Effects of post-thinning density and repeated fertilization on the growth and development of young lodgepole pine

2005 ◽  
Vol 35 (8) ◽  
pp. 1952-1964 ◽  
Author(s):  
R P Brockley

The effects of factorial combinations of post-thinning density and fertilization on the growth and development of young lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) were investigated in central British Columbia. The effects of density and fertilization (repeated every 5 years) on tree height were small relative to the effects on stem radial growth. Tree radial growth increased with thinning intensity, whereas per-hectare growth was greatest at the highest residual density. Fertilizer effects varied across the range of residual densities tested. Tree and stand volume gains following fertilization were less, in both relative and absolute terms, at 600 trees/ha than at 1100 or 1600 trees/ha. Vigorous response of understory vegetation to nutrient additions (and strong competition for water and nutrients) may have reduced the effectiveness of fertilization on tree growth at 600 trees/ha relative to higher stand densities. Results indicate that the combined positive effects of thinning and fertilization on the growth of young lodgepole pine will accelerate stand development, thereby shortening technical rotation length. Results also indicate that significant growth gains following fertilization of thinned lodgepole pine will partially compensate for stand volume losses due to thinning. However, fertilization may be less effective at low stand densities, where negative effects of thinning on harvest volume are greatest.

2005 ◽  
Vol 35 (6) ◽  
pp. 1314-1318 ◽  
Author(s):  
Peter V Blenis ◽  
Wuhan Li

Infection of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) by western gall rust has been shown to decrease with tree height and age, but the effects of those two factors have not been separated. Five replicate artificial inoculations were done on a total of 327 trees of different ages in two height classes. Temperature and percentage of spore germination at the height of inoculation, shoot development (stem elongation at the time of inoculation as a proportion of final shoot elongation), main stem leader length at the time of inoculation, tree height, and tree age were measured. Modeled percentages of infected trees and the number of galls per 10 cm of shoot length decreased by 85% and 88%, respectively, as tree age increased between 2 and 10 years, indicating the undesirability of early, aggressive precommercial thinning of lodgepole pine stands in areas where western gall rust is common. By controlling and (or) statistically accounting for inoculum, microclimate, and phenological factors, it was possible to demonstrate that changes in susceptibility with tree age are sufficient to account for the reduction in infection with tree height.


1999 ◽  
Vol 14 (4) ◽  
pp. 186-193 ◽  
Author(s):  
Shongming Huang

Abstract Using the felled tree data, ecoregion-based height-diameter models were developed for lodgepole pine (Pinus contorta var. latifolia) in Alberta. A large number of height-diameter functions were evaluated, and the Chapman-Richards function was found to produce some of the most satisfactory fits. Residual analysis was conducted to identify the error structure of the models. A weighting factor of wi = 1/Di was found appropriate for achieving the equal error variance assumption. Differences of the height-diameter models among different ecoregions were examined and tested using the nonlinear extra sum of squares method. Most height-diameter relationships were found to be different among different ecoregions. Ecoregions of similar height-diameter relationships were combined to provide a composite model to facilitate the practical use of such relationships. West. J. Appl. For. 14(4):186-193.


2007 ◽  
Vol 37 (11) ◽  
pp. 2115-2129 ◽  
Author(s):  
R. P. Brockley

The effects of different regimes and frequencies of repeated fertilization (applied periodically and yearly) on the foliar nutrition and growth of young lodgepole pine ( Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) were investigated in central British Columbia. After 12 years, tree and stand growth responses indicated modest positive effects of two applications of nitrogen (N) and boron, with relatively large incremental gains to added sulphur and other nutrients (complete). Despite large increases in effective leaf area index and foliar N concentration relative to the control and periodic treatments, yearly applications of fertilizer were relatively ineffective in stimulating growth. When combined with frequent additions of other essential nutrients, annual fertilization with 50–100 kg N/ha over 12 years (825 kg N/ha in total) produced only slightly more “extra” wood than two applications of the multinutrient, complete fertilizer (400 kg N/ha in total) (19.4 m3/ha vs. 17.2 m3/ha, respectively). The most intensive fertilization treatment (1550 kg N/ha plus other nutrients over 12 years) produced shorter trees and less stand volume increment than periodic fertilization with the complete fertilizer. Treatment-induced changes in stand dynamics and growth allocation, disrupted foliar nutrient balance, and changes in soil biota and understory vegetation community structure may have negatively affected tree growth in intensively fertilized treatment plots.


