人工生物质结皮对黄土边坡微生态环境及植被恢复的影响
Effects of artificial soil crusts on micro ecological environment and vegetation restoration on the loess slope
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摘要: 针对黄土干旱阳坡植被恢复问题,以山西省方山县黄土弃土边坡为研究地,在2012年4月26日和7月20日分别布设人工生物质结皮进行试验,并于11月30日结束全部试验。通过2次试验研究人工生物质结皮在黄土边坡植被恢复过程中对土壤微生态环境的改善及对植被生长的影响。结果表明:1)人工生物质结皮可提高浅层土壤温度,最高达1.9°;2)人工生物质结皮可增加土壤含水量,10cm土层土壤含水量比对照区高35.8%;3)人工生物质结皮对边坡侵蚀具有防护作用,结皮区降雨形成的水蚀细沟体积小于对照区的1/2;4)氮源肥料和碳源生物高分子同时施用时边坡植物生物量超过二者单独使用时的4倍;5)人工生物质结皮可促进土壤种子库植物的萌发,其中土壤种子库植物占结皮区植物生物量的83.06%;6)人工生物质结皮区植被盖度超过90%,远高于裸露黄土对照区和自然坡面的30%和35%的覆盖率,植物鲜质量生物量达1.65t/hm2,分别为自然坡面和对照区生物量的10.50和20.48倍;7)利用人工生物质结皮可以在一个生长季内在黄土边坡形成高盖度植被,这种方法适用于水土流失严重的黄土丘陵沟壑区的边坡植被快速恢复。Abstract: To promote vegetation restoration on arid sunny slopes in the loess plateau, artificial soil crusts were adopted on waste soil slopes in Fangshan County, Shanxi Province, and their effects on the improvement of micro ecological environment and vegetation growth were determined. The first test began on April 26, 2012 and the second on July 20, 2012, both finished on November 30, 2012. The results were shown as follows. 1) The artificial soil crusts increased the monthly average temperature of surface soil layer of 10 cm deep by 1.9°. 2) The monthly average soil moisture at 10 cm depth was 35.8% higher than that of the control area. 3) The volume of rainfall erosion rills in the crusted area was 50% less than that in the control area. 4) When nitrogen fertilizers and carbon biological polymers were applied simultaneously, plant biomass was three times larger than that when either of them was applied alone. 5) The artificial soil crusts promoted the germination of seeds in the soil seed bank. The biomass of plants in the soil seed bank accounted for 83.06% of total plant biomass in the crusted area. 6) The vegetation coverage in the artificial soil crust area was over 90%, much higher than that of the control area (30%) and natural slopes (35%). The fresh weight of plants in the artificial soil crust area was 1.65 t/ hm2, which was 9.5 times and 19.48 times larger than that of the control area and natural slopes.7) A high vegetation coverage in the artificial soil crust area could be formed on loess slopes with serious soil erosion within a single growing season, suggesting that this method is suitable for fast vegetation restoration on loess slopes in Loess Hilly-gully Region.