Growth and foliar nutrient response to fertilization and precommercial thinning in a coastal western red cedar stand

1990 ◽  
Vol 20 (6) ◽  
pp. 764-773 ◽  
Author(s):  
Constance A. Harrington ◽  
Charles A. Wierman

Seven silvicultural treatments were applied to a young (15- to 20-year-old), naturally regenerated western red cedar (Thujaplicata Donn ex D. Don) stand growing on a poor-quality site in western Washington. The treatments were as follows: unthinned, unfertilized (untreated); unthinned, fertilized with ammonium nitrate, dicalcium phosphate, and potassium sulfate; thinned, unfertilized; thinned, fertilized with urea; thinned, fertilized with ammonium nitrate; thinned, fertilized with ammonium nitrate and dicalcium phosphate; and thinned, fertilized with ammonium nitrate, dicalcium phosphate, and potassium sulfate. Elemental application rates were 300 kg nitrogen, 100 kg phosphorus, 129 kg calcium, 100 kg potassium, and 41 kg sulfur per hectare. Growth and foliar nutrient concentrations were monitored for 5 years. Five-year height growth and diameter growth of the 20 tallest trees per 0.08-ha measurement plot were both substantially greater in all thinned or fertilized treatments than in the unthinned, unfertilized treatment. The three best treatments for height growth (the treatments containing ammonium nitrate and dicalcium phosphate) had 65% more growth than the unthinned, unfertilized treatment. The two best treatments for diameter growth (thinned, fertilized with ammonium nitrate and dicalcium phosphate) had 106% more growth than the unthinned, unfertilized treatment. The effects of thinning alone were small compared with the effects of fertilization alone or fertilization combined with thinning. Initial foliar nitrogen concentrations showed that the site was nitrogen deficient, and both nitrogen sources, urea and ammonium nitrate, increased growth. The addition of dicalcium phosphate resulted in significantly greater incremental growth above that attributed to nitrogen alone, but the further addition of potassium sulfate did not increase growth significantly. Increases in foliar nitrogen and phosphorus associated with fertilization were still evident 5 years after treatment. All sizes of trees responded to treatment, and growth of the total stand followed the same trends as for the 20 tallest trees per plot. Basal area growth on an absolute basis was best in the unthinned, fertilized treatment (more than twice that of the unthinned, unfertilized treatment) and on a percent basis was best in the thinned treatment fertilized with ammonium nitrate, dicalcium phosphate, and potassium sulfate.

1995 ◽  
Vol 25 (1) ◽  
pp. 18-28 ◽  
Author(s):  
B.J. Hawkins ◽  
M. Davradou ◽  
D. Pier ◽  
R. Shortt

One-year-old seedlings of western red cedar (Thujapiicata Donn ex D.Don) and Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were grown for one season in five nutrient treatments with nitrogen (N) supplied in solution at rates of 20, 100, or 250 mg•L−1 and phosphorus (P) supplied at rates of 4, 20, or 60 mg•L−1. Growth, onset of dormancy, frost hardiness on six dates, and foliar nutrient concentrations in autumn and spring were measured. Midwinter rates of net photosynthesis and transpiration were measured at air temperatures of 4, 7, and 11 °C in seedlings from all nutrient treatments. Recovery of net photosynthesis and transpiration in whole seedlings from the three N treatments was assessed at intervals for 28 days after the seedlings were frozen to −5, −15, and −25°C. Foliar N content differed significantly among nutrient treatments and was positively correlated with supply. Mitotic activity ceased earliest in plants with low N supply. Douglas-fir seedlings in the low-N treatment also ceased height growth earliest. These differences in growth had no significant correlation with frost hardiness. No consistent differences in frost hardiness among nutrient treatments were observed. Higher rates of N and P supply resulted in higher rates of winter net photosynthesis. Net photosynthesis was reduced dramatically by night frost, with greater damage occurring at lower temperatures. Net photosynthesis recovery occurred most quickly in seedlings with the midrate of N and P supply.


