Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Effects of Stand Density and Nitrogen Rate on Growth and Wood Properties of Populus simonii × Populus nigra in Semi-arid Northeast China

Auteur : 张非凡

Grade : Master 2022

Université : Northeast Forestry University

Résumé partiel
Populus（Populus simonii×Populus nigra）is one of the important fast-growing tree species in China,with economic and ecological value.Many varieties have been selected in semi-arid areas of Northeast China.However,the traditional poplar cultivation measures generally have the problems of slow growth and low yield due to poor site conditions,high density,weak water and fertilizer management and other reasons.It has greatly restricted the promotion and application of good poplar species.Especially in recent years,with the development of economy and the promulgation of the policy of prohibiting commercial logging of natural forests,the demand for poplar wood in Northeast China is increasing,and the prices of fertilizer and water are higher and higher.Optimize the cultivation conditions and improve the quality of trees,it’s of great significance to speed up the forestry ecological and economic construction in Northeast China.In this study,three poplar varieties with different planting densities of three years old were used as experimental materials to determine the differences of growth and wood properties of each variety under different density and nitrogen treatment.The main analysis results are as follows :（1）Density and nitrogen fertilizer have significant effects on growth indexes such as height,DBH,volume and crown width.Under the same nitrogen application conditions,with the increase of afforestation density,the growth of tree height,DBH,volume and crown width of each variety decreased gradually ;Increasing the amount of nitrogen application under high density and reducing the amount of nitrogen application under low density are more beneficial to the growth of poplar.The results showed that the best treatments of P.Bailin-3,P.xiaohei and P.xiaohei-14 were D6N1,D6N2 and D5N1 respectively,and the tree height growth of each variety was 3.14 m/a,2.75 m/a and 2.89 m/a respectively ;The increase of DBH was 4.42 cm/a,3.58 cm/a and 3.69 cm/a respectively ;The volume growth was 0.02903 m 3/a,0.01956 m 3/a and0.01966 m 3/a respectively ;The North-South crown widths are 3.70 m,3.45 m and 3.37m respectively ;

Mots clés : Populus simonii × Populus nigra ;Stand Density ;Nitrogen fertilizer ;Growth traits ;Leaf phenotypic traits ;Leaf physiological traits ;Wood properties ;

Présentation (CNKI)