Study On The Characteristics Of Competition And Coexistence In Mixed Planting Of Three Plants And Their Adaptation To Waterlogging Stress

In Waterfront revetment,plant selection plays an important role in landscape construction.On the one hand,there is competition among different plant combinations,and the stability after mixed planting determines the sustainability of plant landscape.On the other hand,the waterfront revetment has the instability of water level.The evaluation of the adaptability of different species to water flooding stress in different water level habitats is the scientific basis for the sustainability of landscape construction.In this study,the selection of species was carried out in accordance with the wild landscape morphology under the combination of wildflowers meadow.Heliopsis helianthoides?Linum perenne?Echium vulgare were used as experimental materials to study the relationship between the competition and survival of wildflower artificial communities in the process of landscape construction under different mixed planting methods.And the water stress tolerance ability of the three plants was studied to determine the feasibility of their application in different water level conditions of the waterfront habitat.The main findings are as follows:(1)Competition and Coexistence of Linum perenne?Heliopsis helianthoides and Echium vulgare in MixtureWhen Heliopsis helianthoides,Linum perenne and Echium vulgare were used to construct the flower landscape,the competition and coexistence of different plant species was the theoretical basis for the sustainable construction of flower landscape morphology and quality.In this study,two sowing modes were set for outdoor broadcast(single sowing of Heliopsis helianthoides,ingle sowing of Linum perenne,single sowing of Echium vulgare,Linum perenne and Heliopsis helianthoides in mixture 1:1,Heliopsis helianthoides and Echium vulgarein mixture 1:1,Linum perenne,Heliopsis helianthoides and Echium vulgare in mixture 1:1:1).High growth rate,relative biomass(RY),relative density(RD),competitive rate(CR)and total relative yield(RYT)of the three plants under different sowing modes were analyzed.In this way,that competition and coexistence mechanism of the three plants were investigated in equal proportion,the results showed that the competitiveness of the three plants was as follows:Echium vulgare>Heliopsis helianthoides>Linum perenne.Among them,the mixed seeding with Linum perenne promoted the growth of Heliopsis helianthoides,and the mixed seeding with other plants had an inhibitory effect on the growth of Linum perenne,but had no significant effect on the growth of Echium vulgare.Under the condition of such as proportion of mixed seeding,T1,T2,T3,T4 are do not have the stability of mixed flowers plant community,is applied to three plants mixed seeding plant landscape should be appropriate to reduce the mixed proportion of blue ji,and improve the perennial root flax mixed seeding rate,so as to ensure the sustainability of the second year in a landscape and enhances the stability of plant community.(2)Evaluation on the adaptability of three plants to water floodingHeliopsis helianthoides and Echium vulgare under the water stress environment,can adjust the internal various physiological indicators of stress environment to make a positive response,have a certain ability of resistance to water,water for a short period of time for the vegetative growth promoting role of Echium vulgare,the three gradient under the condition of water stress can keep the external form of 18 days or more,so the Echium vulgare water resistant capability,in intermittent water waterfront environment,it can be configured in fluctuation period of lower part and above;However,the ability of Heliopsis helianthoides to withstand water flooding was limited.Under root submergence stress,it could only maintain normal external morphology for 15 days,12 days under semi-submergence stress,and 9 days under total submergence stress.Therefore,in the waterfront environment with intermittent submergence,the Heliopsis helianthoides should be configured at or above the fluctuation line.Linum perenne under water stress enironment,although the early can by adjusting the various physiological indicators of internal environment make active response to stress but later suffer more severe,so the water resistant ability is weak,under the Root-merged it can maintain normal external form 18 days,and 12 days under Half-merged stress,Submerged stress 9 days,so in intermittent flood of waterfront environment,Linum perenne can be used in fluctuation line out of water.At the same time,the elevation range of three species of plants should be designed reasonably according to the fluctuation range of water level in different waters environment.(3)Niche and combination of three species of plants which applied to the waterfront wildflower assemblageBased on the competition and coexistence ability of the three plants in the mixed-planting of equal proportion and the adaptability of the three plants to flood under different gradient treatment,considering the sustainability of the waterfront wildflower combination,the following recommended application proportion and application level scale are obtained:Combination 1:Heliopsis helianthoides(65-70)%+Echium vulgare(30?35)%;Combination2:Heliopsi helianthoides(35?40)%+Linum perenne(60?65)%;Combination 3:Echium vulgare(25?30)%+Linum perenne(70?75)%;Combination 4:Single Heliopsis helianthoides apply to segment B;Linum perenne apply to segment A;Echiunm vulgare apply to segment C(The depth of water>The plant height,and the intermittent waterlogging time?15d).