Analysis on Microbial Flora in Three Types of Pinus massoniana Forests in Yunyang County of the Three Gorges Reservoir Area Ⅱ. Microflora in Woodland Air, Leaf and Bark Surface

To explore the microbial flora and its seasonal variation on different types of Pinus massoniana stand, the cultivable bacteria and fungi in the forest air and on the leaf and bark surface of near-matured forest, middle-aged forest and plantation in Yunyang County of the Three Gorges Reservoir Area were analyzed. The results showed that in the aboveground of the three types of pine forest,the microorganisms were consistent with the seasons, the quantities of microorganism in summer and autumn were higher than in winter and spring, the quantities of microorganism in middle-aged natural forest were the largest and the seasonal change was also the largest; the quantity and species of dominant population varied with the seasons and forest types. The fungal species in the air of plantation were 4,3,4,3 respectively in autumn, winter, spring and summer season, while, in near-matured forest and middle-aged forest, the fungal species were 3. The dominant species diversity in plantation was higher than that in near-matured forest and middle-aged forest. The bacterial dominant species on leaf surface in near-matured forest and middle-aged forest were Pseudomonas veronii and Serratia marcescens and in plantation was Enterobacter sp. The fungi species of dominant population on the leaf surface in the middle-aged natural forest and plantation were the same in four seasons, which including Aspergillus versicolor, Pestalotiopsis neglecta and Aspergillus nomius. However, they were Aspergillus versicolor, Pestalotiopsis neglecta and Aspergillus sydowii in the near-matured forest. The dominant bacteria population on the bark surface in near-matured forest was Pseudomonas sp., which took the highest percentage in the dominant species among the three types of forest lands and were 69.05%, 65.58%, 57.08% and 80.57% respectively in autumn, winter, spring and summer. The dominant bacteria species in the middle-aged natural forest was Bacillus subtilis and in plantation was Neisseria sp. The dominant fungi species on the bark surface in near-matured forest were Penicillium waksmanii and Pestalotiopsis neglecta, and in plantation were Penicillium spp. and Aspergillus spp., but in middle-aged forest, there was only one species of Mucorales, its quantity percentage in autumn, winter, spring and summer were 63.38%, 65.76%, 51.23% and 84%, respectively, which was significantly higher than those in the other two types of forest.