| 1. |
- Hong, Bongghi, et al.
(författare)
-
Evaluating regional variation of net anthropogenic nitrogen and phosphorus inputs (NANI/NAPI), major drivers, nutrient retention pattern and management implications in the multinational areas of Baltic Sea basin
- 2012
-
Ingår i: Ecological Modelling. - : Elsevier BV. - 0304-3800 .- 1872-7026. ; 227, s. 117-135
-
Tidskriftsartikel (refereegranskat)abstract
- The NANI/NAPI (net anthropogenic nitrogen/phosphorus input) Calculator Toolbox described in this paper is designed to address the consequences to Baltic Sea nutrient loads of the significant variation in agronomic practices and dietary preferences among European countries whose watersheds comprise the Baltic Sea basin. A primary objective of this work is to develop regional parameters and datasets for this budgeting tool. A previous version of the toolbox was applied to the entire contiguous United States to calculate NANI and its components (atmospheric N deposition, fertilizer N application, agricultural N fixation and N in net food and feed imports). Here, it is modified for application to the Baltic Sea catchments, where coastal watersheds from several countries are draining to international waters. A similar accounting approach is taken for calculating NAPI, which includes fertilizer P application, P in net food and feed imports and non-food use of P by human. Regional variation of NANI/NAPI parameters (agricultural fixation rates, human intake rates and livestock intake and excretion rates) are estimated, and their impact on the regional nutrient budget and the riverine nutrient flux is evaluated. There is a distinct north-to-south gradient in NANI and NAPI across the Baltic Sea catchments, and regional nutrient inputs are strongly related to riverine nutrient fluxes. Analysis of regional nutrient retention pattern indicates that, for some countries, compliance to the Baltic Sea Action Plan would imply enormous changes in the agricultural sector.
|
|
| 2. |
- Lyon, Steve W., et al.
(författare)
-
Seasonal and Regional Patterns in Performance for a Baltic Sea Drainage Basin Hydrologic Model
- 2015
-
Ingår i: Journal of the American Water Resources Association. - : Wiley. - 1093-474X .- 1752-1688. ; 51:2, s. 550-566
-
Tidskriftsartikel (refereegranskat)abstract
- This study evaluates the ability of the Catchment SIMulation (CSIM) hydrologic model to describe seasonal and regional variations in river discharge over the entire Baltic Sea drainage basin (BSDB) based on 31years of monthly simulation from 1970 through 2000. To date, the model has been successfully applied to simulate annual fluxes of water from the catchments draining into the Baltic Sea. Here, we consider spatiotemporal bias in the distribution of monthly modeling errors across the BSDB since it could potentially reduce the fidelity of predictions and negatively affect the design and implementation of land-management strategies. Within the period considered, the CSIM model accurately reproduced the annual flows across the BSDB; however, it tended to underpredict the proportion of discharge during high-flow periods (i.e., spring months) and overpredict during the summer low flow periods. While the general overpredictions during summer periods are spread across all the subbasins of the BSDB, the underprediction during spring periods is seen largely in the northern regions. By implementing a genetic algorithm calibration procedure and/or seasonal parameterization of subsurface water flows for a subset of the catchments modeled, we demonstrate that it is possible to improve the model performance albeit at the cost of increased parameterization and potential loss of parsimony.
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
- McCrackin, Michelle L., et al.
(författare)
-
A Century of Legacy Phosphorus Dynamics in a Large Drainage Basin
- 2018
-
Ingår i: Global Biogeochemical Cycles. - 0886-6236 .- 1944-9224. ; 32:7, s. 1107-1122
-
Tidskriftsartikel (refereegranskat)abstract
- There is growing evidence that the release of phosphorus (P) from legacy stores can frustrate efforts to reduce P loading to surface water from sources such as agriculture and human sewage. Less is known, however, about the magnitude and residence times of these legacy pools. Here we constructed a budget of net anthropogenic P inputs to the Baltic Sea drainage basin and developed a three-parameter, two-box model to describe the movement of anthropogenic P though temporary (mobile) and long-term (stable) storage pools. Phosphorus entered the sea as direct coastal effluent discharge and via rapid transport and slow, legacy pathways. The model reproduced past waterborne P loads and suggested an similar to 30-year residence time in the mobile pool. Between 1900 and 2013, 17 and 27 Mt P has accumulated in the mobile and stable pools, respectively. Phosphorus inputs to the sea have halved since the 1980s due to improvements in coastal sewage treatment and reductions associated with the rapid transport pathway. After decades of accumulation, the system appears to have shifted to a depletion phase; absent further reductions in net anthropogenic P input, future waterborne loads could decrease. Presently, losses from the mobile pool contribute nearly half of P loads, suggesting that it will be difficult to achieve substantial near-term reductions. However, there is still potential to make progress toward eutrophication management goals by addressing rapid transport pathways, such as overland flow, as well as mobile stores, such as cropland with large soil-P reserves.
|
|
| 6. |
- McCrackin, Michelle L., et al.
