Prorocentrum minimum tracks anthropogenic nitrogen and phosphorus inputs on a global basis: Application of spatially explicit nutrient export models

Harmful Algae ◽  
2008 ◽  
Vol 8 (1) ◽  
pp. 33-38 ◽  
Author(s):  
Patricia M. Glibert ◽  
Emilio Mayorga ◽  
Sybil Seitzinger
Keyword(s):  
Prorocentrum Minimum ◽  
Spatially Explicit ◽  
Nutrient Export ◽  
Nitrogen And Phosphorus ◽  
Anthropogenic Nitrogen

scholarly journals Simulation of dissolved nutrient export from the Dongjiang river basin with a grid-based NEWS model

2018 ◽  
Vol 38 ◽  
pp. 01051
Author(s):  
Qiangqiang Rong ◽  
Meirong Su ◽  
Zhifeng Yang ◽  
Yanpeng Cai ◽  
Wencong Yue ◽  
...  
Keyword(s):  
River Basin ◽  
Inorganic Nitrogen ◽  
Fertilizer Application ◽  
Main Stream ◽  
Nutrient Export ◽  
Biological Fixation ◽  
Nitrogen And Phosphorus ◽  
Model Framework ◽  
Dongjiang River ◽  
Grid Based

In this research, a grid-based NEWS model was proposed through coupling the geographic information system (GIS) with the Global NEWS model framework. The model was then applied to the Dongjiang River basin to simulate the dissolved nutrient export from this area. The model results showed that the total amounts of the dissolved nitrogen and phosphorus exported from the Dongjiang River basin were approximately 27154.87 and 1389.33 t, respectively. 90 % of the two loads were inorganic forms (i.e. dissolved inorganic nitrogen and phosphorus, DIN and DIP). Also, the nutrient export loads did not evenly distributed in the basin. The main stream watershed of the Dongjiang River basin has the largest DIN and DIP export loads, while the largest dissolved organic nitrogen and phosphorus (DON and DOP) loads were observed in the middle and upper stream watersheds of the basin, respectively. As for the nutrient exported from each subbasin, different sources had different influences on the output of each nutrient form. For the DIN load in each subbasin, fertilization application, atmospheric deposition and biological fixation were the three main contributors, while eluviation was the most important source for DON. In terms of DIP load, fertilizer application and breeding wastewater were the main contributors, while eluviation and fertilizer application were the two main sources for DOP.

scholarly journals BioRT-Flux-PIHM v1.0: a watershed biogeochemical reactive transport model

2020 ◽  
Author(s):  
Wei Zhi ◽  
Yuning Shi ◽  
Hang Wen ◽  
Leila Saberi ◽  
Gene-Hua Crystal Ng ◽  
...  
Keyword(s):  
Deep Water ◽  
Land Surface ◽  
Reactive Transport ◽  
Transport Model ◽  
Transport Processes ◽  
Spatially Explicit ◽  
Watershed Scale ◽  
Nitrogen And Phosphorus ◽  
Reactive Transport Model ◽  
Component Representation

Abstract. Watersheds are the fundamental Earth surface functioning unit that connects the land to aquatic systems. Existing watershed-scale models typically have physics-based representation of hydrology process but often lack mechanism-based, multi-component representation of reaction thermodynamics and kinetics. This lack of watershed reactive transport models has limited our ability to understand and predict solute export and water quality, particularly under changing climate and anthropogenic conditions. Here we present a recently developed BioRT-Flux-PIHM (BFP) v1.0, a watershed-scale biogeochemical reactive transport model. Augmenting the previously developed RT-Flux-PIHM that integrates land-surface interactions, surface hydrology, and abiotic geochemical reactions (Bao et al., 2017, WRR), the new development enables the simulation of 1) biotic processes including plant uptake and microbe-mediated biogeochemical reactions that are relevant to the transformation of organic matter that involve carbon, nitrogen, and phosphorus; and 2) shallow and deep water partitioning to represent surface and groundwater interactions. The reactive transport part of the code has been verified against the widely used reactive transport code CrunchTope. BioRT-Flux-PIHM v1.0 has recently been applied to understand reactive transport processes in multiple watersheds across different climate, vegetation, and geology conditions. This paper introduces the governing equations and model structure of the code. It also demonstrates examples that simulate shallow and deep water interactions, and biogeochemical reactive transport relevant to nitrate and dissolved organic carbon (DOC). These examples were illustrated in two simulation modes of varying complexity. One is the spatially implicit mode that focuses on processes and average behavior of a watershed. Another is in a spatially explicit mode that includes details of topography, land cover, and soil property conditions. The spatially explicit mode can be used to understand the impacts of spatial structure and identify hot spots of biogeochemical reactions.

Salmon-mediated nutrient flux in selected streams of the Columbia River basin, USA

2013 ◽  
Vol 70 (3) ◽  
pp. 502-512 ◽  
Author(s):  
Andre E. Kohler ◽  
Paul C. Kusnierz ◽  
Timothy Copeland ◽  
David A. Venditti ◽  
Lytle Denny ◽  
...  
Keyword(s):  
Chinook Salmon ◽  
Stream Flow ◽  
Oncorhynchus Tshawytscha ◽  
Nutrient Flux ◽  
Columbia River Basin ◽  
Production Data ◽  
Nutrient Fluxes ◽  
Nutrient Export ◽  
Nitrogen And Phosphorus ◽  
Proportional Rate

Salmon provide an important resource subsidy and linkage between marine and land-based ecosystems. This flow of energy and nutrients is not unidirectional (i.e., upstream only); in addition to passive nutrient export via stream flow, juvenile emigrants actively export nutrients from freshwater environments. In some cases, nutrient export can exceed import. We evaluated nutrient fluxes in streams across central Idaho, USA, using Chinook salmon (Oncorhynchus tshawytscha) adult escapement and juvenile production data from 1998 to 2008. We found in the majority of stream-years evaluated, adults imported more nutrients than progeny exported; however, in 3% of the years, juveniles exported more nutrients than their parents imported. On average, juvenile emigrants exported 22% ± 3% of the nitrogen and 30% ± 4% of the phosphorus their parents imported. This relationship was density-dependent and nonlinear; during periods of low adult abundance, juveniles were larger and exported up to 194% and 268% of parental nitrogen and phosphorus inputs, respectively. We highlight minimum escapement thresholds that appear to (i) maintain consistently positive net nutrient flux and (ii) reduce the average proportional rate of export across study streams. Our results suggest a state shift occurs when adult spawner abundance falls below a threshold to a point where the probability of juvenile nutrient exports exceeding adult imports becomes increasingly likely.

scholarly journals Changes in anthropogenic nitrogen and phosphorus inputs to the St. Lawrence sub-basin over 110 years and impacts on riverine export

2016 ◽  
Vol 30 (7) ◽  
pp. 1000-1014 ◽  
Author(s):  
Jean-Olivier Goyette ◽  
Elena M. Bennett ◽  
Robert W. Howarth ◽  
Roxane Maranger
Keyword(s):  
Nitrogen And Phosphorus ◽  
Anthropogenic Nitrogen ◽  
Riverine Export
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