Environmental factors regulating stream nitrate concentrations at baseflow condition in a large region encompassing a climatic gradient

2021 ◽  
Author(s):  
Soyoka Makino ◽  
Naoko Tokuchi ◽  
Yukio Komai ◽  
Takao Kunimatsu
Keyword(s):  
Environmental Factors ◽  
Large Region ◽  
Climatic Gradient ◽  
Nitrate Concentrations ◽  
Stream Nitrate

REGIONAL COHERENCE OF STREAM NITRATE CONCENTRATIONS: IMPLICATIONS FOR THEORY AND MANAGEMENT

2018 ◽  
Author(s):  
Lauren E. Koenig ◽  
◽  
William H. McDowell ◽  
Lisle E. Snyder ◽  
Jody D. Potter
Keyword(s):  
Nitrate Concentrations ◽  
Stream Nitrate

scholarly journals Factors driving diversity and succession of diatom assemblages in a Neotropical rainforest stream

2018 ◽  
Vol 54 ◽  
pp. 30 ◽  
Author(s):  
Jhon Charles Donato Rondón ◽  
Yaira Ayarith Abuhatab Aragón
Keyword(s):  
Environmental Factors ◽  
Solar Radiation ◽  
Shannon Index ◽  
Diatom Assemblages ◽  
Fluvial Systems ◽  
Neotropical Streams ◽  
Biogeographic Region ◽  
Nitrate Concentrations ◽  
Taxonomic Changes ◽  
Neotropical Rainforest

This study assessed short-term succession and related changes in diversity and succession of benthic diatom assemblages in a tropical rainforest stream in the biogeographic region of Chocó, Colombia. Diatom colonization in situ was studied over a 60-day period, in which we analyzed the number of valves and the taxonomic changes. The Shannon index ranged from 2.06 to 3.02 bits. A total of 127 species were identified and the most abundant were acidophilic species such as Eunotia intermedia, E. veneris, E. bilunaris var. mucophila, E. pirla and E. bilunaris. A Detrended Canonical Correspondence Analysis (DCCA) was used to explore the succession of diatom assemblages and its driving environmental factors. The DCCA explained 74.1% of the correlation between environmental variables and diatom species and 16.2% of the data variance. The species fell into four groups, the first group (Eunotia incisa, Frustulia saxonica, Fragilaria capucina var. acatu, among others) was related to lower nitrate concentrations, acidic pH and lower water temperature. The second group (Fragilaria capensis, Gomphonema olivaceum, Cymbella gracilis, among others) was associated to higher alkalinity and lower solar radiation availability. The third group (Nitzschia obtusa, N. amphibia, Naviculadicta vitabunda, Navicula cryptocephala, among others) was related to lower phosphate, higher nitrate concentrations, lower pH, and higher temperatures. The fourth group (Eunotia soleirolli, Frustulia vulgaris and F. rhomboides) was associated with higher solar radiation and lower alkalinity. These results underscore the importance of diatom diversity in Neotropical streams and the relevance of small variations in environmental factors on the composition of reference assemblages of Neotropical fluvial systems.

scholarly journals Reduction of stream nitrate concentrations by land management in contrasted landscapes

2019 ◽  
Vol 114 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Laurène Casal ◽  
Patrick Durand ◽  
Nouraya Akkal-Corfini ◽  
Cyril Benhamou ◽  
François Laurent ◽  
...  
Keyword(s):  
Land Management ◽  
Nitrate Concentrations ◽  
Stream Nitrate

scholarly journals Export flux of unprocessed atmospheric nitrate from temperate forested catchments: A possible new index for nitrogen saturation

2018 ◽  
Author(s):  
Fumiko Nakagawa ◽  
Urumu Tsunogai ◽  
Yusuke Obata ◽  
Kenta Ando ◽  
Naoyuki Yamashita ◽  
...  
Keyword(s):  
Soil Water ◽  
Nitrogen Saturation ◽  
Weighted Average ◽  
Deposition Flux ◽  
Forested Catchments ◽  
Export Flux ◽  
Stable Isotopic ◽  
Nitrate Concentrations ◽  
Atmospheric Nitrate ◽  
Stream Nitrate

Abstract. To clarify the biological processing of nitrate within temperate forested catchments using unprocessed atmospheric nitrate exported from each catchment as a tracer, we continuously monitored stream nitrate concentrations and stable isotopic compositions including 17O-excess (Δ17O) in three forested catchments in Japan (KJ, IJ1, and IJ2) for more than two years. The catchments showed varying flux-weighted average nitrate concentrations: 58.4, 24.4, and 17.1 µmol L−1 in KJ, IJ1, and IJ2, respectively. In addition to stream nitrate, nitrate concentrations and stable isotopic compositions in soil water were determined for comparison in the most nitrate-enriched catchment (the KJ site). While 17O-excess of nitrate in soil water showed significant seasonal variation, ranging from +0.1 to +5.7 ‰, stream nitrate showed small variation, from +0.8 to +2.0‰ in KJ, +0.7 to +2.8 ‰ in IJ1, and +0.4 to +2.2‰ in IJ2. We concluded that the major source of stream nitrate in each forested catchment was nitrate in groundwater, which buffered the seasonal variations in soil water nitrate. The estimated annual export flux of unprocessed atmospheric nitrate accounted for 9.4 ± 2.6 %, 6.5 ± 1.8 %, and 2.6 ± 0.6 % of the annual deposition flux of atmospheric nitrate in KJ, IJ1, and IJ2, respectively. The export flux of unprocessed atmospheric nitrate relative to the deposition flux showed a clear normal correlation with the flux-weighted average concentration of stream nitrate, indicating that reductions in the biological assimilation rates of nitrate in forested soils, rather than increased nitrification rates, are likely responsible for the enrichment of stream nitrate, probably due to nitrogen saturation. The export flux of unprocessed atmospheric nitrate relative to the deposition flux in each forest ecosystem is applicable as an index for nitrogen saturation.

Climate Effects on Stream Nitrate Concentrations at 16 Forested Catchments in South Central Ontario

2004 ◽  
Vol 38 (8) ◽  
pp. 2383-2388 ◽  
Author(s):  
Shaun A. Watmough ◽  
M. Catherine Eimers ◽  
Julian Aherne ◽  
Peter J. Dillon
Keyword(s):  
Forested Catchments ◽  
Climate Effects ◽  
South Central ◽  
Nitrate Concentrations ◽  
Stream Nitrate

Groundwater dynamics and channel activity as major controls of in-stream nitrate concentrations in a lowland catchment system?

2007 ◽  
Vol 343 (3-4) ◽  
pp. 154-168 ◽  
Author(s):  
Gunter Wriedt ◽  
Joris Spindler ◽  
Tina Neef ◽  
Ralph Meißner ◽  
Michael Rode
Keyword(s):  
Channel Activity ◽  
Groundwater Dynamics ◽  
Nitrate Concentrations ◽  
Stream Nitrate

Long-Term Trends in Stream Nitrate Concentrations and Losses Across Watersheds Undergoing Recovery from Acidification in the Czech Republic

Ecosystems ◽  
2008 ◽  
Vol 11 (3) ◽  
pp. 410-425 ◽  
Author(s):  
Filip Oulehle ◽  
William H. McDowell ◽  
Jacqueline A. Aitkenhead-Peterson ◽  
Pavel Krám ◽  
Jakub Hruška ◽  
...  
Keyword(s):  
Czech Republic ◽  
The Czech Republic ◽  
Nitrate Concentrations ◽  
Recovery From Acidification ◽  
Long Term Trends ◽  
Stream Nitrate
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