Douglas-fir and white fir advance regeneration for renewal of mixed-conifer forests

1993 ◽  
Vol 23 (7) ◽  
pp. 1427-1437 ◽  
Author(s):  
Steven D. Tesch ◽  
Ed J. Korpela
Keyword(s):  
Mediterranean Climate ◽  
Height Growth ◽  
Douglas Fir ◽  
Regression Equations ◽  
Site Class ◽  
Class V ◽  
Advance Regeneration ◽  
White Fir ◽  
Mixed Conifer Forests ◽  
Site Classes

Stem analysis of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and white fir (Abiesconcolor (Gord. & Glend.) Lindl.) advance regeneration 20 years after overstory removal showed that both species can respond in height growth to become dominant components of future stands on medium- to low-quality sites with a Mediterranean climate. Average annual height growth of both species nearly doubled on site classes III and IV during the first 5 years after release and continued to increase over the 20-year period of observation. Trees on the poorer site class V responded more slowly, but achieved similar 5-year periodic annual height growth after 20 years. Regression analyses indicated that prerelease height growth and site class were generally the most important variables in describing height growth after overstory removal, but regression equations left much variability in growth unexplained. Discriminant analysis was used to develop functions that identified trees meeting or exceeding specified levels of average annual height growth 5, 10, or 20 years after release; the classifications were generally successful at least 70% of the time.

Plantations vs. Advance Regeneration: Height Growth Comparisons for Southwestern Oregon

1992 ◽  
Vol 7 (2) ◽  
pp. 44-47 ◽  
Author(s):  
Ed J. Korpela ◽  
Steven D. Tesch ◽  
R. Lewis
Keyword(s):  
Species Composition ◽  
Pseudotsuga Menziesii ◽  
Height Growth ◽  
Douglas Fir ◽  
Abies Concolor ◽  
Initial Height ◽  
Advance Regeneration ◽  
White Fir ◽  
Time Required ◽  
Site Classes

Abstract Model projections of newly planted Douglas-fir (Pseudotsuga menziesii) seedlings grown under three competition regimes were compared across three site classes with growth of three height classes of Douglas-fir and white fir (Abies concolor) advance regeneration for 20 years following overstory removal. Plantations growing without competition were projected to grow about as fast as advance regeneration on the best sites and slower on the poorer sites. However, over the 20-year period, the projected height of planted trees exceeded only that of released small white fir. Competing vegetation reduced projected plantation growth, thus increasing the height advantage of advance regeneration over planted trees after 20 years. Comparisons such as these are influenced by the time required to establish new plantations, competition faced by released and planted trees, and the species composition, vigor, and initial height of the advance regeneration. These results suggest that managing advance regeneration may be a viable reforestation alternative in southwestern Oregon, particularly on poorer sites. West. J. Appl. For. 7(2):44-47

scholarly journals Fate of Overstory Trees and Patterns of Regeneration 12 Years After Clearcutting with Reserve Trees in Southwest Washington

2002 ◽  
Vol 17 (2) ◽  
pp. 78-85 ◽  
Author(s):  
Karl R. Buermeyer ◽  
Constance A. Harrington
Keyword(s):  
Pacific Northwest ◽  
Douglas Fir ◽  
Seedling Density ◽  
Site Class ◽  
Seedling Size ◽  
Advance Regeneration ◽  
Dead Trees ◽  
The Status ◽  
Overstory Trees ◽  
Southwest Washington

