Spatial Distribution of Nutrient Limitation in the Danube River Floodplain in Relation to Hydrological Connectivity
Spatial Distribution of Nutrient Limitation in the Danube River Floodplain in Relation to Hydrological Connectivity
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DOI：
10.1007/s13157-011-0208-1
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发表时间：
2011-07
期刊：
影响因子：
2
通讯作者：
V. Peršić;J. Horvatić
中科院分区：
文献类型：
--
作者：
V. Peršić;J. Horvatić
In this paper, we describe the influence of flooding on nutrient conditions and phytoplankton Chl-aconcentrations in a hydrologically dynamic Danube floodplain in North–Eastern Croatia. Based on hydrological typology, the connectivity gradient extends from the main river stream (Eupotamal) to the backwater channels and side-arms (Parapotamal) to the edge of the floodplain (Paleopotamal). A spatial gradient of phytoplankton Chl-aoccurred during low water levels, while uniformity of Chl-aacross wetland habitats was observed during high water levels. Nutrient enrichment assays indicated that inorganic nutrients in Eupotamal waters (N/P ratio 16–22) could support a higher growth rate of the assay algaChlorella kessleri, while potential N limitation was found in Parapotamal and Paleopotamal waters (both with N/P ratios < 14). Spatial expansion of N limitation toward the main river was observed as inundation continued. Lateral flood pulse connectivity along with the duration of inundation period affects the input and the retention of nutrients, especially of nitrogen. Understanding of the relationship between spatial (location of the floodplain waterbodies regarding the river) and temporal (hydrological connectivity between the river and its floodplain) dimensions contribute to the importance of healthy floodplains for the maintenance of water quality and environmental conditions in the Danube River.
