FIELD SURVEY OF HALOPHYTIC PLANTS OF DISTURBED SITES ON THE CANADIAN PRAIRIES

1984 ◽  
Vol 64 (3) ◽  
pp. 745-751 ◽  
Author(s):  
J. T. BRAIDEK ◽  
P. FEDEC ◽  
D. JONES
Keyword(s):  
Field Study ◽  
Key Words ◽  
Introduced Species ◽  
Field Survey ◽  
Salt Tolerant ◽  
Kochia Scoparia ◽  
Canadian Prairies ◽  
Saline Habitats ◽  
Halophytic Plants

A field study was carried out to survey and collect samples of native and introduced species which have adapted themselves to saline habitats. Ten species were found in 25% or more of the sites surveyed. These included both kochia (Kochia scoparia (L.) Schrad.) and orache (Atriplex patula var. subspicata (Nutt.) S. Wats.). Kochia and A. patual var. hastata (L.) Gray have been investigated by other researchers as potential salt-tolerant crops (Somers 1979).Key words: Saline areas, halophytic plants, Kochia, Salicornia

Ritualinis mandagumas (ta’ârof) šiuolaikinio Irano visuomenėje ir tarpkultūrinėje komunikacijoje: Teherano šiaurinės dalies atvejis

2019 ◽  
Vol 19 (28) 2019 ◽  
pp. 169-190
Author(s):  
Dalia Sabaliauskienė
Keyword(s):  
Field Study ◽  
Key Words ◽  
Intercultural Communication ◽  
Capital City ◽  
Cultural Environment ◽  
City Culture ◽  
Face Maintenance

This paper examines the concept and practices of the Iranian ritual courtesy ta’ârof in northern Tehran, based on field-study findings, and analyses its expression in intercultural communication. It examines how contemporary Iranians perceive ta’ârof, what practices of ritual courtesy are commonly found, and whether configurations of the Iranian code of courtesy remain stable in the changing cultural environment. The study employs the theory of face maintenance and data from Iranian face and diaspora research. It shows emic perceptions of ta’ârof, and reveals its practices in Tehran, alongside tendencies of expression among Iranians living in Lithuania. Key words: ta’ârof, ritual courtesy, capital-city culture, intercultural communication, contemporary Iran.

A field study of competition and interaction between Lemna minor and Lemna trisulca

1989 ◽  
Vol 67 (10) ◽  
pp. 2904-2911 ◽  
Author(s):  
Alexander L. McIlraith ◽  
Gordon G. C. Robinson ◽  
Jennifer M. Shay
Keyword(s):  
Life History ◽  
Field Study ◽  
Key Words ◽  
Field Experiments ◽  
Lemna Minor ◽  
Survey Methods ◽  
The Other ◽  
Transplant Experiment ◽  
Replacement Series ◽  
Vegetative Biomass

Field experiments and survey methods were used to assess competition and interaction between Lemna minor L. and Lemna trisulca L. at Delta Marsh, Manitoba. Sites were dominated by one or the other species or codominated by both. Replacement series experiments predicted codominance of L. minor and L. trisulca in an unshaded eutrophic site but predicted L. minor dominance when run for a longer time. Similar experiments conducted in a shaded eutrophic site predicted L. minor dominance. Addition series experiments showed that intraspecific and interspecific competition occurred in the unshaded site. In a eutrophic unshaded ditch, high densities of L. minor suppressed L. trisulca. In a eutrophic shaded site, high densities of L. minor and green algae inhibited L. trisulca, and in a sunny, less eutrophic site high density of each species inhibited the other. In a transplant experiment, L. minor biomass in shaded enclosures approached that found naturally in two shaded sites. Lemna trisulca persisted when shaded. Vegetative biomass trends in an unshaded eutrophic marsh ditch indicated spring and fall L. trisulca dominance and summer L. minor dominance. Shaded eutrophic sites were dominated by L. minor, whereas a less eutrophic site was dominated by L. trisulca. A model is developed to explain dominance patterns, and seasonal life-history responses are considered. Key words: Lemna, duckweed, competition, interaction, resources, light, nutrients.

