Above- and below-ground net production in 40-year-old Douglas-fir stands on low and high productivity sites

1981 ◽  
Vol 11 (3) ◽  
pp. 599-605 ◽  
Author(s):  
Michael R. Keyes ◽  
Charles C. Grier
Keyword(s):  
Fine Roots ◽  
Dry Matter ◽  
Net Primary Production ◽  
Douglas Fir ◽  
Dry Matter Production ◽  
Net Production ◽  
High Productivity ◽  
Matter Production ◽  
Below Ground ◽  
Productivity Potential

Above- and below-ground net primary production was estimated for 40-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stands growing on sites with apparently large differences in productivity potential. Aboveground net production was estimated from direct measurements of tree growth; belowground productivity was derived from data obtained by sorting live and dead roots from soil cores used in combination with measurements of root growth on observation windows.Aboveground net production was 13.7 t•ha−1 on the high productivity site and 7.3 t•ha−1 on the low productivity site. Belowground dry matter production on the high productivity site was 4.1 t•ha−1 compared with 8.1 t•ha−1 for the poorer site. On the more productive site, 8% of total stand dry matter production was in fine roots in contrast to over 36% on the poorer site. The difference in total net production (aboveground plus belowground) between the two sites was small (2.4 t•ha−1). Apparent differences in aboveground productivity may, to a large extent, result from the need for a greater investment in the fine roots on harsher sites.

AN ANALYSIS OF DRY MATTER PRODUCTION OF DOUGLAS-FIR SEEDLINGS IN RELATION TO TEMPERATURE AND LIGHT INTENSITY

1967 ◽  
Vol 45 (11) ◽  
pp. 2063-2072 ◽  
Author(s):  
Holger Brix
Keyword(s):  
Light Intensity ◽  
Leaf Area ◽  
Dry Matter ◽  
Douglas Fir ◽  
Dry Matter Production ◽  
Dry Matter Distribution ◽  
Pronounced Increase ◽  
Light Intensities ◽  
Matter Production ◽  
Net Assimilation

Seedlings of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) were grown in growth chambers under all combinations of three temperatures (13, 18, and 24 °C) and three light intensities (450, 1000, and 1800 ft-c). Dry matter production of leaves, stem, and roots was determined at 65 and 100 days after germination. The leaf area produced per unit of leaf dry weight and the dry matter distribution to the plant organs was measured. Net assimilation rates between the ages of 65 and 100 days were calculated. Rates of photosynthesis per unit of leaf were determined at different light intensities and temperatures, and rates of respiration of plant top and of roots were found for different temperatures.Increasing light intensity affected dry matter production in two opposing ways: (i) it increased the rate of photosynthesis per unit leaf area, and (ii) it decreased the leaf area added per unit of dry matter produced. A pronounced increase in growth with increase in temperature from 13 to 18 °C was a result of a temperature influence on production of leaf area rather than the effect of photosynthesis per unit of leaf. Net assimilation rates decreased with increase in temperature at all light intensities.

Seasonal dynamics of production, and nutrient accumulation and cycling by Phragmites asutralis (Cav.) Trin. ex Stuedel in a nutrient-enriched swamp in Inland Australia. I. Whole Plants

1989 ◽  
Vol 40 (5) ◽  
pp. 421 ◽  
Author(s):  
P.J. Hocking
Keyword(s):  
Standing Crop ◽  
Dry Matter ◽  
Plant Production ◽  
Dry Matter Production ◽  
Nutrient Accumulation ◽  
Ground Biomass ◽  
Matter Production ◽  
Whole Plant ◽  
Below Ground ◽  
Maximum Minimum

A study was made of the seasonal changes in dry matter production and patterns of nutrient accumulation by Phragmites australis in a nutrient-enriched swamp in inland Australia. The density of live shoots was highest (224 m-2) in October, but the peak standing crop of live shoots (9890 g m-2) occurred in early May. Peak below-ground biomass (21 058 g m-2) occurred in early August. Rhizome biomass constituted 75% of the below-ground biomass, and showed a distinct seasonal pattern. Net annual above-ground primary production (NAAP), estimated by the maximum-minimum method, was 9513 g m-2. Correction for shoot mortality and leaf shedding before, and production after, the maximum standing crop was attained increased NAAP to 12 898 g m-2. Whole plant production estimated by the maximum-minimum method was 9960 g m-2, and the corrected estimate was 14 945 g m-2. A model of dry-matter production indicated that translocation of carbohydrate from rhizomes could have provided 33% of the dry matter of shoots. About 23% of the dry matter of shoots was redistributed to below-ground organs during senescence. Concentrations of N, P, K, S, Cl and Cu declined, but concentrations of Ca, Mg, Na, Fe and Mn increased as shoots aged. Concentrations of N, P and Zn in rhizomes reached maxima in winter, and decreased in spring. Rhizomes usually contained the greatest quantity of a nutrient in the whole plant, and roots usually had less than 25% of the total plant content. There were seasonal fluctuations in the quantities of N, P, K, Zn and Cu in rhizomes. Nutrient accumulation by live shoots was underestimated by 22-55% using the maximum-minimum method. Nutrient budgets showed considerable internal cycling of N, P, K, S and Cu from rhizomes to developing shoots in spring, and from senescing shoots to rhizomes during autumn and winter.

