Effect Of Reclamation History On Plant Diversity In Taizhou Bay

Taizhou bay reclamation has a long history and experience many reclamation,formation of the gradient on the time dimension,with the method of space instead of time,studying the relationship between the plant diversity changes and reclamation area soil environmental changes.Through to investigate plant species diversity,herbaceous plant communities,sesbania population survey and soil environmental factors,research the soil properties change,and the influenceof taizhou bay reclamation history to plant species diversity,plant community.This article selects obvious historical reclamation line 9 sample region,in the summer of 2015?2016,the study of natural vegetation in the area of soil,vegetation sampling investigation.Preliminary research on the soil pH value,conductivity,total nitrogen,total phosphorus,total carbon content and the relationship between the historical reclamation;By herbs taizhou bay mainly studied different history of herbaceous plant community composition and diversity of reclamation and the relationship between different history and sesbania reclamation population structure and its intrinsic mechanism of ecology,in order to investigate reclamation district natural vegetation diversity.The main results were as follows:1,the history of reclamation and soil physical and chemical properties(such as pH,conductivity,total nitrogen,total phosphorus,total carbon content,etc.).As the growth of the history of reclamation,declining soil salinity(conductivity),to the five area(history of reclamation in 80),the basic remain stable,soil salinity fluctuation in a small range.With fixed number of year of the history of reclamation in 80 as the boundary,soil total phosphorus content,soil total carbon content,soil total nitrogen content were stable.That human activities on soil improvement have apparent effect.2,taizhou bay census found local plant has 380 kinds of plants,belonging to 88 families,254 genera,including angiosperms are the main components,there are 201 species wild seed plants,179 kinds of cultivated plants.Genus areal types and analysis results show that the distribution is more in the world,and tropical and temperate and subtropical composition is 50%,which conform to the local flora characteristics,and explains the transitional characteristics of flora.3,reclamation district communities in gramineae,compositae,leguminosae plants in all plants,the largest proportion of the reclamation district plant community plays a main role in theprocess of natural restoration.Reclamation district plants is given priority to with a biennial herb,but has a tendency to gradually replaced by the perennial herbaceous plants.A biennial herbaceous plants plants and historical reclamation percentage was significantly negative relationship,enclose the longer history a lower proportion of biennial herb.Herbaceous plant community plant above ground biomass and the average plant height was significantly positively related to plant,plant density increases along with the history of reclamation.4,reclamation area found that invasion of 15 kinds of plants,including solidago canadensis,subulate asters,peng,a year drought lotus seed grass to occupy a greater advantage in the community.Is close to the beach,the plant,the lower the total abundance and the more the number of invasive plants,solidago canadensis in the history of less than 57 years of reclamation district reclamation are dominant.Green bristlegrass,sesbania,small fleabane,xerophilous lotus seed grass are distributed throughout the reclamation area,wide adaptability,the population development of inhibiting the growth of native plants.5,the tendency of the reclamation district plant species diversity index and evenness variation trend is consistent,has significant positive correlation between,and the plant community diversity has not significant correlation between change and historical reclamation.6,with sesbania population as the representatives of the reclamation of the history and study on the relationship between the plant species found that reclamation district green space area and relatively sesbania relative density and the important value has significant positive correlation,community within the soil conductivity was positively correlated with sesbania average height and important value,history and reclamation sesbania average height has significant negative correlation relationship.As a result of the combination of soil salinity and urbanization sesbania population structure change,the main reasons for both the role of a certain time and space differences,the main control effect on different stages.