ObjectiveNon-commercial forest is a kind of forest, which is focus on promoting the ecological and social benefits. Soil fertility is the basic property and essential characteristics of soil. This study tries to assess the situation of soil fertility under different stand types of non-commercial forest, which is helpful for scientific management and evaluation of forest soil resources and provides the theoretical reference for the management of non-commercial forest.

Method33 sample plots, middle-aged forests under six representative stand types were sampled from the monitoring plots of non-commercial forest in Jiangxi Province of eastern China. Soil chemical properties were examined in these plots. The effects of stand types and soil layers on the variations of soil properties were analyzed by two-way ANOVA. Moreover, the variations of soil chemical properties among different soil layers within a same stand and different stand types in the same soil layer were analyzed by one-way ANOVA. Dimensionality reduction of soil chemical properties was applied by principal component analysis (PCA) and the rank of soil fertility was ordered through the comprehensive scores of PCA for different stand types.

ResultThe results showed that organic matter, total potassium, available nitrogen, available phosphorus, available potassium decreased with the increasing soil depth, whereas pH, total nitrogen and total phosphorus were not changed with the soil depth. Most of soil chemical parameters were not significantly changed, expect for available phosphorus of top soil layer in broadleaved evergreen forest and available potassium of top soil layer in coniferous and broadleaved mixed forest were respectively significantly higher than Chinese fir plantation and Masson pine plantation. The results of PCA showed that the first axis represented for the available nutrient content and organic carbon content, the factor loading values of available nitrogen, available potassium and organic carbon were larger than other parameters. The second axis represented for the total nutrient content and pH. The descending order of soil fertility was bamboo forest, broadleaved evergreen forest, coniferous broadleaved mixed forest, Masson pine plantation, Chinese fir plantation and slash pine plantation.

ConclusionThis result would provide data supporting and theoretical reference for the differential compensation of non-commercial forest from the view of soil conservation. Furthermore, our result reveals that broadleaved evergreen forest and coniferous broadleaved mixed forest are more helpful for soil nutrient accumulation than artificial plantations. Therefore, we are looking forward to converting the stand structure from coniferous plantation to coniferous broadleaved mixed forest, even broadleaved evergreen forest by replanting and transformation, then promoting the ecological and social benefits of non-commercial forest.