title: [Changes of root biomass, root surface area, and root length density in a Populus cathayana plantation].
abstract: By using soil core method, the biomass, surface area, and length density of roots < or =2 mm and 2-5 mm in diameter in a 50-year-old Populus cathayana plantation on the northern slope of Qinling Mountains were determined during growth season. Among the roots <5 mm in diameter, those < or =2 mm and 2-5 mm in diameter accounted for 77.8% and 22.2% of the total root biomass, respectively. The surface area and length density of the roots < or =2 mm in diameter accounted for more than 97% of the total, and those of the roots 2-5 mm in diameter only occupied less than 3%. The biomass, surface area, and root length density of roots < or =2 mm in diameter decreased with soil depth, while those of the roots 2-5 mm in diameter were the least in 20-30 cm soil layer. The biomass, surface area, and length density of roots < or =2 mm in diameter were significantly correlated with soil organic matter and available nitrogen, but no significant correlations were found for the roots 2-5 mm in diameter.
authors.affiliation: Northwest A & F University, Yangling, Shaanxi, China. hnyanhui@yeah.net
authors.forename: Hui
authors.initials: H
authors.lastname: Yan
authors.forename: Guang-quan
authors.initials: GQ
authors.lastname: Liu
authors.forename: Hong-sheng
authors.initials: HS
authors.lastname: Li
mesh_terms: D018533:Biomass; D018517:Plant Roots / Q000033:anatomy & histology / Q000254:growth & development*; D032107:Populus / Q000033:anatomy & histology / Q000254:growth & development*; D012987:Soil / Q000032:analysis
chemical_list: D012987:Soil