风沙土中荒漠植物出苗和生长的比较研究

选择了5种荒漠植物红砂（Reaumuria soongorica）、泡泡刺（Nitraria sphaerocarpo）、花棒（Hedysarum scoparium）、白刺（Nitraria tangutorum）和沙拐枣（Calligonum mongolicum），设计了沙埋和幼苗生长两个控制实验，来研究它们的萌发出苗和生长定植能力。结果表明：5种植物的高出苗率、快出苗现象集中在0～3cm的沙埋深度；红砂、泡泡刺、花棒、白刺、沙拐枣的最佳沙埋深度分别为1cm、2cm、2．5cm、2cm和5cm。出苗率与沙埋深度方程的斜率显著相关于种子重量。种子重量与幼苗的绝对生长率、相对生长率正相关。相对生长率与单位叶速率和叶面积干重比显著正相关，但和叶面积比率和叶干重比率显著负相关。种子重量与根绝对伸长速率无关，但与根长比率和根长叶面积比率显著负相关。种子重量和单位叶速率是出苗和生长的较好的指示者，但仅仅种子重量和幼苗相对生长率并不能预示植物成活能力。

SEEDLING EMERGENCE AND GROWTH OF DESERT PLANTS IN SANDY SOIL

Two controlled experiments were conducted to evaluate the potential for desert species to emerge and establish and to assess whether easily measured plant traits can be used to predict their probable success. In the experiments 5 species of shrubs and semishrubs common in the desert in Northwest China were used. First, a glasshouse experiment was performed to test the effect of sand burial on seedling emergence. Second, a growth experiment was conducted to measure relative growth rate and other growth parameters of seedlings between 7 and 28 days of age. In the burial experiment, the phenomenon of high seedling emergence concentrated at 0 - 3 cm for the most species examined. The number of days from sowing seeds to seedling emergence was significantly affected by sand burial depth. Seed mass was strongly correlated with the slope of emergence versus burial depth. In the seedling growth experiments, seed mass is positively correlated with AGR and RGR, which may help to explain their prevalence in the desert. RGR was positively correlated with ULR and SLA, however, it was negatively correlated with LAR and LWR. Seed mass was not correlated with ARPR, however it was negatively correlated with RLR and RL/LA, indicating that small-seeded species tended to produce much longer and thinner roots in relation to total seedling mass than larger-seeded species. Seed mass and ULR should help predict their emergence and growth in the desert, however, seed mass and relative growth rate alone do not necessarily predict establishment success.