Water and Nutrient Competition Between Salsola Kali and Two Native Grass Species (Agropyron Smithii and Bouteloua Gracilis)

Ecology ◽  
1982 ◽  
Vol 63 (3) ◽  
pp. 732-741 ◽  
Author(s):  
Edith Bach Allen
1975 ◽  
Vol 55 (4) ◽  
pp. 473-480 ◽  
Author(s):  
J. F. DORMAAR

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.


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.


1984 ◽  
Vol 62 (12) ◽  
pp. 2625-2629 ◽  
Author(s):  
Edith Bach Allen ◽  
Michael F. Allen

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.


2012 ◽  
Vol 87 (9) ◽  
pp. 1335-1341 ◽  
Author(s):  
Sabitry Bordoloi ◽  
Budhadev Basumatary ◽  
Rubul Saikia ◽  
Hamendra Chandra Das

2008 ◽  
Vol 1 (1) ◽  
pp. 50-58 ◽  
Author(s):  
Bryan A. Endress ◽  
Catherine G. Parks ◽  
Bridgett J. Naylor ◽  
Steven R. Radosevich

AbstractSulfur cinquefoil is an exotic, perennial forb that invades a wide range of ecosystems in western North America. It forms dense populations and often threatens native plant species and communities. In this study, we address the following questions: (1) what herbicides, rates, and application times are most effective at reducing sulfur cinquefoil abundance while having the least impact on native plants; and (2) does postherbicide seeding with native grass species increase native plant abundance? In 2002, we experimentally examined the effects of five herbicides (dicamba + 2,4-D; metsulfuron-methyl; triclopyr; glyphosate; and picloram) at two rates of application (low and high), three application times (early summer, fall, and a combined early summer–fall treatment), and two postherbicide seed addition treatments (seeded or not seeded) on sulfur cinquefoil abundance, plant community composition, and species richness. Experimental plots were monitored through 2005. Picloram was the most effective herbicide at reducing sulfur cinquefoil density, the proportion of remaining adult plants, and seed production. The effects of picloram continued to be evident after 3 yr, with 80% reduction of sulfur cinquefoil in 2005. In addition, seeding of native grass seeds alone (no herbicide application) reduced the proportion of sulfur cinquefoil plants that were reproductively active. Despite reductions in sulfur cinquefoil abundance, all treatments remained dominated by exotic species because treated areas transitioned from exotic forb- to exotic grass-dominated communities. However, a one-time herbicide application controlled sulfur cinquefoil for at least 3 yr, and therefore might provide a foundation to begin ecological restoration. Herbicide applications alone likely are to be insufficient for long-term sulfur cinquefoil control without further modification of sites through native grass or forb seeding. Integrating herbicides with native plant seeding to promote the development of plant communities that are resistant to sulfur cinquefoil invasion is a promising management approach to ecological restoration.


1999 ◽  
Vol 47 (4) ◽  
pp. 563 ◽  
Author(s):  
Tamara R. Read ◽  
Sean M. Bellairs

The germination responses to plant-derived smoke of seeds of 20 native grass species from New South Wales, Australia, were tested under laboratory conditions. The species belonged to 14 genera including Bothriochloa, Chloris, Cymbopogon, Danthonia, Dichanthium, Digitaria, Eragrostis, Eriochloa, Microlaena, Panicum, Paspalidium, Poa, Stipa and Themeda. The interaction between smoke and husk-imposed dormancy was examined by removing the floral structures surrounding the seeds, when sufficient seeds were available. Smoke was shown to be an important environmental stimulus for breaking the dormancy of native grasses; however, the response differed considerably between different genera and between species of the same genus. For almost half of the species, smoke significantly increased the germination percentage. Panicum decompositum showed the greatest response, with germination increasing from 7.7 to 63.1% when smoke was applied. Panicum effusum had no germination in the absence of smoke, but 16.7% germination when smoke was applied. Stipa scabra subsp. scabra had germination significantly reduced by smoke from 30.2 to 19.9%. Five species had their germination rate, but not the final germination percentage, affected by smoke, and a third of the species were unaffected by smoke. For five of the species, Chloris ventricosa, Dichanthium sericeum, Panicum decompositum, Poa labillardieri and Stipa scabra subsp. falcata, this is the first report of a smoke-stimulated germination response. For those species with germination promoted by smoke, retention of the covering structures did not prevent smoke stimulation of germination. Sowing smoke-treated husked seeds is likely to be preferable as it would still promote greater germination, whereas dehusking seeds can result in the seeds being more susceptible to desiccation and fungal attack in the field. It is suggested that other grassland communities that respond to pyric conditions may also contain species that respond to smoke.


1991 ◽  
Vol 123 (1) ◽  
pp. 89-105 ◽  
Author(s):  
Mark A. Quinn ◽  
R.L. Kepner ◽  
D.D. Walgenbach ◽  
R.A. Bohls ◽  
P.D. Pooler ◽  
...  

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.


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