1998 ◽  
Vol 28 (5) ◽  
pp. 729-736 ◽  
Author(s):  
Raynald Paquin ◽  
Hank A Margolis ◽  
René Doucet

The effect of nutrient addition (fertilization with N, P, and K at a rate of 448, 224, and 224 kg ·ha-1, respectively) on height growth, root biomass, leaf area, and foliar nutrient concentrations of slow-growing layers and newly planted seedlings of black spruce (Picea mariana (Mill.) BSP) was evaluated on an apparently productive mesic site in Quebec. Annual height growth increment of fertilized layers was greater than 20 cm ·year-1compared with 3-4 cm ·year-1for the other three treatments. Fine root biomass (< 2 mm in diameter) and leaf area growth were significantly higher for fertilized layers and seedlings compared with their respective controls. For both current and 1-year-old needles, foliar N concentration on a unit leaf area basis increased significantly for both layers and seedlings, and vector analysis showed that, in all cases, N was the most limiting nutrient. Five growing seasons after treatment, the only residual effect of fertilization on foliar nutrient concentrations was higher foliar N in fertilized seedlings. Thus, it appears that the slow growth of the unfertilized layers on this site was due to resource limitation rather than to the type of regeneration as such.


1988 ◽  
Vol 18 (6) ◽  
pp. 718-722 ◽  
Author(s):  
R. E. Vihnanek ◽  
T. M. Ballard

Stocking, height growth, basal diameter growth, and foliar nutrient levels of 5- to 15-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were evaluated on burned and unburned areas within each of 20 sites on eastern Vancouver Island, which were characterized by ecosystems dominated by salal (Gaultheriashallon Pursh). Burning significantly reduced salal height and cover (P < 0.01). Douglas-fir stocking, height growth, and basal diameter were significantly increased (P < 0.05) as a result of burning. Douglas-fir foliar P, K, Ca, Fe, and B concentrations were significantly increased (P < 0.05) as a result of burning, but foliar concentrations of N, Mg, S, Zn, and Cu were not significantly affected, even at P = 0.10. Foliar Mn concentrations were significantly reduced but remained very far above the deficiency threshold.


1989 ◽  
Vol 19 (12) ◽  
pp. 1501-1511 ◽  
Author(s):  
G. F. Weetman ◽  
R. Fournier ◽  
J. Barker ◽  
E. Schnorbus-Panozzo ◽  
A. Germain

A series of microplot and conventional plot trials were used to determine the nutritional status and required nutrient additions to bring young chlorotic Sitka spruce (Piceasitchensis (Bong.) Carr) plantations out of "check." Check occurs on clear-cut and burned old-growth western red cedar (Thujaplicata Donn ex D. Don) and western hemlock (Tsugaheterophylla (Raf.) Sarg.) stands in the Coastal Western Hemlock biogeoclimatic zone growing on deep morhumus Podzols invaded by dense salal (Gaultheriashallon). Microplot trials identified the requirement for N and P. Checked trees responded to fertilization immediately with a 4- to 8-year temporary increase in leader length. Grubbing out of aboveground salal did not improve tree nutrition. There is a close parallel to "heather check" noted with Sitka spruce in British and Irish moorlands; a possible allelopathic effect of salal is suspected. It is concluded that one or more N and P additions are required to establish crown closure. Fertilized Sitka spruce show a high incidence of spruce weevil attack. The deficient and optimum foliar nutrient concentrations developed in Britain for the diagnosis of Sitka spruce appear to be applicable.


