| 摘要: |
| 【目的】探讨香樟人工林土壤表层（0～20 cm）细根形态特征、生物量及碳氮含量变化动态，为深入研究人工林细根的养分、水分吸收规律及碳在地下的分配特点提供基础资料。【方法】选取四川雅安市雨城区老板山31年生香樟人工林，随机设置20 m×20 m样地3块，于2011年的1，4，7和10月份，在各样地按“S”形选取5个采样点，采用根钻法，分0～10和10～20 cm土层采集根系样品，用WinRHIZO 2005 根系分析系统对细根形态进行分析，并测定细根生物量及碳氮含量。【结果】1）1～5级细根随着根序的增加，平均直径、生物量和细根C含量逐渐增大，比根长（SRL）、根长密度（RLD）和细根N含量逐渐降低。2）细根平均生物量为793.29 kg/hm2，其中0～10 cm土层细根生物量占土壤表层细根总生物量的64.66%；与10～20 cm土层相比，0～10 cm土层细根具有较高的SRL和RLD以及较小的直径；0～10 cm土层细根C、N含量均高于10～20 cm土层。3）细根生物量在春季和秋季较高，在夏季和冬季较低；SRL和RLD夏季最大，冬季最小；而直径夏季最细，冬季最粗；细根C含量冬季最高，夏季最低；N含量夏季最高，春季和冬季均较低。【结论】根序对细根形态、生物量和C、N含量的变化具有极显著影响，而季节对细根形态、生物量和C、N含量变化的影响要远小于根序。 |
| 关键词: 香樟 根序 细根形态特征 生物量 C、N含量 |
| DOI： |
| 分类号: |
| 基金项目:国家科技支撑计划项目（2011BAC09B05）；林业公益性行业科研专项（201104109）；四川省科技支撑计划项目（2010NZ0049）；国家级大学生创新性实验项目（101062622）；长江上游林木种质资源与培育技术创新团队项目（00370503） |
|
| Morphology,biomass and changes in C and N contents of fine roots in top soil of Cinnamomum camphora plantations |
|
ZHANG Teng-fei,LI Xian-wei,FAN Chuan,et al
|
| Abstract: |
| 【Objective】This paper studied the morphology,biomass,and changes in carbon and nitrogen contents of fine roots in top soil (0-20 cm) of Cinnamomum camphora plantations to provide basis for further study of nutrient and moisture absorption of fine roots and underground distribution characteristics of carbon.【Method】Randomly 3 pieces of 20 m×20 m sample plots were set in 31 years old Cinnamomum camphora plantations in the Laoban Mountain,Yucheng District,Ya’an,Sichuan Province and 5 sampling points were picked along the “S” shape in each plot. Samples from depths of 0－10 cm and 10－20 cm were collected by soil coring method in January,April,July and October 2011.WinRHIZO 2005 root analysis system was used to measure root morphological parameters,biomass,carbon content,and nitrogen content.【Result】1) As the increase of root order from the first to the fifth,the mean diameter,biomass and carbon content of fine roots increased gradually,while the specific root length (SRL),root length density (RLD) and nitrogen content decreased.2) The average biomass of fine roots was 793.29 kg/hm2,and the surface layer (0－10 cm) accounted for 64.66% of the total biomass.Compared with the fine roots in deep layer (10－20 cm),the fine roots of surface layer (0－10 cm) were thinner,had greater SRL and RLD,and the carbon and nitrogen contents were larger.3) The biomass of fine roots in spring and autumn was higher than in summer and winter.The lowest SRL and RLD were in summer while the highest were in winter.The mean diameter in winter was the thickest,and in summer was the thinnest.The highest carbon content of fine roots was in winter,and the lowest was in summer.The highest nitrogen content of fine roots was in summer,and the lowest was in spring and winter.【Conclusion】Root order had highly significant effects on morphology,biomass,and changes in carbon and nitrogen contents of fine roots while the effects of season were much less. |
| Key words: Cinnamomum camphora root order fine root morphology biomass C and N contents |
