Geomorphic legacy controls macrophyte distribution within and across disconnected floodplain lakes.
Geomorphic legacy controls macrophyte distribution within and across disconnected floodplain lakes.
复制标题
地貌遗产控制着互不相连的洪泛区湖泊内部和之间的大型植物分布。
DOI：
10.1111/fwb.12317
复制
发表时间：
2014
影响因子：
2.7
通讯作者：
N.
中科院分区：
文献类型：
--
作者：
Negishi;J. N.;Soga;M.;Ishiyama;N.;Suzuki;N.;Yuta;T.;Sueyoshi;M.;... & Yoshimura;N.
随着越来越多的泛滥平原湖泊与河流的河流动力脱节，泛滥平原的退化仍在继续。关于历史地貌形成过程(即地貌遗产)如何决定当代生态系统结构和功能，人们了解有限。我们验证了地貌遗产中介形态测量和导致连通泛滥平原湖中水生植物分布异质性的假设，考察了水生植物盖度分布与环境因素的关系，包括水营养水平、湖泊形态测量和日本石川河沿岸三种类型湖泊之间的斑块遮挡水平。人工湖泊(航道化隔离)、天然牛尾湖和沼泽湖泊由于堤防建设而与天然洪水脉冲中断了40多年。结合当地水深和河床坡度，可以很好地预测大型植物的存在(在5米×15米的区域)。湖泊平均深度越高，表明湖泊切割越深，滨海地带越陡峭，对整个湖泊的大型植物覆盖率的影响最大，也是最负面的。人工湖由于平均水深较大，盖度最小，与其他湖泊类型相比，预测的水生植物覆盖面积明显小于实际覆盖面积。人工湖中的水生植物盖度特别容易受到海浪和风等外部因素的影响。这项研究强调了地貌遗产在解释研究湖泊中水生植物总盖度的很大比例异质性方面的重要性。人工湖不具备天然湖泊的水生植物栖息地质量。当湖泊形态测量需要改变时，应根据河流-泛滥平原动态相互作用留下的地貌遗产，仔细研究当地条件以及斑块尺度特性。
Degradation of floodplains continues with an increasing number of floodplain lakes disconnected from the fluvial dynamics of rivers. Limited understanding is available as to how historical geomorphic formation processes (i.e. geomorphic legacy) determine contemporary ecosystem structure and function. We tested the hypothesis that geomorphic legacy mediates morphometry and results in heterogeneity of macrophyte distributions in disconnected floodplain lakes.The distribution of macrophyte cover was examined in relation to environmental factors, including water nutrient level, morphometry of lakes and patch shelter level across and among three types of lakes along the Ishikari River, Japan. Artificial lakes (isolated by channelisation), natural oxbow lakes and marsh lakes have been disconnected for more than 40 years from natural flood pulses because of dyke construction.The presence of macrophytes (in 5 × 5 m areas) was predicted well by a combination of local water depth and bed slope. Lake average depth, higher values indicating lakes that are more deeply incised with a steeper‐sloped littoral zone, had the strongest and most negative influence on total macrophyte cover across lakes. Cover was least in artificial lakes because of greater average depth.Predicted area of macrophyte cover was significantly less than occupied by actual cover in artificial lakes compared with other lake types. Macrophyte cover in artificial lakes was particularly vulnerable to external factors such as waves and wind.This study underscored the significance of geomorphic legacy in explaining a large proportion of heterogeneity of total macrophyte cover in the study lakes. Artificial lakes did not have the macrophyte habitat quality of natural lakes. When lake morphometry needs to be altered, local conditions as well as patch‐scale properties should be carefully examined in the light of the geomorphic legacy left by dynamic river–floodplain interactions.