Abstract:
Objective To reveal the correlation and variation characteristics among the contents of soil organic carbon (C), total nitrogen (N), total phosphorus (P) and total potassium (K) and stoichiometric ratio under different stands in Maoershan Nature Reserve.
Method The contents of soil organic C, total N, total P and total K nutrients in different depths of Cyclobalanopsis glauca forest, Phyllostachys pubescens forest and Cunninghamia lanceolata forest were measured by the combination of field investigation and sampling and indoor experimental analysis, and their stoichiometric ratios were calculated. The soil ecological stoichiometric characteristics were comprehensively evaluated by multiple comparison and correlation analysis.
Result There were significant differences in soil nutrient contents and eco stoichiometric ratio among different stand types (P < 0.05). The contents of soil organic C and total N were significantly different between stands and soil layers (P < 0.05). Under the same stand, they decreased with the increase of soil depth, that is, they were negatively correlated with soil depths. The contents of soil organic C and total N in the three stands were Cyclobalanopsis glauca forest > Phyllostachys pubescens forest > Cunninghamia lanceolata forest, that is, Cyclobalanopsis glauca stand was the largest, and its average values were 55.91 g kg−1 and 4.20 g kg−1. The overall changes of different nutrient content ratios C/N, C/P, C/K, N/P, N/K and P/K were similar. The order among stands was Cyclobalanopsis glauca forest > Phyllostachys pubescens forest > Cunninghamia lanceolata forest. The results of correlation analysis showed that there was a very significant (P < 0.01) and significant positive correlation among soil organic C and total N, total P and total K, respectively (P < 0.05), but total P was no significant correlation with organic C and total N, and total K was a significant negative correlation with organic C and total N.
Conclusion The soil organic C and total N of natural secongdary forest of Cyclobalanopsis glauca were higher than those of Moso bamboo plantation and Cunninghamia lanceolata plantation.