Characteristics of Soil Fertility and Microbial Populations under Different Forest Types of Wanfeng Mountain

Determinations were conducted in July 2015 on soil microbial populations, nutrient content in forest litter and soil physical and chemical properties under coniferous plantation, mixed forest of coniferous and broad-leaved forest and Machilus pingii forest in Wanfeng Mountain, Linshui county of Sichuan province. Analysis was made on their relationship. The results showed that nutrient content in the soil and litter was the highest under mixed forest, especially content of soil organic carbon and hydrolyzable nitrogen reached 27.000 g·kg-1 and 248.500 g·kg-1. Soil pH was 4.4 under M. pingii forest, higher than that under the other two forest types. Soil microbial populations were ordered by mixed forest > coniferous forest > M. pingii forest, and had close relation with soil total porosity. Mixed forest had significantly more soil bacteria number than the other two forest lands. M. pingii forest had the most number of actinomycetes.