Journal of Resources and Ecology ›› 2022, Vol. 13 ›› Issue (1): 34-40.DOI: 10.5814/j.issn.1674-764x.2022.01.004

• Ecosystems in Response to Global Change • Previous Articles     Next Articles

Leaf Longevity in a Timberline Tree Species Juniperus saltuaria in the Sergymla Mountains, Southeastern Tibet

ZHANG Lin1,2,*(), YANG Liu1,3, GUO Ying1,3, SHEN Wei1, CUI Guangshuai1,3   

  1. 1. State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
    2. Muoto Observation and Research Center for Earth Landscape and Earth System, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
    3. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2021-07-29 Accepted:2021-10-13 Online:2022-01-30 Published:2022-01-08
  • Contact: ZHANG Lin
  • Supported by:
    The Key Scientific and Technological Research Projects in Tibet Autonomous Region(XZ202101ZY0005G);The Second Tibetan Plateau Scientific Expedition and Research (STEP) Program(2019QZKK0301-1)

Abstract:

Leaf longevity is an important adaptive strategy that allows plants to maximize photosynthetic carbon gain. Due to the difficulty of identifying overwintering bud scars and distinguishing the age sequence of twigs, leaf longevity is rarely studied in Cupressaceae species, which further limits our understanding of the leaf economic spectrum (LES) for these populations. Here, we investigated the leaf longevity, as well as mass-based leaf nitrogen concentration (Nmass), of Juniperus saltuaria at different canopy heights for both subalpine and alpine timberline forests in the Sergymla Mountains, southeastern Tibet. We found that the mean leaf longevity was 4.2±1.2 years, and overall it did not differ significantly between different elevations. Along the vertical profiles of juniper canopies, the leaf longevity did not reflect a linear trend. With increasing leaf longevity, Nmass showed declining trends. We further analyzed the relationship between leaf longevity and the corresponding length of green twigs, and found that the length of green twigs could only explain 1%-3% of the variation in leaf longevity, indicating that the length of green twigs is a poor predictor for the variation in leaf longevity. In summary, for the J. saltuaria species in timberline or nearby subalpine forests, the effects of elevation and canopy depths on leaf longevity are minor, and the leaf trait analysis is in accordance with the prediction of LES.

Key words: canopy height, elevation, leaf nitrogen concentration, length of green twigs, Cupressaceae