Spatial distribution and seed mass variation of Strophostyles helvola along Lake Erie

1996 ◽  
Vol 74 (8) ◽  
pp. 1313-1321 ◽  
Author(s):  
Mary Yanful ◽  
M. A. Maun
Keyword(s):  
Spatial Distribution ◽  
Intraspecific Competition ◽  
Lake Erie ◽  
Seed Mass ◽  
Field Studies ◽  
Sandy Beaches ◽  
Recurrent Event ◽  
Limiting Factor ◽  
Probability Of Survival ◽  
The Waves

Field studies were conducted to determine the survival, seed-mass variability, and reproductive strategies of wild bean, Strophostyles helvola (L.) Ell., plants on the foredunes at Port Burwell Provincial Park along Lake Erie. In spring, a large number of seedlings were found on the drift-line (area of beach where detritis deposits are cast on shore by the waves) and a small number both on the lakeward (mid-beach) and landward (high-beach) ends of the drift-line. Plants growing on the mid-beach were larger and produced a significantly greater number of heavier seeds than those on the drift-line. However, during late fall and winter months, a large proportion of these seeds were moved by wind and wave action to the drift-line. Intraspecific competition was not a limiting factor on the mid-beach; however, on the drift-line, the number of seeds per plant decreased significantly with an increase in density of plants from about 1 to 140/m2, suggesting that intraspecific competition may be an important limiting factor in seed production per plant. The mean mass per seed significantly declined over the growing season of S. helvola. There was a significant increase in mean seed mass with increasing pod size. Seeds in the centre of a pod were significantly heavier than those at the proximal and distal ends of a pod. Strophostyles helvola is able to flourish in the constantly shifting shoreline beach habitats along Lake Erie owing to two main factors. First, it is able to fully utilize the highly variable beach microhabitats and maintain high total reproductive output per square metre. Second, since burial in sand is a major recurrent event on sandy beaches, the high variability in seed mass will be of adaptive significance because seedlings from large seeds will not only be able to emerge from greater depths of burial in sand but also will have greater probability of survival under burial conditions. Keywords: seed mass, plant location, Strophostyles helvola, seed position, spatial distribution.

Acentropus niveus (Oliv.) (Lepidoptera: Pyralidae) on the north shore of Lake Erie with a consideration of its distribution in North America

1950 ◽  
Vol 82 (12) ◽  
pp. 250-252 ◽  
Author(s):  
W. W. Judd
Keyword(s):  
North America ◽  
Green Alga ◽  
Lake Erie ◽  
Filamentous Green Alga ◽  
North Shore ◽  
The North ◽  
Lepidoptera Pyralidae ◽  
Shallow Bay ◽  
The Village ◽  
The Waves

On July 12, 1950 a collection of adults of the moth Acentropus niveus (Oliv.) was made on the north shore of Lake Erie near the village of South Cayuga, Ontario (Maps A, B-3). At the southern limits of the townships of Dunn and South Cayuga (Haldimand County) a shallow bay extends for a distance of about two miles along the shore of the lake (Map A). Along this bay is a sandy or gravelly beach ten to twenty yards wide backed by a cliff of clay that rises abruptly above the beach. On the day the collections were made the sky was clear and a brisk southerly breeze was causing waves to wash on the beach. The action of the waves had deposited debris, consisting largely of tangled masses of a filamentous green alga and exuviae of the mayfly Hexagenia occulta, in a windrow six inches to two feet wide along the shore. The moths ere found in this debris, most of them lying dead and with bedraggled wings, while some lay on their backs with wings stuck to the damp surface and with legs kicking and a few were crawling about on the debris.

Spatial Distribution of Nearshore Fish in the Vicinity of Two Thermal Generating Stations, Nanticoke and Douglas Point, on the Great Lakes

1978 ◽  
Vol 35 (6) ◽  
pp. 885-892 ◽  
Author(s):  
C. K. Minns ◽  
J. R. M. Kelso ◽  
W. Hyatt
Keyword(s):  
Spatial Distribution ◽  
Thermal Stratification ◽  
Lake Erie ◽  
Temperature Response ◽  
Incident Radiation ◽  
Fish Distribution ◽  
Lake Huron ◽  
Vertical Variation ◽  
Pelagic Communities ◽  
Key Words Temperature

