[Field investigation on ecological effect of windbreak and soil erosion reduction from sandy grasslands].
Through field observation of the variation of vegetational characteristics and sand transported rate in sandy grasslands at different levels of desertification during the spring erosive period, the ecological effects of windbreak and soil erosion reduction from sandy grasslands of the Horqin Sandy Land were studied. The results showed that vegetational coverage varied obviously from 0.3% in the shifting sand land of the severe desertification to 16% in the fixed sand land of the least desertification in mid May. Increases in vegetational coverage led to a corresponding increase in surface roughness length from 0.013 cm in the shifting sand land to 0.111 cm in the fixed sand land, thus resulting in an increase in friction velocity from 0.272 m.s-1 in the shifting sand land to 0.823 m.s-1 in the fixed sand land and a decrease in mean wind speed near the surfaces from 7.0 m.s-1 in the shifting sand land to 3.8 m.s-1 in the fixed sand land. This in turn led to a reduction in the total sand transported rate within the height of 0-20 cm from 88.8 g.(h.cm2)-1 in the shifting sand land to 1.6 g.(h.cm2)-1 in the fixed sand land. When the experimental data were analyzed by regressing the total sand transported rate (Q) against vegetational coverage (VC), a model of predictive regression was developed: Q = 3.93 + 93.66e-0.60VC(R2 = 0.893, p < 0.0001, n = 40).
Zhang
Hua
H
College of City and Environment, Liaoning Normal University, Dalian 116029, China. zhanghua0323@sina.com
Li
Feng-rui
FR
Fu
Qian-ke
QK
Lü
Zi-jun
ZJ
D003247:Conservation of Natural Resources; D004463:Ecology; D063245:Plant Development; D006109:Poaceae / Q000254:growth & development*; D012822:Silicon Dioxide; D012987:Soil; D014919:Wind
D012987:Soil; D012822:Silicon Dioxide