Research On Concentration Of 13 Elements In Actinothuidium Hookeri (Mitt.) Broth In 5 Forest Floors

In this paper the method of measuring the concentration of chemical elements in moss by means of microwave digestion and ICP-AES is studied by measuring the concentration of chemical elements in Actinothuidium hookeri (Mitt.) Broth in 4 cutovers and 1 primeval forest of Rangtang county, Sichuan province. Then the level and characteristic of the chemical elements in Actinothuidium hookeri (Mitt.) Broth in different conditions is uncovered and the hypothesis we have made that clear-cutting had evident influence on the concentration of the chemical elements of moss in forest floor is verified in order to provide scientific references for deeply studying on the cycle of elements in moss and ecological reconstruction of cutovers.After measuring the concentrations of 13 elements in Actinothuidium hookeri (Mitt.) Broth in 5 different conditions and discussing the results, such conclusions are drew as follows:1. Experiments show that using HNO3-H2O2 for microwave digestion system and ICP-AES to measure the concentration of chemical elements in moss is feasible and reliable.2. The circumstance of Actinothuidium hookeri (Mitt.) Broth in forest floor is changed because of clear-cutting, which is an evident influence on the concentration of the elements. The concentration of 13 elements especial for Ba, Ca, and Mg we measured in the primeval forest is the lowest except for organic C. So the hypothesis we have made is substantiated that clear-cutting had evident influence on the concentrations of the chemical elements of moss in forest floor.Under condition of the experiments, the results of measurement show that clear-cutting has more influence on the concentration of Ba, Ca, and Mg, and little influence on that of the rest elements, which provides scientific references for deeply studying on the cycle of elements in moss and ecological reconstruction of cutovers.3. Among 13 elements we measured, the concentration of 8 elements is higher in 1994 cutover of the 4 cutovers except for Ca, Mn, Na, Zn, organic C, and the concentration of Al, Fe, and Mg is the highest. The concentration of the all elements in 1990, 1997, and 1998 cutovers has less regularity, which is lower than that in 1994 cutover and higher than that in primeval forest. The concentration of Ca, Mn, Na, and organic C show no significant difference. The concentration of Zn is different from others. The highest concentration appears in 1997 cutover, for another in 1998 cutover, and the lowest in 1990 and 1994 cutovers. We divide 13 elements into 4 categories according to the difference of the recovery of cutovers and the characteristic of elements. The first class includes Ca, Mn, Na, and organic C, concentration of which hardly or less changes with time passing. The reason maybe lies in recovering quickly and tending to steady afterward. The second class is Zn., concentration of which is highest in 5-6 years after cutting, and then recovers to original status. The third includes Al, Cr, Cu, Fe, Mg, and Ni, concentration of which in soil increases in the first few years after clear-cutting, and then attains to the maximum in the 8th year, finally tends to steady during the 12 years along with the recovery of vegetation. The final class comprises Ba and Fe, which recovers slower than the other classes and maybe go on increasing with time passing.