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.

Comparing productivity of pure and mixed Douglas-fir and western hemlock plantations in the Pacific Northwest

2006 ◽  
Vol 36 (6) ◽  
pp. 1484-1496 ◽  
Author(s):  
M M Amoroso ◽  
E C Turnblom
Keyword(s):  
Pacific Northwest ◽  
Stand Density ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Mixed Stand ◽  
Mixed Stands ◽  
Individual Tree ◽  
The Pacific ◽  
Increase In Productivity

We studied pure and 50/50 mixtures of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) plantations to compare attained total yields between mixed-species stands as opposed to monocultures of equal densities. Whether overall stand density influences this outcome has not been adequately investigated, and to address this we included three density levels (494, 1111, and 1729 trees/ha) in the analysis. At age 12, as components of the mixed stands, Douglas-fir exhibited greater height, diameter, and individual-tree volume than western hemlock at all densities. At 494 and 1111 trees/ha the monocultures had a higher volume per hectare than the mixed stand, but at 1729 trees/ha the mixed stand appeared to be just as productive as the pure stands. The increase in productivity by the mixture at high densities seems to have resulted from the partial stratification observed and most likely also from better use of the site resources. Because of this, less interspecific competition was probably experienced in the mixed stand than intraspecific competition in the pure stands. This study shows the important role density plays in the productivity of mixed stands and thus in comparing mixed and pure stands.

Effects of species mixtures on growth and stand development of Douglas-fir and red alder

2006 ◽  
Vol 36 (3) ◽  
pp. 768-782 ◽  
Author(s):  
Steven R Radosevich ◽  
David E Hibbs ◽  
Claudio M Ghersa
Keyword(s):  
Pacific Northwest ◽  
Tree Mortality ◽  
Stand Structure ◽  
Stand Density ◽  
Douglas Fir ◽  
Forest Understory ◽  
Red Alder ◽  
Structure Tree ◽  
Species Proportions ◽  
Species Mixtures

In the Pacific Northwest, a mixture of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and red alder (Alnus rubra Bong.) often results when red alder regenerates naturally in planted conifer stands. The relationships among stand structure, tree mortality, tree size, and understory development in the two species mixtures were explored at two sites for the first 16 years after planting. Treatments included a range of species proportions, and red alder was either planted simultaneously with Douglas-fir or planting was delayed for 5 years. Red alder was also removed from some simultaneously planted proportions. Both replacement effects (total stand density held constant) and additive effects (stand density doubled) of the interaction were considered. Red alder grew relatively better at Cascade Head Experimental Forest in the Coast Range, while Douglas-fir grew better at H.J. Andrews Experimental Forest in the less temperate Cascade Mountains. Possible production benefits from mixed plantings were examined using two methods of calculation. Potential production benefits from certain planted proportions of the two species occurred at H.J. Andrews Experimental Forest. No planting time or species proportion resulted in yield improvements over monoculture stands at Cascade Head Experimental Forest. Understory species also varied because of differences in site and stand characteristics that resulted from the differences in planting times and species proportions.

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.

scholarly journals The 1912 Douglas-Fir Heredity Study: Long-Term Effects of Climatic Transfer Distance on Growth and Survival

2019 ◽  
Vol 118 (1) ◽  
pp. 1-13 ◽  
Author(s):  
J Bradley St. Clair ◽  
Glenn T Howe ◽  
Jennifer G Kling
Keyword(s):  
Pacific Northwest ◽  
Douglas Fir ◽  
Future Climate Change ◽  
Long Term Effects ◽  
Term Survival ◽  
Growth And Survival ◽  
Seed Sources ◽  
The Pacific ◽  
Near Term

Abstract The 1912 Douglas-Fir Heredity Study is one of the first studies undertaken by the US Forest Service, and one of the first forest genetics studies in North America. The study considers provenance variation of 120 parent trees from 13 seed sources planted at five test sites in the Pacific Northwest. The unique, long-term nature of the study makes it valuable to revisit and consider its biological and historical significance. This analysis considers how far climatically Douglas-fir populations may be moved without incurring unacceptable declines in growth and survival. Results indicate that Douglas-fir seed sources may be moved at least 2° C cooler or warmer and still retain good long-term survival and productivity. However, projected future climate change beyond 2° C may lead to lower survival and productivity. One option to address these concerns is assisted migration; however, if seed sources are moved beyond 2–3° C to a cooler climate in anticipation of warming, or from a more continental to a maritime climate, we are likely to see increased mortality and associated losses in productivity in the near-term. Lessons from this study include: (1) pay attention to good experimental design; we were able to overcome limitations from the design by using new statistical approaches; (2) maladaptation may take time to develop; poorer survival was not evident until more than two decades after planting; and (3) long-term studies may have value for addressing new, unforeseen issues in the future.

