Nitrogen and phosphorus dynamics during runoff events over a transition from grassland to shrubland in the south-western United States

2010 ◽  
Vol 25 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Laura Turnbull ◽  
John Wainwright ◽  
Richard E. Brazier
Keyword(s):  
United States ◽  
Western United States ◽  
The South ◽  
Nitrogen And Phosphorus ◽  
Phosphorus Dynamics ◽  
Runoff Events

Water Development and Water Planning in the South-Western United States

1969 ◽  
Vol 135 (4) ◽  
pp. 610
Author(s):  
Donald M. Harding ◽  
Johannes Humlum
Keyword(s):  
United States ◽  
Western United States ◽  
The South ◽  
Water Planning ◽  
Water Development

Post-fire water-quality response in the western United States

2018 ◽  
Vol 27 (3) ◽  
pp. 203 ◽  
Author(s):  
Ashley J. Rust ◽  
Terri S. Hogue ◽  
Samuel Saxe ◽  
John McCray
Keyword(s):  
United States ◽  
Water Quality ◽  
Stream Water ◽  
Western United States ◽  
Change Point Analysis ◽  
Quality Data ◽  
Stream Water Quality ◽  
Nitrogen And Phosphorus ◽  
Water Quality Data ◽  
Quality Response

Wildfires are increasing in size and severity in forested landscapes across the Western United States. Not only do fires alter land surfaces, but they also affect the surface water quality in downstream systems. Previous studies of individual fires have observed an increase in various forms of nutrients, ions, sediments and metals in stream water for different post-fire time periods. In this research, data were compiled for over 24 000 fires across the western United States to evaluate post-fire water-quality response. The database included millions of water-quality data points downstream of these fires, and was synthesised along with geophysical data from each burned watershed. Data from 159 fires in 153 burned watersheds were used to identify common water-quality response during the first 5 years after a fire. Within this large dataset, a subset of seven fires was examined further to identify trends in water-quality response. Change-point analysis was used to identify moments in the post-fire water-quality data where significant shifts in analyte concentrations occurred. Evaluating individual fires revealed strong initial increases or decreases in concentrations, depending on the analyte, that are masked when averaged over 5 years. Evidence from this analysis shows significant increases in nutrient flux (different forms of nitrogen and phosphorus), major-ion flux and metal concentrations are the most common changes in stream water quality within the first 5 years after fire. Dissolved constituents of ions and metals tended to decrease in concentration 5 years after fire whereas particulate matter concentration continued to increase. Assembling this unique and extensive dataset provided the opportunity to determine the most common post-fire water-quality changes in the large and diverse Western USA. Results from this study could inform studies in other parts of the world, will help parameterise and validate post-fire water-quality models, and assist communities affected by wildfire to anticipate changes to their water quality.

THE DROUGHT IN THE SOUTH-WESTERN UNITED STATES

Weather ◽  
1953 ◽  
Vol 8 (8) ◽  
pp. 233-236 ◽  
Author(s):  
W. G. V. Balchin ◽  
Norman Pye
Keyword(s):  
United States ◽  
Western United States ◽  
The South

Modern fire regime resembles historical fire regime in a ponderosa pine forest on Native American lands

2014 ◽  
Vol 23 (5) ◽  
pp. 686 ◽  
Author(s):  
Amanda B. Stan ◽  
Peter Z. Fulé ◽  
Kathryn B. Ireland ◽  
Jamie S. Sanderlin
Keyword(s):  
United States ◽  
Native American ◽  
Ponderosa Pine ◽  
Fire Regime ◽  
Temporal Frequency ◽  
Fire Frequency ◽  
Western United States ◽  
The South ◽  
Surface Fire ◽  
Tribal Lands

Forests on tribal lands in the western United States have seen the return of low-intensity surface fires for several decades longer than forests on non-tribal lands. We examined the surface fire regime in a ponderosa pine-dominated (Pinus ponderosa) forest on the Hualapai tribal lands in the south-western United States. Using fire-scarred trees, we inferred temporal (frequency and seasonality) and spatial (synchrony) attributes and regulators of the fire regime over three land-use periods (historical, suppression, modern) between 1702 and 2007. Patterns of fire frequency and synchrony were similar, but fire seasonality was dissimilar, between the historical and modern periods. Logistic regression and generalised linear mixed models identified a suite of variables representing fuels, climate and human land uses that were associated with the probability of a site burning. Combined, these results allow for valuable insights regarding past fire spread and variability in fire frequency throughout our study area. In some respects, the current distinct fire regime in our study area, which predominately consists of prescribed fires implemented since the 1960s, resembles the past frequent surface fire regime that occurred here and in similar forest types on non-tribal lands in the south-western United States. Our results will be useful for informing adaptive management throughout the region as climate warms.

Serum Albumin Polymorphism in Indians of the South-western United States

Nature ◽  
1968 ◽  
Vol 220 (5163) ◽  
pp. 175-176 ◽  
Author(s):  
HERBERT F. POLESKY ◽  
DWIGHT A. ROKALA ◽  
THOMAS A. BURCH
Keyword(s):  
United States ◽  
Serum Albumin ◽  
Western United States ◽  
The South
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