民勤4种主要灌木植物δ13C季节变化及与气象因子的关系

对民勤4种主要灌木植物叶片/同化枝δ¹³C测定，研究不同荒漠灌木植物叶片/同化枝δ¹³C差异及其季节变化，并探讨植物叶片/同化枝δ¹³C与气象因子之间的关系。结果表明:1）4种灌木植物叶片/同化枝δ¹³C值不同月份之间存在极显著差异（P＜0.01），除梭梭外，其他3种植物δ¹³C值生长初期（5月）>生长中后期（6-10月）。4 种灌木植物叶片/同化枝δ¹³C值种间差异在5-10月都达到极显著水平（P＜0.01），沙拐枣＞梭梭＞柠条锦鸡儿＞白刺。2）4种主要灌木植物叶片/同化枝δ¹³C值受到物种、月份、物种×月份的影响，均达到极显著水平(P＜0.01)，但受物种的影响最大。3）4种灌木植物叶片/同化枝δ¹³C值与气象因子的关系因其物种而异；影响梭梭、沙拐枣、白刺、柠条锦鸡儿叶片/同化枝δ¹³C值的主要气象因子分别是平均气温、相对湿度、蒸发量。

Seasonal Variations of δ13C of Four Major Shrub Species and the Relationships between δ13C and Meteorological Factors in Minqin

In order to understand the differences in δ¹³C among the desert plants,seasonal variations of δ¹³C,and the relationships between δ¹³C meteorological factors,values of δ¹³C of the leaves/assimilating branches of four major shrub species s occurring in Minqin were measured.The results showed that 1) there were significant differences in δ¹³C of four major shrub species (P<0.01) among different months,except for Haloxylon ammodendron,the values of δ¹³C of other three plants were greater at the beginning (May) than at the middle and later growing periods (June-October).Interspecific differences of δ¹³C of four shrub species reached extremely significant level from May to October (P<0.01),and the values were in the order of Calligonum mongolicum＞H.ammodendron＞Caragana korshinskii＞Nitraria tangutorum.2) The influence of species,month and species×month on δ¹³C reached very significant level (P<0.01),in which the influence of species was the greatest.3) The relationship between δ¹³C and meteorological factors changed with plants species; the main meteorological factor that affected δ¹³C were average temperature,relative humidity,evaporation capacity,and evaporation capacity.