scholarly journals Pengembangan Bahan Ajar Untuk Meningkatkan Pemahaman Materi Mata Kuliah Demografi Teknik

2012 ◽  
Vol 4 (2) ◽  
Author(s):  
Trisnawati
Keyword(s):  
College Student ◽  
Field Study ◽  
Large Scale ◽  
Field Survey ◽  
Student Understanding ◽  
Average Score ◽  
Study Material ◽  
Study Evaluation ◽  
Post Test ◽  
Or Task

Problems of this research are the difficulty of collage students to understand technique demography study material and the unavailability of appropriate teaching material. This research is aimed to increase college student understanding toward technique demography study material and study achievement. Developing material of teaching was done by: (1) Product analyzed by reducing and increasing study material; (2) Wrote material of teaching; (3) Expert validation and revised, by material of teaching expert, instructional developing, study evaluation, demography and environmental expert; (4) Small group test and revised, toward 10 collage student of geography field study; and (5) Large scale of field survey test and final product, on odd semester 2006/2007, toward 30 collage student of geography field study, FKIP, Lampung University.Pre test and post test was done in every study. The using of teaching study and doing exercise question or task in the last meeting are used in this research. The result are: (1) The increasing of college student understanding toward technique demography study material, average score in post  test higher (57,76) than average score in pre test (30,42); (2) There is a significant relationship between understanding level with collage student study achievement, r-count (0,396) higher than r-table (0,361) in significant level 5% and N = 30.

EFFECTS OF SULPHATE AND CHLORIDE SOIL SALINITY ON GROWTH AND NEEDLE COMPOSITION OF SIBERIAN LARCH

1980 ◽  
Vol 60 (3) ◽  
pp. 903-910 ◽  
Author(s):  
M. R. CARTER
Keyword(s):  
Electrical Conductivity ◽  
Root Growth ◽  
Siberian Larch ◽  
Field Studies ◽  
Physiological Effect ◽  
Chloride Anion ◽  
Salt Tolerant ◽  
Canadian Prairies ◽  
Naturally Occurring ◽  
Chloride Salinity

Greenhouse and field studies were conducted to assess the salinity tolerance of Siberian larch (Larix siberica L.) under conditions found on the Canadian prairies. In greenhouse studies top and root growth of Siberian larch seedlings began to decline under sulphate salinity between 2.0 and 5.3 mmhos/cm (electrical conductivity of saturation paste extract) indicating that Siberian larch is moderately salt-tolerant. The addition of chloride caused an initial top growth decrease, chlorosis, and reduction in survival between 1.4 and 3.6 mmhos/cm; the latter salinity level being associated with 20 meq/L of Cl and 1.5% Cl in the saturation paste extract and needles, respectively. Field studies conducted under naturally occurring sulphate salinity indicated that height of 10-yr-old Siberian larch began to decline between 3.5 and 4.0 mmhos/cm. Changes in needle mineral composition were related to the ratio or increase of ions in the soil solution, and the physiological effect of the sulphate and chloride anion. In general, presence of chloride salinity caused a greater increase to occur in the cation content of the needles than sulphate salinity. Accumulation of organic anions in the needles was also related to cation concentration and needle chlorosis.

