Interferences between root plaque formation and phosphorus availability for isoetids in sediments of oligotrophic lakes
Interferences between root plaque formation and phosphorus availability for isoetids in sediments of oligotrophic lakes
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DOI：
10.1023/a:1006010502422
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发表时间：
1998-11-01
期刊：
影响因子：
4
通讯作者：
Holmer, M
中科院分区：
文献类型：
--
作者：
Christensen, KK;Jensen, HS;Holmer, M
Freshwater isoetids exchanges a high proportion of the photosynthetically produced oxygen over the extensive root system and, therefore, they influence the redox potential (E-h) and phosphorus (P) availability in their sediments. Because isoetids rely on the sediment for P uptake, P may be a key element in controlling the distribution of isoetids. We investigated biomass and P availability to isoetids (Littorella uniflora and Isoetes lacustris) in a transect of five stations across the littoral zone in oligotrophic Lake Kalgaard, Denmark. At the two shallowest stations (0.6 and 1.0 m depth) the redox potential in the low organic rhizosphere sediment was high (>300 mV) and low concentrations of reduced exchangeable iron (Fe) and manganese (Mn) compounds in the sediment and of precipitated Fe and Mn oxides on isoetid roots (plaques) were found. The concentration of sediment P pools was low and so was isoetid P content and isoetid biomass. At intermediate water depth (1.8 m) sediment E-h was high (similar to 300 mV) and isoetids showed low root plaque concentrations. However, higher concentration of P pools in the rhizosphere was found at 1.8 m and isoetids showed the highest P content and biomass. At deeper stations (2.8 and 4.6 m depth) E-h was low (
