Effects of competition on the foliar chemistry of young Douglas-fir in monoculture and mixed stands with young red alder

1995 ◽  
Vol 25 (12) ◽  
pp. 1969-1977 ◽  
Author(s):  
Lauri J. Shainsky ◽  
Cathy L. Rose
Keyword(s):  
Free Amino ◽  
Douglas Fir ◽  
Response Surfaces ◽  
Nonstructural Carbohydrates ◽  
Regression Analyses ◽  
Foliar Chemistry ◽  
Mixed Stands ◽  
Red Alder ◽  
Growth Physiology ◽  
Total Nonstructural Carbohydrates

The effects of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and red alder (Alnusrubra Bong.) densities on foliar chemistry of 4-year-old Douglas-fir were examined in experimentally manipulated stands. The density of each species was varied systematically in a two-way density matrix composed of five monoculture densities and 25 mixtures of all possible pairwise combinations of monoculture densities. Foliage was sampled in July of the second growing season and analysed for concentrations of nitrogen (N), phosphorus (P), starch, sugars, total nonstructural carbohydrates, and free amino acids. Response surfaces were generated, and regression analyses quantified the effects of each species' density on biochemistry. Increasing the overstory alder density resulted in increased N, free amino acid, and P concentrations in the Douglas-fir foliage, and reduced starch and total nonstructural carbohydrate concentrations. Effects of Douglas-fir density were variable and dependent on the red alder density. Trends in biochemistry correlated well with soil moisture, light, and growth rates. Conditions favoring growth were associated with reduced concentrations of N and P and elevated levels of starch and nonstructural carbohydrates. The results strongly suggest that examination of foliar chemistry should be coupled with growth, physiology, and resources if biochemical constituents are to be used for testing tree vigor.

Effects of intra- and inter-specific competition on root and shoot biomass of young Douglas-fir and red alder

1992 ◽  
Vol 22 (1) ◽  
pp. 101-110 ◽  
Author(s):  
L.J. Shainsky ◽  
M. Newton ◽  
S.R. Radosevich
Keyword(s):  
Douglas Fir ◽  
Response Surfaces ◽  
Volume Index ◽  
Stem Volume ◽  
Shoot Biomass ◽  
Total Biomass ◽  
Mixed Stands ◽  
Red Alder ◽  
Biomass Components ◽  
Root And Shoot Biomass

The effects of intra- and inter-specific competition on root and shoot biomass of 5-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and red alder (Alnusrubra Bong.) were studied in experimentally manipulated stands. The density of each species was varied systematically in a two-way density matrix composed of five monoculture densities and 25 mixtures of all possible pairwise combinations of monoculture densities. Roots and shoots were harvested after the fourth growing season. Response surfaces for root, shoot, and total biomass per tree were generated within the matrix. Regression analysis quantified the effect of each species' density on biomass components. Alder overtopped the Douglas-fir in all mixed stands. Alder density influenced the root and shoot biomass of both species more than Douglas-fir density. Douglas-fir density interacted with red alder density to influence all biomass components. While increasing the density of each species reduced root and shoot biomass per tree, allocation of biomass to roots and shoot was not affected by competition, nor were the allometric equations relating biomass to stem diameter and stem volume index.

Influence of short-term atmospheric CO2 enrichment on growth, allocation patterns, and biochemistry of black spruce seedlings at different stages of development

1989 ◽  
Vol 19 (6) ◽  
pp. 773-782 ◽  
Author(s):  
Michel A. Campagna ◽  
Hank A. Margolis
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Black Spruce ◽  
Production Cycle ◽  
Nonstructural Carbohydrates ◽  
Short Term ◽  
Stages Of Development ◽  
Greenhouse Production ◽  
Total Nonstructural Carbohydrates

Black spruce seedlings (Piceamariana Mill.) were exposed to either elevated (1000 ppm) or ambient (340 ppm) atmospheric CO2 levels at different stages of seedling development over a winter greenhouse production cycle. Seedlings germinated in early February and were placed in CO2 chambers for either 3 or 6 weeks during March, April, May, or August. Total seedling biomass increased under high CO2 conditions for the March, April, and May stages of development, but showed no significant response in August. The greater part of the CO2 response occurred during the second 3 weeks of exposure in March and April but during the first 3 weeks of exposure in May. In September, those seedlings exposed to CO2 in April and May had 30 and 14%, respectively, greater biomass than control seedlings, but seedlings from the other stages of development no longer had significant differences remaining from the CO2 treatment. This suggests that it could be very efficient to give a short well-timed CO2 pulse at the beginning of the production cycle in hopes of producing a size difference that is maintained throughout the remainder of the greenhouse production cycle under ambient levels of CO2. Short-term exposure to elevated CO2 also increased the ratio of shoot dry weight to total height for the March, April, and May stages of development. The ratio of total nonstructural carbohydrates to free amino acids was negatively correlated (r2 = 0.98) with the allocation of new growth between shoots and roots as measured by the allocation coefficient, k (milligrams shoot growth per milligrams root growth). As seedlings developed along their seasonal growth cycle, ratios of total nonstructural carbohydrates to free amino acids increased and the values for k decreased. The effect of CO2 enrichment on these two factors is discussed. Monitoring total nonstructural carbohydrate and free amino acid concentrations in foliage could have potential as a method to predict the percentage of carbon allocated to root systems of entire forest stands as well as of individual tree seedlings.

