Seed banks of a southern Australian wetland: the influence of water regime on the final floristic composition
Seed banks of a southern Australian wetland: the influence of water regime on the final floristic composition
复制标题
DOI：
10.1023/a:1024430919811
复制
发表时间：
2003-09-01
期刊：
影响因子：
1.7
通讯作者：
Pelton, GA
中科院分区：
文献类型：
--
作者：
Nicol, JM;Ganf, GG;Pelton, GA
研究了南澳大利亚湿地复合体的沉积物，以确定可发芽种子库。种子的数量从22000米到78000米不等。基于物种组成的非度量多维尺度排序（NMS）将四个盆地分开，但每个盆地都包含陆地、两栖和水下主要功能群的代表。为了测试水分状况对这些种子库最终植物区系组成的影响，沉积物被放置在三个海拔高度（0、30和80厘米），并受到三种水文状况（静态水位和每周2.5和7厘米的下降率（-1））的影响。通过排序分析98 d后的物种组成。尽管初始种子库组成存在显著差异，但最终区系组成与水分状况相关，与初始种子库组成无关。物种组是根据沉积物是否持续暴露于大气、下降速率和水深来划分的。湿润沉积物以属于所有主要官能团的物种为主。快速干燥的沉积物以陆生物种为主，而大部分时间淹水的沉积物以淹没物种为主。
The sediments of a southern Australian wetland complex were investigated to determine the germinable seed bank. The number of seeds ranged from 22,000 to 78,000 m(-2). Non-metric multi dimensional scaling (NMS) ordination based upon species composition separated the four basins but each contained the representatives of the major functional groups: terrestrial, amphibious and submerged. To test the influence of water regime on the final floristic composition derived from these seed banks, sediments were positioned at three elevations ( 0, 30 and 80 cm) and subjected to three hydrologic regimes ( static water level, and draw down rates of 2.5 and 7 cm week(-1)). Species compositions were analysed after 98 days via ordination. Despite significant differences in the initial seed bank composition the final floristic compositions were correlated with the water regime and independent of the initial seed bank composition. Species groups were segregated on a basis of whether sediments were continuously exposed to the atmosphere, the rate of draw down and the water depth. Moist sediments were dominated by species belonging to all the main functional groups. Sediments subject to rapid drying were dominated by terrestrial species whereas sediments that were flooded for the majority of the time were dominated by submerged species.