Effects Of Mowing Management On Soil Function Of Reed Wetland In Dong Ying

Mowing management of wetland plants is very important for ecosystem health.Previous studies have rarely assessed soil function of wetland plant mowing management.With the help of the long-term mowing scientific research and experimental platform of coastal wetlands in the Yellow River Delta,this study explored the effects of different mowing treatments(natural retention,mowing removal,mowing return)on the reed wetlands in autumn and next spring’s soil physio-chemical factors,enzyme activities,and microbial community structure and diversity after three years of mowing in winter.The results as follows:(1)In autumn,the soil electrical conductivity increased with the deepening of the soil layer,and the surface layer is significantly lower than the middle and lower layers;the contents of soil total nitrogen,total carbon,organic matter and nitrate nitrogen decreased with the deepening of the soil layer;Compared with the natural retention,the total nitrogen and organic matter content of the lower soil in the mowing removal treatment decreased by 29.32% and 27.11%,respectively,the total carbon content of the soil surface increased by 9.40% in the mowing return treatment,and the total nitrogen and organic matter content of the lower soil decreased by 28.30% and30.19%,respectively.In the spring of the following year,the soil electrical conductivity in the mowing removal treatment showed the opposite trend;the lower soil total nitrogen and surface nitrate nitrogen in the mowing removal treatment decreased by32.08% and 40.22%,respectively.(2)The activities of soil invertase,catalase,urease and alkaline phosphatase in the two sampling soils all decreased with the deepening of the soil layer,and the surface layer was significantly higher than the lower layer.In autumn sampling,the soil surface invertase activities were significantly increased under both the mowing removal and mowing return treatments,while the alkaline phosphatase activity was significantly decreased.The overall expression of soil alkaline phosphatase activity was natural retention> mowing removal > mowing return.The activity of soil invertase sampled in autumn had a very significant positive correlation with the other three enzyme activities,and the activities of urease and catalase had a very significant positive correlation.Sampling in the following spring,soil invertase activity was significantly positively correlated with urease and alkaline phosphatase activities.(3)In autumn sampling,compared with the natural retention surface soil,each alpha diversity index increased after mowing removal treatment,and decreased after mowing return treatment.Different soil layers and different mowing treatments could significantly change the soil bacterial community structure.Among them,mowing return treatments had the greatest impact on the bacterial community structure.The top three species with relative abundance of bacteria were Proteobacteria,Chloroflexi and Acidobacteriota.Mowing treatments of the two sampling had different effects on different bacterial communities.The mowing return treatments in autumn significantly decreased the relative abundance of Actinobacteriota,and the relative abundance of Actinobacteriota in spring significantly increased.It is related to the aerobic factors of Actinobacteriota.(4)The observed species index of the two soil samples was significantly affected by soil p H.In autumn sampling,soil total nitrogen,total carbon,organic matter and nitrate nitrogen contents were significantly negatively correlated with the relative abundance of Proteobacteria,and positively correlated with the relative abundance of Chloroflexi.Sampling in spring,the relative abundance of Proteobacteria was significantly positively correlated with electrical conductivity,and the relative abundance of Chloroflexi was significantly positively correlated with soil total nitrogen,total carbon,organic matter,total phosphorus,nitrate nitrogen,and ammonia nitrogen content and significant negative correlation with electrical conductivity.The correlation between the relative abundance of Acidobacteriota and soil physio-chemical factors was opposite to that of Chloroflexi.Soil p H,total nitrogen,total carbon,organic matter and nitrate nitrogen were the main controlling factors.Different mowing management can have significant effects on individual soil physio-chemical factors,enzyme activities and microbial communities,but the threeyear mowing treatment did not significantly promote or reduce the soil function of reed wetlands,indicating that mowing treatment would not significantly affect the ecosystem health of the reed wetland in the short term.