Quantifying Degradation Classifications on Alpine Grassland in the Lhasa River Basin, Qinghai-Tibetan Plateau
Abstract
:1. Introduction
2. Materials and Methods
2.1. Study Area
2.2. Field Data
2.3. Remote Sensing Data
2.4. Statistical Analysis
2.5. Spatial Pattern of Alpine Grassland Degradation
3. Results
3.1. Classification of Subsites to Identify Degradation Classes
3.2. Main Biophysical Factors of Classified Subsites
3.3. Thresholds of Variables Affecting Degradation
3.4. Spatial Pattern of Alpine Grassland Degradation
4. Discussion
4.1. Validity of the Classification Method for Alpine Grassland Degradation
4.2. Quantitative Classifications of Alpine Grassland Degradation
4.3. Analysis of Different Classes of Grassland Degradation Combined with Management Measures
5. Conclusions
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
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Type of Variable | Variable | Unit | Range of Values |
---|---|---|---|
Biotic | Total vegetation cover | % | 5–100 |
Dominance of Cyperaceae plants | % | 0–77.61 | |
Dominance of Poaceae plants | % | 0–52 | |
Dominance of inedible plants | % | 0–72.48 | |
Dominance of miscellaneous plants | % | 0–72.48 | |
Abiotic | Bare land cover | % | 13–67 |
Soil moisture content | % | 0.18–135.20 | |
Soil bulk density | 0.33–1.69 | ||
Soil pH | 0.34–8.26 | ||
Soil total carbon content | % | 0.3–20.29 | |
Soil total nitrogen content | % | 0.09–6.21 | |
Soil organic carbon content | % | 0.60–18.72 | |
Soil available nitrogen content | mg kg−1 | 3–1102.5 | |
Soil available phosphorus content | mg kg−1 | 0.36–908 | |
Soil available potassium content | mg kg−1 | 4.2–637.5 | |
Topographic | Elevation | m | 3700–5368 |
Slope | degree | 0.75–45 |
Degradation Level | Score | NDVI | SAVI | RDVI | Bare Land Cover (%) | Elevation (m) | Soil Type |
---|---|---|---|---|---|---|---|
ND | 1 | >0.30 | >0.27 | 12.44–15.00 | <37 | 4130–4200 | Dark felty soils |
SLD | 2 | 0.27–0.30 | 0.20–0.27 | 9.44–12.44 | 37–40 | 4950–5110 | Swamp soil, Alpine frost soil |
MD | 3 | 0.24–0.27 | 0.14–0.20 | >15.00 | 40–46.5 | 4200–4500, 4700–4950, >5110 | Felty soils, Meadow soil |
SD | 4 | 0.08–0.24 | 0.05–0.14 | 5.73–9.44 | 46.5–55 | 3720–4130, 4500–4700 | Frigid calcic soils |
ED | 5 | <0.08 | <0.05 | <5.73 | >55 | <3720 | Cold brown calcic soils |
Variable | ND | SLD | MD | SD | ED | P | F | |||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Mean ± SD | CV% | Mean ± SD | CV% | Mean ± SD | CV% | Mean ± SD | CV% | Mean ± SD | CV% | |||
Total Vegetation cover (%) | 83.17 ± 15.27 a | 18.36 | 75.42 ± 23.31 a | 30.90 | 72.06 ± 24.74 a | 34.33 | 52.53 ± 26.69 b | 50.81 | 24.38 ± 7.03 c | 28.86 | <0.01 | 17.775 |
Dominance of Cyperaceae Plants (%) | 19.66 ± 0.05 c | 0.28 | 46.73 ± 0.09 a | 0.18 | 39.64 ± 0.11 b | 0.28 | 14.37 ± 0.12 c | 0.84 | 7.62 ± 0.10 c | 1.30 | <0.01 | 79.82 |
Dominance of Poaceae Plants (%) | 7.20 ± 0.05 b | 0.73 | 5.10 ± 0.06 b | 1.21 | 5.86 ± 0.07 b | 1.22 | 11.04 ± 0.11 b | 1.03 | 23.98 ± 0.06 a | 0.26 | <0.01 | 13.459 |
