scholarly journals THE GROWTH AND CARBOHYDRATE RESPONSES OF AGROPYRON SMITHII AND BOUTELOUA GRACILIS TO CHANGES IN NITROGEN SUPPLY

1944 ◽  
Vol 19 (3) ◽  
pp. 481-494 ◽  
Author(s):  
H. M. Benedict ◽  
G. B. Brown
Keyword(s):  
Bouteloua Gracilis ◽  
Nitrogen Supply ◽  
Agropyron Smithii

HABITAT CHARACTERISTICS AND GRASSHOPPER COMMUNITY DYNAMICS ON MIXED-GRASS RANGELAND

1991 ◽  
Vol 123 (1) ◽  
pp. 89-105 ◽  
Author(s):  
Mark A. Quinn ◽  
R.L. Kepner ◽  
D.D. Walgenbach ◽  
R.A. Bohls ◽  
P.D. Pooler ◽  
...  
Keyword(s):  
Community Structure ◽  
Community Dynamics ◽  
Detrended Correspondence Analysis ◽  
Bouteloua Gracilis ◽  
Community Change ◽  
Habitat Characteristics ◽  
Agropyron Smithii ◽  
Spatial Gradients ◽  
Mixed Grass ◽  
The Difference

AbstractA study was conducted in Butte County of western South Dakota to determine the relationships between habitat characteristics and spatial and temporal changes in community structure of grasshoppers on mixed-grass rangeland. Detrended correspondence analysis (DCA) of 29 undisturbed grasshopper communities and correlation analysis of DCA axis values and habitat variables denned specific spatial gradients underlying the community structure of grasshoppers. Results indicated that grasshopper communities changed along a primary gradient of percentage of coverage of grasses, particularly Buchloe dactyloides (Nutt.) Engelm., and a secondary gradient of percentage composition of clay and sand in the soil.DCA of 24 grasshopper communities sampled in 1986 and 1987, multiple regression analysis, and factor analysis were used to determine the relationships between specific habitat characteristics and changes in communities of grasshoppers treated with either a nonselective insecticidal spray (malathion) or a selective insecticidal bait (bran bait with carbaryl). Results indicated that between-year change in community composition, or the difference between post-treatment communities in 1986 and 1987, was positively correlated with percentage of coverage of total grasses and forbs. Community malleability, defined as the tendency of a community to return to its predisturbed state, was greater in habitats with high coverages of Agropyron smithii Rydb. and Carex spp., low coverage of Bouteloua gracilis (H.B.K.) Lag. ex Steud., and low species richness of grasses. Our results emphasize the importance of habitat characteristics in structuring undisturbed grasshopper communities and in community change after perturbation with insecticides.

EXPERIMENTS WITH SOME NATIVE AND INTRODUCED PLANTS AS FOODS FOR CAMNULA PELLUCIDA (SCUDD.) (ORTHOPTERA: ACRIDIDAE) IN WESTERN CANADA

1962 ◽  
Vol 42 (4) ◽  
pp. 589-595 ◽  
Author(s):  
L. G. Putnam
Keyword(s):  
Poa Pratensis ◽  
Bouteloua Gracilis ◽  
Population Increase ◽  
Festuca Rubra ◽  
Field Cage ◽  
Agropyron Elongatum ◽  
Agropyron Smithii ◽  
Introduced Plants ◽  
Percentage Survival ◽  
Elymus Canadensis

In field cage experiments, 17 native and introduced grasses and a native sedge, grown in pure culture, differed in their effect on the growth, survival and rate of population increase of the clear-winged grasshopper, Camnula pellucida. In terms of eggs deposited, Festuca rubra permitted a 24-lold population increase in a 1-year test; in tests repeated in 2 consecutive years, Agropyron elongatum, A. cristatum, Elymus junceus, Poa pratensis and P. compressa produced average annual increases of 10- to 18-fold; A. intermedium, A. dasystachyum, A. trachycaulum var. typicum, A. riparium, Poa ampla, and Bromus inermis, 3- to 8-fold. Agropyron smithii, Elymus canadensis, Stipa spartea, S. viridula, Bouteloua gracilis and Carex stenophylla var. enervis (1 year’s results), 2-fold or less. Percentage survival to the adult stage, rate of development, and apparently, robustness, were all positively correlated with population increase, but not strongly.

