Chin J Plant Ecol ›› 2019, Vol. 43 ›› Issue (6): 512-520.DOI: 10.17521/cjpe.2019.0082

• Research Articles • Previous Articles     Next Articles

Characteristic environmental factors in peatlands facilitate the formation of persistent Sphagnum spore banks

FENG Lu1,3,*(),BU Zhao-Jun2,3,WU Yu-Huan4,LIU Sha-Sha2,3,LIU Chao2,3   

  1. 1 Shandong Key Laboratory of Eco-Environmental Science for the Yellow River Delta, Binzhou University, Binzhou, Shandong 256603, China
    2 Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountain, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun 130024, China
    3 State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Institute for Peat and Mire Research, Northeast Normal University, Changchun 130024, China
    4 School of Life and Environment Science, Hangzhou Normal University, Hangzhou 310036, China
  • Received:2019-04-15 Revised:2019-06-03 Online:2019-06-20 Published:2019-09-30
  • Contact: FENG Lu
  • Supported by:
    Supported by the National Natural Science Foundation of China(41471043);Supported by the National Natural Science Foundation of China(41871046);Supported by the National Natural Science Foundation of China(41371103);Jilin Provincial Science and Technology Development Project(20190101025JH);the National Natural Science Foundation of Shandong Province(ZR2019PD008)

Abstract:

Aims To test the effects of environmental factors in peatlands on the persistence of Sphagnum spore germinability. The results may help to understand the mechanisms behind the formation of Sphagnum spore banks in peatlands. They can also provide valuable insights for restoration of degraded peatlands. Methods We determined the initial germination percentage in spores of two Sphagnum species (hummock- forming Sphagnum capillifolium and hollow-forming S. flexuosum) and then stored them for 60 days, either dry, in ultrapure water, peatland surface water or Sphagnum water leachate. We varied oxygen concentration by injecting air at three concentrations during the storage experiment. After retrieval from experimental storage, spore germinability was assessed. Important findings Spore germinability was lower after air-injection than under oxygen-deficiency. Spore germinability was higher after storage in the peatland surface and Sphagnum leachate water, having high concentrations of allelochemicals, than in ultrapure water, under oxygen-deficiency. Path analysis showed that dissolved oxygen is the main factor negatively affecting Sphagnum spore persistence in peatlands. Nitrogen (TN) and phosphorus (TP) also affect spore persistence negatively. These results indicate that once dispersed onto Sphagnum substrates or waterlogged hollows, Sphagnum spores can remain viable longer than when exposed to dry conditions or in water without allelochemicals. Extreme longevity of Sphagnum spores and other plant propagules may be attributed to the oxygen-deficient, nutrient-poor and allelopathic substrates in peatlands.

Key words: Sphagnum, spore persistence, peatland, dissolved oxygen, allelochemicals