摘要:土壤种子库在退化生态系统植被的恢复和演替中起重要作用，为明确外来入侵植物刺萼龙葵（Solanum rostratum Dunal.）土壤种子库特征，评价植物替代控制刺萼龙葵的效果，调查了河滩及农田边缘两个典型生境中的刺萼龙葵土壤种子库特征，分析了刺萼龙葵种子在土壤中的垂直分布与季节变化动态，并利用多种多年生禾本科与豆科牧草对刺萼龙葵进行替代控制研究，以期为刺萼龙葵生态调控提供理论依据。结果表明：1）两个生境中共鉴定出23种植物，禾本科和菊科为优势科；河滩及农田边缘刺萼龙葵种子总储量分别达347粒·m-2和2 600粒·m-2，占整个种子库的2.46%及35.16%。2）河滩生境中刺萼龙葵种子多集中于表层（0~2 cm）土壤，占种子总量的64.3%，且随土层深度的增加而减少；而农田边缘生境0~2 cm、2~5 cm和5~10 cm 3层种子数量差异不大（P>0.05），分别占种子总量的32.7%、38.2%及29.1%。3）两个生境中刺萼龙葵种子主要集中于4月份采集的土样中，分别为273粒·m-2（河滩）和1 970粒·m-2（农田边缘），显著高于6月份与8月份采集的土样种子数（P < 0.05）；4）从替代控制第2年起，刺萼龙葵的密度、生物量及土壤种子储量即被控制在较低水平，均显著低于同期对照（P < 0.05），沙打旺+苇状羊茅+冰草+羊草组合对刺萼龙葵控制效果最佳，同时还可获得牧草鲜重20 396.1 kg·hm-2，干重7 710.6 kg·hm-2（2017年），经济效益可观。5）刺萼龙葵种子库与刺萼龙葵密度（P < 0.01）、生物量（P < 0.05）呈正相关，牧草产量与刺萼龙葵种子库储量、密度、生物量均呈负相关，但相关性不显著（P>0.05）；降雨显著影响刺萼龙葵种子库储量（P < 0.05），可用幂函数模型y=2.619x0.001（R2=0.822，F=18.486，P=0.013）描述二者之间的关系。
关键词:生物入侵/
刺萼龙葵/
入侵植物/
土壤种子库/
时空特性/
替代控制
Abstract:Soil seed bank is important in the restoration and succession of vegetation in degraded ecosystems. In order to determine the characteristics of soil seed bank of the alien invasive plant Solanum rostratum Dunal. and to evaluate the effects of replacement control of S. rostratum, soil seed bank of S. rostratum in two typical habitats (riverside and farmland margin) were studied and its' vertical distribution and seasonal dynamics analyzed. In addition, a study on replacement control of S. rostratum was conducted using varieties of perennial forages of Gramineae and Leguminosea. 1) Based on the results, 23 plants species were identified, and Gramineae and Compositae were the most dominant families. The total reserve of S. rostratum seed banks in the riverside and farmland margin were respectively 347 seeds·m-2 and 2 600 seeds·m-2, which accounted for 2.46% and 35.16% of the whole seed bank. S. rostratum was the dominant family in farmland but another invasive plant (Cenchrus spinifex Cav.) was the main species in riverside; reaching 5 187 seeds·m-2 and accounting for 36.70% of the seed reserve. 2) S. rostratum seeds were mainly stored in the 0-2 cm soil layer in riverside region, accounting for 64.3% and decreasing with increasing soil depth. There was no significant difference in the three soil layers of farmland margin in terms of S. rostratum seed reserve (P>0.05), which accounted for 32.7% (0-2 cm), 38.2% (2-5 cm) and 29.1% (5-10 cm) of the total seed bank. However, it was need to pay attention to potential hazards of seeds in the middle and lower layers (2-10 cm). 3) For the three times of samplings, S. rostratum seeds mainly were collected in April reached 273 seeds·m-2 and 1 970 seeds·m-2 in riverside and farmland margin, significantly fewer in June and August. 4) In the second year of the controlled replacement, the coverage of forage gradually increased, the resources and niches were seized by the forage, and the growth of S. rostratum significantly inhibited. The density, biomass and soil seed reserve of S. rostratum were controlled at a low level, significant lower than CK (P < 0.05). Astragalus adsurgens Pall., Festuca arundinacea Schreb., Agropyron cristatum (L.) Gaertn., combined with Leymus chinensis (Trin.) Tzvel. had the best control effect on S. rostratum. At the same time, it showed obvious economic benefits, which produced forage grass of 20 396.1 kg·hm-2 (fresh weight) and 7 710.6 kg·hm-2 (dry weight). 5) Soil seed reserves of S. rostratum was positively correlation with density (P < 0.01) and biomass (P < 0.05) of S. rostratum, while forage yield was negatively correlation with soil seed reserve, density and biomass of S. rostratum. However, this was not significant (P>0.05). Nevertheless, rainfall significantly affected soil seed reserve of S. rostratum (P < 0.05), which was described by the power function model y=2.619x0.001 (R2=0.822, F=18.486, P=0.013). Therefore, plant replacement combined with physical and chemical methods can be used to establish integrated system to control S. rostratum growth in habitats such as grassland, farmland margin and wasteland.
Key words:Biological invasion/
Solanum rostratum Dunal./
Invasive plant/
Soil seed bank/
Temporal and spatial dynamics/
Replacement control
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