Chlorophyll content of seston in a regulated Rocky Mountain river, Idaho, USA

Hydrobiologia ◽  
1993 ◽  
Vol 259 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Ted R. Angradi
Keyword(s):  
Chlorophyll Content ◽  
Rocky Mountain ◽  
Mountain River

Ecology and coexistence of two species of Brachycentrus (Trichoptera) in a Rocky Mountain river

1986 ◽  
Vol 64 (7) ◽  
pp. 1469-1474 ◽  
Author(s):  
F. Richard Hauer ◽  
Jack A. Stanford
Keyword(s):  
Rocky Mountain ◽  
Late Summer ◽  
Growth Patterns ◽  
Mountain River ◽  
Spring Runoff ◽  
Winter Conditions ◽  
First Instar ◽  
Spring Freshet ◽  
Early Instar ◽  
Peak Runoff

Life-cycle dynamics, growth rates, and relative abundance of Brachycentrus occidentalis and Brachycentrus americanus were studied over a 3-year period in the Flathead River, Montana. Brachycentrus occidentalis appeared as early instar larvae in mid to late summer, grew rapidly during autumn, and reached fourth and fifth instars prior to winter conditions. Most larvae remained active until mid-spring and the onset of spring runoff. Individuals pupated during late April through May and adults emerged after peak runoff in mid-June. Brachycentrus americanus larvae appeared as first instar larvae in autumn and overwintered as early instars. Larvae grew rapidly during spring as temperatures began to rise, but growth was discontinued during spring runoff. Larvae completed growth during summer after the runoff period and emerged in late August and early September. Growth patterns and emergence of both species occurred primarily during fall or spring and late summer, with little growth during winter or spring freshet. Thus growth was associated with quantitatively similar but temporally different periods of organic seston, temperature, and moderate flow.

Microdistributions of filter-feeding caddisflies (Insecta: Trichoptera) in a regulated Rocky Mountain river

1996 ◽  
Vol 74 (4) ◽  
pp. 654-666 ◽  
Author(s):  
Neal J. Voelz ◽  
J. V. Ward
Keyword(s):  
Environmental Gradient ◽  
Rocky Mountain ◽  
Distribution Patterns ◽  
Longitudinal Distribution ◽  
Rock Surface ◽  
Mountain River ◽  
Filter Feeding ◽  
Significant Relationships ◽  
Regulated Stream ◽  
Selection Of

A year-round study was conducted in the Blue River, Colorado, U.S.A., to examine microdistributions of the filter-feeding caddisflies Arctopsyche grandis and Brachycentrus occidentalis along a regulated stream environmental gradient. There was a well-defined longitudinal species replacement, with A. grandis reaching maximum densities 2.3 km below the impoundment and declining downstream as B. occidentalis increased. Arctopsyche grandis was often the only caddisfly found near the dam. The two species co-occurred at two downstream sites, with A. grandis numerically dominant 5.2 km below the impoundment and B. occidentalis at the farthest downstream site (11 km). Near the dam, where densities of filter-feeders were highest, there were significant relationships between individual rock surface area and the number of larvae during most sampling periods. Contrary to our predictions of selection of current-exposed microhabitats, both species occurred primarily on the bottom and lower lateral sides of rocks at all sites. Clumped distribution patterns in the absence of spatial segregation by size class suggests common microhabitat preferenda for species and instars. This use of similar spaces indicates that competitive displacement may occur, partially explaining the longitudinal distribution patterns. At a macroscale the reservoir-induced environmental alterations clearly limit the distribution of organisms, especially at sites directly below the impoundment. As the stream regains its preimpoundment character farther downstream, factors at a microscale may play a more important role in producing the distinct longitudinal distribution patterns.

scholarly journals Assessing Nitrogen Status in Potted Geranium through Discriminant Analysis of Ground-based Spectral Reflectance Data

HortScience ◽  
2012 ◽  
Vol 47 (3) ◽  
pp. 343-348 ◽  
Author(s):  
Yun-wen Wang ◽  
Bruce L. Dunn ◽  
Daryl B. Arnall
Keyword(s):  
Discriminant Analysis ◽  
Chlorophyll Content ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Rocky Mountain ◽  
Flower Color ◽  
Production Costs ◽  
N Application ◽  
Chlorophyll Meter ◽  
N Status

Nitrogen (N) deficiencies can significantly reduce plant growth as well as flower quantity and quality. However, excessive N application leads to increased production costs and may cause water contamination as a result of runoff. Ground-based remote sensing of plant chlorophyll content offers the possibility to rapidly and inexpensively estimate crop N status. The objective of this study was to test the reliability of three different Normalized Difference Vegetation Index (NDVI) measuring methods and Soil-Plant Analyses Development (SPAD) chlorophyll meter values as indicators of geranium (Pelargonium ×hortorum L.H. Bailey) N status. Two potted geranium cultivars, Rocky Mountain White and Rocky Mountain Dark Red, were supplied with N at 0, 50, 100, and 200 mg·L−1 levels, respectively. NDVI readings were measured at 45 cm above the canopy or media of individual plants or 45 cm above the canopy of a group of plants (four plants treated with the same N rate were placed together). Significant correlations existed between indirect chlorophyll content measurements of SPAD values and NDVI readings regardless of four-pot group or single-pot measurements with N application rates and leaf N concentration. Using a cross-validation technique in discriminant analysis, 70.8% to 79.2% of sample cases were correctly categorized to the corresponding N statuses including very deficient, deficient, and sufficient. Therefore, ground-based, non-destructive measurements of a chlorophyll meter and pocket NDVI unit were able to indicate N status. Considering that flower color can interfere with NDVI measurements, the chlorophyll meter may better determine N content when flowers are present.

scholarly journals Impact of rock uplift on rates of late Cenozoic Rocky Mountain river incision

2007 ◽  
Vol 112 (F3) ◽  
Author(s):  
Catherine A. Riihimaki ◽  
Robert S. Anderson ◽  
Elizabeth B. Safran
Keyword(s):  
Rocky Mountain ◽  
Mountain River ◽  
Late Cenozoic ◽  
River Incision
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