论文部分内容阅读
以呼伦贝尔羊草(Leymus chinensis)草甸天然割草场为研究对象,从植物功能群物种丰富度和重要值的变化来探讨施肥对群落物种多样性的影响机理。运用单、双因素方差分析和直线、曲线回归的方法对相关指标进行统计分析。结果表明:(1)施肥增加会使群落物种的丰富度逐渐降低,这一过程还受到施肥年限的影响。其中,豆科和莎草科功能群物种丰富度对施肥浓度的变化较为敏感(P<0.05);毛茛科和莎草科受施肥年限的影响较大(P<0.05);莎草科和杂草类则受到施肥浓度和施肥年限交互作用的影响(P<0.05)。(2)除莎草科和杂类草功能群外,禾本科、豆科、毛茛科、菊科均受施肥浓度显著影响(P<0.05)。禾本科和菊科的功能群重要值随施肥浓度的增加而上升,而豆科、毛茛科、杂草类则相应地下降。随着施肥年限的增加,禾本科和菊科功能群的重要值增大。(3)功能群重要值对年降雨量的响应较为敏感,干旱环境会使禾本科和豆科功能群的重要值降低,其他功能群重要值增加。各功能群丰富度和重要值对施肥的响应趋势均有不同,在确定合理的施肥量同时,还应充分考虑施肥年限和降水条件,从而实现草地资源的可持续性利用。
The natural mowing practices of Leymus chinensis meadow were used to investigate the effects of fertilization on community species diversity based on the changes of plant species richness and important values. Using single and two-way ANOVA and linear regression and regression analysis, the related indicators were statistically analyzed. The results showed that: (1) The increase of fertilization will gradually reduce the richness of community species, and this process is also affected by fertilization years. Among them, the species richness of functional families of Leguminaceae and Cyperaceae were more sensitive to the changes of fertilizer concentration (P <0.05); Ranunculaceae and Cyperaceae were more affected by the years of fertilization (P <0.05); Cyperaceae and miscellaneous Grasses were affected by the interaction between fertilizer concentration and fertilization years (P <0.05). (2) Gramineous, leguminous, Ranunculaceae and Asteraceae were all significantly affected by the fertilization concentration (P <0.05), except for the sedge and miscellaneous grass functional groups. The important functional groups of Poaceae and Asteraceae increased with the increase of fertilizer concentration, while the families of Leguminosae, Ranunculaceae and Weeds decreased correspondingly. With the increase of fertilization years, the important value of gramineous and Compositae functional groups increased. (3) The important values of functional groups are more sensitive to annual rainfall, the arid environment will decrease the important value of gramineous and legume functional groups, and increase the important values of other functional groups. The richness and important value of each functional group have different responses to fertilization. In determining the reasonable fertilization amount, fertilization years and precipitation conditions should also be taken into full consideration so as to realize the sustainable utilization of grassland resources.