Pertes de charge des ancrages actifs injectés dans un massif rocheux

1989 ◽  
Vol 16 (1) ◽  
pp. 72-81 ◽  
Author(s):  
Brahim Benmokrane ◽  
Gérard Ballivy
Keyword(s):  
Epoxy Resin ◽  
Field Study ◽  
Key Words ◽  
Solid Rock ◽  
Rapid Loss ◽  
Prestress Loss ◽  
Massif Rocheux ◽  
Second Stage ◽  
Initial Stage

Estimation of loss of prestress is an essential part of the design of permanent or temporary prstressed anchors since stability of the retained structure must not be compromised. Findings of a field study on long-term behaviour of prestressed anchors are presented herein: different lengths of anchors in solid rock were injected with cement grout or epoxy resin. Load variation in the anchors with time indicated two distinct stages of loss of prestress: an initial stage of rapid loss of prestress and a second stage of very minor and uniform loss ending about 6 months after prestressing. Our study also showed that restressing anchors after a period of time reduces subsequent prestress loss and that overdimensioning of the injected length does not. Key words: rock, prestressed injected anchor, grout, loss of prestress, creep, relaxation.

Comparing fall and spring seeding of Kochia scoparia on saline soil

1993 ◽  
Vol 73 (4) ◽  
pp. 1055-1065 ◽  
Author(s):  
H. Steppuhn ◽  
D. G. Green ◽  
G. Winkleman ◽  
J. A. Kernan ◽  
E. Coxworth
Keyword(s):  
Saline Soil ◽  
Plant Competition ◽  
Early Spring ◽  
Late Spring ◽  
Shoot Biomass ◽  
Forage Production ◽  
Kochia Scoparia ◽  
Canadian Prairies ◽  
Plant Densities ◽  
Growing Conditions

Kochia scoparia naturally invades distributed soils in the Brown soil zone of the Canadian Prairies and offers potential as a forage crop in saline environments. A 3-yr study conducted on severely saline soil near Swift Current, Saskatchewan, compared kochia production resulting from fall (natural- and implement-seeded) and spring (early- and late-seeded) treatments. Late spring-seeded crops produced, on average, 5.4 t of dry, shoot biomass per ha per yr. Early spring and fall-seeded kochia (naturally or implement-placed) yielded between 5.4 and 10.9 t ha−1. Of the nine comparisons between forage yields from fall and spring seedings, six favored fall over spring, two were equal, and one produced more forage from early spring seedings than from the naturally-seeded fall treatment. The late spring treatment consistently produced the least forage. Fall seedings exhibited a greater potential for forage production because fall-seeded plants usually established early in the growing season and in sufficient number to fully exploit soil and water resources when conditions became favorable and effective rooting depths were not restricted by concentrated salt layers. When drier growing conditions prevailed, the lower plant densities associated with early spring seedings tended to minimize plant competition and foster greater forage production. Key words: Kochia forage, seeding dates, salinity, Kochia establishment, Kochia agronomy

The potential of mustard (Brassica juncea (L.) Coss) as an edible oil crop on the Canadian Prairies

1991 ◽  
Vol 71 (1) ◽  
pp. 195-198 ◽  
Author(s):  
D. L. Woods ◽  
J. J. Capcara ◽  
R. K. Downey
Keyword(s):  
Protein Content ◽  
Key Words ◽  
Brassica Juncea ◽  
Oil Content ◽  
Edible Oil ◽  
Canadian Prairies ◽  
Oil Crop

The performance of mustard (Brassica juncea (L.) Coss) was compared with that of canola (B. napus L. and B. rapa L.) on the western prairies. Mustard had a higher yield and protein content and was intermediate in maturity. Improvement in oil content will probably be required. Key words: Mustard, Brassica juncea, edible oil crop

Soil science on the Canadian prairies - Peering into the future from a century ago

2001 ◽  
Vol 81 (4) ◽  
pp. 489-503 ◽  
Author(s):  
H H Janzen
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Key Words ◽  
Crop Rotation ◽  
Soil Science ◽  
Good Time ◽  
Grassland Soils ◽  
Canadian Prairies ◽  
The Future

Now, as a new century begins, may be a good time to reflect on the future of Soil Science on the Canadian prairies. One way to do that is to step back about one hundred years, to the turn of the previous century when our grassland soils were first cultivated. What questions perplexed scientists then? And how did they look for answers? My objective is to listen for our forebears’ thoughts in their writings, now largely buried. From this historical vantage may emerge insights, not only into where our science has been, but also into where it might yet go. Key words: Soil organic matter, crop rotation, grassland soils, history

