作 者 ：王晓荣,程瑞梅*,肖文发,郭泉水,封晓辉,王瑞丽
期 刊 ：生态学报 2010年 30卷 21期 页码：5821~5831
Keywords:Three Gorges Reservoir, water-level-fluctuating zone, the beginning after charging water, standing vegetation, soil seed bank,
摘 要 ：采用种子萌发法，研究了三峡库区消落带水淹初期所形成的已淹区段、未淹区段以及留存原有植被的对照样带地表植被与土壤种子库之间的关系。结果表明：三峡库区消落带已淹区段地表植被分属47科71属100种，未淹区段84科163属223种，优势科主要为菊科、豆科、禾本科、蔷薇科、莎草科。地上植被的物种生活型，已淹区段以生长周期短、适应性较强的1年生草本为主，灌木和乔木共占19%；未淹区段中1年生草本占20.45%，多年生草本占36.36%，灌木或藤本占28.18%，乔木占15%；对照样带中1年生草本占23.24%，多年生草本占41.32%，灌木及藤本占32.02%，乔木占17.05%。与对照样带相比，已淹区段地表植被物种多样性指数和丰富度指数都明显降低，未淹区段地表植被却表现出明显增加的趋势，只有Pielou均匀度指数都降低；已淹区段、未淹区段土壤种子库分别具有物种79种和108种，分别比对照样带增加了9种和38种；已淹区段种子库密度为(12667±2225.25)粒/m2、未淹区段为(38013±979604)粒/m2、对照样带为(18715±8234.77)粒/m2，与对照样带土壤种子库总密度相比，已淹区段降低了32.32%，未淹区段增加了103.12%，都以草本植物占绝大多数比例，且1年生草本所占比例大于多年生草本所占比例。土壤种子库的生物多样性指数、丰富度指数和均匀度指数与地表植被变化相一致，但变化幅度较小。消落带已淹区段、未淹区段、对照样带地表植被和土壤种子库共同出现的物种数分别为9，40和15种，土壤种子库和地表植被间Sorensen相似性系数分别为0.328，0.241，0.186，表明三峡库区消落带水淹初期区域整体相似系数较低，这与消落带形成时间短有很大的关系。
Abstract:Relationship between standing vegetation and soil seed bank in flooded area, non-flooded area and control area in water-level-fluctuating Zone of Three Gorges Reservoir at the beginning after charging water was studied with a germination method. The results showed that the standing vegetation was composed of 100 species in 71 genera of 47 families in flooded area, and 223 species in 163 genera of 84 families in non-flooded area, and, the main families were Asteraceae, Leguminosae, Poaceae, Rosaceae, Cyperaceae. The species life of the standing vegetation is mainly composed of annual herbaceous species which had a short growth cycle and strongly adaptability accounted for majority proportion. Shrub and fluorescence accounted for 19% in flooded area. In non-flooded area, annual herbaceous species, perennial herbage species, shrub, fluorescence and arbor accounted respectively for 20.45%,36.36%, 28.28%, 15%. The life form percentage in control area which existed the original vegetation were respectively 23.24%, 28.18%, 32.02%, 17.05%. Compared with those in control area, both species diversity indices and richness indices of the standing vegetation decreased significantly in flooded area, and however increased significantly in non-flooded area. Evenness indices were all decreased in both flooded and non-flooded area. The species number of the seed bank in flooded area and non-flooded area were respectively 79 and 108, with 9 and 38 species more than that in control area. There existed significant differences in the soil seed bank among flooded area, non-flooded area and control area, with an average seed density being (12667±222525) seed banks per m2, (38013±9796.04) seed banks per m2 and (18715±8234.77) seed banks per m2, respectively. Compared with control area, flooded area had lower seed bank density by 32.32% and non-flooded area had higher seed bank density by 103.12%. Herbaceous species accounted for majority proportion in these two sites, and annual herbaceous species seeds were higher proportion than that of the perennial herbaceous. The indices of biodiversity, richness, evenness of the seed bank had similar trends to the standing vegetation, with a smaller extent of the change. There were 9, 40, and 15, co-occurrence species in both the standing vegetation and the seed bank respectively in flooded area, non-flooded area and control area. Their Sorensen similarity coefficients of species composition between the seed bank and the standing vegetation were respectively 0.328, 0.241and 0.186. The results indicated similarity coefficients were lower in the water-level-fluctuating Zone of Three Gorges Reservoir at the beginning after charging water, and soil seed bank of dominant species that did not quickly form dominant communities in the standing vegetation. Which had a great relationship with the shorter formation time of water-level-fluctuating zone of Three Gorges Reservoir.
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