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Effects of Sheep Rotation Grazing on Soil Respiration and Analysis on Important Impact Factors in Hilly Area of Loess Plateau

Author: ChenJunBo
Tutor: HouFuJiang
School: Lanzhou University
Course: Grassland
Keywords: Loess Plateau Grassland Grazing Sheep Soil respiration Path Analysis Soil temperature Soil moisture Biomass
CLC: S826
Type: Master's thesis
Year: 2009
Downloads: 134
Quote: 4
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Abstract


Grassland accounted for 27.3% -67.5% of the total land area in the Loess Plateau, mainly to grazing utilization is an important agricultural production and ecological barriers. The research in the Longdong Loess Plateau hilly region, mainly to study the different seasons, different stocking rates Tan sheep the rotational grazing district soil respiration characteristics and analysis of soil, grass, animals, etc. main influence factors on soil respiration. In summer, different stocking rates grassland soil respiration Day in dynamic unimodal curve. Warm season grazing lands maximum occurs at about 14:00, cool-season grazing land maximum occurs in around 16:00, the minimum value in 01:00-06:00. Warm-season grazing land soil daily respiration rate of 1.12-1.58μmolCO 2 · m -2 · s -1 , with increasing stocking rates decreases; cool-season grazing land soil daily respiration rate 1.26-1.44μmolCO 2 · m -2 · s -1 , with grazing rate increases; fencing average daily soil respiration rate 2.08μmolCO 2 · m -2 · s -1 . Sine function Rs = a × sin (ωt φ) b better simulate soil respiration dynamic warm season grazing lands theoretical value of the maximum daily respiration rate is smaller than the measured value of 0.21% -4.57%, theoretical value than the minimum daily respiration rate measured value small 1.87% -8.34%; cool-season grazing land the theoretical value of the maximum daily respiration rate 1.38% -4.60% smaller than the measured value, the theoretical value of minimum daily respiration rate 3.13% -10.99% smaller than the measured value: fencing the maximum daily breathing rate theoretical value of 0.82%, smaller than the measured value the the minimum daily respiration rate theoretical value smaller than the measured value of 4.99%. Seasonal dynamics of the warm season and cool-season grazing land soil respiration August> May> November; August, May and November, the warm season grazing areas and cool-season grazing land, soil respiration rate were 1.35,0.79 0.43μmolCO 2 · m -2 · s -1 and 1.36,0.78,0.42 μmolCO of 2 · m -2 · s -1 , the differences between the different stocking rates highly significant (P <0.01). The use 3 Path Analysis Feng impact factor role of soil respiration, warm season grazing lands each directly impact factors on grassland soil respiration path coefficients: belowground biomass in soil moisture (0.52)> (0.49)> soil temperature (0.42), grazing on soil respiration indirect path coefficients as follows: below-ground biomass (-0.089) soil moisture (-0.059) soil temperature (-0.006); cool-season grazing land each directly impact factor of path coefficients : belowground biomass in soil temperature (0.67)> (0.42)> soil water content (0.39), grazing on soil respiration indirect path coefficients as follows: below-ground biomass (0.052)> soil temperature (0.042) soil moisture (-0.004). Whether it is a warm-season grazing land or cool-season grazing land, are greater than the grazing season soil respiration rate, grazing through underground biomass role in soil respiration. Grazing to reduce soil respiration warm season and cool-season grazing increased soil respiration; warm season grazing mainly by reducing the carbon input to soil respiration, cool-season grazing affect soil respiration by reducing carbon output. The study of this article the natural grassland carbon pools and grassland CO 2 emissions to establish a reasonable management approach provides the basic data.

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CLC: > Agricultural Sciences > Livestock, animal medicine,hunting,silkworm,bee > Livestock > Sheep
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