Variability Of Soil Microbial Characteristics In Camellia Oleifera Forests Of Western Jiangxi Province,China

Camellia oleifera Abel belonged to Theaceae, Camellia L, a small evergreen tree or shrub, its oil content is pretty higher, and has comprehensive development and utilization value on nutrition, medicine and health etc. Camellia oleifera has been one of the China's most potential cash forests. In order to achieve high quality, high yield, stable yield, soil environment is particularly important. Because soil quality is an important limiting factor for ecological and economic values of Camellia oleifera forests, soil microbiological characteristics may be a critical indicator for soil quality. However, it is not clear as to what mechanisms control soil microbiological characteristics. In this paper,6 different ages Camellia oleifera forests in Western Jiangxi were used to study this subject. The analysis method was the combination of sample survey, field sampling and laboratory analysis, integrated traditional soil chemical technology, microbial biomass estimation methods and modern molecular biology technology (e.g., denaturing gradient gel electrophoresis). In order to provide scientific basis and technical support for evaluation of soil quality and management situation in the Western Jiangxi, the coupling mechanism on the soil microbial physiological and biochemical characteristics, the microbial diversity, community structure characteristics and soil physicochemical characteristics were assessed with planting ages and tending measures of Camellia oleifera forests.The main results were described as follows:1 Intensive management measures under Camellia oleifera soil microbiological characteristics of 1,6 ages and 10 ages of artificial forest, the overall performance was improved with plant life extension. But the extensive operation soil microbial properties of 10 ages,30 ages and 50 ages of Camellia plantation with plant life extension, their variation was not consistent, microbial biomass carbon and nitrogen (SMBC, SMBN), peroxidase, invertase, protease, urease and acid phosphatase activity were increased with plant life extension, soil bacteria, fungi and actinomycetes showed a decreasing trend, characteristics of soil microbiology planting was significant difference, and also may be related to measures of management.2 Camellia oleifera forests soil microbiological characteristics at seasonal dynamic changes were significantly, and seasonal fluctuation of different biochemical and biological index changed with different planting years. Seasonal fluctuation of Camellia oleifera forests soil enzyme activities were the largest, microbial biomass were the larger, and soil nutrient and its effectivess were the smallest. Visible, the characteristics of soil microbiology were regulated by driving the seasonal variations of water and temperature change, the effect on different stand soil basic physical characteristics, and the plant growth needs.3 Intensive management of 10 ages Camellia oleifera forests soil total nitrogen, total phosphorus, total k, pH, organic matter, hydrolytic nitrogen, available phosphorus, available k, water content, SMBN, microbial biomass phosphorus (SMBP), catalase, peroxidase, invertase, protease, urease and acid phosphatase activity than extensive management 10 ages Camellia oleifera forests respectively were higher 30.43%,48.53%, 18.12%,16.36%,39.91%,32.95%,21.24%,40.63%,8.87%,47.57%,21.39%,31.03%, 35.76%,37.98%,60.89%,43.64%,25.03%. Visible, intensive management can improve the characteristics of soil microbiology.4 The stratification was obvious between soil chemical properties and biological properties. In the surface soil, organic matter, total nitrogen, total phosphorus, total K, SMBC, SMBN, SMBP, catalase, invertase, protease, urease were significantly higher than those in the bottom layer. Visibly, relative to the lower layer, soil microbes in the surface were more active, and they are the main drivers of soil nutrient supply of Camellia oleifera forests.5 By DGGE fingerprint analysis, the 10 ages Camellia oleifera forests bacterial gene diversity was the richest, intensive care and without intensive tending of forests band number of annual mean values were 27.25 and 22, respectively; the number of bacteria species were most in intensive tending 10 ages Camellia oleifera forests. GenBank database sequence for blast sequence comparison, the results showed that the similarity of all the 16S sequence and rDNA sequence were between 84%?99%, among them, for Enterobacter SP and Pantoea SP, Uncultured Bacillus SP 16S rDNA sequence, the similarity was above 97%. Dominant generas were Pantoea SP, Enterobacter ludwigii, Pantoea ananatis.6 Camellia oleifera forests soil microbial characteristics reflected the close relationship among the variables. Principal component analysis indicated the total N and SMBN were the largest contribution, redundancy analysis showed that the effect of hydrolyzable nitrogen on soil microbial properties was significantly. In conclusion, soil nitrogen dynamics were the key indicators of soil quality evolution of Camellia oleifera forests. To sum up, the soil microbial characteristics of Camellia oleifera forests had strong variations, Soil microbial properties were controlled by the seasonal fluctuations and when temperature and water content were similar, soil microbial properties were closely to soil chemical properties. Soil microbial properties may be used as potential evaluation index to reflect the changes of soil quality and nutrient supply conditions. With the Camellia plantation ages increased, soil quality and microbial characteristics would be degraded, and intensive cultivation and management measures can improve the soil microbial properties, promoting the improvement of soil quality.