关键词: 施肥, 腐解特征, 豫南稻区, 毛叶苕子, 养分释放

Abstract: Vegetation restoration is one of the important strategies for environmental recovery in the lithoid hilly area of North China. We investigated the characteristics of soil carbon (C) and nitrogen (N) and their coupling under different restored vegetations (shrubland, Platycladus orientalis forest andPinus tabuliformis forest) in Jiulong Mountain, aiming to provide scientific basis for the selection of restoration tree species and reasonable management of forest ecosystems in this area. Our results showed that: (1) Soil organic carbon (SOC) concentration in each layer over 0-30 cm in shrubland was significantly higher than in P. orientalis forest and P. tabuliformis forest, while SOC concentration in P. orientalis forest and P. tabuliformis forest showed no significant variation. Soil total nitrogen (TN) concentration in each layer was the highest in shrubland and lowest in P. tabuliformis forest, and the difference among soil layers decreased with the depth. Moreover, soil C/N ratio of P. orientalis forest was significantly lower at 0-10 and 20-30 cm layers than that in shrubland andP. tabuliformis forest. (2) SOC and TN enriched in topsoil of the three ecosystems and decreased with the depth. For all the vegetation types, soil C/N ratio showed no significant difference among soil layers. Soil C/N ratio at 0-30 cm layers ranged from 18.40 to 21.97 for shrubland, from 11.70 to 12.52 for P. orientalis forest, and from 18.08 to 20.69 for P. tabuliformis forest, respectively. (3) SOC and TN concentrations were significantly correlated with most of soil physical and chemical properties. They were significantly positively correlated with the concentrations of soil hydrolysable N, available phosphorus, available potassium content (P<0.01) and significantly positively correlated with soil pH (P<0.05). (4) As an important vegetation recovery type in the lithoid hilly area of North China, shrubland had the advantages of higher SOC and TN concentrations, suggesting that using the shrub in non-commercial forest construction would be beneficial for increasing C sequestration in the future.

Key words: nutrient release., decomposition characteristics, Vicia villosa, fertilization, rice fields of South Henan