Detecting the response of Douglas-fir to nitrogen fertilization by regression of periodic annual basal area increment against basal area

1988 ◽  
Vol 18 (10) ◽  
pp. 1343-1346 ◽  
Author(s):  
A. J. Thomson ◽  
K. D. Tudor ◽  
V. J. Korelus ◽  
D. R. Ralph
Keyword(s):  
Temporal Variation ◽  
Growth Rates ◽  
Nitrogen Fertilization ◽  
Basal Area ◽  
Douglas Fir ◽  
Basal Area Increment ◽  
Spatial And Temporal Variation ◽  
Urea Fertilization ◽  
Area Response

Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) basal area response to urea fertilization at 112 and 224 kg N/ha was studied on a medium site. Regression of tree periodic annual basal area increment against basal area was used to estimate within-plot growth rates. Higher growth rates were observed in the fertilized plots. The slope coefficients of the regressions were used to investigate spatial and temporal variation in growth rates.

Four-year Basal Area Growth Response of a 25-year-old Douglas-fir Stand to Thinning and Urea Fertilization

1974 ◽  
Vol 4 (4) ◽  
pp. 568-571 ◽  
Author(s):  
Y. Jim Lee
Keyword(s):  
Nitrogen Fertilization ◽  
Growth Response ◽  
Basal Area ◽  
Douglas Fir ◽  
Site Quality ◽  
Growing Period ◽  
Basal Area Growth ◽  
Area Growth ◽  
Four Levels ◽  
Urea Fertilization

Four-year growth response to nitrogen fertilization and thinning is reported for an experiment established in a 25-year-old Douglas-fir stand of medium site quality. Four levels of nitrogen (0, 112, 224, and 336 kg N/ha), in the form of urea, were tested at two thinning levels in a randomized 4 × 2 × 2 factorial design replicated in 2 Blocks. Fertilizer was applied in spring or fall. Basal area growth per hectare in the thinned stand significantly surpassed that of the unthinned stand in the fourth growing period. Increased rate of nitrogen fertilization resulted in increased growth 1 year after fertilization. Urea applied in the fall resulted in greater growth response than that applied in the spring for the first growing period and over a 4-year period. Increased rate of fertilization increased mortality significantly in the fourth growing period, but had no prior effect. Thinning decreased mortality in all four growing periods.

Spatial variation in CO2 efflux from the soil in a mature beech forest ecosystem.

2021 ◽  
Author(s):  
Yihan Cai ◽  
Takahiro Nishimura ◽  
Hideyuki Ida ◽  
Mitsuru Hirota
Keyword(s):  
Spatial Variation ◽  
Temporal Variation ◽  
Forest Ecosystem ◽  
Linear Regression Analysis ◽  
Basal Area ◽  
Beech Forest ◽  
Controlling Factors ◽  
Spatial And Temporal Variation ◽  
Canopy Openness ◽  
Co2 Efflux

<p> Soil respiration (Rs) is the second largest carbon flux between the atmosphere and terrestrial ecosystem. Because of the large proportion, even small change in Rs would considerably impact the global carbon cycle. Therefore, it is important to accurately estimate Rs by taking its spatial and temporal variation into consideration. While the temporal variation of Rs and its controlling factors have been well-described, large unexplainable part still has been remained in the spatial variation of Rs especially in the forest ecosystems with complex structures. The objective of this study is to fill the knowledge gap about spatial variation of Rs and its controlling factors in a typical mature beech forest in Japan. Hypotheses of this study were, 1) Rs would show large spatial variation in the mature beech forest, 2) the spatial variation of Rs was mainly influenced by soil water content (SWC) and soil temperature (ST), 3) the two key factors were determined by the forest structures. This study was conducted in a 1- ha permanent study plot in the mature beech forest with significant gap-mosaic structures. To examine these hypotheses, Rs, SWC, ST and parameters related to forest structure, i.e. sum of basal area, diameter at breast height, number of trees, number of species within a radius of 5 m from the Rs measurement points, and canopy openness were measured at 121 points in different season between 2012 to 2013. In this study, all the measurements of Rs were conducted by using alkali-absorption technique.</p><p> Coefficient of variation of Rs was between 25 - 28 % which was similar to that of SWC in all the measurements. The spatial variation of Rs was relatively higher in July, August and September than that in June and October. There was no significant relationship in the spatial variation between Rs and ST in all the measurements, meanwhile, Rs was well explained by SWC in measurements conducted in August, September and October. Multiple linear regression analysis indicated that canopy openness and sum of basal area showed significant positive and negative correlation with SWC, respectively. And canopy openness explained SWC much more than sum of basal area did. This result suggested that SWC, the key factor determined the spatial variation of Rs, cannot be only explained by stems distribution and their characteristics, but also canopy architecture in the forest ecosystem.</p>

