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Effects On Soil Respiration Of Mu Us Sandy Land Salix Psammophyla With Intensity Of Cutting

Posted on:2018-08-03Degree:MasterType:Thesis
Country:ChinaCandidate:Y LiFull Text:PDF
GTID:2323330518955737Subject:Forest Engineering
Abstract/Summary:PDF Full Text Request
To analyze the impact of cutting intensity on Salix psammophyla woodland soil respiration,plots are treated that the low cutting intensity was 30%,moderate cutting intensity was 50%,and high cutting intensity was 70%respectively,as well as the control plot,and the Soilbox soil respiration system is used to measure the Soil respiration rate and influencing factors of Salix psammophila woodland with different cutting intensity in Mu Us sandy land.The changing law in seasons and days of respiration rate of soil and its components is studied,this study focuses more on the relationship between soil temperature?soil respiration rate and soil moisture,soil respiration rate to better understand the soil respiration process,the annual flux is also estimated at the same time.Results can be concluded as followings:1.The soil temperature of the cuttings samples are higher than that of the control plot,which makes the temperature sensitivity of the soil respiration rate changing showed by higher Q10.Soil moisture of plots with high cutting intensity is significantly lower than others,which has no significant difference inside.The soil respiration of each cutting plot shows a significant exponential correlation with soil temperature,and in every observation month,temperature can explain at least 62.0%?73.9%of the seasonal variation of soil respiration.Moreover,the correlation between soil moisture and soil respiration rate is too small to describe the soil respiration rate.There is a significant correlation between soil respiration rate,with the combined results of soil moisture and soil temperature,which can explain the change of soil respiration rate by 64.4%?90.4%.2.The soil respiration rate of Salix psammophila in different years shows unimodality all,especially fluctuated by month.It is obvious that cutting improves soil respiration rate,moderate cutting plot soil respiration rate in the first and second year is significantly higher than in other plots.And there is no significant difference of soil respiration rate in high or low cutting intensity plots,but they are still higher than the control soil.3.The daily respiration rate of soil was observed,the diurnal variation of soil respiration rate was from moderate to small,low cutting,high cutting and control plot,the curves of soil respiration rate in the low cutting plot and high cutting plot are close.In the temperature sensitive index Q10 aspects,the control is higher than the other plots.For low cutting,soil moisture has little effect on soil respiration rate;the correlation coefficient of high cutting is simulated by two models,the respiration rate of soils in high cutting is greatly affected by soil moisture.4.The rate of soil respiration was also changed.The change of soil heterotrophic respiration was higher than that of autotrophic respiration.The average autotrophic respiration rate was the highest in moderate cutting plots,lowly litter the smallest;the average heterotrophic respiration rate was the highest in the lowly cutting plot,the minimum size of the moderate cutting plot.The contribution rate of soil autotrophic respiration fluctuated between 24.27%and 54.40%,Size order is:moderare cuttting plot>high cutting plot>Control Plots>low cutting plot.Except for the control of the soil,The other components of the respiratory and temperature reached a significant level,all relationships in the model,can explain the respiration rate with the soil temperature changes of 27.2%to 70.5%.There is a correlation between the rate of heterotrophic respiration and soil moisture in only high cutting plot,his components did not reach a significant level of breathing.In all the respiratory components,The combined effects of two factors are significantly correlated with soil respiration,the range of breathing interpretation is between 34.6%and 76.8%,the range of the two-factor complex can be compared with the soil temperature.Indicating that the two-factor compound effect is affected by soil moisture,but little effect.The two-factor model has a higher accuracy for predicting soil respiration to a certain extent.
Keywords/Search Tags:Salix Psammophyla, Cutting intensity, Soil respiration rate, Soil temperature, Soil moisture, Component respiration rate
PDF Full Text Request
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