Ecological relationships of wild rice, Zizania aquatica. 6. The effects of increases in water depth on vegetative and reproductive production

1987 ◽  
Vol 65 (10) ◽  
pp. 2128-2132 ◽  
Author(s):  
S. C. Stevenson ◽  
P. F. Lee
Keyword(s):  
Plant Height ◽  
Water Depth ◽  
Wild Rice ◽  
Phenological Stage ◽  
Ecological Relationships ◽  
Production Values ◽  
Zizania Aquatica ◽  
Stem Leaf ◽  
Reproductive Production ◽  
Floating Leaf

Wild rice (Zizania aquatica L.) suspended in plastic buckets from specially designed rafts, was subjected to increases in water depth during the submerged-leaf, first floating-leaf, second floating-leaf, and the first aerial-leaf stages. The depth was increased from an initial depth of 45 cm by 0 (control), 15, 30, or 50 cm. With the exception of the 15-cm treatment, increases in water depth resulted in decreases in total and component (root, stem, leaf) dry weights and the number of tillers on each plant. Plant height increased as the depth increased. Similar reductions occurred in the number of inflorescences per plant, the number of pedicels per plant, and the dry weights of the inflorescences. In all cases, the 15-cm treatment had higher production values than the control. The final biomass was influenced by the depth treatment, not the phenological stage when the depth increased.

Ecological relationships of wild rice, Zizania aquatica. 7. Sediment nutrient depletion following introduction of wild rice to a shallow boreal lake

1988 ◽  
Vol 66 (2) ◽  
pp. 236-241 ◽  
Author(s):  
T. J. Keenan ◽  
P. F. Lee
Keyword(s):  
Wild Rice ◽  
Paired Comparison ◽  
Dry Weight ◽  
Nutrient Depletion ◽  
Ecological Relationships ◽  
Manganese Zinc ◽  
Northwestern Ontario ◽  
Zizania Aquatica ◽  
Marked Decline ◽  
Growth Changes

A marked decline in wild rice production was observed 5 years after a northwestern Ontario lake was seeded. A paired-comparison t-test detrmined that sediment manganese, zinc, copper, magnesium, and potassium had all declined in concentration, but nitrogen showed the greatest decrease. Discriminant analysis indicated that sediment nitrogen contributed most to a function distinguishing between years. A controlled experiment using several fertilizer formulations also found that addition of nitrogen to sediment from the lake promoted the greatest increase in wild rice growth. Changes in distribution of wild rice and in values of water depth, organic matter, dry weight of other macrophytes, and wild rice density and dry weight indicated that the decrease in sediment nitrogen was probably associated with movement of wild rice straw within the lake.

Ecological relationships of wild rice, Zizania aquatica. 5. Enhancement of wild rice production by Potamogeton robbinsii

1987 ◽  
Vol 65 (7) ◽  
pp. 1433-1438 ◽  
Author(s):  
P. F. Lee
Keyword(s):  
Discriminant Analysis ◽  
Bulk Density ◽  
Wild Rice ◽  
Organic Content ◽  
Loss On Ignition ◽  
Sediment Samples ◽  
Ecological Relationships ◽  
Zizania Aquatica ◽  
Limiting Nutrient ◽  
Clay Sediment

Production of wild rice in a lake with clay sediment was examined inside and outside clumps of Potamogeton robbinsii (L.). Dry weights of wild rice plants were 10–15 times greater inside than outside these clumps. Analyses of variance of sediment samples revealed that values of loss on ignition, phosphorus, manganese, and zinc were higher inside the clumps of P. robbinsii, while values of bulk density, pH, and water depth were higher outside the clumps. Discriminant analysis was able to separate the samples on the basis of the values of phosphorus, manganese, and zinc relative to bulk density, copper, calcium, and depth. Experiments with various fertilizer treatments under controlled conditions determined that the primary limiting nutrient in the sediment outside the P. robbinsii clumps was phosphorus. It was proposed that as Potamogeton robbinsii decayed, it increased the organic content of the clay sediment, thereby lowering the pH and increasing the availability of nutrients.

