Comparative Analysis Of Microbial Floras Of Poplar Plantations In Beijing

Microorganism is one of most important components in the forestry ecosystem of the city, which plays the transfer role in flows of energy and material cycle. Meanwhile, microorganism is a sensitive Biological indicator to reflect the environmental alteration, and its population quantities and elements are the main parameters to evaluate ecological environmental health of plantation. Therefore, it is meaningful to the healthy development of plantation ecosystem via investigation of micro flora variety of plantations.In this study, three poplar plantations in Beijing, Populus×euramericana cv.'Guariento', Populus×euramiercana cv.'Neva'and Populus tomentosa , were used for comparative analysis of microbial floras. The methods of molecular Biology including morphologic analysis, biochemical experiment and Biolog assays are employed to demonstrate the micro flora of the air, leaves, barks and soil in poplar plantations. Primary results and conclusions of this study are as follows:1. The comparison of bacterial floras in poplar plantations:There was significant difference in bacterial quantities between Populus×euramericana cv.'Guariento'and Populus tomentosa , and between Populus tomentosa and Populus×euramiercana cv.'Neva'in the airy bacterial quantities, while no significant difference between Populus×euramiercana cv.'Neva'and Populus×euramericana cv.'Guariento'; There was remarkably difference in leaf bacterial quanities between Populus×euramiercana cv.'Neva'and Populus×euramericana cv.'Guariento', and between Populus×euramiercana cv.'Neva'and Populus tomentosa, while no significant difference between Populus×euramericana cv.'Guariento'and Populus tomentosa was found. It was almost invariable in bark bacterial quantities of three poplar plantations; Bacterial quantities in the soil were consistent with those in the air. The result, that there was no significant difference between Populus×euramiercana cv.'Neva'and Populus×euramericana cv.'Guariento'which own the similar bacterial growing environment, indicated that the types of plantations are not the principal factors in affecting the bacterial quantities. The alteration of bacterial quantities in the four seasons was remarkably different in the airy bacterial quantities between summer and spring, autumn and winter, respectively, while there was no significant difference among spring, autumn and winter. There was significant difference in leaf bacterial quantities among spring, summer and autumn, and there were no leaves bacteria to be obtained in winter. There was significant difference in bark bacterial quantities among four seasons except between summer and autumn. There was significant difference in soil bacterial quantities among the four seasons except between spring and winter. These results indicated that the alteration of four seasons affected the change of bacterial quantities directly and should be the principal factor of the micro flora variability. The dominant bacterial species were: Pseudomonas argentinensis, Curtobacterium sp.and Bacillus pumilus on the leaves, Brevundimonas nasdae, Pseudomonas sp.and Bacillus subtilis on the bark, and Arthrobacter sp., Bacillus sp., Acetobacter sp. and Streptomyces sp. in the soil.2. The comparison of fungal flora of poplar plantations:There was significant difference in fungal quantities between Populus×euramiercana cv.'Neva'and Populus×euramericana cv.'Guariento', and between Populus×euramiercana cv.'Neva'and Populus tomentosa on the leaf fungal quantities, and no significant difference between Populus×euramericana cv.'Guariento'and Populus tomentosa which is the same as that of leaf bacterial quantities. There was remarkably difference on bark fungal quantities among three types of poplar plantations, and significant difference between Populus×euramiercana cv.'Neva'and Populus×euramericana cv.'Guariento', and in soil fungal quantities between Populus×euramiercana cv.'Neva'and Populus tomentosa, while no significant difference between Populus×euramericana cv.'Guariento'and Populus tomentosa. These results indicated that the types of plantation affected the alteration of fungal quantities partially.The alteration of fungal quantities in four seasons was remarkably different among spring, summer and autumn on the leaf fungal quantities, significant different in bark fungal quantities between summer and spring, autumn and winter, respectively, while no significant differencere among spring, autumn and winter was found. There was significant difference in soil fungal quantities among four seasons except between spring and autumn. In a conclusion, the change of leaf fungal quantities is remarkably different in four seasons, but not on bark fungal quantities, indicating that the alteration of seasons plays important influence on leaf fungal quantities, not on bark fungal quantities. Furthermore, the alteration of seasons plays a certain influence in soil fungal quantities.The fungal dominant species on leaves were Marssonina populi, Paecilomyces sp.and Alternaria longipes, Marssonina populi, Pyrenochaeta sp. and Dothiorella gregaria on the bark, Penicillium sp., Aspergillus sp.and Emericella rugulosa including Penicillium restrictum, Aspergillus ustus and Penicillium sclerotiorum in the soil.3. The soil Bacillus floras of poplar plantations was no significant difference among three types of plantation; is remarkably different among different seasons. These results indicated that the alteration of seasons was the most important factor to affect the soil Bacillus quantities, and the types of plantation was not. The soil Bacillus dominant species of poplar plantation are Bacillus megaterium, Bacillus simplex, Bacillus subtilis and Bacillus thuringiensis.