Spatial extent of impact of red alder on soil chemistry of adjacent conifer stands

1992 ◽  
Vol 22 (9) ◽  
pp. 1434-1437 ◽  
Author(s):  
Charles C. Rhoades ◽  
Dan Binkley
Keyword(s):  
Soil Ph ◽  
Soil Chemistry ◽  
Douglas Fir ◽  
Spatial Extent ◽  
N Availability ◽  
Soil N ◽  
Mixed Stands ◽  
Red Alder ◽  
Soil N Availability ◽  
River Site

We examined patterns in soil N availability and pH along transects extending from mixed stands of conifers (mostly Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco)) and red alder (Alnusrubra Bong.) to pure conifer stands at two locations. At the relatively infertile Wind River site, increased N availability was apparent for about 8–12 m downslope of the alder–conifer stand, but no effect was apparent upslope. At the fertile Cascade Head site, no trend was apparent in N availability across the stand boundaries, but soil pH in the conifer stand was depressed for about 5 m from the alder–conifer stand. Overall, the effects of alder on soil chemistry appeared limited to a distance of less than half the height of the trees.

Influence of species proportion and timing of establishment on stem quality in mixed red alder – Douglas-fir plantations

2004 ◽  
Vol 34 (4) ◽  
pp. 863-873 ◽  
Author(s):  
Amy T Grotta ◽  
Barbara L Gartner ◽  
Steven R Radosevich
Keyword(s):  
Stand Structure ◽  
Stand Density ◽  
Douglas Fir ◽  
Stem Form ◽  
Mixed Stands ◽  
Red Alder ◽  
Stem Quality ◽  
Multiple Stems ◽  
Old Trees ◽  
Species Proportion

The relationships among stand structure, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) branch characteristics, and red alder (Alnus rubra (Bong.)) stem form attributes were explored for 10- to 15-year-old trees growing in mixed Douglas-fir – red alder plantations. Treatments included a range of species proportions, and red alder was either planted simultaneously with Douglas-fir or after 5 years. Both replacement effects (total stand density held constant) and additive effects (stand density doubled) of competition were considered. When the two species were planted simultaneously and red alder proportion was low, red alder trees had low crown bases and much stem defect (lean, sweep, and multiple stems). Douglas-fir grew slowly when the two species were planted simultaneously. When red alder planting was delayed, species proportion did not affect red alder stem form, and height to the base of the Douglas-fir live crown decreased with increasing red alder proportion. Doubling Douglas-fir density increased the height to the base of the Douglas-fir live crown; however, doubling stand density by adding red alder did not affect Douglas-fir crown height. Douglas-fir lumber coming from mixed stands may be inferior because of the changes in knot characteristics associated with these different patterns of crown recession. In stands with a low proportion of red alder, red alder product recovery may be compromised because of the stem defects described above.

Changes in levels of foliar carbohydrates and myo-inositol before premature leaf senescence of Populus nigra induced by a mixture of O3 and SO2

1996 ◽  
Vol 74 (6) ◽  
pp. 965-970 ◽  
Author(s):  
R. C. Fialho ◽  
J. Bücker
Keyword(s):  
Air Pollution ◽  
Leaf Senescence ◽  
Populus Nigra ◽  
Continuous Exposure ◽  
Nonstructural Carbohydrates ◽  
Progressive Decline ◽  
Total Nonstructural Carbohydrates ◽  
Leaf Yellowing ◽  
Premature Leaf Senescence ◽  
Early Indication

Specimens of Populus nigra L. cv. Loenen exhibit premature leaf senescence when exposed for a few weeks to realistic air pollution. In this study, the changes in levels of foliar carbohydrates and myo-inositol (MI) due to 30 ± 1 nL/L O3 + 12 ± 1 nL/L SO2 from the onset of exposure to the occurrence of premature abscission is presented. Petioles and laminae of the 12 oldest leaves were separately analysed on days 0, 4, 8, 12, 16, 20, 22, and 32 of continuous exposure, which was performed in open-top chambers (OTC). On days 8 to 12, clearly prior to yellowing (starting on day 22), total nonstructural carbohydrates (TNC; starch + raffinose + sucrose + glucose + fructose + MI) in the fumigated laminae exceeded that in controls by about 30%. This increase was due to higher amounts of different soluble forms, while starch remained unaltered. From day 20 onwards, the level of TNC in the fumigated laminae progressively fell below that in controls. This decrease was due to a progressive decline in starch, which had started on day 16 and was dominating, although glucose and raffinose increased significantly. In the petioles, starch, sucrose, and glucose decreased because of fumigation with the occurrence of leaf yellowing, while raffinose increased. In contrast, MI in the petioles progressively accumulated directly on exposure until leaf yellowing occurred. The results are discussed in terms of the "general adaption syndrome" of H. Selye (1936. Nature (London), 138: 32). The marked MI response in petioles is concluded to be an early indication of phytorelevant O3 + SO2 pollution. Keywords: air pollution, carbohydrates, myo-inositol, pigments, Populus nigra L., senescence, stress.

scholarly journals Effects of Defoliation and Competition on Total Nonstructural Carbohydrates of Spotted Knapweed

1994 ◽  
Vol 47 (6) ◽  
pp. 481 ◽  
Author(s):  
John R. Lacey ◽  
Kathrin M. Olson-Rutz ◽  
Marshall R. Haferkamp ◽  
Gregory A. Kennett
Keyword(s):  
Spotted Knapweed ◽  
Nonstructural Carbohydrates ◽  
Total Nonstructural Carbohydrates
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