Spatial and temporal patterns in total phosphorus in south-central Ontario streams: the role of wetlands and past disturbance

2013 ◽  
Vol 70 (5) ◽  
pp. 766-774 ◽  
Author(s):  
Heather D. O'Brien ◽  
M. Catherine Eimers ◽  
Shaun A. Watmough ◽  
Nora J. Casson
Keyword(s):  
Water Chemistry ◽  
Total Phosphorus ◽  
Spatial And Temporal Patterns ◽  
Forested Catchments ◽  
The Past ◽  
Research Priority ◽  
South Central ◽  
Longitudinal Measurements ◽  
Wetland Cover

Unraveling the cause(s) of declines in total phosphorus (TP) observed over the past three decades across many forested catchments in central Ontario remains a research priority. The objectives of this paper were firstly to test the assumption that weir water chemistry is representative of catchment changes at two adjacent headwater streams that have shown declines in TP and secondly use long-term measurements of weir water quality (1980–2008) to identify potential drivers of TP declines. Longitudinal measurements confirmed that weir water chemistry is generally representative of the entire stream channel, although channel-associated wetlands have a strong influence on TP. Additionally, processes operating in wetlands dictate seasonal patterns in TP, and differences in wetland cover explain the approximately twofold difference in average TP between the two catchments. Changes in wetland cover or processes, however, cannot explain declines in TP. Rather, declines in TP are most coherent with declines in stream potassium (K) and nitrate (NO3-N), which also occurred over the past 30 years. We suggest that coincident declines in TP, NO3-N, and K may be best explained by recovery from a disturbance event.

Impact of wetland disturbance on phosphorus loadings to lakes

2014 ◽  
Vol 71 (11) ◽  
pp. 1695-1703 ◽  
Author(s):  
Kieran C. Pinder ◽  
M. Catherine Eimers ◽  
Shaun A. Watmough
Keyword(s):  
Tree Mortality ◽  
Field Surveys ◽  
The Past ◽  
South Central ◽  
Tree Community ◽  
Dead Trees ◽  
Standing Dead ◽  
Mixed Age ◽  
Wetland Cover

Total phosphorus (TP) concentrations have declined in many lakes and streams across south-central Ontario, Canada, over the past three decades, and changes have been most pronounced in wetland-dominated catchments. In this study, long-term (1980–2007) patterns in TP concentrations in streams were assessed at four wetland-dominated catchments that drain into Dickie Lake (DE) in south-central Ontario. Two of the subcatchments (DE5 and DE6) have particularly large wetland components (31%–34% of catchment area), and these wetlands are characterized by numerous standing dead trees and many young live trees (18–27 years old). These two streams exhibited large peaks in TP and potassium (K) export in the early 1980s. In contrast, TP and K export from DE8 and DE10 (wetland cover 19%–20%) were relatively flat over the entire record (1980–2007), and field surveys indicated negligible standing dead biomass in these wetlands and a relatively healthy, mixed-age tree community. The coincidence of high TP and K concentrations in the DE5 and DE6 streams as well as evidence of a disturbance event in their wetlands during the early 1980s suggest that disturbance events (e.g., flooding) that lead to wetland tree mortality may contribute to patterns in surface water TP observed in this region.

scholarly journals Can recovery from disturbance explain observed declines in total phosphorus in Precambrian Shield catchments?

2016 ◽  
Vol 73 (8) ◽  
pp. 1202-1212 ◽  
Author(s):  
Jill Crossman ◽  
M. Catherine Eimers ◽  
Shaun A. Watmough ◽  
Martyn N. Futter ◽  
Jason Kerr ◽  
...  
Keyword(s):  
Total Phosphorus ◽  
Soil Acidification ◽  
Model Performance ◽  
Timber Harvesting ◽  
Oligotrophic Lakes ◽  
The Past ◽  
Land Disturbance ◽  
South Central ◽  
And Performance ◽  
P Fluxes

The plausibility of land disturbance as a cause of declining phosphorus (P) concentrations in oligotrophic lakes within south-central Ontario, Canada, is evaluated using the process-based model INCA-P. The model was calibrated upon three catchments in the Muskoka–Haliburton region (MHR): Harp (HP), Dickie (DE), and Plastic (PC), which have varying degrees of declining P export and different forms of historic disturbances (timber harvesting, tree death, and soil acidification, respectively). Hindcasts (1978–2007) were run with and without simulated disturbances. Model performance of both DE and HP was greatly improved when effects of wetland tree deaths (DE) and harvesting (HP) were included. In PC, with no record of timber harvesting and relatively minor declines in P, initial hindcasts successfully accounted for the majority of interannual P fluxes, and performance was only marginally improved through the simulation of soil acidification. Vegetation decay, harvesting, and catchment acidification accounted for 63%, 24%, and 0.6%, respectively, of P export over the past 30 years. Of all disturbances, wetland vegetation death had the highest impact on areal P exports, indicating that riparian stability is particularly important.

