J Plant Ecol ›› 2021, Vol. 14 ›› Issue (1): 147-159 .DOI: 10.1093/jpe/rtaa074

• Research Articles • Previous Articles     Next Articles

Effects of warming and fertilization interacting with intraspecific competition on fine root traits of Picea asperata

Dan-Dan Li1, *, Hong-Wei Nan2 , Chun-Zhang Zhao1 , Chun-Ying Yin1 and Qing Liu1   

  1. 1 Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China, 2 College of Forestry, Shanxi Agricultural University, Jinzhong 030801, China

    *Corresponding author. E-mail: lidd@cib.ac.cn
  • Received:2020-03-23 Revised:2020-11-04 Accepted:2020-11-09 Online:2020-11-17 Published:2021-02-01



Competition, temperature and nutrient are the most important determinants of tree growth in the cold climate on the eastern Tibetan Plateau. Although many studies have reported their individual effects on tree growth, little is known about how the interactions of competition with fertilization and temperature affect root growth. We aim to test whether climate warming and fertilization promote competition and to explore the functional strategies of Picea asperata in response to the interactions of these factors.


We conducted a paired experiment including competition and non-competition treatments under elevated temperature (ET) and fertilization. We measured root traits, including the root tip number over the root surface (RTRS), the root branching events over the root surface (RBRS), the specific root length (SRL), the specific root area (SRA), the total fine root length and area (RL and RA), the root tips (RTs) and root branching (RB) events. These root traits are considered to be indicators of plant resource uptake capacity and root growth. The root biomass and the nutrient concentrations in the roots were also determined.

Important Findings

The results indicated that ET, fertilization and competition individually enhanced the nitrogen (N) and potassium (K) concentrations in fine roots, but they did not affect fine root biomass or root traits, including RL, RT, RA and RB. However, both temperature and fertilization, as well as their interaction, interacting with competition increased RL, RA, RT, RB and nutrient uptake. In addition, the SRL, SRA, RTRS and RBRS decreased under fertilization, the interaction between temperature and competition decreased SRL and SRA, while the other parameters were not affected by temperature or competition. These results indicate that P. asperata maintains a conservative nutrient strategy in response to competition, climate warming, fertilization and their interactions. Our results improve our understanding of the physiological and ecological adaptability of trees to global change.

Key words: competition, climate warming, fine root traits, nutrient availability, Picea asperata

物种竞争、气温和土壤养分是青藏高原东部高寒地区影响树木生长的重要因素。虽然已开展了大量关于物种竞争、气温、施肥单因素对树木生长的影响研究,但关于这三者的交互作用对根系生长的影响还知之甚少。因此,本研究拟通过测量根系属性(细根长、根表面积、比根长、比表面积、根尖数、根系分支数等)、根生物量,以及根系养分吸收,研究施肥和增温对物种竞争的影响,并进一步探讨施肥、增温与物种竞争的交互作用对云杉(Picea asperata)生长的影响机制以及所采取的适应策略。研究结果表明,增温、施肥和竞争均提高了细根的氮、钾浓度,但并未影响细根生物量和根长、根表面积、根尖数和根分支数等根系特征。然而,无论是增温、施肥,或是它们的联合作用,与物种竞争进行交互时,均增加了根长、根表面积、根尖数、根系分支数和养分吸收。此外,施肥降低了根比表面积、比根长和单位面积的根尖数和根分支数,增温和竞争的交互作用使根比表面积、比根长下降,其他参数不受温度和竞争的影响。该结果表明,云杉在物种竞争、气候变暖、施肥及其交互作用下保持着保守的营养策略。该研究加强了对树木应对全球变化的生理和生态适应性的理解。

关键词: 竞争, 气候变暖, 根系属性, 养分有效性, 云杉