Ecological relationships of wild rice, Zizania aquatica. 4. Environmental regions within a wild rice lake

1986 ◽  
Vol 64 (9) ◽  
pp. 2037-2044 ◽  
Author(s):  
P. F. Lee
Keyword(s):  
Cluster Analysis ◽  
Discriminant Analysis ◽  
Wild Rice ◽  
Rice Plant ◽  
Plant Competition ◽  
Organic Content ◽  
Ecological Relationships ◽  
Zizania Aquatica ◽  
Low Phosphorus ◽  
Phosphorus Levels

Four environmental regions with similar characteristics were identified within a lake that had been uniformly seeded with wild rice. Q-type cluster analysis was used to identify the environmental regions and discriminant analysis verified their existence. The regions differed from one another in the amount of plant competition and the phosphorus, zinc, and organic content of the sediment. By superimposing weight per wild rice plant categories with the locations of the environmental regions, it was found that the environmental regions were related to wild rice production. Low weights per wild rice plant were due to low phosphorus levels, low organic content of the sediment, or high plant competition values. Only where these variables were at suitable levels were high weights per wild rice plant obtained.

Ecological relationships of wild rice, Zizania aquatica. 9. Production in organic–flocculent sediments

1990 ◽  
Vol 68 (7) ◽  
pp. 1542-1548 ◽  
Author(s):  
W. R. Day ◽  
P. F. Lee
Keyword(s):  
Organic Matter ◽  
Primary Production ◽  
Wild Rice ◽  
Rice Production ◽  
Nutrient Concentrations ◽  
Limiting Factor ◽  
Ecological Relationships ◽  
Zizania Aquatica ◽  
Stems And Leaves ◽  
Chemical Trends

Season chemical trends and wild rice production were examined in unproductive organic–flocculent sediments from three lakes. Variations occurred in the level of organic matter and nutrient concentrations among these lakes. However, these among-lake variations were not as distinct as the differences that occurred between these lakes and a productive wild rice lake. The three organic–flocculent lakes exhibited similar poor wild rice production, retarded phenological development, and red colouration on wild rice stems and leaves. Although nutrient variations did occur among the organic–flocculent lakes, it was hypothesized that a common limiting factor was affecting wild rice production in this type of sediment. Key words: Zizania aquatica, nutrients, phosphorus, sediment, primary production, establishment.

Ecological relationships of wild rice, Zizania aquatica. 2. Sediment – plant tissue nutrient relationships

1983 ◽  
Vol 61 (6) ◽  
pp. 1775-1784 ◽  
Author(s):  
P. F. Lee ◽  
J. M. Stewart
Keyword(s):  
Wild Rice ◽  
Growth Characteristics ◽  
Unit Weight ◽  
Logistic Growth ◽  
Growth Data ◽  
Seasonal Fluctuations ◽  
Simple Correlation ◽  
Ecological Relationships ◽  
Zizania Aquatica ◽  
Rice Tissue

In this study the concentrations of elements in wild-rice tissue were related to the concentrations of elements in the sediment. In particular, the occurrence of similar concentrations and seasonal fluctuations of elements in wild-rice tissue was investigated. A model, based on the assumption of constant absorption per unit weight, illustrated how wild rice could have similar concentrations of elements in its tissue, even though the concentrations of the elements in the sediment varied both among and within stations. For a theoretical example with logistic growth characteristics, the model produced patterns which resembled the concentration fluctuations of elements found in wild-rice tissue. Utilizing actual leaf magnesium and wild-rice growth data, the model produced accurate representations of leaf magnesium concentrations but only after the emergent-leaf stage was reached. Seasonal fluctuations of concentrations of elements occurred in wild-rice tissue. Such fluctuations would negate any correlations with the concentrations of elements in the sediment. However, when these seasonal fluctuations were removed, those elements which differed in concentration in the tissue among the four sampling stations still had poor correlations with the corresponding elements in the sediment. Simple correlation with concentrations of elements in the sediment would therefore not account for the observed concentrations of elements in wild-rice tissue in this case.