Salinity tolerance during germination of seashore halophytes and salt-tolerant grass cultivars

2005 ◽  
Vol 15 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Hans Martin Hanslin ◽  
Trine Eggen
Keyword(s):  
High Salinity ◽  
Germination Percentage ◽  
Distilled Water ◽  
Artemisia Vulgaris ◽  
Salt Tolerant ◽  
Salinity Response ◽  
Tolerant Species ◽  
High Germination ◽  
Juncus Gerardii ◽  
Saline Habitats

Direct sowing is the simplest method of plant establishment for restoration and remediation purposes, but relatively few plants can establish under high salinity conditions. In this study, the ability of different seashore plants and grass cultivars to germinate in different dilutions of seawater (0–400 mM NaCl) was tested. Highest germination was found in distilled water or seawater dilutions up to 100 mM NaCl. When seawater concentrations were increased from 100 to 200 mM NaCl, a strong decline in germination percentage and rate was observed in less salt-tolerant species, such as Matricaria maritima and Achillea millefolium. The more salt-tolerant species, Plantago maritima, Juncus gerardii, Artemisia vulgaris, Agrostis spp. and Rumex spp., had a threshold salinity, where germination was significantly decreased in seawater dilutions between 200 and 400 mM NaCl. Even among the salt-tolerant species, only two, Agrostis stolonifera and Artemisia vulgaris, germinated at 400 mM. Variation in salinity response was observed among populations of Artemisia vulgaris and among cultivars of Festuca spp. Increasing salinity to 200 mM NaCl delayed germination in most species. Ungerminated seeds of most salinity-tolerant species were still viable after 21 d at the highest salinity (400 mM), and showed a rapid and high germination when transferred to distilled water. These species would be able to survive high salinity and germinate when the salinity of the sediments decreases through dilution or leaching of salts. The experiment revealed species and cultivars that will be of interest in further testing for restoration and remediation in saline habitats.

Effectiveness of three Bt corn events against feeding damage by the true armyworm (Pseudaletia unipuncta Haworth)

2007 ◽  
Vol 87 (3) ◽  
pp. 599-603 ◽  
Author(s):  
A. W. Schaafsma ◽  
M. L. Holmes ◽  
J. Whistlecraft ◽  
S. A. Dudley
Keyword(s):  
Field Study ◽  
Key Words ◽  
Fresh Mass ◽  
Insecticidal Protein ◽  
Bt Corn ◽  
Feeding Damage ◽  
Mass Measurements ◽  
Pseudaletia Unipuncta ◽  
True Armyworm

A 3-yr study (2002-2004) was conducted to evaluate the resistance of three Bt corn events to herbivory damage by the armyworm, Pseudaletia unipuncta (Haworth). Resistance was assessed by damage ratings and fresh mass measurements. Greenhouse studies were run in 2002 and 2004, and a field study was conducted in 2003. Hybrids expressing the Cry1A(b) insecticidal protein, Mon810 and Bt176 events, and their near isolines, as well as the TC1507 event, which expresses the Cry1F protein, were evaluated. Bt hybrids suffered less damage in all 3 yr and had higher fresh masses in 2002 and 2003 than the non-transgenic isolines. In 2002 and 2003, hybrids expressing the Cry1A(b) protein were significantly less damaged than the hybrid expressing Cry1F. In both 2002 and 2004, the Mon810 event suffered less damage than the Bt176 event, despite expressing the same Cry1A(b) protein. Bt corn, especially the Mon810 event may be used as an effective method of preventing P. unipuncta herbivory damage in corn. Key words: True armyworm, Pseudaletia unipuncta, Bt corn, Cry1A(b), Cry1F, epistasis

Sign in / Sign up

Export Citation Format

Share Document