Abstract: In this study, the effect of coal mining activities on lead and cadmium concentrations and distribution in soil was investigated in Hyrcanian forest, North Iran. 16 plots (20×20 m2) were established by systematic-randomly (60×60 m2) in an area of 4 ha (200×200 m2-mine entrance placed at center). An area adjacent to the mine was not affected by the mining activity; considered as the controlled area. In order to investigate soil lead and cadmium concentration, one sample was taken from the 0-10 cm in each plot. To study the spatial pattern of soil properties and lead and cadmium concentrations in the mining area, an area of 80×80m2 (the mine as the center) was considered and 80 soil samples were systematic-randomly taken (10 m intervals). Geostatistical analysis was performed via Kriging method and GS+ software (version 5.1). In order to estimate the impact of coal mining activities on soil quality, pollution index was measured. Lead and cadmium concentrations were significantly higher in mine area (Pb: 10.97±0.30, Cd: 184.47±6.26 mg.kg-1) in comparison to control area (Pb: 9.42±0.17, Cd: 131.71±15.77 mg.kg-1). The mean values of the PI index indicate that Pb (1.16) and Cd (1.77) presented slightly polluted. Results of the NIPI index showed that Pb (1.44) and Cd (2.52) presented slight pollution and moderate pollution respectively. Results of variography and kriging method showed that it is possible to prepare interpolation maps of lead and cadmium around the mining areas in Hyrcanian forest. According to results of pollution and risk assessments, forest soil was contaminated by heavy metals (lead and cadmium); therefore, using reclamation and remediation techniques in these areas is necessary.
Abstract: Soil enzyme activities in Kasuga-yama Hill Primeval Forest (Nara, Japan) were examined to determine levels of mineralization and metabolism. Samples were selected from the soil surrounding laurel-leaved (BB-1) and Carpinus japonica (BB-2 and Pw) trees for analysis. Cellulase, β-xylosidase, and protease activities were higher in BB-1 samples those in BB-2 samples. These activity levels corresponded to the distribution of cellulose and hemicellulose in the soil horizons. Cellulase, β-xylosidase, and chymotrypsin activities were higher in soil from the Pw forest than in that from the BB-2 forest. The relationships between the soil enzymes calculated by Spearman’s rank correlation indicate that the interactions between enzymes in BB-2 samples were more complex than those in Pw samples.
Abstract: We assessed the ecology of the organic and mineral soil
layers of laurel-leaved (BB-1) and Cryptomeria japonica (BB-2 and Pw)
forests in the Kasugayama Hill Primeval Forest (Nara, Japan). The soil
respiration rate was higher in the deeper horizons (F and H) of organic
layers than in those of mineral soil layers, suggesting organic layers
may be where active microbial metabolism occurs. Respiration rates in
the soil of BB-1, BB-2 and Pw forests were closely similar at 5 and 10°C.
However, the soil respiration rate increased in proportion to
temperatures of 15°C or above. We therefore consider the activity of
soil microorganisms to markedly decrease at temperatures below 10°C.
At a temperature of 15°C or above, the soil respiration rate in the BB-1
organic layers was higher than in those of the BB-2 and Pw organic
layers, due to differences in forest vegetation that appeared to
influence several salient soil properties, particularly pH and the carbon
(C) and nitrogen (N) content of the F and H horizons.
Abstract: The soil ecology of the organic and mineral soil layers
of laurel-leaved and Cryptomeria japonica forest in the Kasuga-yama
Hill Primeval Forest (Nara, Japan) was assessed. The number of
bacteria obtained by the dilution plate count method was less than
0.05% of those counted by the direct microscopic count. We therefore
found that forest soil contains large numbers of non-culturable
bacteria compared with agricultural soils. The numbers of bacteria and
fungi obtained by both the dilution plate count and the direct
microscopic count were larger in the deeper horizons (F and H) of the
organic layer than in the mineral soil layer. This suggests that active
microbial metabolism takes place in the organic layer. The numbers of
bacteria and the length of fungal hyphae obtained by the direct count
method were greater in the H horizon than in the F horizon. The direct
microscopic count revealed numerous non-culturable bacteria and
fungi in the soil. The ratio of fungal to bacterial biomass was lower in
the laurel-leaved forest soil. The fungal biomass was therefore
relatively low in the laurel-leaved forest soil due to differences in
forest vegetation.