Foliage and stand growth responses of semimature lodgepole pine to thinning and fertilization

1998 ◽  
Vol 28 (12) ◽  
pp. 1794-1804 ◽  
Author(s):  
Richard C Yang

The aim of this study was to quantify the interactive response of lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) to thinning and nitrogen (N) fertilization in midrotation stands by assessing foliar and stand growth response relationships and determining the optimum fertilizer regime. The experiment design was a factorial arrangement of treatments with two thinning intensities (thinned and unthinned control) and four N levels (0, 180, 360, and 540 kg·ha-1). Foliage was sampled annually from trees in buffers for 4 years following treatment and plot trees measured at a 5-year interval. Results indicated that the effect of fertilization on fascicle length and needle dry mass disappeared 2 years after N treatment, while thinning effects on foliage emerged 3 years after fertilization. Both first year fascicle length and dry mass were reliable predictors (r2 = 0.87 and 0.82, respectively) of subsequent stand volume growth. Applications of N at 360 kg·ha-1 to thinned and unthinned plots, respectively, improved 10-year periodic height increment by 20 and 19%, diameter at breast height by 29 and 34%, basal area by 21 and 36%, and total volume by 25 and 28%. Fertilization of N at this level appears to be optimal based on foliar and mensurational responses. High N loadings increased tree mortality and accelerated stand development and so it could be advantageously used as a tool for managing overstocked stands.

1984 ◽  
Vol 14 (2) ◽  
pp. 155-162 ◽  
Author(s):  
M. A. Radwan ◽  
D. S. DeBell ◽  
S. R. Webster ◽  
S. P. Gessel

Effects of different sources of fertilizer N on selected chemical characteristics of soils and foliage, and on growth of western hemlock (Tsugaheterophylla (Raf.) Sarg.) were compared at three different sites in western Washington. Treatments were the following: untreated control (O), ammonium nitrate (AN), ammonium sulfate (AS), calcium nitrate (CN), urea (U), and urea – ammonium sulfate (US). Fertilizers were applied in the spring (April–May) at 224 kg N/ha. Forest floor and mineral soil, to a depth of 5 cm, and foliage were sampled periodically for 2 years. Height and diameter of selected trees were measured periodically for 4 years. Results are reported mostly for two sites, one in the Cascade Range and one in the coastal zone in western Washington. The pH of forest floor and mineral soil varied by treatment, and the two urea fertilizers caused substantial initial rise. Effects on soil and foliar nutrients varied by fertilizer, sampling date, and location. In general, all fertilizers increased NH4 N, N03 N, and total N in the forest floor and mineral soil, and total N in the foliage. Also, with some exceptions, especially with foliar P in the Cascade site, fertilization reduced foliar content of important nutrients. At the Cascade site, 4-year growth responses in height, basal area, and volume averaged over all fertilizers were 30, 34, and 32%, respectively. AN, AS, CN, and urea resulted in height growth significantly (P < 0.20) higher than that of the control. Significant basal area growth and volume-growth responses were produced by AN, CN, and US. No significant height-growth response to any fertilizer occurred in the coastal stand; basal area growth and volume-growth responses averaged 27 and 21%, respectively, and best response occurred with urea. These results suggest that the low and inconsistent response of hemlock to N fertilization cannot be improved by applying some N fertilizer other than urea. Factors limiting response to N fertilization may be associated with availability of native N and other nutrients or other characteristics of hemlock sites and stands.


