Impacts of Nitrogen Fertilization on Wood Properties of Two Populus Species

• 1、College of Life Sciences, Northwest Agriculture and Forestry University, Shaanxi YangLing 712100
• 2、Key Laboratory of Environment and Ecology in Western China of Ministry of Education, College of Forestry, Northwest Agriculture and Forestry University, Yangling, Shaanxi, 712100, PR China

Abstract：Nitrogen (N) is an essential macronutrient which can impact wood productivities and properties. However, little is known about how N may affect wood properties of poplar species. To address the influences of N fertilization on wood properties of woody plants, saplings of two poplar species (Populus popularis and Populus alba × P. glandulosa) were exposed to 0, 5 and 10 mM NH4NO3 for 7 weeks and subsequently, wood properties were analyzed. Vessel and fiber characteristics were affected by N fertilization. The samples from the two species treated with 10 mM NH4NO3 contained significantly shorter fibers and vessels than the lower N treatments. Vessel and fiber widths were larger under higher N supply. Thicker fiber cell walls were formed under higher N levels. High N availability increased cellulose deposition in xylem fiber cell walls which is mainly due to the formation of a G-layer in P. popularis. Lignin concentrations were tended to decline after N fertilization in both species. These results indicate that N fertilizaiton leading to changes in wood properties of poplar wood may affect end-use of wood products derived from N fertilized poplar forests.

Keywords： Cultivation of forest plantation Nitrogen fertilizaiton Wood properties Lignin Poplar