1990 ◽  
Vol 20 (2) ◽  
pp. 144-151 ◽  
Author(s):  
David W. Valentine ◽  
H. Lee Allen

Postfertilization patterns of fascicle weight and foliar nutrient concentration can diagnose nutrient limitation and stem growth response of coniferous species that have one annual needle flush. We tested this approach on loblolly pine (Pinustaeda L.), a species with several annual growth flushes, by using only foliage from the first annual growth flush following fertilization. We analyzed the responses of foliage weight and nutrient concentrations to a 4 × 3 factorial application of nitrogen (0–336 kg/ha) and phosphorus (0–56 kg/ha), and used the results to predict growth limitation. Nitrogen fertilization increased fascicle weight and foliar nitrogen concentration in eight of the nine study sites, implying nitrogen limitation. Phosphorus fertilization increased fascicle weight and foliar phosphorus concentration in three sites, implying phosphorus limitation. Two- and 4-year diameter growth response data generally supported these predictions. Diameter growth responded to nitrogen or nitrogen plus phosphorus in all predicted sites, but the technique failed to identify phosphorus limitation in one site and nitrogen plus phosphorus limitation in another. Growth response predictions based on initial foliar nutrient concentrations or foliar responses to fertilization were equally accurate. The greater expense of using the foliar response method may not be justified in operational assessments of forest nutrition.


1993 ◽  
Vol 23 (6) ◽  
pp. 1052-1059 ◽  
Author(s):  
Rodney J. Keenan ◽  
Cindy E. Prescott ◽  
J.P. Hamish Kimmins

Biomass and C, N, P, and K contents of woody debris and the forest floor were surveyed in adjacent stands of old-growth western red cedar (Thujaplicata Donn)–western hemlock (Tsugaheterophylla (Raf.) Sarg.) (CH type), and 85-year-old, windstorm-derived, second-growth western hemlock–amabilis fir (Abiesamabilis (Dougl.) Forbes) (HA type) at three sites on northern Vancouver Island. Carbon concentrations were relatively constant across all detrital categories (mean = 556.8 mg/g); concentrations of N and P generally increased, and K generally decreased, with increasing degree of decomposition. The mean mass of woody debris was 363 Mg/ha in the CH and 226 Mg/ha in the HA type. The mean forest floor mass was 280 Mg/ha in the CH and 211 Mg/ha in the HA stands. Approximately 60% of the forest floor mass in each forest type was decaying wood. Dead woody material above and within the forest floor represented a significant store of biomass and nutrients in both forest types, containing 82% of the aboveground detrital biomass, 51–59% of the N, and 58–61% of the detrital P. Forest floors in the CH and HA types contained similar total quantities of N, suggesting that the lower N availability in CH forests is not caused by greater immobilization in detritus. The large accumulation of forest floor and woody debris in this region is attributed to slow decomposition in the cool, wet climate, high rates of detrital input following windstorms, and the large size and decay resistance of western red cedar boles.


1984 ◽  
Vol 14 (5) ◽  
pp. 731-739 ◽  
Author(s):  
Thomas M. Hinckley ◽  
Hiromi Imoto ◽  
Katharine Lee ◽  
Susan Lacker ◽  
Yasushi Morikawa ◽  
...  

Seven sites ranging from 15 to 135 km from Mount St. Helens were selected to study the impact of air-fall tephra on the growth of Abiesamabilis (Dougl.) Forbes, A. procera Rehd., Pseudotsugamenziesii (Mirb.) Franco, Tsugaheterophylla (Raf.) Sarg., and T. mertensiana (Bong.) Carr. As tephra depth increased, there was a corresponding increase in visible foliar damage and associated decreases in diameter and height growth. Reduction in diameter growth was greater than reduction in height growth. The reduction in diameter growth approached 50% in both trees and saplings of A. amabilis. Growth reduction in true firs was greater than in associated species. This difference was related to their greater capacity for interception and retention of air-fall tephra. Damage to trees, and resulting growth reductions, were due to tephra coverage of both the foliage and the soil. Coverage of the foliage resulted in foliar damage, foliage abscission and reduction of total tree foliar area, and increased fine root mortality. Tephra coverage of the soil had the potential to restrict oxygen diffusion into the soil. However, soil oxygen concentrations less than 10% were measured only once over a 2-year period.


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