Tree vigor and stand growth of Douglas-fir as influenced by laminated root rot

1985 ◽  
Vol 15 (5) ◽  
pp. 985-988 ◽  
Author(s):  
Ram Oren ◽  
Walter G. Thies ◽  
Richard H. Waring
Keyword(s):  
Leaf Area ◽  
Root Rot ◽  
Basal Area ◽  
Douglas Fir ◽  
Basal Area Increment ◽  
Sapwood Area ◽  
Stand Growth ◽  
Area Growth ◽  
The Impact ◽  
Stand Basal Area

Total stand sapwood basal area, a measure of competing canopy leaf area, was reduced 30% by laminated root rot induced by Phellinusweirii (Murr.) Gilb. in a heavily infected 40-year-old coastal stand of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) compared with that of a similar uninfected stand. Annual basal area increment per unit of sapwood area, an index of tree vigor, was expected to increase in uninfected trees in the infected stand as surrounding trees died from root rot; vigor of the uninfected trees did increase by an average of 30%, offsetting the reduction in canopy leaf area. This increase, although less than might be expected in an evenly spaced thinned stand, was sufficient to maintain stand basal area growth at levels similar to those of unthinned forests. These findings indicate that increased growth by residual trees must be taken into account when the impact of disease-induced mortality on stand production is assessed.

Development and growth of even-aged stands of Douglas-fir and grand fir

1986 ◽  
Vol 16 (2) ◽  
pp. 367-372 ◽  
Author(s):  
Bruce C. Larson
Keyword(s):  
Growth Rates ◽  
Volume Growth ◽  
Basal Area ◽  
Douglas Fir ◽  
Stem Volume ◽  
Mixed Stands ◽  
Site Class ◽  
Development Patterns ◽  
Western Washington ◽  
Eastern Washington

Stand development patterns and growth rates of even-aged mixed stands of Douglas-fir (Pseudotsugamensiesii Mirb. Franco) and grand fir (Abiesgrandis Dougl. Lindl.) were investigated by stand reconstruction in eastern Washington. Although Douglas-fir dominated the stands early, grand fir of the same age eventually overtook the tallest Douglas-firs. Dominant trees of both species were found to have highly variable taper form (based on basal area to height ratios), although a linear relationship existed in other crown classes. Stem volume growth rates were determined by reconstructing past diameters and heights and were found comparable to site class IV Douglas-fir in western Washington. Intensive management, especially planting and thinning, could improve upon the observed mean annual increments of 800 board feet per acre at 80 years of age.

Effects of thinning and nitrogen fertilization on branch and foliage production in Douglas-fir

1981 ◽  
Vol 11 (3) ◽  
pp. 502-511 ◽  
Author(s):  
H. Brix
Keyword(s):  
Nitrogen Fertilization ◽  
Basal Area ◽  
Douglas Fir ◽  
Needle Size ◽  
Crown Width ◽  
Thinning Effect ◽  
Needle Mass ◽  
Crown Size ◽  
Number Of Shoots

The effect of two levels of thinning (zero and [Formula: see text] of basal area removed) and three levels of nitrogen fertilization (0,224, and 448 kg N/ha) on crown development of codominant, 24-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) trees was studied over a 5- to 7-year period. Thinning and heavy ferilization separately increased needle mass per tree after 7 years by 90% and, when combined, by 271%. Yearly needle production peaked 2–3 years after fertilization and resulted from an increase in needle size, needle number per shoot, and number of shoots produced. Maximum foliage mass per tree was reached 4–7 years after fertilization. Thinning effect on needle production was lower initially, but increased throughout the study period. A continuing foliage production in branches low in the crown contributed to thinning effect on foliage mass and crown size. Foliage distribution was affected most in the top half of the crown by fertilization and in the bottom half of the crown by thinning. Fertilization increased branch elongation at all crown heights, but thinning alone had no effect on crown width down to whorl 12.

scholarly journals Does Raking Basal Duff Affect Tree Growth Rates or Mortality?

