caa a22 4500 445893818 CHVBK 20180317145625.0 cr unu---uuuuu 170323e20110501xx s 000 0 eng 10.1007/s10750-011-0614-7 doi (NATIONALLICENCE)springer-10.1007/s10750-011-0614-7 The periphyton index of trophic status PIT: a new eutrophication metric based on non-diatomaceous benthic algae in Nordic rivers [Elektronische Daten] [Susanne Schneider, Eli-Anne Lindstrøm] Eutrophication is one of the major problems for surface water quality in Norway, particularly in the lowlands near settlements and agricultural areas. Here, we present a new index based on non-diatomaceous benthic algae (Periphyton index of trophic status, PIT) which is developed on a dataset of >500 samples from >350 sites from the Norwegian mainland and can be used to describe trophic status at a river site. PIT indicator values for benthic algae taxa are derived from water total phosphorus concentrations and range from 1.87 for Stigonema hormoides to 68.91 for Tribonema sp. PIT site values range from 3.42 to 44.45 and cover a range from oligotrophic to eutrophic conditions. The relationship between the PIT and the total phosphorus concentration has one major threshold at 10μg/l TP, with a slow increase below and a steep increase above 10μg/l. We conclude that benthic algae species composition at nutrient poor sites reacts only slightly to small increases in phosphorus concentration, while it is most sensible to eutrophication in the range between 10 and 30μg TP/l. For the genus Oedogonium, we found a significant positive correlation between filament width and TP concentration, making Oedogonium an easy to use eutrophication indicator. Springer Science+Business Media B.V., 2011 Periphyton nationallicence Epilithon nationallicence Phytobenthos nationallicence Phosphorus nationallicence Indicator nationallicence Oedogonium nationallicence Schneider Susanne Norwegian Institute of Water Research, Gaustadalleen 21, 0349, Oslo, Norway aut Lindstrøm Eli-Anne Norwegian Institute of Water Research, Gaustadalleen 21, 0349, Oslo, Norway aut Hydrobiologia Springer Netherlands 665/1(2011-05-01), 143-155 0018-8158 665:1<143 2011 665 10750 https://doi.org/10.1007/s10750-011-0614-7 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10750-011-0614-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Schneider Susanne Norwegian Institute of Water Research, Gaustadalleen 21, 0349, Oslo, Norway aut NATIONALLICENCE 700 1- Lindstrøm Eli-Anne Norwegian Institute of Water Research, Gaustadalleen 21, 0349, Oslo, Norway aut NATIONALLICENCE 773 0- Hydrobiologia Springer Netherlands 665/1(2011-05-01), 143-155 0018-8158 665:1<143 2011 665 10750 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer