Effects of afforestation drainage on <i>Sphagnum</i> spore banks

Persistent spore banks may play a significant role in the maintenance of bryophyte populations. However, the impact of afforestation drainage on <i>Sphagnum</i> spore banks remains rarely known. In two drained peatlands of northeastern China, peat cores were obtained from near-pristine (high water table - <i>Sphagnum</i>), moderately-drained (low water table - <i>Sphagnum</i>) and severely-drained areas (low water table - shrub) for <i>Sphagnum</i> spore bank analysis. Quantitative properties of spore banks were compared among the areas with different drainage intensity. Our results indicate that drainage experienced by the two peatlands, generally reduced the spore accumulation rate in the peatlands, and the intensified aerobic decomposition following drainage also led to spore bank loss. After drainage, the germinability of the <i>Sphagnum</i> spores was significantly enhanced probably due to dormancy releasing. This may deplete <i>Sphagnum</i> spore bank in the long run. Our study suggests that rewetting practice in drained peatlands is needed to conserve <i>Sphagnum</i> spore banks and maintain the potential for restoring peatland vegetation after serious disturbance.