(författare)
-
Opportunities to reduce nutrient inputs to the Baltic Sea by improving manure use efficiency in agriculture
- 2018
-
Ingår i: Regional Environmental Change. - : Springer Science and Business Media LLC. - 1436-3798 .- 1436-378X. ; 18:6, s. 1843-1854
-
Tidskriftsartikel (refereegranskat)abstract
- While progress has been made in reducing external nutrient inputs to the Baltic Sea, further actions are needed to meet the goals of the Baltic Sea Action Plan (BSAP), especially for the Baltic Proper, Gulf of Finland, and Gulf of Riga sub-basins. We used the net anthropogenic nitrogen and phosphorus inputs (NANI and NAPI, respectively) nutrient accounting approach to construct three scenarios of reduced NANI-NAPI. Reductions assumed that manure nutrients were redistributed from areas with intense animal production to areas that focus on crop production and would otherwise import synthetic and mineral fertilizers. We also used the Simple as Necessary Baltic Long Term Large Scale (SANBALTS) model to compare eutrophication conditions for the scenarios to current and BSAP-target conditions. The scenarios suggest that reducing NANI-NAPI by redistributing manure nutrients, together with improving agronomic practices, could meet 54–82% of the N reductions targets (28–43 kt N reduction) and 38–64% P reduction targets (4–6.6 kt P reduction), depending on scenario. SANBALTS output showed that even partial fulfillment of nutrient reduction targets could have ameliorating effects on eutrophication conditions. Meeting BSAP targets will require addressing additional sources, such as sewage. A common approach to apportioning sources to external nutrients loads could enable further assessment of the feasibility of eutrophication management targets.
|
|
| 7. |
- Smith, S.V., et al.
(författare)
-
River nutrient loads and catchment size
- 2005
-
Ingår i: Biogeochemistry. - : Springer. - 0168-2563 .- 1573-515X. ; 75, s. 83-107
-
Tidskriftsartikel (refereegranskat)abstract
- We have used a total of 496 sample sites to calibrate a simple regression model for calculating dissolved inorganic nutrient fluxes via runoff to the ocean. The regression uses the logarithms of runoff and human population as the independent variables and estimates the logarithms of dissolved inorganic nitrogen and phosphorus loading with R2 values near 0.8. This predictive capability is about the same as has been derived for total nutrient loading with process-based models requiring more detailed information on independent variables. We conclude that population and runoff are robust proxies for the more detailed application, landscape modification, and in-stream processing estimated by more process-based models. The regression model has then been applied to a demonstration data set of 1353 river catchments draining to the sea from the North American continent south of the Canadian border. The geographic extents of these basins were extracted from a 1-km digital elevation model for North America, and both runoff and population were estimated for each basin. Most of the basins (72% of the total) are smaller than 103 km2, and both runoff and population density are higher and more variable among small basins than among larger ones.While total load to the ocean can probably be adequately estimated from large systems only, analysis of the geographic distribution of nutrient loading requires consideration of the small basins, which can exhibit significant hydrologic and demographic heterogeneity between systems over their range even within the same geographic region. High-resolution regional and local analysis is necessary for environmental assessment and management.
|
|
| 8. |
- Svanbäck, Annika, et al.