At Nanticoke, Lake Erie, 1974, mean fish density varied considerably, range 162–14 204/10 000 m3, as estimated by digital acoustic fish enumeration. At Douglas Point, Lake Huron, 1975, mean density varied less, range 108–671/10 000 m3. At both sites fish densities were generally greatest in the shallowest, 3–5 m, depths. At Nanticoke, where the nearshore has low relief, there were no distinguishable communities. At Douglas Point, where depth increases rapidly offshore, there was evidence of benthic and pelagic communities. There was no evidence of altered fish distribution in relation to temperature. At Nanticoke there was no vertical variation in temperature and no vertical response was to be expected. At Douglas Point there was thermal stratification present in the summer and there was no apparent response. The influence of incident radiation was uncertain because of the effects of diurnal migrations. At both locations fish were clustered horizontally to varying degrees in the spring and fall, while in the summer fish were distributed more evenly. Densest clusters were usually in the vicinity of the turbulent discharge at both locations. The lack of temperature response and the similarity of Nanticoke with situations at nearby streams on Lake Erie suggest that the fish are responding to currents and perhaps topography. Key words: temperature, acoustic enumeration, topography, light

scholarly journals A PARAMETRIC HURRICANE WAVE PREDICTION MODEL

1988 ◽  
Vol 1 (21) ◽  
pp. 82
Author(s):  
Ian R. Young
Keyword(s):  
Spatial Distribution ◽  
Radiative Transfer Equation ◽  
Synthetic Data ◽  
Wave Model ◽  
Limited Growth ◽  
Forward Movement ◽  
Spectral Wave Model ◽  
Wave Conditions ◽  
Two Parameters ◽  
The Waves

A spectral wave model based on a numerical solution of the Radiative Transfer Equation is used to create a synthetic data base on wave conditions within hurricanes. The results indicate that both the velocity of forward movement and maximum wind velocity within the storm play an important role in determining both the magnitude of the waves generated and also the spatial distribution of these waves. An equivalent fetch for hurricane wave generation which is a function of these two parameters is proposed. This concept, together with the standard JONSWAP fetch limited growth relationships, provide a simple means for estimating wave conditions within hurricanes.

scholarly journals Crustaceans composition in sandy beaches of Sepetiba Bay, Rio de Janeiro, Brazil

Check List ◽  
2011 ◽  
Vol 7 (6) ◽  
pp. 778 ◽  
Author(s):  
Ricardo S. Cardoso ◽  
Felipe Meireis ◽  
Gustavo Mattos
Keyword(s):  
Spatial Distribution ◽  
Rio De Janeiro ◽  
Sandy Beaches ◽  
Southeastern Brazil ◽  
Sepetiba Bay ◽  
Main Species ◽  
Janeiro State ◽  
Made In

A crustacean survey was made in Sepetiba bay, Rio de Janeiro state, southeastern Brazil. Twelve sandy beaches were sampled on five islands in this embayment. A total of 3024 individuals were collected, belonging to 21 species, which are grouped in 16 families, seven infraorders, seven suborders, and four orders. Isopods, followed by amphipods and tanaids, showed the highest abundance, amounting to over 92% of the dominance of crustaceans. The main species were Excirolana armata, Excirolana braziliensis (isopods), Atlantorchestoidea brasiliensis (amphipod), and Monokalliapseudes schubarti (tanaid), which together accounted about 80% of crustaceans of the beaches studied. Excirolana braziliensis had the highest frequency. The majority of species found are typical of sandy beaches, with large spatial distribution.

Dog mustard (Erucastrum gallicum) response to crop competition

Weed Science ◽  
1997 ◽  
Vol 45 (3) ◽  
pp. 397-403
Author(s):  
David A. Wall
Keyword(s):  
Interspecific Competition ◽  
Leaf Area ◽  
Seed Production ◽  
Growth And Development ◽  
Dry Weight ◽  
Field Studies ◽  
Limiting Factor ◽  
Shoot Dry Weight ◽  
Summer Fallow ◽  
Crop Competition

Greenhouse studies suggested that dog mustard was less competitive than wheat, but of similar competitiveness to flax. In field studies, dog mustard growth and development were markedly affected by crop competition. Competition from flax and wheat reduced dog mustard leaf area, shoot dry weight, plant height, and seed production compared with the weed grown on summer-fallow. Dog mustard was a prolific seed producer when grown in the absence of interspecific competition. On summer-fallow, dog mustard produced as many as 79,100 seeds plant−1when moisture was not a limiting factor. However, average seed production was 19,400 and 8000 seeds plant−1in 1994 and 1995, respectively.

