近30年川中丘陵区不同土地利用方式土壤碳氮磷生态化学计量特征变化

基于1981年第二次土壤普查数据和2012年实地采样数据,分析了紫色丘陵区1981—2012年不同土地利用方式下表层土壤碳氮磷含量及生态化学计量特征变化。结果表明:研究区近30年来土壤碳、氮含量增幅分别为109.98%、27.27%,磷含量基本稳定。1981年土壤C︰N︰P比为7.28︰1︰1,2012年C︰N︰P比为16.41︰1.37︰1。各土地利用方式土壤碳、氮含量均有不同程度提升,尤以林草地、园地提升最为明显;水田、旱地、园地土壤磷含量基本稳定而林草地下降明显;土壤C/N、C/P、N/P均有提升。30年来表层土壤碳储量明显增加,氮储量基本稳定而磷储量有所下降。

Last 30a Changes of C, N and P Ecological Stoichiometry of Different Land Use Types in Hilly Area of Mid-Sichuan Basin, Southwest China

Based on the 2nd National Soil Survey Data in 1981 and the measured data of 555 soil samples(0~20cm) in 2012, Changes of C, N and P ecological stoichiometry on different land use types over 30 years were analyzed in this paper. The results show that: The soil carbon and nitrogen increased 109.98%, 27.27% respectively, while phosphorus content remained stable in the last 30 years. Soil C: N: P ratio of 1981 was7.28: 1: 1and the C: N: P ratio of 2012 was 16.41: 1.37: 1. The content of soil carbon and nitrogen all enhance in each land use type, especially forest and grassland, garden to increase more obviously; the content of soil phosphorus in paddy field, dry land, orchard retain stable while forest and grassland decreased significantly. Soil C/N,C/P,N/P have increased on each land use type but the C: N: P show different trends. The topsoil of carbon storage increased significantly, nitrogen storage remained stable and phosphorus storage has declined in the last 30 years.