Wheat Crops and Native Prairie in Relation to the Nutritional Ecology of Camnula pellucida (Scudder) (Orthoptera: Acrididae) in Saskatchewan

1963 ◽  
Vol 95 (7) ◽  
pp. 764-770 ◽  
Author(s):  
R. Pickford
Keyword(s):  
Dominant Role ◽  
Nutritional Ecology ◽  
Bouteloua Gracilis ◽  
Field Cage ◽  
Agropyron Smithii ◽  
Native Prairie ◽  
Prairie Grasses ◽  
Complete Life Cycle ◽  
Stipa Comata ◽  
Mixed Prairie

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.

SUSCEPTIBILITY OF ORGANIC MATTER OF CHERNOZEMIC Ah HORIZONS TO BIOLOGICAL DECOMPOSITION

1975 ◽  
Vol 55 (4) ◽  
pp. 473-480 ◽  
Author(s):  
J. F. DORMAAR
Keyword(s):  
Organic Matter ◽  
Bouteloua Gracilis ◽  
Black Soil ◽  
Grass Species ◽  
Hydrothermal Conditions ◽  
Agropyron Smithii ◽  
Brown Soil ◽  
Chelex 100 ◽  
Soil Zone ◽  
Biological Decomposition

Samples of five Chernozemic Ah horizons from soils under prairie of predominantly single grass species were incubated at 30 C with moisture maintained at 300 mbars for 74 days with and without uniformly labelled 14C-glucose. The 14CO2 formed during decomposition was collected in NaOH and its activity measured by scintillation spectrometry. Within the Brown soil zone, soils covered by Stipa comata Trin. & Rupr. and Agropyron smithii Rydb. contained considerably more organic matter that was readily decomposable than a soil covered by Bouteloua gracilis (HBK.) Lag. when the cumulative CO2 evolved was expressed in terms of the C in the soil. In comparison with the three Brown soils, the organic matter of a Dark Brown soil covered by Stipa spartea var. curtiseta Hitchc. and a Black soil covered by Festuca scabrella Torr. was found to be very resistant to biological decomposition, as the percentage of C lost during incubation of the latter soils was less than half the percentage mineralized by any of the former soils. Between 80.4 and 91.4% of the added 14C was mineralized as 14CO2 in four of the soils and between 20 and 35% of the remaining 14C was extractable with Chelex-100. In the fifth soil, the Black Chernozemic soil covered by F. scabrella, only 50% of the added 14C was mineralized and only 8% of the remaining 14C was extractable with Chelex-100. The potential susceptibility to biological decomposition of the organic matter of various Chernozemic Ah horizons gave a measure of the proportion of the oxidizable component still present. It thereby helped with the interpretation of the genesis of the whole organic matter formed under different hydrothermal conditions in the field.

Competition between plants of different successional stages: mycorrhizae as regulators

1984 ◽  
Vol 62 (12) ◽  
pp. 2625-2629 ◽  
Author(s):  
Edith Bach Allen ◽  
Michael F. Allen
Keyword(s):  
Stomatal Conductance ◽  
Mixed Culture ◽  
Mycorrhizal Fungi ◽  
Pure Culture ◽  
Arbuscular Mycorrhizae ◽  
Bouteloua Gracilis ◽  
Dry Mass ◽  
Mycorrhizal Infection ◽  
Agropyron Smithii ◽  
Salsola Kali

Salsola kali, a colonizing annual which does not form vesicular–arbuscular mycorrhizae (nonmycotrophic), was grown in pure culture and in mixtures with two mycotrophic grasses which are late successional dominants, Agropyron smithii and Bouteloua gracilis. Soils were either left sterile or inoculated with mycorrhizal fungi. In pure culture mycorrhizae caused no significant increase in dry mass of either grass, but in mixed culture with S. kali, mycorrhizal infection was significantly related to increased mass of grasses. Mycorrhizal infection was related to increased stomatal conductance of the grasses in both pure and mixed culture. Salsola kali had lower stomatal conductance but not a significantly reduced mass with mycorrhizal fungi. Hyphae of mycorrhizal fungi, but not vesicles or arbuscules, were observed in the rhizosphere and occasionally the cortex of S. kali. Where competition between colonizing nonmycorrhizal species and later successional mycorrhizal species is a mechanism which drives succession, the inoculum density may determine the rate of succession.

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