2010 ◽  
Vol 25 (4) ◽  
pp. 199-202 ◽  
Author(s):  
Erin Noonan-Wright ◽  
Sharon M. Hood ◽  
Danny R. Cluck
Keyword(s):  
Tree Growth ◽  
Growth Rates ◽  
Tree Mortality ◽  
Large Diameter ◽  
Mineral Soil ◽  
Basal Area ◽  
Basal Area Increment ◽  
National Forest ◽  
Jeffrey Pine ◽  
Pine Trees

Abstract Mortality and reduced growth rates due to raking accumulated basal duff were evaluated for old, large-diameter ponderosa and Jeffrey pine trees on the Lassen National Forest, California. No fire treatments were included to isolate the effect of raking from fire. Trees were monitored annually for 5 years after the raking treatment for mortality and then cored to measure basal area increment. Results showed that raking basal duff and litter to mineral soil from the bole out to 60 cm had no effect on basal area increment or mortality for 5 years posttreatment. Results are pertinent to managers who question whether raking basal duff will decrease tree vigor or increase tree mortality of large and old ponderosa and Jeffrey pine trees in northern California.

Effects of Nitrogen Fertilization on Growth of Grand Fir and Douglas-Fir Stands in Northern Idaho

1989 ◽  
Vol 4 (2) ◽  
pp. 54-57 ◽  
Author(s):  
Bahman Shafii ◽  
James A. Moore ◽  
John R. Olson
Keyword(s):  
Pseudotsuga Menziesii ◽  
Nitrogen Fertilization ◽  
Basal Area ◽  
Douglas Fir ◽  
Tree Size ◽  
Stand Development ◽  
Height Increment ◽  
Area Growth ◽  
Nitrogen Treatment ◽  
Northern Idaho

Abstract A study of nitrogen fertilization response in thinned and unthinned stands of grand fir (Abies grandis) and Douglas-fir (Pseudotsuga menziesii) in northern Idaho showed that the application of one urea nitrogen treatment applied at a rate of 200 lb N/ac resulted in a significantly higher average basal area growth over a 6-year post-treatment period. Nitrogen fertilization also resulted in a significant height increment increase over the same period. Fourteen years after treatment, fertilization had increased average tree size, in terms of total cubic volume, by 14% in unthinned and by 23% in thinned stands. A comparison of thinned and unthinned stands suggested an increase in tree size (>300%) over the same period without significant reduction in average total cubic volume per acre. Patterns of stand development were altered by nitrogen fertilization. West. J. Appl. For. 4(2):54-57, April 1989.

Annual rates and elemental concentrations of litter fall in thinned and fertilized Douglas-fir

1991 ◽  
Vol 21 (11) ◽  
pp. 1601-1615 ◽  
Author(s):  
J. A. Trofymow ◽  
H. J. Barclay ◽  
K. M. McCullough
Keyword(s):  
British Columbia ◽  
Ammonium Nitrate ◽  
Nitrogen Fertilization ◽  
Basal Area ◽  
Stand Density ◽  
Douglas Fir ◽  
Control Plot ◽  
Annual Rate ◽  
Litter Fall ◽  
Elemental Concentrations

Overstory litter fall, primarily needles, was collected for 15 years within control and treated plots in a stand of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) located near Shawnigan Lake, British Columbia. Treated plots were thinned or fertilized, or both; thinned plots had two-thirds of their basal area removed, fertilized plots were treated with 448 kg N•ha−1 of either urea or ammonium nitrate, and half the fertilized plots were refertifized at the same rate 9 years later. The annual rate of litter fall in control plots averaged 1890 kg•ha−1. In control plots significant yearly variations were observed in litter-fall mass and concentrations of K, Mg, and Ca but not N or P. Thinning decreased rates of litter fall by 80%, but rates returned to control-plot levels after 13–15 years in unfertilized plots and after 8–10 years in fertilized plots. Fertilization without thinning depressed litter fall in the year of treatment but increased the rate by 20–80% in subsequent years. Litter-fall N concentrations increased by 40–80% the year of fertilization and then began declining 3–6 years later. Nitrogen fertilization reduced litter-fall P, K, and Mg concentrations for 8, 4, and 1 year(s), respectively, following fertilization. The effects were greater in ammonium nitrate plots than in urea plots. Rates of litter fall correlated poorly with stand density but well with basal area and stemwood increment. Correlations with the latter two variables varied with time and treatment.

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