Abstract Changes in management objectives for some forestlands in the Pacific Northwest have spurred interest in the creation of multistoried stands and the use of natural regeneration systems, but data on such systems are lacking. We assessed the status of the overstory trees and the regeneration 12 yr after a clearcut harvest with reserve trees in an even-aged, 145-yr-old Douglas-fir stand on a moderately productive site (site class 3) in southwest Washington. The 15 ha harvest unit was superimposed over two areas differentially thinned 15 and 34 yr before clearcutting. The clearcut harvest retained 18 trees/ha with a mean diameter of 63 cm. The reserved overstory trees had a 93% survival rate after 12 yr; most dead trees had been windthrown. Diameter growth for the reserved trees averaged 3.3 cm and was greatest during the most recent 3 yr period, which also had the highest growing-season precipitation. In a 1 ha mapped area, there were 5,854 seedlings/ha, and more than 99% of the regeneration was Douglas-fir. Most seedlings were less than 2 m tall. Seedling density was somewhat clumped (value of 2.1 for Pielou's index of nonrandomness), but 79% of randomly located 4.04 m2 (mil-acre) plots and 98% of 5 × 5 m grid cells had at least one conifer seedling. There was no obvious pattern of regeneration based on direction from the reserved trees, but both seedling density and seedling size within the drip lines of reserved tree crowns were less than in the rest of the area. The number of seedlings was similar on the two halves of the plot corresponding to the original thinning blocks, but seedling size and age differed. In the half of the study plot that had been twice lightly thinned, only 14% of the seedlings were >0.5 m tall; however, 41% of the seedlings were >0.5 m in the block that had been thinned more heavily. There was no difference between the thinning blocks in the ages of seedlings ≤0.5 m tall (mean age of 5 yr). This example of clearcutting with reserve trees resulted in reasonable survival of the overstory trees and adequate stocking but slow growth rates in the naturally regenerated Douglas-fir. Heavier thinning before harvest was associated with more advance regeneration, more shrub cover, and less windthrow of the reserved trees than in the more lightly thinned block. If an abundance of tree species other than Douglas-fir was desired on this site, interplanting would be required. West. J. Appl. For.17(2):78–85.

scholarly journals RELATIVE QUALITY OF THE MAJOR FOREST ASSOCIATIONS OF THE SOUTHERN B.C. INTERIOR FOR GROWTH OF LODGEPOLE PINE, ENGELMANN SPRUCE, DOUGLAS-FIR AND ALPINE FIR

1966 ◽  
Vol 42 (3) ◽  
pp. 306-313 ◽  
Author(s):  
Walter Stanek
Keyword(s):  
British Columbia ◽  
Lodgepole Pine ◽  
Site Index ◽  
Height Growth ◽  
Douglas Fir ◽  
Regression Equations ◽  
Common Occurrence ◽  
Engelmann Spruce ◽  
Relative Quality

Height growth of lodgepole pine, Engelmann spruce, Douglas-fir and alpine fir was investigated in the Douglas-fir and Engelmann Spruce-Alpine Fir Zones of the Interior of British Columbia. In the same forest association each species has a characteristic site index at the age of 100 years (SI/100). Regression equations were calculated for predicting SI/100 of several species in different associations. Regression equations were also developed for estimating SI/100 of Engelmann spruce, Douglas-fir and alpine fir from known SI/100 of lodgepole pine. The latter species was selected because of its common occurrence in the two zones. In addition regression equation was calculated for predicting SI/100 of lodgepole pine from known SI/100 of Engelmann spruce. All regression equations apply to naturally established stands in the study area.

Patterns of above- and below-ground response of understory conifer release 6 years after partial cutting

2002 ◽  
Vol 32 (2) ◽  
pp. 255-265 ◽  
Author(s):  
Daniel D Kneeshaw ◽  
Harry Williams ◽  
Eero Nikinmaa ◽  
Christian Messier
Keyword(s):  
Root Growth ◽  
Height Growth ◽  
Douglas Fir ◽  
Stem Growth ◽  
Radial Increment ◽  
Growth Responses ◽  
Partial Cutting ◽  
Size Classes ◽  
Clear Cutting ◽  
Advance Regeneration

