Big old cottonwoods

2003 ◽  
Vol 81 (7) ◽  
pp. 764-767 ◽  
Author(s):  
Stewart B Rood ◽  
Mary Louise Polzin

In studying riparian woodlands along streams across western North America, we observed a grove of exceptionally large and old black cottonwoods, Populus trichocarpa Torr. & A. Gray, along the Elk River in southeastern British Columbia. Situated in a floodplain forest dominated by western red cedar, Thuja plicata Donn ex D. Don, the cottonwoods were up to 2.2 m in diameter, and although heart rot prevented precise aging, increment cores indicated ages of up to 400 years. This demonstrated the potential for substantial longevity of section Tacamahaca cottonwoods (including Populus angustifolia James and Populus balsamifera L.) compared with section Aigeiros species (Populus deltoides Bartr. and Populus fremontii Wats.), which are shorter lived (about 150 year maximum). Very old cottonwoods make distinctive contributions to habitat structure of riparian woodlands and reveal stable floodplain locations that have not been eroded by the river channel for the duration of the trees' lives.Key words: aging, poplars, riparian, trees.

1999 ◽  
Vol 77 (8) ◽  
pp. 1095-1105 ◽  
Author(s):  
Lori A Gom ◽  
Stewart B Rood

The conservation of the remaining riparian woodlands of western North America will benefit from a better understanding of cottonwood (poplar) regeneration. Following our discrimination of the 67 cottonwood clones present in an island population of 391 trunks, the present investigation characterized the grove's clonal architecture in terms of species, sex, spatial patterns, and beaver impacts. Large clones containing up to 53 trunks occurred near the river channel in areas prone to flooding, scouring, deposition, and beaver damage. Populus section Tacamahaca Spach. species Populus angustifolia James and Populus balsamifera L. produced larger (mean diameter = 9.2 m) clones with more ramets (mean = 6.7) than the section Aigeiros Duby species Populus deltoides Bartr. (7.3 m diameter, 2.7 ramets). The increased clonal nature of the Tacamahaca species is probably adaptive along steeper gradient streams in foothill regions where increased physical disturbance encourages clonal sprouting. Conversely, P. deltoides occurs along more gradually sloped reaches with finer substrates and smoother stage patterns that would favor seedling recruitment. The grove's clonal structure accounted for the female-biased sex ratio among trunks (204 females : 116 males) since the sex ratio was even among genets (49 females : 51 males). Clonality has contributed substantially to regeneration and grove composition, favoring certain genotypes and influencing woodland structural diversity and spatial distributions. Clonal characteristics differ across Alberta's cottonwood species and would influence the distribution of these native trees.Key words: asexual reproduction, beavers, clonality, cottonwoods, Populus, sex.


1967 ◽  
Vol 45 (3) ◽  
pp. 305-309 ◽  
Author(s):  
Harold MacLean ◽  
Koji Murakami

Proof of structure is presented for another lignan of the thujaplicatin series, 2,3-dihydroxy-2-(4″-hydroxy-3″,5″-dimethoxybenzyl)-3-(4′-hydroxy-3′-methoxybenzyl)-butyrolactone (I) (dihydroxythujaplicatin methyl ether). Analytical and spectral (ultraviolet, infrared, and nuclear magnetic resonance) data on derivatives and degradation products, in addition to the parent compound, are presented.


Botany ◽  
2020 ◽  
Vol 98 (7) ◽  
pp. 353-359
Author(s):  
Kermit Ritland ◽  
Allyson Miscampbell ◽  
Annette Van Niejenhuis ◽  
Patti Brown ◽  
John Russell

We used microsatellite genetic markers to evaluate the mating system of western red cedar (Thuja plicata Donn ex D. Don) under various seed orchard pollen management schemes. We primarily examined whether supplemental mass pollination (SMP) can reduce the observed selfing rates. Pollen blowing and “hooding” were also examined in smaller tests. Only SMP was consistently effective in reducing the selfing rate, from 30% to 20%. The correlation of paternity was quite high (60%–90%) in two of three orchards, and in these two orchards the application of SMP reduced this correlation by about 10% as well. The correlation of paternity is the fraction of full-sibling vs. half-sibling progeny, and unbiased estimates can be obtained with few loci, even single loci, in contrast to other types of paternity analysis. We also find the microsatellite amplicon sizes should be pooled into “bins” of 2–4 nucleotides, owing to unintended errors of assay; otherwise the estimates are biased. This new feature of mating system estimation was incorporated into the computer program MLTR.


