Ecology of Species of Megachile Latreille in the Mixed Prairie Region of Southern Alberta with Special Reference to Pollination of Alfalfa

Ecology ◽  
1954 ◽  
Vol 35 (4) ◽  
pp. 453-462 ◽  
Author(s):  
G. A. Hobbs ◽  
C. E. Lilly
Keyword(s):  
Special Reference ◽  
Southern Alberta ◽  
Mixed Prairie

Ecology of the Leaf-cutter Bee Megachile perihirta Ckll. (Hymenoptera: Megachilidae) in Relation to Production of Alfalfa Seed

1956 ◽  
Vol 88 (11) ◽  
pp. 625-631 ◽  
Author(s):  
G. A. Hobbs
Keyword(s):  
Flight Period ◽  
Relative Importance ◽  
Southern Alberta ◽  
Alfalfa Seed ◽  
Nesting Habits ◽  
Mixed Prairie ◽  
Ground Nesting ◽  
Distribution Frequency

The relative importance as pollinators of alfalfa of each of the 14 species of Megachile that occur in southern Alberta has been assessed on the basis of Alberta distribution, frequency and abundance in mixed prairie, nesting habits, pollen preferences, and flight period; two ground-nesting species of the subgenus Xanthosarus Rob., Megachile perihirta Ckll. and M. dentitarsus Slad., were judged the principal pollinators (Hobbs and Lilly, 1954).

ANALYSIS OF SPECTRAL DATA FOR COMPARING RANGELAND AND CULTURAL PRACTICES IN SOUTHERN ALBERTA

1988 ◽  
Vol 68 (4) ◽  
pp. 1017-1023 ◽  
Author(s):  
D. J. MAJOR ◽  
S. SMOLIAK ◽  
G. ASRAR ◽  
E. T. KANEMASU
Keyword(s):  
Spectral Reflectance ◽  
Cultural Practices ◽  
Photochemical Efficiency ◽  
Moisture Stress ◽  
Canopy Reflectance ◽  
Data Set ◽  
Southern Alberta ◽  
Green Vegetation ◽  
Highly Correlated ◽  
Mixed Prairie

Spectral reflectance characteristics of rangeland provide quantitative and qualitative information which can be useful for assessing range condition and phytomass. The data set in this study consisted of phytomass estimates and ground-based reflectance measurements in four wave bands between 0.5 and 1.1 μm taken from eight range improvement treatments near Lethbridge, Alberta from April through July in 1983 and 1984. The treatments consisted of subjecting native range to reseeding with grasses or legumes and fertilizer and herbicide additions. Spectral reflectance was highly correlated (R2 = 0.82 – 0.99) with the seasonal trajectory of phytomass production in spite of low amounts of green vegetation and high amounts of senescent vegetation. The data were analyzed by determining the relationship between accumulated phytomass and intercepted photosynthetically active radiation calculated from canopy reflectance. The regression coefficient of this relationship was an estimate of photochemical efficiency. The estimates of photochemical efficiency (1.09 and 0.76 g MJ−1 in 1983 and 1984, respectively) were lower than those reported in the literature (1.4 g MJ−1), presumably due to moisture stress in both years.Key words: Mixed prairie, short-grass, biomass, phytomass, remote sensing

CHANGES IN SOIL WATER REGIME AFTER PIPELINE CONSTRUCTION IN SOLONETZIC MIXED PRAIRIE RANGELAND

1988 ◽  
Vol 68 (3) ◽  
pp. 603-610 ◽  
Author(s):  
M. A. NAETH ◽  
A. W. BAILEY ◽  
D. S. CHANASYK ◽  
W. B. McGILL ◽  
R. T. HARDIN
Keyword(s):  
Soil Water ◽  
Overland Flow ◽  
Water Status ◽  
Pipeline Construction ◽  
Natural Gas Pipelines ◽  
Neutron Probe ◽  
Short Period ◽  
Southern Alberta ◽  
Construction Activity ◽  
Mixed Prairie

A study was conducted in the Solonetzic mixed prairie rangeland of southern Alberta to evaluate soil water responses to pipeline construction. Five adjacent natural gas pipelines on a series of rights-of-way (ROW) were studied at three sites. The pipelines were installed in 1957, 1963, 1968, 1972 and 1981. Soil water contents were monitored throughout the year using a neutron probe. Water-holding capacity of the soil was determined using the pressure-plate extraction method. Pipeline construction in Solonetzic mixed prairie ecosystems caused total soil water to a depth of 50 cm in the trench to increase over that in the undisturbed prairie. There were no significant effects on available water capacity. Berm construction over the trench impeded overland flow, particularly during springmelt, causing short periods of ponding. Construction activity had no significant effect on total water within zones of a given ROW. Soil water status was affected for a short period of time with a trend towards predisturbance conditions within 10 yr. Key words: Pipelines, Solonetzic soils, rangeland, reclamation, soil water

The ultrastructure of the double membrane-bound bodies and endoplasmic reticulum in serial sections of wheat spot mosaic-affected wheat plants

1990 ◽  
Vol 48 (3) ◽  
pp. 694-695
Author(s):  
M. H. Chen ◽  
C. Hiruki
Keyword(s):  
Endoplasmic Reticulum ◽  
High Resolution ◽  
Membrane Structure ◽  
Mosaic Disease ◽  
Serial Sections ◽  
Thin Sections ◽  
Double Membrane ◽  
Southern Alberta ◽  
Membrane Bound ◽  
Scanning Em

Wheat spot mosaic disease was first discovered in southern Alberta, Canada, in 1956. A hitherto unidentified disease-causing agent, transmitted by the eriophyid mite, caused chlorosis, stunting and finally severe necrosis resulting in the death of the affected plants. Double membrane-bound bodies (DMBB), 0.1-0.2 μm in diameter were found to be associated with the disease.Young tissues of leaf and root from 4-wk-old infected wheat plants were fixed, dehydrated, and embedded in Spurr’s resin. Serial sections were collected on slot copper grids and stained. The thin sections were then examined with a Hitachi H-7000 TEM at 75 kV. The membrane structure of the DMBBs was studied by numbering them individually and tracing along the sections to see any physical connection with endoplasmic reticulum (ER) membranes. For high resolution scanning EM, a modification of Tanaka’s method was used. The specimens were examined with a Hitachi Model S-570 SEM in its high resolution mode at 20 kV.

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