Characteristics of the Stipa Comata-Bouteloua Gracilis-Bouteloua Curtipendula Association in Northern Colorado

Ecology ◽  
1955 ◽  
Vol 36 (2) ◽  
pp. 269-280 ◽  
Author(s):  
Herbert C. Hanson
1987 ◽  
Vol 65 (7) ◽  
pp. 1371-1378 ◽  
Author(s):  
V. J. Lieffers ◽  
P. A. Larkin-Lieffers

Vegetation and environmental variables were examined in some coulees of the Oldman River near Lethbridge, Alta. Principal components analysis of environmental variables indicated that solar energy, aspect, soil Mg2+, [Formula: see text], and moisture were related to the first axis of variation. Slope position, soil [Formula: see text], moisture, K+, [Formula: see text], and amount of bare ground were related to a second axis of variation. There was a large range in species diversity among plots; most diverse plots were on north-facing slopes. Direct ordination of vegetation data indicated that slope position and aspect were most important in describing distribution of species. Koeleria macrantha, Bouteloua gracilis, Stipa comata, and Artemisia frigida were found on most coulee positions. Hymenoxys richardsonii, Machaeranthera grindeloides, Astragalus spatulatus, and Eriogonum flavum were mostly restricted to summit and upper slope positions. Anemone patens, Geum triflorum, Thermopsis rhombifolia, and others were most abundant on north- and east-facing slopes. Fewer species (e.g., the C4 Aristida longiseta and the cactus Coryphantha vivipara) were mostly confined to south-facing positions.


1963 ◽  
Vol 95 (7) ◽  
pp. 764-770 ◽  
Author(s):  
R. Pickford

AbstractField cage experiments conducted through the complete life cycle of Camnula pellucida (Scudder) demonstrated that wheat, the major cereal crop grown in Saskatchewan, played the dominant role in the nutritional ecology of this grasshopper. A native sod mixture, comprising Stipa comata, Bouteloua gracilis, Agropyron smithii, and Carex eleocharis, four of the dominant species of the mixed prairie association, was consistently unfavourable during all stages of grasshopper growth and development. Grasshoppers reared on wheat survived better, were considerably larger and laid up to 20 times more eggs than those reared on the native prairie grasses. The presence of the native sod with wheat contributed nothing nutritionally to the food combination. The unfavourable qualities of the native grasses, although resulting in small adults, low fecundity and small pods, did not affect the hatchability of eggs laid or the development and survival of nymphs that hatched from them.


1968 ◽  
Vol 48 (2) ◽  
pp. 119-127 ◽  
Author(s):  
S. Smoliak ◽  
A. Johnston

Six native grass species, Bouteloua gracilis, Stipa comata, Koeleria cristata, Festuca scabrella, Andropogon scoparius, and Danthonia parryi, and six introduced grass species, Elymus junceus, Bromus inermis, Agropyron cristatum, Agropyron tricophorum, Festuca rubra, and Dactylis glomerata, were germinated and grown for 90 days at root-zone temperatures of 7, 13, 18, and 27 °C. In general, the introduced species were superior to the native species in percentage germination and speed of germination and germinated, emerged and grew more readily at lower root-zone temperatures. Introduced species produced about 10 times as much weight of leaf and about eight times as much weight of root as did the native species at comparable growth stages. The chances of establishment and successful early growth of seeded stands appeared to be better with introduced grass species than with native grass species.


Weed Science ◽  
1984 ◽  
Vol 32 (2) ◽  
pp. 180-184 ◽  
Author(s):  
Thomas D. Whitson ◽  
Harold P. Alley

Tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N′-dimethylurea} was evaluated on three Wyoming soil types for control of big sagebrush (Artemisia tridentata Nutt.), silver sagebrush (Artemisia cana Pursh.), and phytotoxic effects on associated vegetation. Big sagebrush was controlled with tebuthiuron at application rates of 0.6 to 1.1 kg ai/ha, whereas silver sagebrush was not completely controlled. Prairie junegrass [Koeleria pyramidata (Cam.) Beauv.], western wheatgrass (Agropyron smithii Rydb. ♯3 AGRSM), needleandthread (Stipa comata Trin. ♯ STDCO), and green needlegrass (Stipa viritdula Trin. ♯ STOVI) were not significantly reduced with tebuthiuron up to 1.1 kg ai/ha. Blue grama (Bouteloua gracilis H.B.K. ♯ BOBGR), downy brome (Bromus tectorum L. ♯ BROTE), plains pricklypear (Opuntia polyacantha Haw. ♯ OPUPO), and broom snakeweed [Gutierrezia sarothrae (Pursh.) Britt. and Rugsby, ♯ GUESA] were tolerant to tebuthiuron at rates up to 1.1 kg ai/ha.


2015 ◽  
Vol 38 (4) ◽  
pp. 359
Author(s):  
Álvaro Bernal-Flores ◽  
Adrián R. Quero-Carrillo ◽  
Alejandrina Robledo-Paz ◽  
H. Araceli Zavaleta-Mancera ◽  
Paulino Pérez-Rodríguez

En el presente estudio varios medios de cultivo con diferentes auxinas fueron establecidos para la regeneración de plantas normales en pasto Banderita Bouteloua curtipendula (Michx.) Torr., a partir de callos inducidos en cariópsides (explantes) maduros cultivados en medio MS basal suplementado con 2,4-ácido diclorofenoxiacético y varias citocininas. Los medios MS+2,4-D+BAP suplementados con sorbitol (MI-13, MI-14) dieron origen a callos con características morfogénicas con potencial de regeneración. Los callos embriogénicos obtenidos a partir de MI-14 fueron colocados en diferentes medios de regeneración, entre los que MR-2 mostró la mayor frecuencia de regeneración (95.8 %) y eficiencia de conversión (13.9 %). Plántulas verdes, morfológicamente normales, fueron obtenidas con medio suplementado con cinetina (1 mg L-1), ácido naftalenacético (0.2 mg L-1) y ácido giberélico (0.2 mg L-1). El estrés osmótico y el balance hormonal resultante de la adición de sorbitol, estimuló la formación de proembroides en callos friables y de embriones somáticos en pasto Banderita. Se presenta aquí el primer protocolo de regeneración en esta especie apomíctica recalcitrante, que pueda ser útil en trabajos futuros basados en técnicas de cultivo de tejidos.


Sign in / Sign up

Export Citation Format

Share Document