Forests ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 552 ◽  
Author(s):  
Howard Williams ◽  
Sharon Hood ◽  
Christopher Keyes ◽  
Joel Egan ◽  
José Negrón

Mountain pine beetle (Dendroctonus ponderosae Hopkins; MPB) is an aggressive bark beetle that attacks numerous Pinus spp. and causes extensive mortality in lodgepole pine (Pinus contorta Douglas ex Loudon; LPP) forests in the western United States and Canada. We used pre-outbreak LPP attributes, cumulative MPB attack severity, and areal extent of mortality data to identify subwatershed-scale forest attributes associated with severe MPB-caused tree mortality that occurred across the Northern Rockies, USA from 1999–2014. We upscaled stand-level data to the subwatershed scale to allow identification of large LPP areas vulnerable to MPB. The highest mortality occurred in subwatersheds where LPP mean basal area was greater than 11.5 m2 ha−1 and LPP quadratic mean diameter was greater than or equal to 18 cm. A coarse assessment of federally-owned LPP-dominated forestland in the analysis area indicated about 42% could potentially be silviculturally treated. Silvicultural management may be a suitable option for many LPP forests, and our hazard model can be used to identify subwatersheds with LPP attributes associated with high susceptibility to MPB across landscape spatial scales. Identifying highly susceptible subwatersheds can help prioritize general areas for potential treatments, especially where spatially extensive areas of contiguous, highly susceptible LPP occur.


2005 ◽  
Vol 35 (12) ◽  
pp. 2851-2859 ◽  
Author(s):  
David P Blevins ◽  
Cindy E Prescott ◽  
H Lee Allen ◽  
Teresa A Newsome

A factorial thinning and fertilization experiment was established in central British Columbia in a 36-year-old high-density fire-origin lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) stand to examine the effects of density, nutrition, and their interaction on tree and stand growth, foliage biomass per hectare, and growth efficiency. Volume growth was increased from 2 to 7 m3·ha–1·year–1 when fertilizer was applied without thinning and to 5 m3·ha–1·year–1 when fertilizer was applied with thinning. Thinning increased tree-level foliage biomass and growth efficiency by concentrating limited resources onto fewer trees, resulting in increased tree-level volume growth. Stand-level volume growth was reduced by thinning because of the large reduction in stocking. However, by year 4, stand-level volume growth was the same on control and thinned plots, suggesting that thinned trees have already recaptured the site potential. Fertilization increased both tree-level and stand-level productivity through increases in resource availability per tree and per hectare. This resulted in increased foliage biomass and growth efficiency at the tree and stand level. The combination of thinning and fertilization resulted in the greatest tree-level growth because of increased tree-level foliage biomass and growth efficiency. Boron appears to be the most limiting element followed by sulfur and nitrogen.


2019 ◽  
Vol 95 (03) ◽  
pp. 207-221 ◽  
Author(s):  
Cindy Prescott ◽  
Louise deMontigny ◽  
George Harper

Challenges to the mid-term timber supply in interior British Columbia resulting from losses to insect outbreaks and wild-fires have prompted interest in silvicultural interventions to hasten growth of regenerating forests, including high-density(overstocked), height-repressed stands of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.). A trialwas established in a dense (4000 to 30 000 trees ha-1) 36-year-old wildfire-origin pine stand in the Cariboo-Chilcotinregion of interior BC to assess the efficacy of thinning, fertilization and a combination of the two treatments for improv-ing tree growth and stand development. Height and diameter of the 36 crop trees in each plot was greater in fertilizedplots then control plots for six years following fertilization, while the height and diameter responses to thinning and thin-ning + fertilization were sustained throughout the 18-year measurement period. Cumulative basal area and volumegrowth of crop trees and all stand trees over the 18-year period was significantly greater in thinned and thinned + fertil-ized treatments than control plots. Projections based on the TASS growth and yield model suggested that total stand vol-umes in thinned plots would surpass that of the control at age 74 and would surpass that of the fertilized treatment at 89years. Unthinned stands (i.e., control and fertilized treatments), did not accumulate significant merchantable volume; inthinned stands (i.e., thinned and thinned + fertilized treatments), the minimum harvest criteria of 80 m3 ha-1 for pine-leading stands in this region was reached at age 102 years. Repeated fertilization would be needed to further hasten standdevelopment. The potential long-term benefits of these silvicultural interventions for timber supply must be weighedagainst treatment costs and risks of mortality related to wildfire, insects and disease. These results highlight the value oflong-term research trials for informing silviculture decisions.


