ORNL FACE Fine Root Data

This report documents 3 data files with names of root_production.dat,
root_mortality.dat, and root_crop.dat. These data were recorded biweekly
during the growing season on five FACE plots from 1998 through 2006.
Beginning in 2004, data also were recorded monthly during the winter.
The calculation of root-length production, mortality, and standing
crop is described in Hendrick, R.L. and K.S.Pregitzer (1993)
The dynamics of fine root length, biomass, and nitrogen content in
two northern hardwood ecosystems. Can. J. For. Res. 23:2507-2520.

Methods for collecting these data are documented in Norby, R.J., J. Ledford,
C.D. Reilly, N.E. Miller, and E.G. O'Neill (2004) Fine-root production
dominates response of a deciduous forest to atmospheric CO2 enrichment.
Proc. Natl. Acad. Sci. 101:9689-9693. Also, the conversion factors needed
to convert the fine-root data from mm/tube to g/m**2 are discussed in
this paper.

本报告记录了3个数据文件，文件名分别为root_production.dat、root_mortality.dat及root_crop.dat。1998年至2006年间，研究人员在生长季每两周对5个自由空气CO2富集（Free Air CO2 Enrichment, FACE）样地开展监测并记录数据；2004年起，冬季期间也会每月进行数据记录。

根长生产量、死亡率及现存现存量的计算方法详见Hendrick R.L.与Pregitzer K.S.1993年发表的论文《两个北方硬木生态系统中细根长度、生物量与氮含量的动态变化》，刊载于《加拿大森林研究杂志（Can. J. For. Res.）》第23卷，页码范围2507-2520。

本数据集的采集方法详见Norby R.J.、Ledford J.、Reilly C.D.、Miller N.E.及O'Neill E.G.2004年的研究《细根生产量主导落叶林对大气CO2富集的响应》，刊载于《美国国家科学院院刊（Proc. Natl. Acad. Sci.）》第101卷，页码范围9689-9693。此外，该论文还讨论了将细根数据从毫米/管（mm/tube）转换为克/平方米（g/m²）所需的转换系数。