1999 ◽  
Vol 77 (8) ◽  
pp. 1084-1094 ◽  
Author(s):  
Lori A Gom ◽  
Stewart B Rood

In southwestern Alberta, the prairie cottonwood (Populus deltoides Bartr.), balsam poplar (Populus balsamifera L.), narrowleaf cottonwood (Populus angustifolia James), and interspecific hybrids provide the foundation of the biologically rich riparian forests. In addition to seedling-based reproduction, these cottonwoods are capable of clonal propagation, the extent of which is poorly understood. To investigate clonality in mature cottonwoods, a method for clone recognition was investigated. Between 1995 and 1997, the morphology and phenology of each tree in a mature cottonwood grove along the Oldman River were characterized. In decreasing order of utility, the characteristics most effective in revealing clones were sex, leaf shape, floral (inflorescence) phenology, and leaf phenology: flushing, senescence, and abscission. Independent traits of poplar bud gall mite (Aceria parapopuli Keifer) susceptibility and trunk architecture were less useful in clone delineation but validated the clonal determinations. Based on the analysis, the grove's 391 trunks (>10 cm diameter) included 115 genotypes, 48 single-trunked individuals, and 67 multiple-trunked clones. The clones (genets) contained from 2 to 53 trunks (ramets). It was found that 88% of trunks belonged to clonal groups, a proportion that was higher than anticipated. The extensive capacity for clonal recruitment should thus be considered in analyses of cottonwood reproductive ecology and cottonwood conservation and restoration programs.Key words: asexual reproduction, clone delineation, cottonwoods, morphology, phenology, Populus.


1958 ◽  
Vol 36 (12) ◽  
pp. 1612-1615 ◽  
Author(s):  
J. A. F. Gardner ◽  
G. M. Barton

The steam-volatile oil of western red cedar contains traces of a fifth tropolone, β-dolabrin (4-isopropenyltropolone), in addition to α-, β-, and γ-thujaplicin and 7-hydroxy-4-isopropyltropolone. The presence of β-dolabrin, previously obtained from Japanese "Hiba" wood by Nozoe, was detected by paper chromatography and proved by isolation of a sample from the steam-volatile oil by a combination of sodium salt precipitation, fractional crystallization, and preparative paper chromatography. The approximate composition of the steam-volatile oil from butt heartwood is given.


1967 ◽  
Vol 45 (7) ◽  
pp. 739-740 ◽  
Author(s):  
Harold MacLean ◽  
B. F. MacDonald

The structure of a seventh lignan from the hot-water extractive of western red cedar, which was partially separated in a previous paper, has been determined as 2,3-dihydroxy-2-(3″,4″-dihydroxy-5″-methoxybenzyl)-3-(4′-hydroxy-3′-methoxybenzyl)-butyrolactone (I). This lignan is the fifth member of the thujaplicatin series and is trivially named dihydroxythujaplicatin. Methylation, ethylation, and degradation studies provide proof of structure by comparison with known compounds.


1993 ◽  
Vol 71 (8) ◽  
pp. 1087-1092
Author(s):  
Salim N. Silim ◽  
Robert D. Guy ◽  
Denis P. Lavender

Short-term effects of the plant growth retardant mefluidide on drought resistance were investigated in seedlings of western red cedar (Thuja plicata Donn), yellow cedar (Chamaecyparis nootkatensis D. Don), and white spruce (Picea glauca (Moench) Voss). Mefluidide was applied as a root drench at concentrations of 0, 0.1, and 0.4 mg∙L−1. Following this, seedlings were stressed by withholding water for a period of up to 7 days and then watering regularly thereafter. Stomatal conductance of the mefluidide-treated seedlings decreased significantly and remained lower than the control seedlings throughout the stress period. As a result of the decreased conductance, shoot water potentials in mefluidide-treated seedlings remained higher throughout the stress period. There was a decrease in net photosynthesis that was partially caused by stomatal limitations, the severity of which depended upon the concentration of mefluidide applied. Mefluidide treatment also resulted in an accumulation of abscisic acid in all three species, and this may have been responsible for the effects on stomatal conductance and water relations. In contrast, the mefluidide-treated seedlings had the highest rates of photosynthesis after rewatering, resulting primarily from a promotion of stomatal opening. Key words: stomatal conductance, water potential, photosynthesis, plant growth inhibitors, abscisic acid, cold hardiness.


1967 ◽  
Vol 45 (9) ◽  
pp. 1519-1524 ◽  
Author(s):  
Richard P. Pharis ◽  
William Morf

Induction of staminate and ovulate strobili was obtained on western red cedar (Thuja plicata Donn) by foliar application of gibberellin A3. Staminate strobili could be induced as early as age 4 months after 3.5 months of treatment under long-day conditions, but further development of the strobilus required a photoperiodic sequence of long-day — short-day — long-day. Induction of the ovulate strobilus may also have occurred under long-day conditions at an early age, but development did not become apparent until the above photoperiodic sequence had been given. Age at this time was 12 months. It is concluded that induction and development of the strobilus is under photoperiodic as well as hormonal control.Foliar application of gibberellin A3 and a gibberellin A4/A7 mixture to pygmy cypress (Cupressus pygmaea Sarg.), Portuguese cypress (Cupressus lusitanica Mill.), and Arizona cypress (Cupressus arizonica Greene) at age 7–9 months resulted in induction of staminate strobili on all plants. Length of time to flowering varied both with species of plant and gibberellin. Application of gibberellin A3 to Arizona and Portuguese cypress seedlings resulted in production of ovulate as well as staminate strobili at ages 21 and 10 months respectively. Mourning cypress (Cupressus funebris Endl.) still in a juvenile needle stage at age 9 months has proved unresponsive to foliar application of gibberellin A3 for at least 100 days.


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