黑河干流上游不同护坡工程对垂穗披碱草根系特征的影响

Effects of different slope protection projects on root characteristics ofElymus nutans in upper reaches of Heihe River

【目的】研究不同护坡工程对常用护坡植物垂穗披碱草(Elymus nutans)根系特征的影响,为植被护坡工程的科学建设提供参考。【方法】以黑河黄藏寺水利枢纽工程区高次团粒喷播植草工程、格状框条护坡植草工程和直接撒播草籽工程3种植被护坡工程的垂穗披碱草为研究对象,通过野外植物根系取样和土壤取样,室内WinRHIZO根系扫描分析和土壤理化性质分析,探讨3种护坡方式下垂穗披碱草的根系特征及其与土壤理化性质之间的关系。【结果】高次团粒喷播植草工程、格状框条护坡植草工程和直接撒播草籽工程3种护坡工程下,垂穗披碱草的根系均以细根为主,其中格状框条护坡植草工程下垂穗披碱草总根长为616.0 cm,根表面积为36.8 cm~2,根体积为0.24 cm~3,均显著高于直接撒播草籽工程。格状框条护坡植草工程下垂穗披碱草立地土壤的有机质、速效磷和速效钾含量较其他两种护坡方式高,而高次团粒喷播植草工程下0~10 cm土层土壤含水率和土壤体积质量较其他两种护坡方式高。土壤理化性质对垂穗披碱草根系生长的影响较大,相关分析表明,0~10 cm土层土壤含水率与总根长、根表面积和根体积均呈显著正相关关系(P<0.05);10~20 cm土层土壤速效钾含量与根表面积呈显著正相关关系(P<0.05)。【结论】格状框条护坡植草工程下垂穗披碱草的总根长、根表面积、根体积最高,其立地土壤的有机质、速效磷和速效钾含量也高,说明在黑河黄藏寺水利枢纽工程区及类似工程区选择格状框条护坡植草工程种植垂穗披碱草效果好。

【Objective】The effects of different vegetation slope protection projects on root characteristics of common vegetation Elymus nutans were studied to provide reference for scientific construction of vegetation slope protection projects.【Method】Elymus nutans affected by projects of aggregate spray seeding,grass planting engineering with lattice frame and direct sowing of grass seeds in the Heihe Huangzhaosi water conservancy project area were selected.Based on field survey of plant root and soil,indoor WinRHIZO root scanning analysis and soil physical and chemical properties analysis,root system characteristics of Elymus nutans and their relationship with soil physical and chemical properties were investigated.【Result】Under the slope protection projects of aggregate spray seeding,grass planting engineering with lattice frame and direct sowing of grass seeds,root systems of Elymus nutans mainly contained fine roots.The total root length,root surface area and root volume of grass planting engineering with lattice frame were 616.0 cm,36.8 cm 2 and 0.24 cm 3,all were significantly higher than those of direct sowing of grass seeds.The contents of organic matter,available phosphorus and available potassium of grass planting engineering using lattice frame were also higher than those of the other two methods,while 0-10 cm soil moisture content and soil bulk density under aggregate spray seeding project were the highest.Physical and chemical properties of soil had significant impacts on root system growth of Elymus nutans.Correlation analysis showed that there were significant positive correlations between soil water content and total root length,root surface area and root volume(P<0.05).There was a significant positive correlation between soil available potassium and root surface area(P<0.05).【Conclusion】The total root length,total volume and total surface area of Elymus nutans in the grass planting engineering with lattice frame were the highest and the soil also had high contents of organic matter,available phosphorus and available potassium,indicating it was the best for similar areas.