高寒草甸退化对甘肃马先蒿生长状况与花期资源分配的影响

甘肃马先蒿（Pedicularis kansuensis）作为高寒草甸退化进程中的一种入侵毒杂草,其生长状况和繁殖特征为草地退化状况的重要指标,也是衡量高寒草甸演替进程的重要指示植物。通过比较重度退化和未退化高寒草甸的群落特征,甘肃马先蒿的生长状况与花期资源分配,结果表明：退化的高寒草甸土壤-植被系统变化明显,高寒草甸退化显著影响了甘肃马先蒿的生长状况和资源分配特征。在重度退化的黑土滩样地中,甘肃马先蒿个体形态特征如株高、根长、分叉数、叶片数、花数、总生物量都显著高于未退化高寒矮嵩草草甸样地;重度退化草甸中甘肃马先蒿花期各器官的资源投资状况,如根系投资、茎叶投资、繁殖投资分别为7.46%、48.76%、43.78%,未退化样地中甘肃马先蒿的根系投资、茎叶投资、繁殖投资分别为10.12%、54.34%、35.54%。在重度退化高寒草甸中甘肃马先蒿占据较大的生态位,长势良好,且将资源更多地用于繁殖投入。而未退化草甸中甘肃马先蒿优势度不大,更多的是将资源分配到根系和茎叶等营养器官,以期获得较多的水分、无机盐、光照等资源,增强个体竞争力。甘肃马先蒿在不同生境下资源分配的显著差异实质反映了草地退化的影响,亦是植物对外部环境改变的一种适应机制,同时也是植物可塑性的重要表现形式。

The effect of Alpine meadow degradation on Pedicularis kansuensis's growth and resource allocation in blooming date

Pedicularis kansuensis is an invasion weed in the process of alpine meadow degradation,which growth and reproductive characters are an important index about grassland degradation.It is also the instruction plant to measure alpine meadow succession.In this study,we compared the community characteristics of heavily degraded alpine meadow with non-degraded one,analyzed P.kansuensis＇s growth and resource allocation in blooming date.All this showed that soil-vegetation system had obvious changed in degraded alpine meadow,alpine meadow degradation significantly affects the growth and resource allocation of it.P.kansuensis in the ＂Black Soil＂ type degraded grassland,about individual form such as plant height,root length,branch number,leaf number,flower number,total biomass are significantly higher than those in non-degraded alpine meadow plot.The biomass investment ratio of P.kansuensis＇s root,stem and reproductive are 7.46%,48.76%,43.78% in heavily degraded alpine meadow during blooming,and these indicators of the non-degraded grassland are 10.12%,54.34%,35.54%.P.kansuensis in degraded alpine meadow are growing well,occupy a larger niche in degraded alpine meadow,and will invest more resources for reproduction.But in non-degraded meadow,the dominance of P.kansuensis is low,and more resources are allocated to root and stem and other vegetative organs in order to obtain higher prices of water,mineral nutrition,light and other resources.They can enhance individual competitiveness after the trade-off of resource allocation.The significant difference resource allocation of P.kansuensis in the two types of habitats is really reflects the impact of grassland degradation.It is not only the adaptation mechanism for plants to adapt environment change,but also an important form of plant plasticity.