2000 ◽  
Vol 30 (9) ◽  
pp. 1389-1399 ◽  
Author(s):  
R P Brockley

Six-year basal area responses to nitrogen (N) fertilizer, alone and in combination with sulphur (S), in 31 lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) stands in the interior of British Columbia were compared with pre-treatment measures of foliar N and S and first-year increases in fascicle mass to determine the utility of these variables for predicting growth response and for determining appropriate fertilizer prescriptions. Results indicate that pre-fertilization levels of foliar N or inorganic sulphate-S (SO4) may be more reliable than the fascicle mass screening method for predicting whether or not a significant stemwood response will occur following N fertilization. When combined, N and SO4 levels in unfertilized foliage explained 68% of the variation in relative basal area response to fertilization with N alone. Foliar nutrients were also useful for determining whether or not lodgepole pine would respond incrementally to S when added in combination with N. Stands in which pre-fertilization foliar SO4 was [Formula: see text]60 mg/kg and N/S ratio was [Formula: see text]13 did not respond significantly to N alone but always responded significantly to N + S. Conversely, a foliar SO4 level >60 mg/kg combined with a N/S ratio of [Formula: see text]12 always resulted in a favourable response to N with no incremental benefit of added S.


2002 ◽  
Vol 32 (1) ◽  
pp. 153-160 ◽  
Author(s):  
Barbara E Kishchuk ◽  
Gordon F Weetman ◽  
Robert P Brockley ◽  
Cindy E Prescott

Four rates of N (0, 50, 100, and 150 kg·ha–1) with and without a fertilizer mix containing P, K, S, Ca, Mg, and micronutrients were applied to a stand of 8-year-old lodgepole pine (Pinus contorta var. latifolia Engelm.) in four applications during 7 years. Fourteen years after the first fertilization, mean tree basal area and volume were significantly increased in the treatments containing the two highest rates of N plus the fertilizer mix. Mean tree basal area was 38% greater and mean tree volume was 42% greater in the highest N (525 kg·ha–1) plus mix treatment than in the control treatment. Stand basal area increased 48% over the control in the highest N plus mix treatment. Mean tree basal area and volume were 27 and 25% greater than the control under the intermediate N rate (350 kg·ha–1) with mix, respectively. Height growth was not significantly increased by fertilization. Both higher rates of N (four applications of >100 kg·ha–1) and the fertilizer mix were required for significant growth responses to occur. Addition of N alone or mix alone had a negative effect on mean tree basal area and volume. Addition of higher N rates without the mix decreased foliar total S and SO4-S concentration and increased the N/S ratio. Addition of the higher rates of N without the mix aggravated slight K deficiencies. The responses to the higher N rates in combination with the fertilizer mix are mainly attributable to S.


2004 ◽  
Vol 34 (11) ◽  
pp. 2217-2229 ◽  
Author(s):  
Douglas B Mainwaring ◽  
Douglas A Maguire

Basal area and height growth were analyzed for individual trees in uneven-aged ponderosa pine (Pinus ponderosa Dougl. ex Laws.) and lodgepole pine (Pinus contorta Dougl. ex. Loud.) stands in central Oregon. Basal area growth was modeled as a function of other stand and tree variables to address three general objectives: (1) to compare the predictive ability of distance-dependent versus distance-independent stand density variables; (2) to determine the degree to which small trees negatively affect the growth of overstory trees; and (3) to test for differences in growth efficiency between species and between indices of spatial occupancy used to define efficiency (area potentially available, crown projection area, and a surrogate for total tree leaf area). Distance-dependent variables were found to improve growth predictions when added to models with only distance-independent variables, and small trees were found to have a quantifiably negative effect on the growth of larger trees. While volume growth efficiency declined with increasing levels of spatial occupancy for lodgepole pine, ponderosa pine volume growth efficiency was greatest at the highest levels of crown base sapwood area and crown projection area. The behavior in ponderosa pine resulted from the previously recognized correlation between tree height and total leaf area or crown size. The final statistical models distinguished between the positive effect of relative height and the negative effect of increasing tree size.