Ecological relationships of wild rice, Zizania aquatica. 3. Factors affecting seeding success

1984 ◽  
Vol 62 (8) ◽  
pp. 1608-1615 ◽  
Author(s):  
P. F. Lee ◽  
J. M. Stewart
Keyword(s):  
Discriminant Function ◽  
Wild Rice ◽  
Temporal Variations ◽  
Commercial Production ◽  
Phosphorus Concentration ◽  
Sediment Type ◽  
Light Penetration ◽  
Factors Affecting ◽  
Ecological Relationships ◽  
Zizania Aquatica

Thirty-two sites were seeded with wild rice. Based on the number of panicles per square metre, production in the sites was categorized as commercial, marginally commercial, or unsuitable for commercial production. Discriminant analysis was used to derive two functions which explained these production differences. High values for the first discriminant function, which was interpreted as a factor of sediment phosphorus concentration and sediment type, separated the sites suitable for commercial production. The second discriminant function separated the remaining two categories on the basis of sediment type and light penetration through the water column. Those sites unsuitable for commercial production had higher values for this function than those sites which produced marginally commercial growth. Further research is needed into the spatial and temporal variations of the significant environmental variables before any recommendations can be made on the criteria for selecting potential wild rice sites.

Effects of water depth and seed provenance on the growth of wild rice (Zizania aquatica L.)

2011 ◽  
Vol 94 (3) ◽  
pp. 113-118 ◽  
Author(s):  
Rebecca C. Tucker ◽  
Michael J. Zanis ◽  
Nancy C. Emery ◽  
Kevin D. Gibson
Keyword(s):  
Water Depth ◽  
Wild Rice ◽  
Zizania Aquatica ◽  
Seed Provenance

Ecological relationships of wild rice, Zizania aquatica. 1. A model for among-site growth

1981 ◽  
Vol 59 (11) ◽  
pp. 2140-2151 ◽  
Author(s):  
P. F. Lee ◽  
J. M. Stewart
Keyword(s):  
Discriminant Analysis ◽  
Mississippi River ◽  
Wild Rice ◽  
Rice Plant ◽  
Ecological Relationships ◽  
Growing Seasons ◽  
Zizania Aquatica ◽  
Electric Station ◽  
Physical Variables ◽  
Temperature Water

During the 1976 and 1977 growing seasons the growth of wild rice was quantified at four sampling stations on the Mississippi River near the Clay Boswell Steam Electric Station at Cohasset, Minnesota. Cluster analysis was used to illustrate the intercorrelations and seasonal trends which existed among the water and sediment chemical variables. All biological, chemical, and physical variables were corrected for any time dependency, and discriminant analysis isolated those factors which could separate the four sampling stations. The discriminant functions were composed of biological (wild rice density), chemical (alkalinity), and physical (water temperature, water depth) factors previously known to influence wild rice growth. A model of the growth of wild rice was predicted effectively for each of the four sampling stations by combining (i) a time-independent equation formed from a multiple regression analysis of the time-corrected biological, chemical, and physical variables isolated as being significant in the discriminant analysis, versus the time-corrected dry weights per wild rice plant, and (ii) a time-dependent equation formed by fitting a logistic equation to the overall mean weights per wild rice plant at the four sampling stations.

GENETIC VARIATION OF FOUR TRAITS IN A POPULATION OF ZIZANIA AQUATICA

1980 ◽  
Vol 60 (1) ◽  
pp. 1-4 ◽  
Author(s):  
K. W. FOSTER ◽  
J. N. RUTGER
Keyword(s):  
Genetic Variation ◽  
Plant Height ◽  
Random Sample ◽  
Wild Rice ◽  
Heading Date ◽  
Tiller Number ◽  
Seed Length ◽  
Additive Variance ◽  
Phenotypic Correlations ◽  
Zizania Aquatica

Genetic variation for four characters in a population of wild rice (Zizania aquatica L.) was investigated using a random sample of 100 open-pollinated progenies grown in a single environment. Additive variance was present in significant amounts for heading date, plant height, tiller number, and seed length. Expected gains from selection were substantial for all traits. All phenotypic correlations among the four characters were significant, except for the correlation of plant height with seed length. Thus, correlated selection responses are possible.

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