Effects of fertilization and thinning on 8-year growth responses of second-growth Douglas-fir stands

1991 ◽  
Vol 21 (4) ◽  
pp. 516-521 ◽  
Author(s):  
K. A. Stegemoeller ◽  
H. N. Chappell
Keyword(s):  
Combined Treatment ◽  
Volume Growth ◽  
Basal Area ◽  
Douglas Fir ◽  
Site Quality ◽  
Growth Responses ◽  
Positive Interaction ◽  
Individual Tree ◽  
Growing Stock ◽  
Area And Volume

Fertilization of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stands generally increased both basal area and volume growth for at least 8 years. Thinning tended to have an even greater effect than fertilization on basal area and volume growth, increasing both on an individual-tree basis. On a land-area basis, however, the removal of growing stock by thinning caused volume growth to be less than that of the control. The magnitude and duration of this negative response was dependent on the level of thinning and the site quality. A significant positive interaction between fertilization and thinning exists. The combined treatment resulted in the greatest absolute basal area and volume increments, and the response became greater than that to fertilizer alone in the 3rd and 4th years, and remained so through at least 8 years.

Effects of high levels of fertilization with urea on growth of thinned and unthinned Douglas-fir stands

1985 ◽  
Vol 15 (4) ◽  
pp. 730-733 ◽  
Author(s):  
H. J. Barclay ◽  
H. Brix
Keyword(s):  
Volume Growth ◽  
Basal Area ◽  
Douglas Fir ◽  
Stem Volume ◽  
Growth Responses ◽  
Positive Interaction ◽  
Fertilizer Use ◽  
Response Period ◽  
Volume Response ◽  
Fertilizer Rates

The diameter and volume growth of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were documented 9 years after thinning and fertilization. The treatments involved three levels of thinning (0, 1/3, and 2/3 of basal area removed) and six levels of fertilization (0–1344 kg N/ha) with urea. Increments for both diameter and gross volume increased with the rate of fertilization and responses were still apparent 9 years after treatment. For unthinned plots, the 9-year volume growth responses were 30, 50, and 80% with fertilizer rates of 224, 448, and 896 kg N/ha, respectively. The efficiency of fertilizer use, measured as stem volume response per unit of nitrogen applied, decreased with the rate of fertilization, but this picture may change over a longer response period. There was a positive interaction between fertilization and thinning such that high levels of both mutually enhanced growth. Mortality increased with fertilization, but only noticeably in unthinned plots.

Growth response of young, thinned Douglas-fir stands to nitrogen fertilizer in relation to soil properties and tree nutrition

1994 ◽  
Vol 24 (8) ◽  
pp. 1684-1688 ◽  
Author(s):  
P. Hopmans ◽  
H.N. Chappell
Keyword(s):  
Basal Area ◽  
N Fertilization ◽  
Douglas Fir ◽  
Relative Volume ◽  
Strongly Correlated ◽  
Growth Responses ◽  
Total N ◽  
Soil Variables ◽  
Volume Increment ◽  
Area And Volume

Application of 224 kg N/ha to young, thinned stands of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) at 35 sites in western Oregon and Washington significantly increased basal area and volume increment over 8 years following treatment. However, response varied considerably between sites, and relative volume increment exceeded 10% at only 19 of the 35 sites. Response to applied N was evaluated in relation to forest floor and soil variables as well as to levels of N in foliage. Relative responses in basal area and volume were significantly correlated with total N concentration and the C/N ratio of the soil. However, these relationships explained only part (18–22%) of the observed variation in response. In contrast, relative response was strongly correlated with the level of N in the foliage of nonfertilized trees at 11 sites, accounting for 94% of the variation between sites. Use of foliar N data clearly has potential to predict growth responses to N fertilization of young thinned Douglas-fir stands, although further work is needed to test the relationship for a wider range of sites and stands.

