甘肃马先蒿生物量分配及其寄主物候对覆雪的响应

The response of biomass allocation and hosts phenology of Pedicularis kansuensis to snow cover

在研究区冬季平均降雪深±21.54%的覆雪处理水平下,对新疆巴音布鲁克高寒草原甘肃马先蒿(Pedicularis kansuensis)及其寄主的物候以及甘肃马先蒿的生物量分配进行研究,并揭示其和寄主的竞争及繁殖策略。结果表明,1)覆雪处理对甘肃马先蒿及其寄主生长季变化的影响无一致规律;2)覆雪处理使得甘肃马先蒿及其大部分寄主的花期物候提前,秋季物候延后,甘肃马先蒿物候开始时间从结实期开始逐渐提前,到种子散播期几乎完全领先寄主;3)覆雪处理后甘肃马先蒿的繁殖分配和根冠比显著降低(P<0.05);4)增雪处理后甘肃马先蒿的株高、冠幅、花柱高度以及侧根尺寸与自然降雪间均有显著差异(P<0.05),而减雪处理后除侧根外各部分差异不大。总体上,甘肃马先蒿与寄主的物候在覆雪处理后存在一定程度分化;其生物量分配及个体形态对增雪处理的响应更显著,覆雪处理后甘肃马先蒿降低繁殖投资从而增加营养投资。

In the present study,the response of biomass allocation of Pedicularis kansuensis and the phenology of P.kansuensis and its hosts to the snow cover changes with the level±21.54 %for annual average snowfall depth in winter of alpine grassland in Bayinbuluke of Xinjiang were study to analyze their competition and reproductive strategies.Our results showed that the snow cover made the growing season of P.kansuensis and hosts having no consistent change law compared to CK.The flowering phenology of P.kansuensis and most typical hosts advanced under snow cover,which made their autumn phenology postponed.The beginning time of phenology period of P.kansuensis keep ahead of hosts from productive phase to seed dispersal.The reproductive allocation and root to shoot ratio of P.kansuensis significantly decreased（P0.05）.The plant height,canopy,column height and the size of lateral root of P.kansuensis under snow cover addition had significant difference with CK（P0.05）,however,except with lateral root,plants had no significant difference after snow cover removed.Totally,the same phenology stages of P.kansuensis and its hosts had certain differentiation after snow cover change,while the biomass allocation and individual morphology were more sensitive to snow cover which reduced reproductive investment and enhanced nutrient investment under snow cover change.