Chin J Plant Ecol ›› 2020, Vol. 44 ›› Issue (11): 1154-1163.DOI: 10.17521/cjpe.2020.0124

• Research Articles • Previous Articles     Next Articles

Altitudinal variation in flowering area and position and their ecological significances of an alpine cushion Arenaria polytrichoides, a gynodioecious herb

ZHANG Ya-Zhou1,2, WANG Song-Wei1,3, HE Xiao-Fang1,2, YANG Yang1, CHEN Jian-Guo1,**(), SUN Hang1,**()   

  1. 1CAS Key Laboratory for Plant Biodiversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
    2University of Chinese Academy of Sciences, Beijing 100049, China
    3School of Life Science, Yunnan University, Kunming 650091, China
  • Received:2020-04-27 Accepted:2020-09-12 Online:2020-11-20 Published:2020-11-30
  • Contact: CHEN Jian-Guo,SUN Hang
  • About author:First author contact:

    *Contributed equally to this work.

  • Supported by:
    National Key R&D Program of China(2017YFC0505200);Key Projects of the Joint Fund of the National Natural Science Foundation of China(U1802232);Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0502);Yunnan Applied Basic Research Project(202001AT070060);Ten-thousand Talents Program of Yunnan Province(YNWR-QNBJ-2018-318)

Abstract:

Aims As foundation species in the alpine ecosystems, the reproduction and recruitment of alpine cushion plants are very important for sustaining the alpine ecosystem functions. However, it still remains unclear that how cushion plants effectively allocate resources to optimize reproductive fitness.
Methods Here we selected five populations of a gynodioecious herb Arenaria polytrichoides with different exposures and slopes along an altitudinal gradient on the Baima snow mountain in northwest Yunnan, southwest China, to investigate and compare flowering area and positions, within and among populations and between female and hermaphroditic morphs. By doing so, we further discuss how the environmental stresses affect the cushion’s flowering attributes thus the population-level reproduction.
Important findings The results showed that, individual plant size and resources allocated to flowering (flowering area %) both decreased with increasing elevation, indicating that the reproductive allocation strategy was significantly affected by elevation. However, a population at lower elevation showed lower reproductive investment than higher populations, suggesting that elevation was not the only factor affecting the cushion’s reproductive allocation. In addition, absolute flowering area increased with increasing individual size, but the flowering area ratio decreased, indicating that the increases in reproductive allocation are fewer than that in vegetative allocation. Hermaphroditic individuals invested more resources to flowering than females did, but again, such effect was affected by elevation. Moreover, within a single population, the flowering areas were significantly different among the four directions (east, south, west and north) within one single individual canopy, but such differences varied in different populations.

Key words: alpine plant, flowering area, reproductive allocation, resource limitation