Analysis On The Causes Of Sphaeroma Outbreak In Mangrove Of Dongzhai Harbor

Mangrove lies in the transition zone between land and sea,in which has high primary productivity providing rich food,ideal habitat and reproduction for the living creatures,and also has high biodiversity,its plays an important role in maintaining species diversity and coastal zone stability.Therefore,its has higher ecological services value.Hainan province has the largest number of mangrove plants and the largest protected area,among the other mangrove reserve of Hainan,Dongzhai Harbor mangrove reserve covers the largest area and has high value of ecological services,which is very important for sustaining social and economic development.Therefore,it is of great significance to study the protection of Dongzhai Harbor mangrove forest.However,in recent years,a large area of mangrove death had occurred in Hainan,and researchers have found that this phenomenon is caused by the degeneration of mangrove forests caused by the outbreak of mass Sphaeroma.For prevention and control Sphaeroma mangrove reserve in this paper,based on the study of Dongzhai Harbor Sphaeroma to harm,and focuses on studying the differences and similarities of temperature,salinity,pH,DIN,DIP,COD,Suspended Solids,Chlorophyll a,Large benthic,Zooplankton in seawater between the damaged mangrove community in Hainan and the neighboring undamaged mangrove community of the same type were mainly studied.It has accumulated basic data for the prevention and treatment of Sphaeroma and the protection of mangrove ecosystem,which has certain theoretical reference value.Sampling points were set up in 4 places(A,B,C and D)of Dongzhai Harbor mangrove reserve,the field exploration to select the group specialised to harm serious mangrove communities as the damaged group(A2,B2,C2 and D2),and the same type of healthy mangrove community adjacent to each damaged sample points as the undamaged group(A],B1,C1,D1),A1 and A2 are the Bruguiera sexangula community,B1 and B2,C1 and C2,D1 and D2 are the Bruguiera gymnorrhiza community,with a total of 8 sampling points.Using GPS to navigate sampling points,samples were collected at sampling sites in March,June,September and December 2016,the surface water temperature and salinity of the sample point were measured in the field,and the pH of the water sample was measured in the laboratory,the dry weight of suspended substance,chlorophyll a and zooplankton in seawater,as well as the wet weight of large benthos,were measured respectively in the laboratory after the sample was brought back to the laboratory.Each measurement index was repeated three times at a time,and the average value was taken.Research results show that:(1)Investigate the Temperature,Salinity,pH,DIN,DIP,COD and Suspended Solids of the abiotic environmental factors in the seawater of the damaged and undamaged sample points,and T test the seawater temperature,Salinity,pH,DIN,DIP,COD and Suspended Solids of the damaged and undamaged sample points of the research stations A,B,C and D in the four quarters respectively.P>0.05 of temperature,salinity,pH,DIN,DIP and COD showed no significant differences.The results showed that the seawater Temperature,Salinity and pH of the damaged(experimental group)and the undamaged(control group)were not significantly different,because the sampling points of the damaged and undamaged were not far from each other.The suspended substance P<0.05,the difference between the damaged and undamaged samples was significant.(2)Survey to investigate the damaged and undamaged sample biological environmental factors in the seawater chlorophyll a,zooplankton,wetland macrobenthos,damaged group are higher than the intact samples,about four quarters research station A,B,C,D group damaged and undamaged sample of chlorophyll a,zooplankton,wetland macrobenthos in the sea water,were tested by T test,P<0.05,differences significant difference results indicate that the damaged(experimental group)and the intact(control group)of chlorophyll a and zooplankton in the sea water,wetland large benthic are comparatively large difference.(3)B,C,D are the three locations of mangrove forest,where are Bruguiera gymnorrhiza community,in the same place,The community of mangrove in the Bruguiera gymnorrhiza have been specialised to abuse,also has not been group specialised,can infer mangrove group specialised injury has nothing to do with the mangrove is a Bruguiera gymnorrhiza community;A is the same place,the Bruguiera sexangula community is also are specialised to abuse,also has not been specialised to abuse,also can infer mangrove group specialised injury has nothing to do with whether mangrove Bruguiera sexangula mangrove communities;Therefore,the infestation of mangroves by Sphaeroma has nothing to do with the species of mangrove plants being Bruguiera gymnorrhiza or Bruguiera sexangula.(4)According to the annual survey data by means of factor analysis and Principal Component Analysis(PCA)for mangrove wetland ecological factors,Salinity,pH,DIN and DIP,COD,Suspended Solids,Chlorophyll a Zooplankton,Large Benthos,a total of nine factor analysis,principal component score is worth according to size,the results showed that the mass of specialised A2 area certain radioactive-polluted area the main cause of mangrove damaged is suspended solids;Large Benthos were the main factors in B2 area of mangrove damaged by Sphaeroma.Large Benthos were the main factors in C2 area of mangrove damaged by Sphaeroma.DIN was the main factor in D2 area of mangrove damaged by Sphaeroma.Therefore,the ecological factors of mangrove damage caused by Sphaeroma are the causes of various aspects and cannot be generalized.The ecological factors of mangrove damage caused by Sphaeroma are different in different places and time.For the investigation of sea area,it is confirmed that the ecological factors of mangrove damage caused by Sphaeroma in Dongzhai Harbor mangrove wetland cluster are mainly Large Benthos,Suspended Solids and DIN changes.