关键词: 多年生植物, 幼苗出土, 土壤水分, 流动沙丘, 过渡带

Abstract:

The role of sexual reproduction of perennials always is underestimated in restoration of vegetation in active dune fields. The objective of this study was to clarify that sexual reproduction of Phragmites communis would play an important role in revegetation of active dunes. Seedling emergence and establishment of P. communis were examined in two transition zones between active dunes and interdune lowlands. The soil seed bank of P. communis and the dynamics of soil moisture were also monitored. When most seedlings emerged, there was a significantly positive correlation between soil moisture and seedling emergence (P<0.05). Seedling establishment was significantly and positively correlated with seedling emergence (P<0.05), and 54.1% of the emergent seedlings were established by the end of the growing season. These results indicated that: (a) seeds dispersed before the rainy season; (b) seeds germinated as soon as they contacted a moist surface and germination and seedling emergence relied on soil moisture. In natural conditions, restoration of active dune fields generally commences with revegetation of transition zones, where sexual reproduction of perennials initiates a new succession procedure, and hence plays a major role in restoration of active dune fields. Furthermore, aeolian erosion in transition zones, leading to good soil moisture, facilitates germination, seedling emergence and establishment of perennials.

Key words: perennial, seedling emergence, soil moisture, active dune, transition zone