Plant Diversity ›› 2022, Vol. 44 ›› Issue (05): 445-454.DOI: 10.1016/j.pld.2021.10.003

• Research paper • Previous Articles     Next Articles

Forest gaps regulate seed germination rate and radicle growth of an endangered plant species in a subtropical natural forest

Jing Zhua, Lan Jianga, De-Huang Zhub, Cong Xinga, Meng-Ran Jina, Jin-Fu Liua, Zhong-Sheng Hea   

  1. a. Key Laboratory of Fujian Universities for Ecology and Resource Statistics, College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, 350002, China;
    b. College of Ecology and Resources Engineering, Wuyi University, Wuyishan, Fujian, 354300, China
  • Received:2021-06-08 Revised:2021-08-19 Online:2022-09-25 Published:2022-10-14
  • Supported by:
    We wish to express our thanks for the support received from the Castanopsis kawakamii Nature Reserve in Sanming City,Fujian province to allow us to collect samples.The authors wish to thank Xin-Guang Gu,Meng-Jia Li,Yao-Shun Lu and Yuan-Zhi Wu for the field and experimental work.We also thank Yu-Xin Chen from Xiamen University for helpful discussions and valuable suggestions during the revision of the manuscript.The authors also sincerely appreciate the helpful and constructive comments provided by the reviewers of the draft manuscript.This research was funded by the National Natural Science Foundation of China,grant numbers 31700550 and 31770678;the Nature Science Fund of the Fujian Province Science and Technology of China,grant number 2019J01367;the Science and Technology Promotion of Project Forestry Bureau of the Fujian Province,grant number 2018TG14-2;and the Innovation and Technology Fund of Fujian Agriculture and Forestry University,grant number CXZX2018125.

Abstract: The survival rate of Castanopsis kawakamii from seed to seedling is relatively low, leading to difficulties in the regeneration of its natural forests. Forest gaps play a vital role in plant regeneration and biodiversity maintenance in forest ecosystems. Unfortunately, our understanding of the effects of gap size and within-gap position on the seed germination and radicle growth of C.kawakamii is still limited. In particular, our knowledge on the relationship between gap size and environmental factors and their influence on seed germination and radicle growth is incomplete. In the present study, we studied the influences of forest gaps and within-gap position on seed regeneration on the germination and radicle growth of an endangered species C.kawakamii in a subtropical natural forest in China. We selected three large gaps (LG, gap size above 200m2), three medium gaps (MG, gap size 50–100m2), three small gaps (SG, gap size 30–50m2), and non-gap (NG), and planted the seeds of C.kawakamii in five positions within each gap. The results showed that (1) the influence of forest gaps on seed germination rate was, from highest to lowest, medium gaps (51%), non-gap (47%), small gaps (40%) and large gaps (17%), and the seed germination rate was the highest in all positions in medium gaps, with the exception of the east position. (2) Radicle length in forest gaps was, from highest to lowest, medium gaps, small gaps, large gaps and non-gap, and it was the highest in the east, south, west and north positions of medium gaps. (3) Canopy openness (gap size) and air temperature were the main factors influencing seed germination and radicle growth of C.kawakamii. We concluded that medium-sized gaps were the most suitable for seed germination and radicle growth of C.kawakamii, and they promote the regeneration of this endangered species in the investigated natural forest.

Key words: Forest gap, Within-gap position, Seed germination, Radicle growth, Castanopsis kawakamii