长白山哈泥泥炭地丘间生境泥炭藓孢子的寿命

长寿有性繁殖体对于植物种群的长存具有重要意义,迄今,泥炭地苔藓植物孢子长寿性研究还很少。在长白山哈泥泥炭地钻取丘间表层泥炭样品,测定泥炭腐殖化度和烧失量,逐层提取和培养泥炭藓孢子,研究埋藏时间对孢子萌发的影响。结果表明,丘间泥炭藓孢子埋藏环境中,随着埋深的增加即埋藏年限的增加,泥炭腐殖化度和烧失量总体上分别呈现增加和递减的趋势,而地层泥炭藓孢子萌发率呈现直线递减的规律,但在埋藏近150余年后孢子萌发率仍可达40%。研究进一步证明泥炭藓具有长期持久孢子库,根据推算,泥炭地丘间埋藏环境中,泥炭藓孢子最大寿命可超过400a。

Longevity of sphagnum spores in the hollow habitats of Hani Peatland, Changbai Mountains

Longevous sexual propagules are of great importance for persistence of plant populations. In natural environment, Sphagnum spores have potential to germinate and regenerate. They may play an important role in maintaining population persistence of Sphagnum when great natural or man-made disturbance happens. However, quite few studies about spore longevity of peatland bryophytes have been reported so far. In Hani Peatland of the Changbai Mountains, we took peat cores in hollow habitats, determined peat humification degree and ignition loss and extracted the spores of Sphagnum from the peat cores layer by layer. We cultivated the spores, to investigate the effect of burial time on spore germination rate. In the burial environment of hollows for Sphagnum spores, with the increase of depth namely burial time, peat humification degree and ignition loss generally showed a trend of increase and decrease, respectively. The germination rate of Sphagnum spores decreases linearly, but it can still reach 40% after the spores were buried for more than 150 years. Our study further proves that there are long-term persistent spore banks in peatlands. If we define the maximum longevity of spores as the time that when germination rate of spores is 1% in the burial environment, the maximum longevity for Sphagnum spores can be older than 400 years. The longevity mechanism of Sphagnum spores may be related with the special burial environment of peatlands. It is necessary to carry out experiments to test effects of environment factors such as hydrology, water chemistry and even microbiological diversity on spore viability in the future.