Dominance of inedible Plants (%) | 20.80 ± 0.08 cd | 0.41 | 17.84 ± 0.07 d | 0.41 | 23.63 ± 0.11 c | 0.46 | 30.73 ± 0.16 b | 0.51 | 54.40 ± 0.11 a | 0.21 | <0.01 | 21.928 |
Dominance of miscellaneous Plants (%) | 52.34 ± 0.06 a | 0.12 | 30.32 ± 0.08 b | 0.28 | 30.87 ± 0.11 b | 0.35 | 43.86 ± 0.16 a | 0.36 | 14.00 ± 0.06 c | 0.40 | <0.01 | 26.981 |
Bare Land Cover (%) | 40.67 ± 4.47 bc | 11.00 | 36.04 ± 11.62 c | 32.25 | 39.32 ± 13.02 bc | 33.10 | 42.19 ± 11.56 b | 27.40 | 55.38 ± 0.48 a | 0.87 | <0.01 | 5.773 |
Soil Moisture Content (%) | 50.95 ± 19.54 a | 38.34 | 53.22 ± 23.65 a | 44.43 | 48.75 ± 27.20 a | 55.80 | 29.31 ± 28.24 b | 96.35 | 8.79 ± 4.03 b | 45.81 | <0.01 | 12.549 |
Soil Bulk Density | 0.70 ± 0.17 bc | 24.74 | 0.77 ± 0.19 c | 24.42 | 0.81 ± 0.24 bc | 29.99 | 1.06 ± 0.27 b | 25.52 | 1.51 ± 0.07 a | 4.96 | <0.01 | 12.063 |
Soil pH | 5.78 ± 0.26 c | 4.42 | 5.63 ± 0.41 c | 7.32 | 5.76 ± 0.75 c | 13.04 | 6.36 ± 0.77 b | 12.08 | 8.04 ± 0.30 a | 3.76 | <0.01 | 24.683 |
Soil Total Carbon Content (%) | 7.35 ± 2.69 a | 36.63 | 6.94 ± 3.73 b | 53.68 | 5.22 ± 1.96 c | 37.54 | 4.51 ± 3.18 c | 70.50 | 0.82 ± 0.08 d | 10.00 | <0.01 | 13.246 |
Soil Total Nitrogen Content (%) | 0.59 ± 0.20 a | 33.55 | 0.55 ± 0.26 a | 46.56 | 0.42 ± 0.13 b | 31.43 | 0.40 ± 0.25 b | 62.02 | 0.11 ± 0.01 b | 13.26 | <0.01 | 7.726 |
Soil Organic Carbon Content (%) | 6.86 ± 2.82 a | 41.12 | 6.87 ± 3.64 a | 53.06 | 5.14 ± 1.96 b | 38.19 | 4.45 ± 3.08 b | 69.29 | 0.78 ± 0.10 c | 12.64 | <0.01 | 12.389 |
Soil Available Nitrogen Content (mg kg−1) | 578.66 ± 237.09 a | 40.97 | 509.69 ± 93.43 a | 18.33 | 449.80 ± 169.09 ab | 37.59 | 369.16 ± 266.57 b | 72.21 | 57.15 ± 27.33 c | 47.82 | <0.01 | 12.095 |
Soil Available Phosphorus Content (mg kg−1) | 8.65 ± 5.34 a | 61.70 | 7.37 ± 2.57 a | 34.90 | 14.58 ± 86.04 a | 590.03 | 7.41 ± 6.38 a | 86.13 | 1.48 ± 0.69 a | 46.65 | 0.87 | 0.307 |
Soil Available Potassium Content (mg kg−1) | 214.47 ± 117.47 a | 54.77 | 177.59 ± 93.43 ab | 52.61 | 163.87 ± 88.49 ab | 54.00 | 146.46 ± 67.75 b | 46.26 | 96.31 ± 39.61 b | 41.12 | <0.01 | 3.914 |
Elevation (m) | 4416.06 ± 245.56 b | 5.56 | 4801.97 ± 284.65 a | 5.93 | 4693.73 ± 306.99 a | 6.54 | 4479.46 ± 413.53 b | 9.23 | 4256.88 ± 431.35 b | 10.13 | <0.01 | 12.52 |
Slope (degree) | 14.41 ± 3.55 ab | 24.61 | 10.14 ± 9.44 b | 93.08 | 11.12 ± 10.15 b | 91.30 | 15.37 ± 10.74 a | 69.89 | 4.77 ± 0.29 b | 6.15 | <0.01 | 4.413 |
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Han, W.; Lu, H.; Liu, G.; Wang, J.; Su, X. Quantifying Degradation Classifications on Alpine Grassland in the Lhasa River Basin, Qinghai-Tibetan Plateau. Sustainability 2019, 11, 7067. https://doi.org/10.3390/su11247067
Han W, Lu H, Liu G, Wang J, Su X. Quantifying Degradation Classifications on Alpine Grassland in the Lhasa River Basin, Qinghai-Tibetan Plateau. Sustainability. 2019; 11(24):7067. https://doi.org/10.3390/su11247067
Chicago/Turabian StyleHan, Wangya, Huiting Lu, Guohua Liu, Jingsheng Wang, and Xukun Su. 2019. "Quantifying Degradation Classifications on Alpine Grassland in the Lhasa River Basin, Qinghai-Tibetan Plateau" Sustainability 11, no. 24: 7067. https://doi.org/10.3390/su11247067