鄂尔多斯站高瑞如博士生气生和土壤种子库确保沙地生态系统一年生植物种群更新正式发表在Annals of Botany

作者：综合研究中心站   更新时间：2014-10-09

Aerial and soil seed banks enable populations of an annual species to cope with an unpredictable dune ecosystem

Abstract
BACKGROUND AND AIMS:
Simultaneous formation of aerial and soil seed banks by a species provides a mechanism for population maintenance in unpredictable environments. Eolian activity greatly affects growth and regeneration of plants in a sand dune system, but we know little about the difference in the contributions of these two seed banks to population dynamics in sand dunes.
METHODS:
Seed release, germination, seedling emergence and survival of a desert annual, Agriophyllum squarrosum (Chenopodiaceae), inhabiting the Ordos Sandland in China, were determined in order to explore the different functions of the aerial and soil seed banks.
KEY RESULTS:
The size of the aerial seed bank was higher than that of the soil seed bank throughout the growing season. Seed release was positively related to wind velocity. Compared with the soil seed bank, seed germination from the aerial seed bank was lower at low temperature (5/15 °C night/day) but higher in the light. Seedling emergence from the soil seed bank was earlier than that from the aerial seed bank. Early-emerged (15 April-15 May) seedlings died due to frost, but seedlings that emerged during the following months survived to reproduce successfully.
CONCLUSIONS:
The timing of seed release and different germination behaviour resulted in a temporal heterogeneity of seedling emergence and establishment between the two seed banks. The study suggests that a bet-hedging strategy for the two seed banks enables A. squarrosum populations to cope successfully with the unpredictable desert environment.