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| Titel |
Land preparation techniques and vegetation type commonly determine soil conditions in a typical hilly watershed, Loess Plateau of China. |
| VerfasserIn |
Yang Yu, Wei Wei, Liding Chen, Tianjiao Feng, Wei Qin |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250137600
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| Publikation (Nr.) |
 EGU/EGU2017-367.pdf |
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| Zusammenfassung |
| Soil is a key component of the earth, it plays important role in regulating the chemical,
hydrological and biological cycles. Land preparation techniques (e.g., leveled ditches, leveled
benches, adversely graded tableland and fish-scale pits) is one of the most effective ecological
engineering practices to reduce water erosion. Land preparation greatly affects soil
physicochemical properties, soil moisture variation, runoff and sediment prevention. This
study investigated the influence of different land preparation techniques on soil conditions,
runoff and erosion during vegetation restoration, which remained poorly understand to date.
Soil samples were collected from depths of 0–10 cm, 10–20 cm, 20–40 cm, 40–60 cm,
60–80 cm and 80–100 cm, in the typical hilly watershed of Dingxi City, Loess
Plateau. Soil bulk density (BD), soil organic matter (SOM) and total nitrogen (TN)
were determined for different land preparations and vegetation type (Caragana
korshinskii, Platycladus orientalis, Pinus tabulaeformis and Prunus armeniaca)
combinations. Fractal theory was used to analyze the soil particle size distribution (PSD).
Redundancy analyses were conducted to distinguish the relationships between soil
conditions and the factors influencing them (land preparation and vegetation). The
analysis of runoff coefficient and erosion rates were calculated considering the
monitoring time. The results indicated that: 1) the effect of land preparation on soil
properties and PSD varies with soil depth. For each land preparation category, SOM
and TN values showed a significant difference between the top soil layer and the
underlying soil depth. 2) The 20 cm soil layer was a boundary that distinguished the
explanatory factors, with land preparation and vegetation type as the controlling
factors in the 0-20 cm and 20-100 cm soil layers, respectively. Land preparation and
vegetation significantly affected soil properties in the surface soil layer, while land
preparation (41.6%) was the more important driver for this layer compared with
vegetation (37.2%). Land preparation affected the soil properties by abiotic factors (e.g.,
surface runoff and sediment transport), while vegetation influenced soil physical
and chemical properties via biotic factors (e.g., canopy and root). 3) Fish-scale
pits-Pinus tabulaeformis had the highest runoff coefficient (3.91%) and adverse grade
tableland-Platycladus orientalis had the lowest (1.10%). The runoff coefficient
of level bench-Caragana korshinskii, fish-scale pits-Platycladus orientalis, level
ditch-Prunus armeniaca and adverse grade tableland-Pinus tabulaeformis were 3.02%,
2.59%, 2.42% and 1.58%, respectively. Level bench-Caragana korshinskii had the
highest erosion modulus (0.036 t/ha) and adverse grade tableland-Pinus tabulaeformis
showed the lowest (0.006 t/ha). Erosion modulus of fish-scale pits-Platycladus
orientalis, level ditch-Prunus armeniaca and adverse grade tableland-Platycladus
orientalis were 0.026 t/ha, 0.019 t/ha and 0.015 t/ha, respectively. Compared with
control, the runoff coefficient could be reduced 37.7%, 31.9%, 44.3%, 60.5%, 18.2%
and 63%, respectively. Erosion modulus could be reduced 77.8%, 62.9%, 82.6%,
84.7%, 53.9% and 76.3%, respectively. Our study demonstrated that land preparation
techniques and vegetation type commonly determine soil conditions and that land
preparation is a recommended method to improve and rehabilitate degraded ecosystems.
Applications of land preparation to vegetation restoration in the fragile ecosystems were an
effective way for preventing water loss and soil erosion. Considering site-specific land
preparation-plant species combinations could be critical to ensure long-term land
stabilization. |
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