Study On Eco-Physiological Responding Of Scirpus Mariqueter On Coupling Of Salinity And Flooding Time

The coastal wetland vegetation plays an important role in providing habitat for wetland waterbirds,maintaining biodiversity,reducing wave,reinforcing bank and promoting sediment settlement,and is the key to the restoration and reconstruction of degraded ecosystem.Scirpus mariqueter is endemic to China,In recent years,the increasing reclaiming land from the sea and the invasive species intercalated Spartina alterniflora Loisel rapidly in the coastal wetland of changjiang estuary,which led to the rapid decrease of the area of Scirpus mariqueter.The restoration and protection of the rice-grass population were extremely urgent.In this study,by analyzing the response characteristics of ribes at each growth stage under the interaction of different flooding duration and salinity,the specific wetland environment suitable for ribes at each growth stage was explored.Based on the analysis of plant physiology and ecology,the characteristics of ribes at the same growing stage to different water and salt were studied.It is expected to provide theoretical basis for the expansion of grossularis grossularis in the Yangtze river delta and even other regions,and provide important reference for the expansion of wetland vegetation at different growth stages,so as to provide scientific and technological support for improving the coastal ecosystem in the future.The research results are as follows:(1)For seeds and bulbs,germination of the seeds and bulbs was significantly inhibited at a salinity of 15.In this study,germination rate and index of seeds and bulbs generally were 8h/d,10h/d and 12h/d higher than 14h/d.It was proved that the increase of salinity inhibited the germination of seeds,which adapted to the environment with low salinity and short duration of water submergence.The increase of salinity inhibited the germination of bulbs which adapted to the low salinity and longer flooded condition.(2)Plant height and branch number of seedling were analyzed: with the increase of salinity,the branch number of seedlings increased firstly and then decreased.It reaches its maximum salinity at 10.At 10h/d and 12h/d,the seedlings had more points number at 8h/d and 14h/d than that at 8h/d and 14h/d,It gets to thr highest when the salinity was 10 at 12h/d was the highest,reaching 140%.High salinity and long flooding time inhibited the growth of seedlings.Analysis of chlorophyll,SOD content,DMA content and chlorophyll fluorescence parameters showed that the seedlings were not suitable to grow at high salinity and long flooding time,but grew well at medium salinity and short/medium duration of water submergence.(3)Analysis of plant height and branch number of plants shows: adult plants can grow normally at a salinity of 0-15.At a salinity of 0-10,plants got better growth and higher height,and more branch number.When the salinity is 5,the number of plants is the highest at 10h/d.The salinity was 5,8 h/d and 14h/d is the second.The number of plants with salinity of 15 was significantly less than that of other treatment groups which plant height was inhibited.In the range of salinity,similar to the seedlings,with the increasement of the flooding time,the number of adult plants increased firstly and then decreased.The results showed that high salinity and long flooding time inhibited the growth and propagation of r adult plants.The analysis of chlorophyll,SOD content,DMA content and chlorophyll fluorescence parameters showed that the adult plants were not suitable to grow at high salinity and long flooding time,but grew well at low salinity and medium flooding time.(4)From the above conclusions,it can be seen that responses of Scrirpus mariqueter at different growth stages to water-salt duration and salinity are different.Wetlands which have the low salinity and short flooding time(high elevation),seeds can be considered for the expansion of vegetation propagation.Wetlands which have the low salinity and medium flooding time,seedlings can be considered in the expansion of vegetation propagation.Wetlands which have the low salinity and long flooding time(low elevation),bulbs can be considered for the expansion of vegetation propagation.Wetlands which have the medium salinity and medium/short flooding time,adult plants can be considered in the expansion of vegetation propagation.