Study On The Bryophyte Spore Viability In A Peatland Of Changbai Mountains Based On Larch Dating

Sphagnum, in general, is the dominant plant species in bryophytes ground layer in boreal peatlands, and it also is the main peat-forming plant in peatlands. Sphagnum spores have an important reproductive ecological significance, but they have been neglected by scientists for a long time. Under the background global change, studying on the Sphagnum spore viability and spore bank in peatlands can contribute to the bryophytes reproductive ecology, and also can provide a new thoughtfulness for the ecological restoration of the degenerated peatlands.In this study, Larch dating method was used with Larix olgensis as material to determine the time scale of surface layer peat profile in Hani Peatland of Changbai Mountains. I extracted Sphagnum capillifolium spores in peat profile by sifting method and cultured them in a artificial growth chamber to try to answer whether the Sphagnum spore have the ability to forming a persistent spore bank. The main results and conclusions in this study are as follows:(1) The Larix olgensis population growing in the Sphagnum hummocks is more suitable for peat layer dating than the population growing in lawns or hollows. By dating with Larix olgensis growing in hummocks, I can determine the time scale of the peat'surface layer.(2) In peatlands, the spore dispersed by the Sphagnum can germinate into protonema, and produce new shoots. In this experiment, most of the spores didn't grow after they developed into green protonema stage. Only a few developed into leaf protonema stage, and no bud stage was found. The most possible reason is that they need different nutrient conditions in different stages.(3) In this study, the germination speed of Sphagnum spores in the peat profile was slow, and it generally took 20-30 days for them to germinate. The speed of germination in the surface layers was quicker than that in the bottom layers. The spores in the first two surface layers didn't germinate probably due to desiccation,(4) In the peatland, with the increase of the depth, the number of spores decreased, and so did the vitality.(5) The results of this study clearly showed that Sphagnum has the ability to form a lasting spore bank. In this study, life-span of most Sphagnum capillifolium spores exceeding 5 years, which showed that Sphagnum can form a persistent spore bank.(6) In this experiment, the maximum viability of Sphagnum capillifolium spore was 396.4 years. The prediction on the viability of Sphagnum capillifoium spores indicates that the half-life of spore bank is 6.9 years under the suitable environmental condition.(7) The study showed that Sphagnum spore has the important significance of reproduction ecology. In peat layers, Sphagnum spores has potential to germinate and regenerate. They may play an important role in maintaining population persistence of Sphagnum when great disturbance caused by natural or human being happens.