LEAF AREA AS A MEASURE OF STANDING CROP OF FLOATING AQUATIC MACROPHYTES

Maximum standing crop in an Eleocharis quadrangulata population was estimated at 881 g dry wt./m2. Net daily productivity was highest during May when about 50% of the total standing crop was produced. Net productivity for the entire period of vegetative increase, April 1 to August 4, was 7.0 g/m2 per day. The accumulation of several nutrients, especially nitrogen, phosphorus, and potassium was proportionately more rapid than dry matter production during early spring growth. Net chlorophyll synthesis was also greater during early spring. Patterns of change in dry matter and chemical substances in the E. quadrangulata population were similar to those in populations of other emergent aquatic macrophytes.

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Diurnal temperature gradients in shallow water produced by populations of artificial aquatic macrophytes

Canadian Journal of Botany ◽

10.1139/b78-122 ◽

1978 ◽

Vol 56 (9) ◽

pp. 1099-1106 ◽

Cited By ~ 14

Author(s):

H. M. Dale ◽

T. J. Gillespie

Keyword(s):

Temperature Gradient ◽

Leaf Area ◽

Aquatic Macrophytes ◽

Time Of Day ◽

Maximum Temperature ◽

Water Evaporation ◽

Vertical Temperature ◽

Area Index ◽

Leaf Arrangement ◽

Maximum Temperature Gradient

Three artificial populations, with leaf area indices (L) of 4.4, 1.5, and 0.54 were submerged in identical tubs of 1-m3 capacity. Experiments showed that the maximum vertical temperature gradient of the water varied and was dependent on the ratio of solar radiation to wind speed, the leaf area index, and the arrangement of the leaves in the population. The time of day of the maximum temperature gradient was also dependent on L and leaf arrangement. The interception of the light energy by the leaf surface heated the water locally, while the shadow beneath caused the temperature to remain low. With fewer plants, water evaporation was slightly greater. Evaporation resulted in a marl deposit which was confined to the upper surface of the leaves.

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Aboveground standing crop, leaf area, and caloric value in an aspen clone near Calgary, Alberta

Canadian Journal of Botany ◽

10.1139/b70-220 ◽

1970 ◽

Vol 48 (8) ◽

pp. 1459-1469 ◽

Cited By ~ 13

Author(s):

E. B. Peterson ◽

Y. H. Chan ◽

J. B. Cragg

Keyword(s):

Leaf Area ◽

Populus Tremuloides ◽

Standing Crop ◽

Phenotypic Expression ◽

Tree Height ◽

Dry Weight ◽

Area Index ◽

Topographic Position ◽

International Biological Programme ◽

Allometric Relations

A 1967 aboveground harvest of 49 ramets of aspen (Populus tremuloides Michx.), aged from 66 to 89 years, at an altitude of 1430 m in Alberta revealed a leaf area index of 1.8 (one side of foliage) and a clone standing crop of 77.11 metric tons/hectare (oven-dry weight) with an energy equivalent of 3630 × 108 gram calories/hectare. This standing crop estimate fell within the range of 58 to 290 metric tons/hectare reported elsewhere for aspen. The amount of aspen foliage and branch wood, as a percentage of total aboveground standing crop, increased from the bottom to the top of a slope gradient within the 0.02-hectare sample plot, indicating that topographic position exerted a phenotypic expression on production structure within the clone. Topographic position did not have a significant influence on the applicability of the two most reliable independent variables ((i) diameter at breast height squared × tree height, (ii) diameter of trunk at crown base) for prediction of the total aboveground weight and component weights of aspen ramets. The allometric relations reported here are not necessarily applicable to other clones of the species but the allometric methods have potential application to other studies of the International Biological Programme.

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Structure and function of C3and C4Chihuahuan Desert plant communities. Standing crop and leaf area index

Journal of Arid Environments ◽

10.1006/jare.1996.0092 ◽

1996 ◽

Vol 34 (1) ◽

pp. 47-62 ◽

Cited By ~ 12

Author(s):

Robert P. Gibbens ◽

Ralph A. Hicks ◽

William A. Dugas

Keyword(s):

Leaf Area Index ◽

Leaf Area ◽

Plant Communities ◽

Standing Crop ◽

Structure And Function ◽

Desert Plant ◽

Area Index ◽

And Function

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DETERMINATION OF TOTAL NITROGEN AND CRUDE PROTEIN IN EICHHORNIA CRASSIPES PRESENTS IN RIVER APODI / MOSSORÓ - RN.

Periódico Tchê Química ◽

10.52571/ptq.v8.n15.2011.8_periodico15_pgs_7_13.pdf ◽

2011 ◽

Vol 08 (15) ◽

pp. 7-13

Author(s):

Daniel Freitas Freire MARTINS ◽

Maria de Fátima Vitória MOURA ◽

Luiz Di SOUZA ◽

Ramiro Gustavo Valera CAMACHO ◽

Alriberto Germano SILVA ◽

...

Keyword(s):

Plant Growth ◽

Protein Content ◽

Leaf Area ◽

Total Nitrogen ◽

Temporal Variability ◽

Crude Protein ◽

Eichhornia Crassipes ◽

Aquatic Macrophytes ◽

Crude Protein Content

As aquatic macrophytes absorb a large amount of essential nutrients or not to their development. The goal of this work was to determine the amount of total nitrogen [EMBRAPA, 1999] and the crude protein content [Boyd, 1970] present in aquatic macrophytes of the species Eichhornia crassipes, relating the values ??obtained with the temporal variability . From the results of leaf area (23.17; 67.21; 88.59 and 100.29 cm2), total nitrogen (4.4088; 3.1649; 2.1241 and 1.5256 g / 100g) and protein (27.5549; 19.7805; 13.2755 and 9.5351 g/100g), it can be concluded that levels of total nitrogen and crude protein decrease or remain constant with plant growth. In this way, the smaller plants are those that present higher concentrations of these nutrients.

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Influence of Nutrient Enrichment and Light Availability on the Abundance of Aquatic Macrophytes in Florida Streams

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f88-171 ◽

1988 ◽

Vol 45 (8) ◽

pp. 1467-1472 ◽

Cited By ~ 48

Author(s):

Daniel E. Canfield Jr. ◽

Mark V. Hoyer

Keyword(s):

Total Nitrogen ◽

Nutrient Enrichment ◽

Riparian Vegetation ◽

Standing Crop ◽

Aquatic Macrophytes ◽

Light Availability ◽

Dominant Factor ◽

Fresh Weight ◽

Nitrogen Concentrations ◽

Nutrient Discharge

A survey of 17 Florida streams was conducted between October 1984 and August 1986 to determine if the abundance of aquatic macrophytes was related to nutrient enrichment. Macrophyte standing crops were not correlated with in-stream total phosphorus or total nitrogen concentrations. Aquatic macrophytes contained less than 2% of the annual nutrient discharge in nearly all streams. Nutrients are, therefore, not considered to be the primary factor regulating the abundance of aquatic macrophytes in most Florida streams. Shading by riparian vegetation seems to be the dominant factor controlling the location and abundance of aquatic macrophytes. Statistical analyses indicated that the potential average and maximum standing crop of aquatic macrophytes in the sampled streams could be estimated by the equations[Formula: see text]where SCavg and SCmax are the average and maximum standing crop of aquatic macrophytes (kilograms fresh weight per square metre), respectively, and %C is the percent canopy coverage by riparian vegetation.

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