Chin J Plant Ecol ›› 2023, Vol. 47 ›› Issue (11): 1523-1539.DOI: 10.17521/cjpe.2022.0390

• Research Articles • Previous Articles     Next Articles

Crown characteristics and its relationship with tree growth on different slope aspects for Larix olgensis var. changbaiensis plantation in eastern Liaoning mountainous area, China

HE Lu-Lu1, ZHANG Xuan1, ZHANG Yu-Wen1, WANG Xiao-Xia1, LIU Ya-Dong1, LIU Yan1, FAN Zi-Ying1, HE Yuan-Yang2, XI Ben-Ye1, DUAN Jie1,**()   

  1. 1College of Forestry, Beijing Forestry University, Beijing 100083, China
    2Chongqing Forestry Bureau, Chongqing 401147, China
  • Received:2022-10-07 Accepted:2023-02-24 Online:2023-11-20 Published:2023-12-22
  • Contact: DUAN Jie(duanjie@bjfu.edu.cn)
  • About author:First author contact:*Contributed equally to this work
  • Supported by:
    Fundamental Research Funds for the Central Universities(2021ZY18);Forestry Science and Technology Promotion Project(2011-44)

Abstract:

Aims Tree crown plays vital roles in carbohydrate accumulation and productivity formation, clarifying the variation pattern of tree growth and crown development, as well as their responses to the growing environment such as slope aspects, can help us to understand the adaption strategies of trees.

Methods In this study, Larix olgensis var. changbaiensis from 60 sites in east Liaoning were selected, and the responses of tree growth and crown development to different slope aspects (shady or sunny slope) and age classes (15-16 a, 23-26 a, 49-56 a) were analyzed. The three types of crown indicators, including objective indicators, subjective indicators, and composite indicators, were used to analyze the crown development in this study.

Important findings The results showed that: (1) No significant difference was found in diameter at breast height (DBH), tree height (H), wood volume, and relative dominant tree height among age classes. In comparison, the differentiation of DBH on the sunny slopes was significantly higher than that on the shady slopes in the mature age class. (2) By the comprehensive analysis of the three types of crown indicators, the crown exhibited distinct growth adaptation strategies but depending on slope aspects. Tree growing on the sunny slopes generally showed small crown length and width with uniform crown layer and high crown production efficiency. By contrast, tree growing on the shady slopes showed large crown length and width with large crown volume and low crown production efficiency. (3) Except for the ratio of H to DBH, all objective crown indicators were positively correlated to growth indicators. On the sunny slopes, the contribution of the crown to wood volume decreased with stand age, which could be proved by the significant negative correlation between crown length, crown ratio, and growth indicators. In addition, the crown position and crown fullness ratio were also the main factors that promoted stand growth at the shady slopes. (4) All the objective indicators were positively correlated to the biomass of each organ. On both slope aspects, whole tree biomass was positively correlated to crown light exposure, crown surface area, and crown volume, but negatively correlated to crown dieback. On the sunny slopes, whole tree biomass decreased with the increase of foliage transparency, ratio of crown density to DBH, and crown ratio, while on the shady slopes, biomass increased with higher crown position and crown fullness ratio. (5) Among all indicators, crown surface area showed the best indicator for explaining the biomass of each organ in this study. Overall, better crown development could significantly promote tree growth on Larix olgensis var. changbaiensis plantation, but the trade-off between crown development and tree growth that varies with slope aspects should be considered in such stand management.

Key words: tree crown, slope aspect, Larix olgensis var. changbaiensis, biomass, trade-off, environmental adaptation