摘要
将三峡库区消落带回水区次生灌丛和弃耕地分成水淹区段、未水淹区段和对照样带,通过萌发法对其土壤种子库进行研究.结果表明:两种植被类型的土壤种子库储量存在极显著差异,次生灌丛种子密度为(6991±954)粒·m-2、弃耕地种子密度为(26193±6928)粒·m-2.3种生境中,水淹区段的种子密度最低,未水淹区段最高.随着土层加深,种子库密度逐渐下降.土壤种子库萌发试验出现的物种分属45科97属118种,以一年生和多年生草本植物为主,其中菊科、禾本科、玄参科和十字花科为优势科;个体数量占土壤种子库总储量小于0.01%的物种有34种,占28.8%.两种植被类型的土壤种子库中物种数较接近,物种多样性指数和均匀度较高,但优势物种组成差异很大,生态优势度较低.3种生境中,未水淹区段的生物多样性最高,水淹区段的生态优势度最高;而水淹区段和未水淹区段相似性指数最大.
A germination test was made to study the characteristics of soil seed banks in the backwater area （including the flooded,non-flooded,and control areas of secondary bush and abandoned farmland） of Three Gorges Reservoir water-level-fluctuating zone. There existed significant differences in the soil seed banks between secondary bush and abandoned farmland,with an average seed density being 6991±954 seed per m^2 and 26193±6928 seed per m^2,respectively. Flooded area had the lowest seed density,while non-flooded area had the highest one. The seed density decreased with soil depth. A total of 118 species belonging to 45 families and 97 genera were detected in the soil seed banks of secondary bush and abandoned farmland,most of which were annual and perennial herbage species,belonging to Asteraceae,Poaceae,Scrophulariaceae,and Cruciferae. Among the 118 species,there were 34 species （occupying 28.8%） whose individuals accounted for less than 0.01% of the total. In the soil seed banks of secondary bush and abandoned farmland,the species number was similar,species diversity index and evenness index were relatively high,but the dominant species differed greatly,and the ecological dominance was relatively low. The species diversity in non-flooded area and the ecological dominance in flooded area were the highest,and the similarity index between the flooded and non-flooded areas was the highest.
出处
《应用生态学报》
CAS
CSCD
北大核心
2009年第12期2891-2897,共7页
Chinese Journal of Applied Ecology
基金
中国林业科学研究院公益基金项目(CAFYBB2007023)
国家林业科技支撑计划项目(2006BAD03A1302/03
2006BAD03A07)资助
关键词
三峡库区
消落带
回水区
土壤种子库
水淹初期
Three Gorges Reservoir water-level-fluctuating zone backwater area soil seed bank initial stage of river-flooding.