An increased pressure to use silvicultural techniques not based on clear-cutting followed by planting has led to an interest in systems that take advantage of existing understory seedlings (advance regeneration). Earlier studies have suggested that following harvesting, understory seedlings may experience growth reductions before responding with growth increases. We hypothesize that this "growth shock" following release results because seedlings are ill adjusted to the new growing conditions and that this can be investigated through a comparison of growth in different parts of the tree over a 6-year period. This study compares the growth response of three size classes of lodgepole pine (Pinus contorta Dougl. ex Loud.) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings to a partial overstory removal in relatively dry conifer forests of central British Columbia. Growth was evaluated in four parts of the studied trees: radial increment in roots, in the base of the stem, and in branches, as well as leader height growth extension. Our findings show that following release from the overstory, early growth increases were largest in the roots and stems irrespective of the species or the size class. Differences between the species were observed in greater absolute height growth for pine, whereas Douglas-fir invested in greater stem growth, especially in the larger individuals. Important differences also occurred temporally. Both species (and all size classes) responded with an immediate increase in root growth followed, after a 1-year delay, by an increase in stem growth. Branch radial increment (for pine) and leader height growth (both species), however, experienced 2 to 3 year growth reductions before responding. It is therefore suggested that individuals restore the root–shoot balance by greater initial investments to root growth to offset the increased transpiration losses associated with the greater light and higher temperature conditions and the relative changes in the photosynthetic versus nutrient uptake capacity following the canopy opening. Foresters may therefore be able to manipulate tree growth responses by using an appropriate degree of overstory removal or opening size.

Effect of urea fertilization on allometric relations in young Douglas-fir trees

1984 ◽  
Vol 14 (6) ◽  
pp. 900-904 ◽  
Author(s):  
Charles C. Grier ◽  
Katharine M. Lee ◽  
Ruth M. Archibald
Keyword(s):  
Nitrogen Availability ◽  
Regional Analysis ◽  
N Fertilization ◽  
Douglas Fir ◽  
Leaf Biomass ◽  
Regression Equations ◽  
Class Iii ◽  
Site Class ◽  
Allometric Relations ◽  
Urea Fertilization

The effect of nitrogen fertilization on allometric relations was examined for 23-year-old site class III Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees 2 years after urea fertilization. Logarithmic regression equations using stem diameter (centimetres) to predict tree biomass components (kilograms) were not significantly (p = 0.05) different between fertilized and control trees for total foliage, total branch, dead branch, stembark, or stemwood. New foliage and new twig components, however, were higher in fertilized trees than in control trees. Analysis of data from this and earlier studies suggests fertilization will increase leaf biomass per tree relative to control trees on sites having low nitrogen availability; however, this response will decrease with increasing nitrogen availability. Regression equations based on regional analysis of unfertilized trees yield estimates of foliage biomass for average trees on average sites. If N fertilization brings the site above average in terms of nitrogen availability then these regression equations will underestimate foliage biomass. However, on sites that are initially very nitrogen deficient, N fertilization will bring the site closer to average in terms of nitrogen availability, resulting in more accurate predictions of foliage biomass for fertilized stands than for control stands.

Short- and long-term growth characteristics associated with tree mortality in southwestern mixed-conifer forests

2014 ◽  
Vol 44 (10) ◽  
pp. 1227-1235 ◽  
Author(s):  
Jeffrey M. Kane ◽  
Thomas E. Kolb
Keyword(s):  
Tree Mortality ◽  
Douglas Fir ◽  
Growth Characteristics ◽  
Conifer Forests ◽  
Mixed Conifer ◽  
Dead Trees ◽  
White Fir ◽  
Mixed Conifer Forests ◽  
Short And Long Term