Stand development following precommercial thinning and fertilization treatments in a western redcedar (Thuja plicata) dominated forest

2011 ◽  
Vol 41 (1) ◽  
pp. 151-164 ◽  
Author(s):  
Constance A. Harrington ◽  
Warren D. Devine
Keyword(s):  
Volume Growth ◽  
Basal Area ◽  
Site Quality ◽  
Thuja Plicata ◽  
Nitrogen And Phosphorus ◽  
Western Redcedar ◽  
Large Trees ◽  
Wide Range ◽  
Individual Trees ◽  
Area And Volume

Western redcedar (Thuja plicata Donn ex D. Don.) is an important North American tree species, but little information is available on its long-term responses to silvicultural treatments. Stand responses (mortality, ingrowth, basal area and volume growth, and distributions of trees by diameter and height classes) were followed for 25 years after thinning and fertilization treatments (alone and in combination) were applied to a naturally regenerated, low site quality western redcedar stand on the Olympic Peninsula in western Washington, USA. Mortality was low overall, but the densest stands experienced competition-related mortality. Thinning resulted in additional stem recruitment; after 25 years, the number of ingrowth trees exceeded the number of trees in the cohort left after thinning. Fertilization (with nitrogen and phosphorus) flattened size distributions and skewed them to larger size classes. Thinning plus fertilization resulted in the largest individual trees and the most large trees, but also many trees in a wide range of diameter classes. The recruitment of a second cohort did not result in a two-storied stand. Fertilization without thinning resulted in the greatest stand basal area and volume, as well as trees with fewer live lower branches.

Stand structure and growing space efficiency following thinning in an even-aged Douglas-fir stand

1988 ◽  
Vol 18 (7) ◽  
pp. 859-866 ◽  
Author(s):  
K. L. O'Hara
Keyword(s):  
Stand Structure ◽  
Volume Growth ◽  
Basal Area ◽  
Stand Density ◽  
Douglas Fir ◽  
Stem Volume ◽  
Projection Area ◽  
Individual Tree ◽  
Space Efficiency ◽  
Individual Trees

The growth of individual trees from four thinning treatments in a 64-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stand was analyzed to determine desirable residual stand structures after thinning. Dominant and codominant trees had the highest individual tree stem volume growth rates over the previous 5 years, and accounted for most stand volume growth in thinned and unthinned stands. Two measures of growing space, crown projection area and sapwood basal area (a surrogate for leaf area), were used to measure how efficiently individual trees used their growing space. Crown classes were useful in characterizing growing space efficiency (volume growth per unit of growing space) only in the unthinned treatment. In thinned treatments, tall trees with medium-sized crowns were most efficient, while in the unthinned treatment, tall trees with relatively large crowns were most efficient. A large crown in an unthinned stand was comparable in size to a medium-sized crown in a thinned stand. Results suggest growing space is not limiting individual tree growth in thinned stands and that thinning to a particular stand structure is more appropriate than thinning to a particular level of stand density.

Growth responses to commercial thinning in Douglas-fir stands with varying severity of Swiss needle cast in Oregon, USA

2005 ◽  
Vol 35 (10) ◽  
pp. 2394-2402 ◽  
Author(s):  
Douglas B Mainwaring ◽  
Douglas A Maguire ◽  
Alan Kanaskie ◽  
Jeff Brandt
Keyword(s):  
Basal Area ◽  
Douglas Fir ◽  
Growth Responses ◽  
Infection Level ◽  
Individual Tree ◽  
Needle Cast ◽  
Commercial Thinning ◽  
Basal Area Growth ◽  
Area Growth ◽  
Swiss Needle Cast

Concern has risen about the degree to which Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands with severe infections of Swiss needle cast (SNC) respond to thinning. A retrospective study was established in the fall of 2001 to assess the growth of Douglas-fir stands that were commercially thinned between 4 and 10 years ago. Current SNC infection levels in these stands ranged from severe to very light. Past volume and basal area growth declined with increasing severity of SNC, as measured by current foliage retention and crown length / sapwood ratio. As has been observed in many other studies, thinning to lower residual stock reduced stand level growth; however, individual tree growth increased with lower residual stand density. The ratio of growth in successive periods and analysis of annual basal area growth since thinning suggested that trees did respond to thinning, although less so as SNC increased. A positive response to thinning, regardless of infection level, was confirmed by an analysis of annual trends in basal area growth over the first 5 years after thinning.

