干旱矿区利用夏季和上年秋季土壤种子库恢复植被研究

Using soil seed bank in summer and previous autumn to restore vegetation in arid mining area

【目的】针对西部干旱矿区实际情况,探究该地区表土资源中土壤种子库的可利用性以及制约因素,筛选出有效的利用模式,为矿区植被恢复提供理论依据和技术参考。【方法】对内蒙古自治区乌海市新星矿区周边低扰动区域的表土在上年度10月(秋季)和当年6月(夏季)进行剥离,采用覆土厚度、补种量和每日灌溉量3因素3水平的正交试验对不同季节表土中土壤种子库萌发效果影响进行研究,并结合生态和经济效益,评选出适宜干旱矿区植被恢复的技术组合。【结果】(1)10月土壤种子库萌发植物数量为(83.72±10.88)株/m^(2),物种共出现20种,6月土壤种子库萌发植物数量为(44.83±8.96)株/m^(2),物种共出现13种。秋季土壤种子库密度和物种丰富度均高于夏季土壤种子库。(2)灌溉对秋季土壤种子库萌发影响最重要,其次是覆土厚度,最后是补种。3种因素对夏季土壤种子库萌发影响程度基本相同。(3)覆土厚度因素对两组土壤种子库的植被覆盖度、群落高度物种丰富度的影响显著(P<0.05)。灌溉量对两组土壤种子库萌发植物数量、植被覆盖度和群落高度的影响显著(P<0.05)。补种因素未对两组任何相同指标产生显著影响。【结论】干旱矿区排土场植被恢复最优实施方案组合:利用秋季剥离的表土,覆土厚度2 cm,补种量50粒/m^(2),每日灌溉量2 L/m^(2)。该结论可为今后矿区植被恢复提供技术参考。

[Objective]Based on the actual situation of arid mining area in western China,this study explored the availability and constraints of soil seed bank in topsoil resources in the area,selected effective utilization models,and provided theoretical basis and technical reference for vegetation restoration in mining area.[Method]The topsoil in the low-disturbance area around the Xinxing Mining Area in Wuhai City,Inner Mongolia of northern China was stripped in October of the previous year(autumn)and June of the current year(summer),and three factors including soil thickness,reseeding amount and daily irrigation amount were used,three horizontal orthogonal experiments were conducted to study the effects of soil seed bank germination in topsoil in different seasons,and combined with ecological and economic benefits,a combination of technologies suitable for vegetation restoration in arid mining area was selected.[Result](1)The number of plants germinated in the soil seed bank in October was(83.72±10.88)plant/m^(2),and a total of 20 species appeared.The number of plants germinated in the soil seed bank in June was(44.83±8.96)plant/m^(2),and a total of 13 species appeared.The soil seed bank density and species richness in autumn were higher than those in summer soil seed bank.(2)Irrigation had the most important impact on soil seed bank germination in autumn,followed by soil covering thickness,and finally reseeding.The three factors had basically the same impact on soil seed bank germination in summer.(3)The soil thickness factor had a significant impact on vegetation coverage and community height species richness of the two groups of soil seed bank(P<0.05).The amount of irrigation had a significant impact on the number of plants germinated in two groups of soil seed bank,vegetation coverage and community height(P<0.05).In both sets of trials,the reseeding factors did not simultaneously produce significantly different indicators.[Conclusion]The optimal combination of implementation plans for vegetation restoration in dumpsites in arid mining areas is:using topsoil stripped off in autumn,with a covering soil thickness of 2 cm,a reseeding amount of 50 grain/m^(2),and a daily irrigation volume of 2 L/m^(2).This conclusion can provide technical reference for future vegetation restoration in mining area.