梭梭林下土壤结皮发育对黄花补血草种群发育格局的影响

通过梭梭林下黄花补血草种群调查,研究土壤结皮发育过程中的无结皮沙地(前期NSC1、后期NSC2)、物理结皮沙地(前期PSC1、后期PSC2)和生物结皮沙地(前期BSC1、后期BSC2)的黄花补血草种群发育格局特征,以揭示梭梭林下土壤结皮发育对黄花补血草种群发育的影响以及植被恢复技术。结果表明:(1)梭梭林下土壤结皮的发育对黄花补血草的种群密度具有显著的促进作用,在BSC1样地达到最大,而对个体冠幅具有前期促进后期抑制的作用,在NSC2样地达到最大,故导致种群总盖度变化不稳定。(2)种群个体发育值呈先增加后减小的趋势,在NSC2样地达到最大;在NSC1-NSC2过程中,土壤结皮发育对种群个体发育具有促进作用,其值逐渐增大,而在NSC2-BSC2发育过程中,土壤结皮发育对种群个体发育的抑制作用逐渐增强,其值逐渐减小。(3)黄花补血草种群优势级层位于较低级层,随着土壤结皮的发育,呈先增加后减小的趋势,其峰值在BSC1样地,而种群级层越高,该级层的峰值则逐渐向土壤结皮发育前期移动,其峰值在NSC2或PSC1样地。研究认为,梭梭林下土壤结皮发育对黄花补血草种群密度具有促进作用,但对种群内植株个体发育具有前期促进后期抑制的作用,该结论对梭梭林下黄花补血草植被恢复具有积极的指导意义。

Effect of Soil Crust Development on Populations Development Pattern of Limonium aureum under Haloxylon ammodendron Plantations

Based on the investigation of Limonium aureum populations under Haloxylon ammodendron plantations, we studied the development pattern characteristics of the populations in non crusted sand (early stage NSC1, late stage NSC2), physical crusted sand (early stage PSC1, late stage PSC2) and biological crusted sand (early stage BSC1, late stage BSC2) during the soil crusts development in order to master the influence of soil crust development on population development and the planting technology of the vegetation under H. ammodendron plantations. The results showed that: (1) the soil crust development had a significant promoting effect on the population density. The valuereached the maximum in BSC1 plot, while it had a promoting effect on the individual crown width in the early stage and a inhibiting effect in the late stage. It reached the maximum in NSC2 plot, thus leading to the instable change of the total population coverage. (2) The development value of population individual increased firstly and then decreased, and reached the maximum in NSC2 plot. In the development process of NSC1 NSC2 promoted the population individual development and the value gradually increased, while in the development process, NSC2 BSC2 can inhibited the population individual development and the value gradually decreased. (3) The dominant layer of the population is located in the lower layer, with the soil crust development. The value increased firstly and then decreased. The peak value is in BSC1 plot, while the higher the population layer is, the peak value gradually moved to the earlier stage, and the peak value is in NSC2 or PSC1 plot. The above analysis showed that the soil crust development promoted the population density, but it promoted the population individual development in the early stage and inhibited in the later stage. The conclusion had positive guiding significance for the establishment of the L.aureum vegetations under H.ammodendron plantations.