高原季节性湿地消落带土壤种子库水淹耐受性研究

Study on Flood Tolerance of Soil Seed Bank of Water-level-fluctuating Zone of Plateau Seasonal Wetland

以高原季节性湿地阿哈水库消落带土壤种子库为研究对象,采用室内模拟水淹的方法,分别设置水淹0、2、5、10、20、30、40、60、90 d试验,共9个处理,研究库区4种典型的类型(乔木林地、灌木林地、草丛地、弃耕农田)未淹带土壤种子库在不同水淹时间后的萌发能力,以期为消落带生态恢复人工种子库的构建提供依据。结果表明,4种类型土壤种子库的密度介于1 651~3 730粒·m-2之间,表现为草丛地>弃耕农田>灌木林地>乔木林地。土壤种子库数量集中分布在0~5 cm的土层,占总数量的70%~75%。4种类型未淹带土壤种子库共萌发出71种物种,隶属于31科。萌发最多的物种是菊科,其次是禾本科。4种类型未淹带土壤种子库水淹2、5、10、20、30、40、60、90 d不同处理后,其萌发数量分别占萌发总数的99.50%、97.53%、93.33%、86.66%、78.02%、66.42%、54.57%、42.22%。萌发物种数分别占总萌发数的100%、98.59%、95.77%、88.72%、77.46%、67.61%、57.75%、47.89%。说明短时间水淹对土壤种子库的影响不大,但长时间的水淹会严重抑制种子的萌发。水淹90 d后萌发的优势物种有牛膝菊(Galinsoga parviflora Cav)、酸模(Rumex acetosa L.)、水芹(Oenanthe javanica(Bl.) DC.)、鬼针草(Bidens pilosa L.)、小飞蓬(Conyza canadensis(L.) Cronq.),说明这些植物的种子具有较强的水淹耐受能力,可被利用在湿地消落带人工植被恢复措施中。

In this paper, the soil seed bank in the water-level-fluctuating zone of Aha Lake reservoir of plateau seasonal wetland was selected as the research object to investigate the germination ability of 4 typical types of unflooded soil seed banks including arbor forest, shrub land, grass land and abandoned farmland in Aha Lake reservoir area, and 9 treatments were set for 0, 2, 5, 10, 20, 30, 40, 60 and 90 days of waterlogging respectively. The results of this study were expected to provide a basis for the construction of artificial seed banks for ecological restoration in water-level-fluctuating zones. The results showed the density of the 4 soil seed banks ranged from 1 651 to 3 730 seeds·m-2, which showed as grass field > abandoned farmland>shrub land>arbor land. The number of soil seed banks was concentrated in the 0-5 cm soil layer, accounting for 70%-75% of the total number. In addition, a total of 71 species belonging to 31 families germinated from 4 types of unflooded soil seed banks, and the most germinated species belonged to Compositae, followed by Gramineae. After 2, 5, 10, 20, 30, 40, 60 and 90 days of water flooding in 4 types of unflooded soil seed banks, the number of germination accounted for 99.50%, 97.53%, 93.33%, 86.66%, 78.02%, 66.42%, 54.57%, 42.22% of the total germination, respectively, while the number of germination species accounted for 100%, 98.59%, 95.77%, 88.72%, 77.46%, 67.61%, 57.75% and 47.89% of the total germination number respectively, which implied the short-term flooding had little effect on the soil seed bank, while the long-term flooding could seriously inhibit the germination of seeds. After 90 d of water flooding, the species with an excellent budding potential were Galinsoga parviflora Cav., Rumex acetosa L., Oenanthe javanica(Bl.) Dc., Bidens pilosa L. and Conyza canadensis(L.) Cronq., which indicated that the seeds of these plants had strong waterlogging tolerance and could be used in artificial vegetation restoration measures in the water-level-fluctuating zone of wetlands.