Long-term declines in phosphorus export from forested catchments in south-central Ontario

2009 ◽  
Vol 66 (10) ◽  
pp. 1682-1692 ◽  
Author(s):  
M. Catherine Eimers ◽  
Shaun A. Watmough ◽  
Andrew M. Paterson ◽  
Peter J. Dillon ◽  
Huaxia Yao
Keyword(s):  
Stream Flow ◽  
Seasonal Patterns ◽  
Forested Catchments ◽  
Annual Average ◽  
Temporal And Spatial Patterns ◽  
South Central ◽  
Hydrologic Event ◽  
Temporal And Spatial ◽  
Shield Lakes

Total phosphorus (TP) levels in many Canadian Shield lakes in central Ontario have declined over recent decades, despite increases in human activity in most watersheds. To investigate the contribution of changes in catchment export to long-term declines in lake TP, we examined temporal and spatial patterns in TP concentrations and export (1980–1981 to 2001–2002) across 11 subcatchments that drain into three lakes in which average ice-free TP levels have declined by approximately 35%. Annual stream export of TP decreased significantly by 30%–89% in eight of the 11 subcatchments, and decreases in export were driven by declines in TP concentration, not changes in stream flow. Annual average TP concentrations varied fivefold among adjacent subcatchments, and temporal patterns in annual average TP concentrations were poorly correlated. Seasonal patterns of TP concentration were most similar among streams in the spring (March–April–May), and TP export in the spring declined significantly in 10 of the 11 subcatchments. Because spring melt is the principal hydrologic event in these seasonally snow-covered basins, decreases in TP export during the spring were primarily responsible for declines observed in annual export. The drivers of changes in TP over time are unclear at this point but are the focus of current research.

Enabling Community Well-being Self-Monitoring in the Context of Mining: The Naskapi Nation of Kawawachikamach

2016 ◽  
Vol 1 (2) ◽  
Author(s):  
Robert Klinck ◽  
Ben Bradshaw ◽  
Ruby Sandy ◽  
Silas Nabinacaboo ◽  
Mannie Mameanskum ◽  
...  
Keyword(s):  
Indigenous Peoples ◽  
Well Being ◽  
Aboriginal Community ◽  
Self Monitoring ◽  
Community Engaged Research ◽  
The Past ◽  
Mineral Development ◽  
Iron Deposits ◽  
Term Monitoring

The Naskapi Nation of Kawawachikamach is an Aboriginal community located in northern Quebec near the Labrador Border. Given the region’s rich iron deposits, the Naskapi Nation has considerable experience with major mineral development, first in the 1950s to the 1980s, and again in the past decade as companies implement plans for further extraction. This has raised concerns regarding a range of environmental and socio-economic impacts that may be caused by renewed development. These concerns have led to an interest among the Naskapi to develop a means to track community well-being over time using indicators of their own design. Exemplifying community-engaged research, this paper describes the beginning development of such a tool in fall 2012—the creation of a baseline of community well-being against which mining-induced change can be identified. Its development owes much to the remarkable and sustained contribution of many key members of the Naskapi Nation. If on-going surveying is completed based on the chosen indicators, the Nation will be better positioned to recognize shifts in its well-being and to communicate these shifts to its partners. In addition, long-term monitoring will allow the Naskapi Nation to contribute to more universal understanding of the impacts of mining for Indigenous peoples.

Courting the Youth Vote in 2008: The Obama Effect

2009 ◽  
Vol 5 ◽  
Author(s):  
Lindsey C Bohl
Keyword(s):  
Presidential Elections ◽  
Voter Registration ◽  
The Internet ◽  
The Past ◽  
Several Variables ◽  
High Turnout ◽  
Short And Long Term ◽  
Use Of The Internet ◽  
Youth Vote

This paper examines a few of the numerous factors that may have led to increased youth turnout in 2008 Election. First, theories of voter behavior and turnout are related to courting the youth vote. Several variables that are perceived to affect youth turnout such as party polarization, perceived candidate difference, voter registration, effective campaigning and mobilization, and use of the Internet, are examined. Over the past 40 years, presidential elections have failed to engage the majority of young citizens (ages 18-29) to the point that they became inclined to participate. This trend began to reverse starting in 2000 Election and the youth turnout reached its peak in 2008. While both short and long-term factors played a significant role in recent elections, high turnout among youth voters in 2008 can be largely attributed to the Obama candidacy and campaign, which mobilized young citizens in unprecedented ways.

