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通过设置对照(CK)、连续性水淹(CF)和间歇性水淹(PF)3个水分处理,模拟三峡库区库岸带土壤水分变化,研究乡土树种枫杨当年实生幼苗的生理生态适应机制.结果表明:不同水分处理均显著影响枫杨幼苗的光合作用、生物量积累和生长.与CK相比,CF和PF组枫杨幼苗除胞间CO2浓度升高,净光合速率(Pn)、气孔导度(gs)均显著降低.其变化趋势是枫杨幼苗的Pn、gs在试验初期下降,然后逐渐恢复或趋于稳定.随着处理时间的延长,CF和PF组枫杨幼苗的总生物量、根生物量、茎生物量、叶生物量、株高和地径均呈现上升趋势.CF和PF组的总生物量、根生物量、叶生物量和株高,以及PF组的茎生物量均显著低于CK,而CF组的茎生物量与CK无显著差异,其地径还高于CK.枫杨幼苗具有耐受水湿而不耐水淹-干旱交替的生理生态特征.
The changes of soil moisture in the three banks of the Three Gorges Reservoir were simulated by setting three CK treatments: CK, CF and PF. The physiological and ecological adaptation of native seedlings The results showed that: different water treatments significantly affected the photosynthesis, biomass accumulation and growth of Pinus tabulaeformis seedlings.Compared with CK, the intercellular CO2 concentration of P. miltiorrhiza seedlings increased and the net photosynthetic rate (Pn) , Stomatal conductance (gs) decreased significantly.The trend was that Pn and gs of Pterocarya stenoptera seedlings decreased at the beginning of the experiment and then recovered gradually or stabilized.The root length, Total biomass, root biomass, stem biomass, leaf biomass, plant height and root diameter all showed an upward trend.The total biomass, root biomass, leaf biomass and plant height of CF and PF groups, Stem biomass was significantly lower than that of CK, but the stalk biomass of CF group was not significantly different from that of CK, and its diameter was higher than that of CK.The P.caphyllum seedlings had the ecophysiological characteristics of alternate waterlogging and drought resistance.