Fertilization biology of the abalone Haliotis laevigata: laboratory and field studies

1999 ◽  
Vol 56 (9) ◽  
pp. 1668-1678 ◽  
Author(s):  
Russ Babcock ◽  
John Keesing
Keyword(s):  
Field Experiments ◽  
Nearest Neighbor ◽  
Field Studies ◽  
Fertilization Success ◽  
Limiting Factor ◽  
Fertilization Rates ◽  
Abalone Species ◽  
Nearest Neighbor Distances

A combination of laboratory and field experiments with the commercial abalone species Haliotis laevigata showed that fertilization may be a limiting factor in some exploited populations when distances separating spawning individuals are too large. The effects of gamete age, gamete concentration, and gamete contact time in the laboratory were used to model fertilization success in situ and compared with experimental fertilization rates in the field. Highest fertilization rates in vitro (80%) were found for sperm concentrations in the range of 1 × 104 to 1 × 106·mL-1. Fertilization rates of 48 ± 1.7% (95% CI) were measured at separation distances of 2 m and dropped to 2.8 ± 0.7% (95% CI) at 16 m downstream, agreeing closely with rates predicted by the model. Recruitment failures reported for South Australian populations of H. laevigata have occurred when densities fell below ca.0.3 animals·m-2, or mean nearest-neighbor distances between 1 and 2 m. This density corresponds well to critical nearest-neighbor distances for fertilization success. Stocks at higher densities are predicted to have higher fertilization rates (ca.90%) such that fertilization success is not a factor limiting recruitment.

Effects of burial of seeds and seedlings from different seed sizes on the emergence and growth of Strophostyles helvola

1996 ◽  
Vol 74 (8) ◽  
pp. 1322-1330 ◽  
Author(s):  
Mary Yanful ◽  
M. A. Maun
Keyword(s):  
Lake Erie ◽  
Sandy Beach ◽  
Seedling Emergence ◽  
Seed Mass ◽  
Large Mass ◽  
Burial Depth ◽  
Different Depths ◽  
Mass Burial ◽  
Provincial Park

Field and greenhouse studies were conducted to examine the role of seed mass in (i) the emergence of seedlings of Strophostyles helvola (L.) Ell. from different depths of burial in sand and (ii) the ability of seedlings originating from seeds of different seed mass (weight per seed) to re-emerge from sand deposits. Seeds were sorted into four different seed mass classes (small, < 55 mg; medium, 55–65 mg; large, 65–75 mg; and extra large, > 75 mg) and sown at different depths ranging from 2 to 24 cm in sand on a sandy beach at Port Burwell Provincial Park along Lake Erie. Seeds of large mass class (65–75 mg) sown at 18 cm depth produced the largest plants. Under greenhouse conditions, all S. helvola seedlings buried to 100 and 125% of their height survived the treatment, but survival declined to 66% when they were buried to 150% of their height. Stimulation in growth was observed only when the seedlings were buried to 50 and 75% of their height. Seedlings originating from large seed masses took fewer days to re-emerge from different burial depths than seedlings from small seeds. However, the interaction term between seed mass and burial depth for the re-emergence of seedlings was not significant. Keywords: seed mass, burial of seeds, burial of seedlings, Strophostyles helvola, seedling emergence.

Seed size effects and competitive ability in Thlaspi arvense L. (Brassicaceae)

Botany ◽  
2008 ◽  
Vol 86 (3) ◽  
pp. 259-267 ◽  
Author(s):  
David J. Susko ◽  
Paul B. Cavers
Keyword(s):  
Soil Fertility ◽  
Seed Size ◽  
Intraspecific Competition ◽  
Competitive Ability ◽  
Plant Biomass ◽  
Seed Mass ◽  
Soil Nutrient ◽  
Plant Size ◽  
Thlaspi Arvense ◽  
High Nutrient

We examined the effects of seed size on plant size and competitive ability of Thlaspi arvense L. grown with and without intraspecific competition under contrasting soil fertility regimes. For solitary plants from each of four half-sibship families, seed mass was positively correlated with percentage germination, cotyledon size, and plant biomass after 15 d of growth, but differences in plant biomass largely disappeared at later dates. Small and large seeds of a single maternal family were sown in uniform or mixed arrangements of seed size classes (small:large; 100%:0%; 75%:25%; 50%:50%; 25%:75%; 0%:100%) at each of two densities (8 or 16 seeds·pot–1) under low and high soil nutrient regimes. In mixtures at low density under low soil fertility, plants from small seeds had significantly lower relative yields than expected. At high density, under either low or high nutrient conditions, plants from large seeds had significantly greater relative yields than expected. Hence, under most conditions, size inequalities between plants from seeds of different size resulted in a relative competitive advantage for plants from large seeds. The duration and extent of differences in plant size arising from T. arvense seeds of contrasting size depends on maternal genetic differences, intensity of intraspecific competition, and soil fertility.

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