Continued increases in global temperatures and incidences of drought have been implicated in elevated tree mortality in many regions, prompting interest in better understanding tree mortality processes. A recent extreme drought in the southwestern U.S. (1996–2003) contributed to elevated tree mortality throughout the region. We used this event to investigate the relationship of short- and long-term tree growth characteristics to recent (1996–2008) tree mortality in the mixed-conifer forests in northern Arizona. We compared radial growth characteristics over a 50-year period between paired live and recently dead white fir (Abies concolor (Gordon & Glend.) Lindl. ex Hildebr.), limber pine (Pinus flexilis E. James), trembling aspen (Populus tremuloides Michx.), and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). We found that (i) dead trees of all species typically had lower mean growth rates than live trees, (ii) dead trees of most species had a greater coefficient of variation in growth over long time periods (>20 years) than live trees, (iii) dead aspen and dead Douglas-fir trees had larger negative growth trends than live trees for some time periods, (iv) dead trees of most species had larger numbers of abrupt growth declines than live trees, and (v) a combination of short- and long-term growth characteristics distinguished live and dead trees, with greater importance of short-term growth for aspen, long-term growth for limber pine, and a mix of short- and long-term growth for white fir and Douglas-fir. These results strongly suggest that recent tree mortality in southwestern mixed-conifer forests is caused by a mixture of short- and long-term processes.

ESTIMATION OF GROWTH – TIME TEMPERATURE CHARACTERISTICS FOR ISOLATES OF FOMES PINI, A HEART ROT FUNGUS

1964 ◽  
Vol 42 (12) ◽  
pp. 1635-1652 ◽  
Author(s):  
Lee A. Paine ◽  
Gideon Schwarzbart ◽  
William G. O'Regan
Keyword(s):  
Regression Analysis ◽  
Cross Section ◽  
Growth Pattern ◽  
Storage Temperature ◽  
Three Dimensional ◽  
Douglas Fir ◽  
Growth Time ◽  
Optimum Temperature ◽  
Analysis Techniques ◽  
White Fir

Regression analysis techniques were applied to an estimation of three-dimensional surfaces representing the growth of Fomes pini as a function of time and temperature. These methods were judged to be valuable in their economy of data and in their provision of readily available plotting points for any desired cross section of the surface.The growth pattern of F. pini taken from Douglas fir was distinct from that of the form of F. pini found on nearby white fir. Growth of isolates from Douglas fir was more than twice that of white fir isolates after 18 days at near-optimum temperatures on malt agar. Estimates of growth trends and optimum temperatures were examined both for individual isolates of F. pini and for averages of isolates from the two host species, Douglas fir and white fir. Results suggest that chronological changes in the optimum temperature may be affected by the relation between the storage temperature preceding initial measurements and the terminal optimum temperature.

The effects of summer shoot production on height growth components of seedlings of California red and white fir

1992 ◽  
Vol 22 (5) ◽  
pp. 690-698 ◽  
Author(s):  
Stephen W. Hallgren ◽  
John A. Helms
Keyword(s):  
Soil Moisture ◽  
Growing Season ◽  
Shoot Elongation ◽  
Height Growth ◽  
Shoot Morphology ◽  
Apical Dome ◽  
White Fir ◽  
Shoot Production ◽  
Terminal Shoot ◽  
Needle Primordia

Morphogenesis of the terminal shoot was studied in 2-year-old seedlings of California red fir (Abiesmagnifica A. Murr.) and two elevational sources of white fir (Abiesconcolor (Gord. & Glend.) Lindl.). Seedlings were either watered or left unwatered during the growing season in order to produce different shoot morphologies and seedlings with and without a summer shoot. Under favorable soil moisture, the frequency of summer shoot production was 32, 53, and 82% for red fir and high- and low-elevation white fir, respectively. Drought from mid-May to mid-September reduced summer shoot production to less than 1% in both species. Spring shoot morphology was not an indicator of capacity to produce a summer shoot. Rate of primordium production was directly related to apical dome diameter. However, when the normal spring increase in apical dome diameter was arrested by summer shoot elongation, the rate of primordium production appeared to be unaffected. Although the apical and subapical meristems were active at the same time, they did not appear to be antagonistic. The major effects of producing a summer shoot were as follows: (i) elongation of 60–120% more intemodes in the current growing season, (ii) production of 15–40% more needle primordia in the overwintering bud, (iii) production of 30–60% more primordia annually, and (iv) increase in the percentage of total primordium production that developed into needles from 60% to 75–80%.

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