梭梭林下土壤结皮发育对黄花补血草生物量及资源配置的影响

Effects of Soil Crust Development on Biomass and Resource Allocation of Limonium aureum under Haloxylon ammodendron Plantations

通过梭梭(Haloxylon ammodendron)林下土壤结皮发育过程中3个典型阶段(无结皮发育的沙地NSC、土壤物理结皮发育的沙地PSC、土壤生物结皮发育的沙地BSC)样地的黄花补血草(Limonium aureum)种群为研究对象,在个体和种群水平上研究了土壤结皮发育对黄花补血草生物量及资源配置的影响,旨在为其种群建植以及灌草结合的治沙模式提供理论依据。结果表明,(1)随着土壤结皮发育,黄花补血草在个体水平上各构件生物量逐渐减小,其中根系无显著差异,生殖枝差异显著,花在NSC与PSC、BSC之间差异极显著,而PSC与BSC之间无显著差异。在种群水平上各构件生物量逐渐增加,根系和生殖枝在NSC与PSC、BSC之间差异极显著,而PSC与BSC之间无显著差异,花无显著差异。(2)随着土壤结皮的发育,在个体和种群水平上根系和生殖枝资源配置逐渐增大,花的资源配置逐渐减小;在NSC与PSC、BSC之间,其差异极显著,而PSC与BSC之间差异显著,其中生殖枝占资源配置的50%左右,占据绝对优势。随着土壤结皮发育,黄花补血草生物量和资源配置在个体水平上有利于根系发育,而在种群水平上有利于花的发育,个体与种群在生殖对策和生存对策上相互补充,是黄花补血草适应干旱环境的主要机理之一。生殖枝既是营养组织,又是生殖组织,在土壤结皮发育过程中始终占据绝对优势,是一种高效的资源配置模式,根系和花之间存在权衡关系。

The effects of soil crust development on biomass and resource allocation of Limonium aureum in three typical stages of soil crust development(NSC refered as an sandy without soil crust,PSC as an sandy with soil physical crust and BSC as an sandy with soil biological crust)under Haloxylon ammodendron plantations were studied at individual and population levels,in order to provide a theoretical basis for its population establishment and desert control model combining shrubs and grasses.The results showed that:(1)With the development of soil crust,the biomass of L.aureum components decreased gradually at an individual level,where there was no significant difference in root system,extremely significant difference in reproductive branch,and extremely significant difference in flowering between NSC and PSC,BSC,but,there was no significant difference between PSC and BSC.At the population level,the biomass of each component gradually increased,the root system and reproductive branches were significantly different between NSC,PSC and BSC,but there was no significant difference between PSC and BSC,also,the flowers showed the same results with no significant difference in each treatment.(2)With the development of soil crust,the biomass allocation of roots and reproductive branches gradually increased both at the individual level and population level,while,the biomass allocation of flowers gradually decreased.There was extremely significant difference between NSC and PSC,BSC,while there was a significant difference between PSC and BSC,the biomass of the reproductive branches reached to about 50%of the total resource allocation with an absolute advantage.With the development of soil crust,the biomass and resource allocation of L.aureum were beneficial to root development at the individual level,but to flower development at the population level.It is one of the main mechanisms for L.aureum to adapt to the drought environment that both individual and population complement each other in reproductive and survival strategies.Reproductive branches were both vegetative and reproductive tissues,which occupied an absolute advantage in the process of the soil crust development.This was an efficient resource allocation model which existed a trade-off relationship between roots and flowers.