• 论文与研究报告 •

### 樟子松天然林土壤碳氮含量与水解酶活性坡位差异及月动态

VuongThi Minh Dien,曾健勇,满秀玲*

1. 东北林业大学林学院 森林生态系统可持续经营教育部重点实验室 哈尔滨 150040
• 收稿日期:2019-04-23 出版日期:2020-02-25 发布日期:2020-03-17
• 通讯作者: 满秀玲
• 基金资助:
国家自然科学基金项目(31770488)

### Slope Locational Differences and Monthly Dynamics of Soil Carbon and Nitrogen Contents and Hydrolases Activity in the Natural Forest of Pinus sylvestris var. mongolica

Thi Minh Dien Vuong,Jianyong Zeng,Xiuling Man*

1. Key Laboratory of Sustainable Management of Forest Ecosystem of Ministry of Education School of Forestry, Northeast Forestry University Harbin 150040
• Received:2019-04-23 Online:2020-02-25 Published:2020-03-17
• Contact: Xiuling Man

Abstract:

Objective: The study was conducted to reveal the slope locational differences and monthly dynamics of soil carbon and nitrogen contents and hydrolase activities in natural forest of Pinus sylvestris var. mongolica Litv. The correlation between carbon/nitrogen contents and hydrolase activities, and the effect of soil temperature and moisture. Method: The study was performed in a natural forest of Pinus sylvestris var. mongolica located in Mohe Town, Daxing'anling Region. In the middle of every month from May to October, 2018, three blocks (20 m×30 m) in every slope location (upper slope, middle slope, lower slope) were selected as sample region. Three sampling points were selected in every sample region. Soil temperatures at depths of 2.5 cm, 7.5 cm, 15 cm, 25 cm were measured after removing litters. Soil samples at different depths (0-5, 5-10, 10-20, and 20-30 cm), on different slope locations, and in different months were collected by excavating soil profiles. Subsequently, the moistures, organic carbon contents, total nitrogen contents, and hydrolase (urease, protease, sucrase, and cellulase) activities of soil samples were determined in laboratory. Result: Result showed that the contents of carbon and nitrogen were decreased with the increase of soil depth, and increased with the lowering the slope locations, and the highest contents of both were showed in September. The soil organic carbon contents in the soil layers of depth 0-5, 5-10, 10-20, 20-30 cm were 68.53-80.38, 40.28-46.66, 15.86-21.08, and 1.91-13.79 g·kg-1 respectively, and soil total nitrogen contents in these layers 5.34-5.96, 2.98-3.68, 2.35-2.61, and 1.54-1.75 g·kg-1 respectively. However, organic carbon contents and total nitrogen contents among slope locations did not show great differencs (P>0.05). Additionally, activities of urease, protease, sucrase, and cellulase were decreased with soil depth, urease and sucrase maintained higher activities in a lower slope location, but the protease, cellulase did the opposite. Furthermore, hydrolases always showed their highest activities in July or August. Finally, the results also indicated that contents of soil carbon and nitrogen were significantly and positively correlated with activities of detected soil hydrolytic enzymes (P < 0.01); soil carbon and nitrogen contents were significantly and positively correlated with soil moisture (P < 0.01); and soil temperature was significantly and positively correlated with soil carbon content (P>0.05), but negatively correlated with total soil nitrogen content (P < 0.05). Conclusion: The study demonstrated that soil carbon/nitrogen contents and hydrolase activities in P. sylvestris var. mongolica forest maintains a common pattern that 0-5 cm > 5-10 cm > 10-20 cm > 20-30 cm; contents and activities at different slope locations were indistinguishable (P>0.05); the highest soil carbon and nitrogen contents were found in September; and the highest hydrolase activities were found from July to August. It also proved that contents of carbon and nitrogen were significantly correlated with hydrolytic enzyme activities (P < 0.01); ant the soil temperature and moisture had significan affects on the carbon and nitrogen contents and hydrolase activities (P < 0.05).