准噶尔荒漠十字花科植物不开裂角果的土壤种子库研究

土壤种子库是荒漠生态系统的重要组成部分，在荒漠植物群落的形成与维持、种群更新以及荒漠植被的保育和恢复中具有重要作用。十字花科植物是准噶尔荒漠植物群落的优势类群及重要组成成分，在该区域荒漠植被的形成及其生态系统维持中具有重要的生态价值。本项目以准噶尔荒漠中十字花科植物角果的不开裂特性为切入点，选取6种果实不开裂的十字花科植物作为研究材料，通过对果皮解剖结构与种子休眠特性、土壤种子库分布格局、果皮及水分在土壤种子库形成中的作用等研究，分析影响种子休眠的因素及土壤种子库时空动态，明确其种子休眠类型及其土壤种子库类型，揭示其种子在土壤中的命运、果皮及土壤水分条件对种子库的贡献。有关研究结果不仅可为进一步探讨十字花科植物对准噶尔荒漠环境的适应策略及其在荒漠植物群落形成中的作用提供重要理论依据，还可为全面揭示荒漠植物土壤种子库的多样性、成因及其动态变化、探讨其在荒漠生态系统中的功能提供重要理论资料。

Soil seed bank is one of important components in desert ecosystem. Thus, knowledge about soil seed banks is of great importance to our government and to basic scientific research on form and maintainence of plant community, regeneration of population, and restoration and regeneration of the desert vegetation. The plant family Brassicaceae is considered to be one of the dominant groups and the importance members in plant community of the Junggar Desert. The species of this family assumed important responsibilities for vegetation form and desert ecosystem maintainence of this region. Some species of Brassicaceae produce indehiscent fruits with lignified pericarp, which could form persistent soil seed banks. Thus, six species of Brassicaceae with indehiscent fruits in the Junggar Desert will be choose as the study materials. The effects of inherent and environmental factors on seed dormancy, the dynamics of spatial and temporal change in soil seed banks, and the role of pericarp and soil water content in the form of soil seed banks will be quantified for these six species of Brassicaceae with indehiscent fruits. Through the above study, we will determine the main reasons for seed dormancy and the dynamic characteristics of soil seed banks. Thereby, the types of seed dormancy and the patterns of soil seed banks will be ascertained. More specifically, the fate of seeds in soil and the contribution of pericarp and soil water content to the seed bank of these species that produce indehiscent fruits will be detected. Moreover, we will explore the ecological adaptive strategies of a suite of Brassicaceae species with indehiscent fruits to the Junggar Desert and the effects of these speices on form of plant community in the cold desert. In addition, this information will be an important resource to people working to the function of desert ecosystem by develop a general theoretical basis for diversity, form and dynamics of soil seed banks in the desert.