Effects Of Habitat Heterogeneity On The Growth Of Clonal Plant Triolium Repen

Spatial heterogeneity of resources(such as light,water,and soil nutrients)is ubiquitous in nature.The effect of habitat heterogeneity on the growth of clonal plants is one of the hotspots in plant ecology.Currently,the effects of habitat heterogeneity on the growth of clonal plants are diverse(i.e.,positive,neutral or negative effects).However,it is unclear whether the difference of experimental design or the difference of plants contributes to this diversity.Studying the response mechanism of clonal plants to habitat heterogeneity can provide theoretical reference for the management,protection and ecological restoration of damaged vegetation.Therefore,in this study,we first identified potential factors influencing the response of clonal plants to habitat heterogeneity through meta-analysis,and then explored how these factors change the effect of habitat heterogeneity on the growth of clonal plant Trifolium repens.1.In a meta-analysis of 732 data extracted from 58 selected articles,we investigated the effects of different experimental designs(i.e.,different patch size,different competition)and plant differences(i.e.,invasive and native species)on the response of clonal plants to habitat heterogeneity.The results showed that:(1)Regardless of the differences of experimental design and plants,there were no significant differences of total biomass,aboveground biomass,belowground biomass,root/shoot ratio,number of ramets,and length of clone organs between in homogeneous and heterogeneous habitats.However,the total heterogeneity was high,and it was necessary to further explore the sources of data heterogeneity;(2)Through subgroup or regression analysis,it was found that there were significant differences in aboveground biomass and belowground biomass among groups under different competition types(i.e.,no competition,intra-,inter-,both intra-and inter-specific competition);(3)There were no significant differences in growth indices between homogeneous and heterogeneous habitats under different patch sizes or invasive and native species classifications.The results indicated that competition affected the response of clonal plants to habitat heterogeneity.2.In order to study the influence of patch size of heterogeneous habitats on the growth of T.repens in heterogeneous habitats,five patch size treatments were set up.The results showed that:(1)Patch size of heterogeneous habitat had no significant effect on the total biomass,aboveground biomass,belowground biomass,root/shoot ratio,stolon number,and stolon length of T.repens;(2)T.repens had foraging response in different patch sizes,i.e.,the belowground biomass in nutrient-rich patch was significantly higher than that in nutrient-poor patch.The results indicated that the foraging response of plant roots might cause the biomass of T.repens to have no significant difference under different patch sizes3.In order to investigate the effects of intraspecific competition and habitat heterogeneity on the growth of T.repens,two factors were set up: competition treatment(i.e.,no competition and intra-specific competition)and soil substrate treatment(i.e.,homogeneous and heterogeneous).The results showed that:(1)Two-way non-parametric ANOVA showed that habitat heterogeneity had no significant effect on total biomass,aboveground biomass,belowground biomass,root/shoot ratio,stolon number,longest stolon length,longest root length,and root volume of T.repens,while the existence of intraspecific competition significantly reduced total biomass,aboveground biomass,belowground biomass,and stolon number of T.repens;(2)When there exists no competition,the belowground biomass in nutrient-rich patches was significantly higher than that in nutrient-poor patches.When there exists intraspecific competition,there was no significant difference in underground biomass between the two patches.The results indicated that competition could change the root foraging strategy of plants in heterogeneous habitats,which might lead to no significant difference in biomass of T.repens in homogeneous and heterogeneous habitats.In conclusion,there is no significant difference in the growth of clonal plant T.repens in homogeneous and heterogeneous habitats.Competition affects the response of clonal plants to habitat heterogeneity.