草地植物群落组成对鹅绒委陵菜无性系拓展能力及生物量配置的影响

以不同优势种的6个草地植物群落中鹅绒委陵菜(Potentilla anserina)为材料,通过测定基株、母株、无性系3个等级的构件数量性状及生物量结构,分析鹅绒委陵菜在不同群落中的空间拓展及生物量分配差异,探讨其应对草地群落组成差异的生长策略。结果表明,1)群落组成对母株根系有极显著影响(P0.01),6个群落中母株根长和根数均显著下降(P0.05),基株的子株数及子株根长也显著降低,但子株根数未受显著影响。2)群落组成对无性系匍匐茎茎长、茎直径及间隔子长有显著影响(P0.05),群落中鹅绒委陵菜通过降低茎直径、增大间隔子长,增加基株的空间拓展能力。3)群落组成对基株纵向、横向拓展参数有显著影响(P0.05),群落中鹅绒委陵菜显著增加基株拓展面积和拓展空间,降低拓展熵和拓展效益,以游击型生长方式,觅养或逃离环境资源。4)群落组成显著降低了基株、母株、无性系生物量累积(P0.05),群落中基株生物量优先向母株分配,母株生物量优先向叶分配,群落中无性系生物量分配比虽下降,但匍匐茎分配比呈增加趋势。5)群落组成对基株生物量配置有显著影响(P0.05),多数群落中显著增大了基株根茎比、叶茎比。综上所述,鹅绒委陵菜通过形态可塑性,在6个群落中均可存活和生长,其基株拓展能力和生物量配置除受群落盖度影响外,或许还受群落物种的生物学特点和无性系子株间竞争的影响,有待深入研究。

Effects of grassland plant communities on ramet expansion ability and biomass allocation of Potentilla anserina

In this study,Potentilla anserina plants were grown in six types of plant communities characterized by different dominant species.Quantitative traits and biomass structure at three levels (genet,mother ramet,and clone) were measured.The objective of this study was to analyse the differences in space expansion and biomass distribution of P.anserina grown in the different plant communities,and to determine its growth strategies in response to the different communities.The results showed: 1) Community composition had a highly significant effect on the roots of the mother ramet (P<0.01).Compared to the control,root length and root number of the mother ramet in all other communities significantly decreased (P<0.05),and the number of roots and root length of the daughter ramet also showed a decline.However,the number of roots of the daughter ramet was not significantly different in any community.2) Community composition had a significant effect on the length and diameter of clone stolons and spacer length (P<0.05).P.anserina grown in different communities exhibited greater expansion ability of the genet by reducing stem diameter and increasing spacer length.3) Community composition had a significant effect on both the horizontal and vertical expansion indices of the genet (P<0.05).P.anserina grown in different communities significantly increased expansion area and space,and decreased expansion entropy,thus increasing efficiency by using the guerrilla growth pattern to obtain needed environmental resources.4) Community composition significantly reduced biomass accumulation in the levels of ramets (P<0.05).Biomass of the genet preferentially allocated to the mother ramet,and biomass of the mother ramet was preferentially allocated to the leaves.Compared to the control,the biomass allocation ratio of clones declined,but the allocation ratio of stolons exhibited an increasing trend.5) Community composition had a significant impact on biomass structure of the genet (P<0.05).Compared to the control,the ratio of root to stem and leaf to stem of the genet grown in most communities significantly increased.In summary,P.anserina can survive and grow because it has characteristics of morphological plasticity.Expansion ability and biomass allocation of P.anserina genets perhaps change because of the biological characteristics of the community species and competition among daughter ramets of clones.Further research is needed.