MS medium with addition of 500 mg/l uranyl nitrate for the same time (3 months), uptake of uranium reached 0.8 mM. The comparison between TXRF analysis of uranium accumulated in plant tissues and CZE efficiency in detecting uranium level in cell sap of both leaves and callus cells, it was shown that both techniques prove that A.albida plants can accumulate uranium with a level double as that taken by callus cells