Plant Diversity ›› 2018, Vol. 40 ›› Issue (06): 277-283.doi: 10.1016/j.pld.2018.11.004

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Factors limiting the recruitment of Quercus schottkyana, a dominant evergreen oak in SW China

Ke Xiaa, Roy Turkingtonb, Hong-yu Tanc, Lei Fana   

  1. a Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China;
    b Botany Department, and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada;
    c Department of Statistics, Colorado State University, Fort Collins, CO, 80523, USA
  • Received:2018-08-09 Revised:2018-11-23 Online:2018-12-25 Published:2019-01-30
  • Contact: Ke Xia E-mail:xiakk@mail.kib.ac.cn
  • Supported by:
    This work was supported by the NSFC-Yunnan joint fund to support key projects (Nos. U1502231) and the National Natural Science Foundation of China (NSFC) (No. 31770358) to KX.

Abstract: Quercus schottkyana is a dominant species of oak in the Asian evergreen broad-leaved forests in southwestern China but seedlings are uncommon and recruitment is rare. Annual acorn production by Q. schottkyana is variable and the acorns are exposed to a series of mortality risks. Understanding the factors that limit recruitment of the oak requires knowledge of the oak's life cycle from acorn production to germination and seedling establishment. In this study, we first tested the effects of acorn density on establishment of seedlings by placing batches of acorns at different densities throughout the study area. Second, we tested the effects of herbivores on seedling survival by erecting fences around both natural and transplanted seedling populations. Our results show that even though the rate of seedling establishment increases as acorn density increases (for 32-8000 acorns·m-2), survival rates of seedlings in the field were generally low (0-0.6%). We show that seedling recruitment of Q. schottkyana is mainly limited to the acorn stage where 88% of the acorns died from the combined effects of desiccation and predation by weevils (Curculio) and bark beetles (Coccotrypes sp.). Herbivory results in the death of some seedlings and consequently also affects the recruitment of seedlings of Q. schottkyana.

Key words: Cyclobalanopsis glaucoides, Desiccation, Predation, Recalcitrant seeds, Seedling, Yunnan