黄土丘陵区典型草地演替中植物群落特征与土壤储水量关系

目的]阐明草地植被演替过程中植被生产力、植物多样性等生态学特征与土壤储水量的关系,为探明黄土高原地区植被恢复的生态环境效应提供一定的科学依据。方法]采用时空互代的方法对宁夏回族自治区固原市云雾山保护区自然恢复3,8,13,46,66,89a的样地进行取样,分析0—100cm土层土壤储水量的分布及其与地上地下植物生物量、物种多样性的关系。结果]随着草地演替的进行,植被群落盖度、生物量和物种多样性指数在恢复13a之前显著增加,之后渐趋稳定;土壤含水量逐渐增加,容重逐渐降低。植被群落演替对0—40cm土层土壤储水量没有显著影响,但演替后期对40cm以下土层水分有明显消耗。植被群落生物量及物种多样性指标与表层0—10cm水分呈显著正相关。结论]草地演替过程中,植被群落生物量和物种多样性的增加与表层土壤储水能力的提升密切相关,但深层根系生物量的增加对下层土壤储水的消耗也逐渐增大。

Relationship Between Plant Community Characteristics and Soil Water Storage Along Typical Grassland Succession in Loess Hilly Region

Objective] To identify the relationships between plant community characteristics and soil water storage following natural vegetation restoration after farmland abandonment, in order to provide a reference for vegetation restoration on the Loess Plateau. Methods] Samples were collected in plots with different natural restoration years (3, 8, 13, 46, 66 and 89 a), to quantify the changes in soil water (0-100 cm) and ecological characteristics such as plant biomass and plant diversity in the Yunwu Mountain in Guyuan City, the Ningxia Hui Autonomous Region. Results] With the succession of grassland, the plant community coverage, biomass and species diversity index increased dramatically at the early successional stages (before 13 a), and then gradually stabilized. Soil water content showed an increasing trend along the vegetation restoration years. The succession of vegetation communities had no significant effect on soil water storage in the 0-40 cm soil depths, but in the later stage of succession, the water content below 40 cm depths showed an obvious decreasing trend. Vegetation biomass and species diversity index were positively correlated with soil water content at 0-10 cm depths. Conclusion] Soil water in the topsoil played a positive role in the variations of plant biomass and species diversity induced by vegetation restoration. However, the increase of the root biomass in the deep soil increased the consumption of soil water storage, especially in the later successional stage.