Ordas plateau is a classical semi-dry sandland in China. The dry ecosystem responds sensitively to water-heat pattern of global change there. The distribution pattern and productivity of terrestrial ecosystem are greatly affected by global warming. Ecological adaptation strategies of seedlings of Caragana intermedia Kuang et H. C. Fu, Hedysarum mongolicum Turcz. and Artemisia ordosica Kraschen.，three dominant shrubs in Ordas plateau, were investigated in terms of morphological plasticities, biomass effects and photosynthetic and physiological characters, to the global warming by artificially controlling two temperature levels. The results show that the effects of temperature enhancement on growth and photosynthetic and physiological characters were obviously different among these three plant species. Temperature enhancement significantly increased tree height, leaf number, leaf area, biomass, photosynthetic rate, transpiration rate and stomatal conductance of C. intermedia and H. mongolicum seedlings, indicating that elevated temperature significantly affected the growth of these seedlings positively. Elevated temperature had almost no significant effect on the growth of A. ordosica seedlings. Their leaf number, leaf size, leaf area, biomass, transpiration rate and stomatal conductance did not increase obviously, but tree height and photosynthetic rate obviously increased with increasing temperature. Interspecific growth was significantly different among C. intermedia, H. mongolicum and A. ordosica seedlings. Except leaf size, values of the other seven characters of C. intermedia seedlings were greater than those of H. mongolicum and A. ordosica seedlings.
肖春旺1,2 张新时1 赵景柱2 吴钢2
摘要：鄂尔多斯高原是中国半干旱沙区典型沙地, 这里的干旱生态系统对全球的水热分配格局具有灵敏的响应。随着未来全球变暖,将给这里的陆地生态系统分布格局和生产力带来巨大影响。选择鄂尔多斯高原优势灌木柠条(Caragana intermedia Kuang et H. C. Fu)、杨柴 (Hedysarum mongolicum Turcz.)和油蒿(Artemisia ordosica Kraschen.)幼苗为研究对象,人为控制2种温度水平来探讨它们的幼苗形态可塑性、生物量效应和光合生理特征对增温条件下的生态适应策略。研究结果表明,增温处理对3种植物种类生长和光合生理特征的影响是不同的。增温对柠条和杨柴幼苗株高、叶数、叶面积、生物量、净光合速率、蒸腾速率和气孔导度等特征有显著的增大作用。表明增温对柠条和杨柴幼苗生长具有显著正效应。增温对油蒿幼苗生长总体影响不显著,叶数、叶大小、叶面积、生物量、蒸腾速率和气孔导度随着温度增高没有显著增大, 但树高和净光合速率随着温度增高而显著增大。柠条、杨柴和油蒿幼苗之间的种间生长差异显著,除叶大小外,其余7个特征值均为柠条幼苗显著高于杨柴和油蒿幼苗。