Impact of FII’s and FDI’s on Indian Stock Market

2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Dr. Kamlesh Kumar Shukla
Keyword(s):  
Stock Market ◽  
Financial Markets ◽  
Global Economy ◽  
Short Term ◽  
Earnings Growth ◽  
The Past ◽  
Bull Market ◽  
Indian Stock Market

FIIs are companies registered outside India. In the past four years there has been more than $41 trillion worth of FII funds invested in India. This has been one of the major reasons on the bull market witnessing unprecedented growth with the BSE Sensex rising 221% in absolute terms in this span. The present downfall of the market too is influenced as these FIIs are taking out some of their invested money. Though there is a lot of value in this market and fundamentally there is a lot of upside in it. For long-term value investors, there’s little because for worry but short term traders are adversely getting affected by the role of FIIs are playing at the present. Investors should not panic and should remain invested in sectors where underlying earnings growth has little to do with financial markets or global economy.

Modelling the Effects of Acid Deposition: Estimation of Long-Term Water Quality Responses in Forested Catchments in Finland

1988 ◽  
Vol 19 (2) ◽  
pp. 99-120 ◽  
Author(s):  
A. Lepistö ◽  
P. G. Whitehead ◽  
C. Neal ◽  
B. J. Cosby
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Base Cations ◽  
Surface Water Quality ◽  
Mineral Weathering ◽  
Co2 Solubility ◽  
Forested Catchments ◽  
Deposition Rates ◽  
Magic Model

A modelling study has been undertaken to investigate long-term changes in surface water quality in two contrasting forested catchments; Yli-Knuutila, with high concentrations of base cations and sulphate, in southern Finland; and organically rich, acid Liuhapuro in eastern Finland. The MAGIC model is based on the assumption that certain chemical processes (anion retention, cation exchange, primary mineral weathering, aluminium dissolution and CO2 solubility) in catchment soils are likely keys to the responses of surface water quality to acidic deposition. The model was applied for the first time to an organically rich catchment with high quantities of humic substances. The historical reconstruction of water quality at Yli-Knuutila indicates that the catchment surface waters have lost about 90 μeq l−1 of alkalinity in 140 years, which is about 60% of their preacidification alkalinity. The model reproduces the declining pH levels of recent decades as indicated by paleoecological analysis. Stream acidity trends are investigated assuming two scenarios for future deposition. Assuming deposition rates are maintained in the future at 1984 levels, the model indicates that stream pH is likely to continue to decline below presently measured levels. A 50% reduction in deposition rates would likely result in an increase in pH and alkalinity of the stream, although not to estimated preacidification levels. Because of the high load of organic acids to the Liuhapuro stream it has been acid before atmospheric pollution; a decline of 0.2 pH-units was estimated with increasing leaching of base cations from the soil despite the partial pH buffering of the system by organic compounds.

Chinese Medicine Protein and Peptide in Gene and Cell Therapy

2019 ◽  
Vol 20 (3) ◽  
pp. 251-264 ◽  
Author(s):  
Yinlu Feng ◽  
Zifei Yin ◽  
Daniel Zhang ◽  
Arun Srivastava ◽  
Chen Ling
Keyword(s):  
Chinese Medicine ◽  
Cell Therapy ◽  
Future Research ◽  
The Past ◽  
Promising Strategy ◽  
Wide Range ◽  
New Directions ◽  
Gene And Cell Therapy ◽  
Proteins And Peptides

The success of gene and cell therapy in clinic during the past two decades as well as our expanding ability to manipulate these biomaterials are leading to new therapeutic options for a wide range of inherited and acquired diseases. Combining conventional therapies with this emerging field is a promising strategy to treat those previously-thought untreatable diseases. Traditional Chinese medicine (TCM) has evolved for thousands of years in China and still plays an important role in human health. As part of the active ingredients of TCM, proteins and peptides have attracted long-term enthusiasm of researchers. More recently, they have been utilized in gene and cell therapy, resulting in promising novel strategies to treat both cancer and non-cancer diseases. This manuscript presents a critical review on this field, accompanied with perspectives on the challenges and new directions for future research in this emerging frontier.

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