The Interaction Between Individuals And Functional Traits Of Phragmites Australis Under Different Habitats

The Yellow River Delta has a special geographical location, it is located in an interface with a wide variety of ecological factors. Under the effect of rivers, ocean and land, a unique ecosystem was created. Plant functional trait is the factor that can affect ecosystem processes, and it can be alone or in combination to reflect the response of ecosystem to environmental changes. It is a new perspective of ecologists to re-examine the complex ecological processes. Using plant functional traits to reflect the adaptation of different plants to different habitats is the hot spot in ecological research.In this paper, the coastal meadow in the Yellow River Delta was chosen as the object of study. Two Phragmites australis Communities in different conditions were selected for investigation, sampling and analysis. Using adjacent body removal experiments with measuring plant functional traits can reflect changes in the interaction between plants. In this paper, the adaptation strategies of reed individuals and communities in different environmental conditions were analyzed. The relationship between the individual interaction intensity and the environmental conditions was also analyzed to provide the theoretical basis for the construction of plant communities in the Yellow River Delta, and to put forward feasible suggestions for the protection of vegetation resources in the area.In April to August 2014, two sites in different locations were selected as the study area and ten 1m × 1m quadrats were set up at each site. The relative chlorophyll content, leaf number, nodule number, internode height, basal diameter and aboveground biomass of Phragmites australis were measured at the same time. And after the end of the community survey a total of 20 samples in the two regions were collected and measured leaf area, leaf thickness, leaf nitrogen and phosphorus content, soil water content, conductivity, pH value, nitrogen content and calculate the species diversity index. The results showed that there were significant differences in soil salt content between two plots and high soil salt content reduced the species diversity. In this study, aboveground biomass, plant height and the number of tiller in high salt environment reduced with the increase of salinity. In the soil plot of low salinity, Phragmites australis got weak inhibition effect, rapid growth rate, intense intraspecific and interspecific competition. In the face of fierce competition, In order to gain the advantage of competition, the reed individual will put most of the energy into the growth, mainly in the increase of plant height, the increase of leaf, the increase of chlorophyll content and the increase of leaf number. In general, the higher salinity conditions had some effect on the leaf traits of Phragmites australis communities, but it promoted the biomass and base diameter of the reed, which indicated that the reed was a kind of salt-tolerant species, will have different adaptations to different environments.Within each study area, the author in April 2014 randomly selected 12 plots and fixed mark with a bamboo pole. Quadrat size was about 3 × 3 m2 and the author selected a medium sized health reeds in the center of each plot as a blank control, recorded as G1 plant. Within the scope of lm, the author selected 3 similar healthy reeds which got the similar environment and the same size as G1 and respectively carried out adjacent body removal experiments with a radius of 5cm,15cm and 25cm. These plants were recorded as G2, G3 and G4 plant. The author every 15 days carried out adjacent body removal experiments to ensure the experimental result. After one growth season in the experiment, in late August the light intensity, air temperature and humidity around each experimental plant were measured and recorded. Plants and soil samples were taken back to the laboratory for measurement and analysis of relevant indicators, such as leaf number, leaf number, plant height, basal diameter, leaf thickness, leaf relative chlorophyll content, leaf nitrogen and phosphorus content, aboveground biomass and other traits. By measuring and comparing the plant functional traits, the interaction between plants were analyzed. At the same time, by setting different removing scopes, the author compared functional traits of the target reeds and the controlled reeds to explore the occurrence area and intensity of individual interactions in different growing environments. The results showed that the negative interaction is widespread in the Yellow River Delta. Its intensity and occurrence area vary due to differences in soil salt conditions. Negative interaction significantly affected the plant biomass, especially the plants in a radius of 15cm. The study also found that in the Yellow River Delta reed growth are significantly affected by coupling nutrients and soil salinity. At the same time, the effect of light on the growth of reeds is also obvious.In this paper, field experiments and field control experiments were conducted to study the adaptation strategies and individual interactions of reeds under different salt conditions in the Yellow River Delta by measuring plant functional traits. Which indicated that Phragmites australis had a good adaptability to different environmental conditions, and the difference of traits was determined by environmental factors and biological factors (adjacent individuals), which provided support for the study of community construction mechanism in the Yellow River Delta. The study of the removal of the body in different communities and different target species is the future research direction.