Extreme flooding events on the Rhine and the survival and distribution of riparian plant species
Extreme flooding events on the Rhine and the survival and distribution of riparian plant species
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DOI：
10.1046/j.1365-2745.2003.00749.x
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发表时间：
2003-02-01
影响因子：
5.5
通讯作者：
de Kroon, H
中科院分区：
文献类型：
--
作者：
Vervuren, PJA;Blom, CWPM;de Kroon, H
(1)夏季洪水对滨水植物的地带性有较大影响，其严重程度受洪水持续时间、淹没深度和水下光照有效性的影响我们分析了莱茵河中这些洪水成分的范围和变动性，并量化了它们在实验条件下对黄菖蒲（Arrhenatherum elatius）、千叶菖蒲（Achillea millefolium）、油菖蒲（Rumex acetosa）和红菖蒲（Rumex crispus）在淹没期生存能力的影响利用生存特征模拟了极端洪水和平均洪水下物种的下分布边界，并与目前的野外分布进行了比较。通过实施三种悬载场景，模拟了不同的光照条件莱茵河极深洪水的特点是中等透光率非常低（即低于0.5%）。在如此低的水平(0.4-3.5 μ mol m（-2) s(-1)）下观察到最大的生存反应。光的作用对赤杨和千叶的影响较强，对白杨和白杨的影响较弱。淹没深度也会影响生存，但没有光线那么强烈在正常光照条件下，平均洪水对不耐涝树种（千叶橐吾和黄花橐吾）的田间分布影响不大。然而，它们在2000年的实际场分布与极端年份的预测下限相对应。这表明极端年份决定了这些物种多年的分布。悬载情景显著地修正了极端年和平均年的预测下限，这意味着植物分布下限可能会随着水系悬载的变化而显著地向上或向下移动2000年预测的中度耐油松和高度耐油松极端年和平均年的下限均低于田间实际分布。这表明，它们目前的分布仅部分受到大洪水干扰的影响，其他因素，无论是近因因素还是历史因素，都可能起着重要作用。
1 Summer floods whose severity is affected by flooding duration, submergence depth and underwater light availability, have a large impact on the zonation of riparian plant species.2 We analysed the range and variability of these flooding components in the River Rhine and quantified their effects on the ability of Arrhenatherum elatius , Achillea millefolium , Rumex acetosa and Rumex crispus , to survive periods of submergence under experimental conditions.3 Survival characteristics were used to model species' lower distribution boundaries for extreme and average floods and were compared with the current field distribution. Different light conditions were simulated by implementing three scenarios of suspended load.4 Extreme deep Rhine floods are characterized by very low median light transmission levels (i.e. below 0.5%). The largest survival responses in the experiment were observed at such low levels (0.4-3.5 mumol m(-2) s(-1) ). Strong effects of light were found in R. crispus and A. millefolium , but responses were weaker in A. elatius and R. acetosa . Submergence depth also affected survival, but not as strongly as light.5 For the flood intolerant species (A. millefolium and A. elatius ) the average flood was predicted to have little effect on field distributions under normal light conditions. However, their actual field distributions in 2000 corresponded to the predicted lower boundaries in the extreme years. This suggests that extreme years determine the distributions of these species for many years. The suspended load scenarios significantly modified the predicted lower boundaries in both extreme and average years, implying that plant lower distribution limits may be significantly shifted upwards or downwards depending on the suspended load of the river system.6 The predicted lower boundaries of the intermediately tolerant R. acetosa and the highly tolerant R. crispus for both extreme and average years were below the actual field distribution in 2000. This suggests that their current distribution is only partly influenced by major flood disturbances and that other factors, either proximate or historical, may play a prominent role.