Modeling the long-term effects of disturbances on forest succession, Olympic Peninsula, Washington

1986 ◽  
Vol 16 (1) ◽  
pp. 56-67 ◽  
Author(s):  
Virginia H. Dale ◽  
Miles Hemstrom ◽  
Jerry Franklin
Keyword(s):  
Leaf Area ◽  
Pacific Northwest ◽  
Forest Succession ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Forest Composition ◽  
Silver Fir ◽  
Long Term Effects ◽  
Olympic Peninsula

A model of forest development has been adapted for the Pacific Northwest. The regeneration, growth, and death of individual trees are tracked for simulated 0.2 ha plots and tree attributes are aggregated to provide stand measures. The model includes the influence of temperature, soil moisture, light tolerance, and competition on tree growth. Long-term simulations for Douglas-fir dominated forests on the western Olympic Peninsula show that the stand is eventually dominated by western hemlock with silver fir being codominant. Even after 1200 years of subsequent stand development, silver fir fails to replace western hemlock indicating that this is a self-replicating and stable community. Fire, windthrows, insect disturbance, and clear-cut logging followed by replanting are incorporated into the model as single-event disturbances to a 500-year-old forest. For those cases where large Douglas-fir survive the disturbance, stand biomass and leaf area patterns are not significantly impacted until the death of the last large Douglas-fir. The projections were all carried out to the time when the forest is dominated by western hemlock and silver fir. At that time, the differential effect of the earlier disturbance is not apparent from the forest composition, biomass, or leaf area patterns except for the insect disturbance. Following the removal of all Douglas-fir by an insect, leaf area fluctuates regularly with a period of 600 years.

scholarly journals Long-Term Effects of Drainage, Bedding, and Fertilization on Growth of Loblolly Pine (Pinus taeda L.) in the Coastal Plain of Virginia

2005 ◽  
Vol 29 (4) ◽  
pp. 205-214 ◽  
Author(s):  
Thomas R. Fox ◽  
Kevin H. Kyle ◽  
Lisa J. Andrews ◽  
W. Michael Aust ◽  
James A. Burger ◽  
...  
Keyword(s):  
Loblolly Pine ◽  
Coastal Plain ◽  
Growth Response ◽  
Block Design ◽  
Basal Area ◽  
Stand Density ◽  
Site Preparation ◽  
The Other ◽  
Long Term Effects ◽  
Lime Treatment

Abstract A site preparation study was established in 1968 at three locations in the Coastal Plain of Virginia. Three treatments were installed in a randomized complete block design: (1) chop, (2) bed, and (3) ditch. In 1978, four fertilizer treatments were superimposed on the site preparation study: (1) check, (2) phosphorus (P) only, (3) P + nitrogen (N), and (4) P + N + lime, converting it into a split-plot design. At age 33 years, height of the dominant loblolly pine in the ditch treatment was significantly greater than in the other site preparation treatments. However, there were no differences in stand density, diameter at breast height (dbh), basal area, or volume because of site preparation. This contrasts with the data collected at age 21 years, when total volume in both the bed treatment and the ditch treatment was greater than in the chop treatment. Changes in water table depths through time were the probable cause for decreased response to bedding and ditching. There was a large response to fertilization through age 33 years in this study. The P + N + lime treatment had significantly greater dbh, basal area, and volume than the other fertilizer treatments, which significantly increased pine stumpage value. The size of the growth response was greater at age 33 years than it was at age 21 years. Soil and foliage analysis suggests that the sustained growth response at this site was due to the added Ca. South. J. Appl. For. 29(4):205–214.

Prediction of Douglas-fir fertilizer response using biogeoclimatic properties in the coastal Pacific Northwest

2014 ◽  
Vol 44 (10) ◽  
pp. 1253-1264 ◽  
Author(s):  
K.M. Littke ◽  
R.B. Harrison ◽  
D. Zabowski ◽  
M.A. Ciol ◽  
D.G. Briggs
Keyword(s):  
Pacific Northwest ◽  
Pearson Correlation ◽  
Regression Tree ◽  
Correlation Coefficients ◽  
Basal Area ◽  
Site Index ◽  
Douglas Fir ◽  
Annual Increment ◽  
Fertilizer Response ◽  
Boosted Regression Tree

Fertilizer response of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) has been related to site and soil properties in the past, but the models have explained only about half of the variation in these investigations. Fertilizer response and percent response after two years were examined, according to mapped and measured biogeoclimatic variables, for 71 Douglas-fir installations in the coastal Pacific Northwest. Paired-tree installations consisted of 12–20 pairs of Douglas-fir trees with one tree fertilized with urea at 224 kg N·ha−1. Pearson correlation coefficients and boosted regression tree (BRT) models were used to determine the best predictor variables and models of Douglas-fir fertilizer response. The BRT models, using the combination of mapped and measured variables, performed the best for predicting fertilizer response. Basal area and volume responses were most related to high forest floor and surface soil carbon to nitrogen ratios. Basal area mean annual increment (MAI) and site index were both negatively correlated with fertilizer response. Also, low basal area MAI was the most important tree measurement for predicting fertilizer response in the BRT models. Installations with many of the predictors from the BRT models (>66% of the model criteria) were found to have a significantly greater fertilizer response than installations with only a few predictors (<33% of the model criteria). These findings support the use of these models for predicting fertilizer response of similar Douglas-fir stands in the coastal Pacific Northwest.

Long-term effects of stand density management and genotype on wood properties of loblolly pine (Pinus taeda L.) in the mid-South USA

2021 ◽  
Vol 491 ◽  
pp. 119176
Author(s):  
Michael A. Blazier ◽  
Thomas Hennessey ◽  
Laurence Schimleck ◽  
Scott Abbey ◽  
Ryan Holbrook ◽  
...  
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Stand Density ◽  
Wood Properties ◽  
Long Term Effects ◽  
Stand Density Management ◽  
Pinus Taeda L

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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