(författare)
-
Reducing agricultural nutrient surpluses in a large catchment - Links to livestock density
- 2019
-
Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 648, s. 1549-1559
-
Tidskriftsartikel (refereegranskat)abstract
- The separation between crop- and livestock production is an important driver of agricultural nutrient surpluses in many parts of the world. Nutrient surpluses can be symptomatic of poor resource use efficiency and contribute to environmental problems. Thus, it is important not only to identify where surpluses can be reduced, but also the potential policy tools that could facilitate reductions. Here, we explored linkages between livestock production and nutrient flows for the Baltic Sea catchment and discuss management practices and policies that influence the magnitude of nutrient surpluses. We found that the majority of nutrients cycled through the livestock sector and that large nitrogen and phosphorus surpluses often occurred in regions with high livestock density. Imports of mineral fertilizers and feed to the catchment increased overall surpluses, which in turn increased the risk of nutrient losses from agriculture to the aquatic environment. Many things can be done to reduce agricultural nutrient surpluses; an important example is using manure nutrients more efficiently in crop production, thereby reducing the need to import mineral fertilizers. Also, existing soil P reserves could be used to a greater extent, which further emphasizes the need to improve nutrient management practices. The countries around the Baltic Sea used different approaches to manage agricultural nutrient surpluses, and because eight of the coastal countries are members in the European Union (EU), common EU policies play an important role in management. We observed reductions in surpluses between 2000 and 2010 in some countries, which suggested the influence of different approaches to management and policy and that there are opportunities for further improvement. However, the separation between crop and livestock production in agriculture appears to be an underlying cause of nutrient surpluses; thus, further research is needed to understand how policy can address these structural issues and increase sustainability in food production.
|
|
| 9. |
- Swaney, D. P., et al.
(författare)
-
Five critical questions of scale for the coastal zone
- 2012
-
Ingår i: Estuarine, Coastal and Shelf Science. - : Elsevier BV. - 0272-7714 .- 1096-0015. ; 96, s. 9-21
-
Tidskriftsartikel (refereegranskat)abstract
- Social and ecological systems around the world are becoming increasingly globalized. From the standpoint of understanding coastal ecosystem behavior, system boundaries are not sufficient to define causes of change. A flutter in the stock market in Tokyo or Hong Kong can affect salmon producers in Norway or farmers in Togo. The globalization of opportunistic species and the disempowerment of people trying to manage their own affairs on a local scale seem to coincide with the globalization of trade. Human-accelerated environmental change, including climate change, can exacerbate this sense of disenfranchisement. The structure and functioning of coastal ecosystems have been developed over thousands of years subject to environmental forces and constraints imposed mainly on local scales. However, phenomena that transcend these conventional scales have emerged with the explosion of human population, and especially with the rise of modern global culture. Here, we examine five broad questions of scale in the coastal zone: (1) How big are coastal ecosystems and why should we care? (2) Temporal scales of change in coastal waters and watersheds: Can we detect shifting baselines due to economic development and other drivers? (3) Are footprints more important than boundaries? (4) What makes a decision big? The tyranny of small decisions in coastal regions. (5) Scales of complexity in coastal waters: the simple, the complicated or the complex? These questions do not have straightforward answers. There is no single scale for coastal ecosystems; their multiscale nature complicates our understanding and management of them. Coastal ecosystems depend on their watersheds as well as spatially-diffuse footprints associated with modern trade and material flows. Change occurs both rapidly and slowly on human time scales, and observing and responding to changes in coastal environments is a fundamental challenge. Apparently small human decisions collectively have potentially enormous consequences for coastal environmental quality, and our success in managing the effects of these decisions will determine the quality of life in the coastal zone in the 21st century and beyond. Vigilant monitoring, creative synthesis of information, and continued research will be necessary to properly understand and govern our coastal environments into the future.
|
|
| 10. |
- Swaney, Dennis P., et al.
(författare)
-
Net anthropogenic nitrogen inputs to watersheds and riverine N export to coastal waters : a brief overview
- 2012
-
Ingår i: Current Opinion in Environmental Sustainability. - : Elsevier BV. - 1877-3435 .- 1877-3443. ; 4:2, s. 203-211
-
Tidskriftsartikel (refereegranskat)abstract
- In recent years, watershed-scale nutrient accounting methods have been developed which provide a simple yet powerful approach to estimate major anthropogenic sources of nutrients to terrestrial and aquatic ecosystems. For nitrogen (N), 'anthropogenic sources' include fertilizer, atmospheric N deposition, N fixation by plants (e.g. legumes), and the net import or export of N in human food and livestock feed, and are collectively referred to as Net Anthropogenic Nitrogen Inputs (NANI). Since the development of industrial N-fixing processes early in the 20th century, anthropogenic N inputs have grown to dominate the global N cycle, and have become the main sources of N in most watersheds affected by humans. It is now clear that riverine N transport from human-influenced watersheds to coastal waters is strongly related to NANI, as well as to hydroclimatic variables (precipitation, discharge, temperature) that can affect the amount of N retained in or removed from watersheds. Potential implications for increased N load from NANI include increased eutrophication, loss of species diversity and habitat, and growth of hypoxic areas ('dead zones') in coastal waters.
|
|
