摘要
Soil properties were investigated in sites where three succeeding generationsof Chinese fir (Gunning-hamia lanceolata, (Lambert) Hooker) in Nanping, Fujian, China, werecultivated in order to show the impact of a repeated monoculture on site productivity. Compared withthe first generation (FG) stand the soil structure deteriorated in the second generation (SG) andthe third generation (TG) stands. For instance, the destruction rate of the peds increased by 55%-115% in the SG and the TG stands compared to the FG stand. Soil nutrient storage and nutrientavailability also decreased in the SG and the TG stands. For surface soils of 0-20 cm, the organicmatter content, total N and P, and available N and P decreased by 3%-20% relative to those in the FGstand. For many soil parameters, the differences between the FG stand and the SG and the TG standswere statistically significant (LSD test, P < 0.05). Furthermore, with each succeeding generation ofChinese fir, the total number of soil microbes declined, the soil enzyme activity weakened, and thesoil biological activity decreased. In order to maintain sustainable site productivity, newsilvicultural practices need to be developed for management of Chinese fir plantations.
Soil properties were investigated in sites where three succeeding generations of Chinese fir (Cunninghamia lanceolata (Lambert) Hooker) in Nanping, Fujian, China, were cultivated in order to show the impact of a repeated monoculture on site productivity. Compared with the first generation (FG) stand the soil structure deteriorated in the second generation (SG) and the third generation (TG) stands. For instance,the destruction rate of the peds increased by 55%-115% in the SG and the TG stands compared to the FG stand. Soil nutrient storage and nutrient availability also decreased in the SG and the TG stands. For surface soils of 0-20 cm, the organic matter content, total N and P, and available N and P decreased by 3%-20% relative to those in the FG stand. For many soil parameters, the differences between the FG stand and the SG and the TG stands were statistically significant (LSD test, P ＜ 0.05). Furthermore, with each succeeding generation of Chinese fir, the total number of soil microbes declined, the soil enzyme activity weakened, and the soil biological activity decreased. In order to maintain sustainable site productivity, new silvicultural practices need to be developed for management of Chinese fir plantations.
基金
Project supported by the National Natural Science Foundation of China (No. 30170770).