2019 ◽  
Vol 49 (11) ◽  
pp. 1471-1482
Author(s):  
Woongsoon Jang ◽  
Bianca N.I. Eskelson ◽  
Louise de Montigny ◽  
Catherine A. Bealle Statland ◽  
Derek F. Sattler ◽  
...  

This study was conducted to quantify growth responses of three major commercial conifer species (lodgepole pine (Pinus contorta Douglas ex Loudon var. latifolia Engelm. ex S. Watson), interior Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. glauca (Beissn.) Franco), and spruce (white spruce (Picea glauca (Moench) Voss) and hybrid spruce (Picea engelmannii Parry ex. Engelm. × Picea glauca (Moench) Voss × Picea sitchensis (Bong.) Carrière))) to various fertilizer blends in interior British Columbia, Canada. Over 25 years, growth-response data were repeatedly collected across 46 installations. The fertilizer blends were classified into three groups: nitrogen only; nitrogen and sulfur combined; and nitrogen, sulfur, and boron combined. The growth responses for stand volume, basal area, and top height were calculated through absolute and relative growth rate ratios relative to a controlled group. Fertilizer blend, inverse years since fertilization, site index, stand density at fertilization, and their interactions with the fertilizer blend were used as explanatory variables. The magnitude and significance of volume and basal area growth responses to fertilization differed by species, fertilizer-blend groups, and stand-condition variables (i.e., site index and stand density). In contrast, the response in top height growth did not differ among fertilization blends, with the exception of the nitrogen and sulfur fertilizer subgroup for lodgepole pine. The models developed in this study will be incorporated into the current growth and yield fertilization module (i.e., Table Interpolation Program for Stand Yields (TIPSY)), thereby supporting guidance of fertilization applications in interior forests in British Columbia.


1991 ◽  
Vol 15 (1) ◽  
pp. 22-27
Author(s):  
Terry R. Clason

Abstract A hardwood suppression treatment applied to a 7-year-old, loblolly pine (Pinus taeda L.) plantation enhanced projected productivity through a 35-year rotation that included three commercial thinnings. By age 22, growth data showed that hardwood removal treatments had larger pines and smaller hardwoods than check treatments. Fifteen-year pine basal area and merchantable volume growth on hardwood removal plots exceeded the check plots by 25 and 27%. Projected growth between ages 22 and 35 indicated that 28 years after early hardwood removal thinned plantation merchantable volume yields improved by 840 ft³ per acre. South. J. Appl. For. 15(1):22-27.


1993 ◽  
Vol 17 (3) ◽  
pp. 135-138 ◽  
Author(s):  
Eric J. Jokela ◽  
Stephen C. Stearns-Smith

Abstract Data from six fertilizer trials established in semimature southern pine stands (five slash pine, Pinus elliottii Engelm. var. elliottii; one loblolly pine, Pinus taeda L.) were analyzed to determine the efficacy of single vs. split fertilizer treatments. Both fertilizer treatments supplied an elemental equivalent of 200 lb nitrogen (N)/ac and 50 lb phosphorus (P)/ac; however, the first treatment was delivered as a single dose, and the second treatment was a split N application (i.e., 50 lb N and 50 lb P/ac (initial); 150 lb N/ac (2 yr later). Cumulative responses of fertilized plots were still significantly greater than the controls in five trials after 8 yr and averaged 43% (15.7 ft²/ac) and 39% (607 ft³/ac) for basal area and stand volume growth, respectively. In general, no significant differences in either the magnitude or duration of response were detected between the single and split N fertilizer treatments. This suggests that delaying a portion of the N application for 2 yr will not diminish the level of growth responses attained. Therefore, land managers have flexibility in using either application method when implementing midrotation fertilizer prescriptions. South. J. Appl. For. 17(3):135-138.


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