Growth response of western hemlock and Douglas-fir seedlings to temperature regimes during day and night

1971 ◽  
Vol 49 (2) ◽  
pp. 289-294 ◽  
Author(s):  
H. Brix
Keyword(s):  
Dry Matter ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Stem Length ◽  
Dry Matter Production ◽  
Night Temperature ◽  
Temperature Regimes ◽  
Matter Production ◽  
Production And Distribution ◽  
Growing Conditions

Growth of western hemlock and Douglas-fir seedlings was studied under 11 controlled day–night temperature regimes ranging from 8 to 28 °C, and with light intensities of 450 and 1000 ft-c for 100 days after seed germination. Production and distribution of dry matter, together with length and diameter of stem, were measured. Douglas fir had a broad optimum temperature for growth between 18 and 24 °C, whereas hemlock had a pronounced optimum at 18 °C, especially at high light. High temperature was more detrimental to growth of hemlock than of Douglas fir. At 28 °C, dry matter production of hemlock was 7, and of Douglas fir 40% of the maximum. Low temperature similarly affected the two plants. A constant day–night temperature regime was as good or better than alternating temperatures for both plants. Day temperature was more effective in increasing growth than night temperature. Light intensity, for most temperature regimes, had a pronounced effect on dry matter production, less on stem diameter, and little or none on stem length. Dry matter production of hemlock was considerably lower than for Douglas fir for all growing conditions.

Effect of temperature on dry matter production of Douglas-fir seedlings during bud dormancy

1969 ◽  
Vol 47 (7) ◽  
pp. 1143-1146 ◽  
Author(s):  
Holger Brix
Keyword(s):  
Temperature Effect ◽  
Dry Matter ◽  
Growth Period ◽  
Dry Weight ◽  
Douglas Fir ◽  
Bud Dormancy ◽  
Dry Matter Production ◽  
Effect Of Temperature ◽  
Leaf Production ◽  
Matter Production

Bud dormancy was induced in Douglas-fir seedlings 90 days after seed germination. Dry matter production of bud-dormant plants was determined for a 7-week growth period at five controlled temperatures from 2 to 24 °C. There was no significant temperature effect between 7 and 24 °C on total dry matter production, which at 2 °C was reduced. Dry weight of the root was affected more by temperature than that of the plant top. A pronounced temperature effect on dry matter production was found previously between 13 and 18 °C for plants in the stage of leaf production. This did not occur for bud-dormant plants because temperature effect on leaf production was not present. Net assimilation rates during bud dormancy were generally lower than during the stage of leaf production, especially at low temperature. This may have been caused by a reduced "sink" for use of photosynthates during bud dormancy.

Dry matter production of green pea influenced by herbicides

2005 ◽  
Vol 33 (1) ◽  
pp. 377-380
Author(s):  
Erzsébet Nádasy ◽  
Gábor Wágner
Keyword(s):  
Dry Matter ◽  
Dry Matter Production ◽  
Matter Production ◽  
Green Pea

Effects of Drought Stress on Physiological Characteristics and Dry Matter Production in Maize Silking Stage

2013 ◽  
Vol 38 (10) ◽  
pp. 1884-1890 ◽  
Author(s):  
Ren-He ZHANG ◽  
Dong-Wei GUO ◽  
Xing-Hua ZHANG ◽  
Hai-Dong LU ◽  
Jian-Chao LIU ◽  
...  
Keyword(s):  
Drought Stress ◽  
Dry Matter ◽  
Physiological Characteristics ◽  
Dry Matter Production ◽  
Matter Production ◽  
Effects Of Drought

Effects of Soil Tillage Practice on Dry Matter Production and Water Use Effi-ciency in Wheat

2011 ◽  
Vol 37 (8) ◽  
pp. 1432-1440
Author(s):  
Cheng-Yan ZHENG ◽  
Shi-Ming CUI ◽  
Dong WANG ◽  
Zhen-Wen YU ◽  
Yong-Li ZHANG ◽  
...  
Keyword(s):  
Water Use ◽  
Dry Matter ◽  
Soil Tillage ◽  
Dry Matter Production ◽  
Tillage Practice ◽  
Matter Production ◽  
Effi Ciency
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