Nitrogen Fertilizer Response of Rocky Mountain Douglas-Fir by Geographic Area Across the Inland Northwest1

1991 ◽  
Vol 6 (4) ◽  
pp. 94-98 ◽  
Author(s):  
James A. Moore ◽  
Peter G. Mika ◽  
James L. Vander Ploeg
Keyword(s):  
Volume Growth ◽  
Basal Area ◽  
Rocky Mountain ◽  
Geographic Area ◽  
Douglas Fir ◽  
Fertilizer Response ◽  
Inland Northwest ◽  
Geographic Regions ◽  
Nitrogen Treatments ◽  
Area And Volume

Abstract Response to nitrogen fertilization treatments in Rocky Mountain Douglas-fir (Pseudotsuga menziesii var. glauca) differed significantly among geographic regions within the inland northwest. Gross basal area and volume growth on fertilized plots were significantly greater than growth on controls for all geographic regions, but only in northern Idaho and central Washington was gross response significantly greater on 400 lb/ac N plots than on 200 lb N plots. Net basal area and volume growth on treated plots in Montana, central Idaho, and northeast Oregon were not significantly greater than the controls for either nitrogen treatment. Analysis of 2-year periodic basal area increment indicated that, while response did decline through time, treated plots continued to produce more gross growth than control plots 6 years after treatment. Similar operational nitrogen treatments applied to the Douglas-fir population sampled in this study should produce gross responses exceeding 10% after 6 years three out of four times. West. J. Appl. For. 6(4):94-98.

scholarly journals Growth of Young Douglas-Fir Plantations Across a Gradient in Swiss Needle Cast Severity

2002 ◽  
Vol 17 (2) ◽  
pp. 86-95 ◽  
Author(s):  
Douglas A. Maguire ◽  
Alan Kanaskie ◽  
William Voelker ◽  
Randy Johnson ◽  
Greg Johnson
Keyword(s):  
Volume Growth ◽  
Basal Area ◽  
Height Growth ◽  
Douglas Fir ◽  
Site Quality ◽  
North Coast ◽  
Needle Cast ◽  
Basal Area Growth ◽  
Area Growth ◽  
Swiss Needle Cast

Abstract During the past decade, Swiss needle cast (SNC) damage has intensified in many Douglas-fir plantations in the Coast Range of Oregon, particularly along the immediate north coast. In plantations with severe symptoms, growth losses and reduced tree vigor are evident, but the magnitude of growth losses associated with varying intensities of damage is not known. A growth impact study was conducted in 1997 to quantify retrospectively the relationship between growth losses and visual symptoms in 10- to 30-yr-old Douglas-fir plantations in coastal northwestern Oregon, a population totaling 75,700 ha. A random sample of 70 Douglas-fir plantations was selected from the population and evaluated for Swiss needle cast severity. One 0.02 ha plot was destructively sampled in each plantation to reconstruct past height and basal area growth trends and to characterize foliage loss and distribution. The SNC “effect” was assessed by comparing growth of plantations with varying degrees of Swiss needle cast to growth of those that retained maximal amounts of foliage, after correcting for initial stand density, Douglas-fir growing stock, age, and site index. Of numerous possible SNC indices, mean needle retention (yr) explained the largest amount of variation in both basal area and top height growth. Prior to 1990, top height growth was similar across all plantations after correcting for site quality and plantation age; but, by 1992, top height growth losses appeared and were proportional to apparent foliage losses. In 1996, top height growth was reduced by up to 25% relative to plantations with little or no SNC. Basal area growth reductions began to appear around 1990, and in 1996 basal area growth of the most heavily damaged plantations was 35% less than the growth that would be expected in absence of SNC damage. The inferred volume growth loss for 1996 averaged 23% for the 75,700 ha target population, but this loss averaged as high as 52% for the most severely impacted plantations. West. J. Appl. For. 17(2):86ߝ95.

