Effects of stand density on the growth of young Douglas-fir trees

2002 ◽  
Vol 32 (3) ◽  
pp. 420-427 ◽  
Author(s):  
David R Woodruff ◽  
Barbara J Bond ◽  
Gary A Ritchie ◽  
William Scott
Keyword(s):  
Growth Response ◽  
Stand Density ◽  
Early Growth ◽  
Douglas Fir ◽  
Volume Index ◽  
Annual Rings ◽  
Wood Cellulose ◽  
Positive Growth ◽  
Second Year ◽  
Old Trees

The objectives of this study were (i) to provide further evidence of a positive correlation of stand density with early growth of coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii); (ii) to determine when after planting the positive growth response occurs and how long it lasts; and (iii) to use stable isotopes of carbon to test whether the mechanism(s) responsible for the positive growth response to density are related to variables affecting photosynthesis, such as nutrient or moisture availability. We measured annual height (h) and diameter (d) growth (retrospectively) of 8- and 12-year-old trees in initial planting densities of 300, 1360, and 2960 trees/ha. Both height and diameter growth increased with density through the fifth year after planting and decreased with density by year 7. Diameter squared × height (d2h) was used as a volume index to assess increase in tree volume. Second-year increase in d2h for the high-density treatments was 300% of that in the low-density treatments. The δ13C values of wood cellulose from annual rings of the second and third years after planting were not significantly different among densities, suggesting either (i) no significant differences in the effects of water availability, nutrient availability, or source air on photosynthesis in the three density treatments or (ii) differences that produced no net effect on δ13C.

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.

The use of various soil and site variables for estimating growth response of Douglas-fir to multiple applications of urea and determining potential long-term effects on soil properties

2008 ◽  
Vol 38 (6) ◽  
pp. 1458-1469 ◽  
Author(s):  
Eric B. Sucre ◽  
Robert B. Harrison ◽  
Eric C. Turnblom ◽  
David G. Briggs
Keyword(s):  
Pacific Northwest ◽  
Growth Response ◽  
Stand Density ◽  
Douglas Fir ◽  
Long Term Effects ◽  
Annual Increment ◽  
Concentration Data ◽  
Soil Variables ◽  
Management Regime ◽  
Cumulative Volume

Estimating the growth response of Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) stands after nitrogen (N) fertilization is difficult because of the high site variability present in the Pacific Northwest. Our objective was to determine how site and soil variables relate to stand response to repeat applications of 224 kg N·ha–1 as urea once every 4 years. The unstandardized residuals of two dependent variables (total cumulative volume and 4-year periodic annual increment, or PAI) were regressed against site and soil variables using stepwise regression. Data were stratified by three different stand density treatments: unaltered stand density (SD), one-half SD (SD/2), and one-quarter SD (SD/4). Both total cumulative volume and 4-year PAI after the second application of urea was significantly higher in the fertilized plots (p = 0.008; 0.009), whereas only total cumulative volume was significant after the third fertilizer application (p = 0.021). Thinning effects were highly significant (p < 0.001) for all three fertilizer applications. The strongest related stand, site, or soil variable to fertilization response existed between percent N at the 30–50 cm depth and total cumulative volume (R2 = 0.833) for the SD/2 stand density management regime. Regression analysis showed that C, N, NH4+, and NO3– concentration data explained the most variation, while stand and site variables contributing the least. The results demonstrate that multiple applications of urea provide significant increases in total volume, but effects of successive applications diminish over time.

Bone Marrow Mesenchymal Stem Cell mediated Ultrasmall Gold Nanoclusters and hNIS Gene Synergize Radiotherapy in Breast Cancer

2021 ◽  
Author(s):  
Lu Zhang ◽  
Benchao Zheng ◽  
Rui Guo ◽  
Ying Miao ◽  
Biao Li
Keyword(s):  
Breast Cancer ◽  
Bone Marrow ◽  
Stem Cell ◽  
Growth Response ◽  
Sodium Iodide ◽  
Gold Nanoclusters ◽  
Early Growth ◽  
Sodium Iodide Symporter ◽  
Early Growth Response ◽  
131I Treatment

The human sodium iodide symporter (hNIS) can be linked to the downstream of radiation-sensitive early growth response protein1 (Egr1) promoter, and activated by the Egr1 following 131I treatment. However, the...

scholarly journals Growth Response of Bigcone Douglas Fir (Pseudotsuga macrocarpa) to Long-Term Ozone Exposure in Southern California

1995 ◽  
Vol 45 (1) ◽  
pp. 36-45 ◽  
Author(s):  
David L. Peterson ◽  
David G. Silsbee ◽  
Mark Poth ◽  
Michael J. Arbaugh ◽  
Frances E. Biles
Keyword(s):  
Southern California ◽  
Growth Response ◽  
Douglas Fir ◽  
Ozone Exposure
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