Growth response of unthinned and thinned Douglas-fir stands to single and multiple applications of nitrogen

1990 ◽  
Vol 20 (3) ◽  
pp. 343-349 ◽  
Author(s):  
K. A. Stegemoeller ◽  
H. N. Chappell
Keyword(s):  
Growth Response ◽  
Regional Scale ◽  
Volume Growth ◽  
Basal Area ◽  
Douglas Fir ◽  
Untreated Plot ◽  
Growth Responses ◽  
Average Growth ◽  
Duration Of Response ◽  
And Control

Basal area and volume growth response of unthinned and thinned Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stands to single and multiple applications of nitrogen fertilizer were estimated for eight 2-year periods. Response estimates, as differences between growth rates on fertilized and control plots after adjusting for initial volume (or basal area), and trends were analyzed on a regional scale. Average responses to the initial fertilization and to both the second and third fertilizer applications, 8 and 12 years later, were statistically significant (p < 0.05). In thinned stands, average duration of response to the initial treatment was approximately 8 years; unthinned stands continued to show significant volume growth response through 14 years, although basal area growth response decreased to nonsignificant levels between years 10 and 12. In both cases, the response to refertilization, while significant, was smaller than the response to the initial fertilization. Nitrogen applied after the 8th year, and a refertilization after the 12th, on one initially untreated plot at each installation also produced significant average growth responses.

Growth, yield, and structure of extended rotation Pinus resinosa stands in Minnesota, USA

2010 ◽  
Vol 40 (5) ◽  
pp. 1000-1010 ◽  
Author(s):  
Anthony W. D’Amato ◽  
Brian J. Palik ◽  
Christel C. Kern
Keyword(s):  
Volume Growth ◽  
Growth Yield ◽  
Basal Area ◽  
Pinus Resinosa ◽  
Red Pine ◽  
Growth And Yield ◽  
Growth Responses ◽  
Growing Stock ◽  
Ecological Objectives

Extended rotations are increasingly used to meet ecological objectives on forestland; however, information about long-term growth and yield of these systems is lacking for most forests in North America. Additionally, long-term growth responses to repeated thinnings in older stands have received little attention. We addressed these needs by examining the growth and yield of red pine ( Pinus resinosa Ait.) in a growing stock experiment in northern Minnesota. Stands were 85 years old at the onset of this experiment and were repeatedly thinned to five levels of basal area (13.8, 18.4, 23.0, 27.5, and 32.1 m2·ha–1) over 58 years. Cumulative volume production and volume growth were lowest within the lowest stocking treatment and similar across other stocking levels. Late-successional structural attributes, such as the density of trees with ≥40 cm diameter at breast height, was similar across stocking levels. The mean annual volume growth culminated between 130 and 140 years. Additionally, positive growth responses were observed within the highest stocking-level treatments after thinning at 138 years, demonstrating the ability of older red pine to respond to reductions in competition. These results illustrate that extended rotations with repeated thinnings in red pine help achieve ecological goals, including the restoration of old-forest structure, while also maintaining high levels of stand productivity.

Analyses of a Forest Drainage Experiment in Northern Ontario. I: Growth Analysis

1973 ◽  
Vol 3 (3) ◽  
pp. 387-398 ◽  
Author(s):  
Bijan Payandeh
Keyword(s):  
Water Flow ◽  
Growth Analysis ◽  
Volume Growth ◽  
Basal Area ◽  
Height Growth ◽  
Site Quality ◽  
Stand Age ◽  
Northern Ontario ◽  
Individual Tree ◽  
Forest Drainage

This paper presents a growth analysis of a forest drainage experiment carried out over 40 years in northern Ontario. It is based on remeasurement data obtained in 1969 from 38 growth plots established following drainage in 1929 and from increment cores and sectioned trees.Results indicate that both annual tree diameter and height growth increased significantly after draining; that tree growth before draining was related to site quality only, while after draining it was related also to tree vigor and distance of water flow from the nearest ditch; that both stand diameter and height growth were related to site index, stand age, and initial stocking; and that stand basal area and volume growth were, in addition, related to a product sine function of distance of water flow from the ditch, peat moisture, decomposition, and depth.Both individual tree and stand growth responded well to draining, with younger and more vigorous trees that were growing on better-quality sites showing the greatest response. For a given site, growth response was not greatest for trees and stands nearest the ditch, but for those some distance away.

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