2003 ◽  
Vol 18 (3) ◽  
pp. 149-154 ◽  
Author(s):  
Chad E. Keyser ◽  
Kelsey S. Milner

Abstract This study examined long-term diameter and height response of ponderosa pine (Pinus ponderosa) and lodgepole pine (Pinus contorta var. latifolia) to a one-time application of herbicide during seedling establishment in western Montana. Two herbicide trials initiated in 1981 and 1983 by Champion International Corporation were resurrected during the summer of 1997. Analysis of variance (ANOVA) F-tests along with Duncan's Multiple Range tests (DMR) were performed on mean tree dbh, tree height, and competing vegetation percent cover estimates. In addition, a graphical analysis of mean annual height growth over time was performed. Significant increases (alpha = 0.05) in ponderosa pine dbh (25 to 44%) and height (11 to 28%) were found after 16 yr of growth on Velpar L. (hexazinone) treated plots, while lodgepole pine had significant increases in dbh (70 to 118%) and height (41 to 82%) after 15 yr of growth on Velpar L. treated plots. Graphical analyses indicated a positive height growth effect for a period of 11 to 13 yr following treatment for ponderosa pine; however, total height gains had decreased in recent years. Positive increases in height growth for lodgepole pine were continuing after 15 yr of growth. These results indicate that a one-time application of herbicide applied during seedling establishment will promote faster tree growth in western Montana. We also note that proper density management will be necessary early in the life of the stand to maintain height gains. West. J. Appl. For. 18(3):149–154.


2011 ◽  
Vol 262 (2) ◽  
pp. 115-123 ◽  
Author(s):  
Sierra C. McLane ◽  
Lori D. Daniels ◽  
Sally N. Aitken

2003 ◽  
Vol 33 (7) ◽  
pp. 1227-1237 ◽  
Author(s):  
H YH Chen ◽  
K Klinka ◽  
A -H Mathey ◽  
X Wang ◽  
P Varga ◽  
...  

Stand volumes were determined for naturally established, even-aged, single- and mixed-species stands involving three combinations of shade-tolerant and shade-intolerant conifers on similar sites: (i) western redcedar – western hemlock (Thuja plicata Donn ex D. Don – Tsuga heterophylla (Raf.) Sarg.), (ii) lodgepole pine – western larch (Pinus contorta Dougl. ex Loud. – Larix occidentalis Nutt.), and (iii) lodgepole pine – black spruce (Pinus contorta – Picea mariana (Mill.) BSP). Stand volume was significantly increased with site index and breast-height age in all three studies. Stand volume was also related to relative stand density in the lodgepole pine – black spruce study. When both species were shade tolerant (hemlock–redcedar), stand volume increased linearly with the proportion of hemlock; the mixed-species stands had intermediate volume compared with single-species stands. The combination of two shade-intolerant species (pine–larch) had lower stand volume than that anticipated from single-species stands, implying that one species may inhibiting the growth of the other. Mixtures of shade-intolerant and shade-tolerant species with different growth patterns (spruce–pine) may be more productive than single-species stands in specific ecological contexts and developmental stages. The effect of one species on the productivity of another species is tree-species and site specific: at maturity, even-aged, mixed-species coniferous stands are not necessarily more productive than single-species stands.


Forests ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 606 ◽  
Author(s):  
Dingcai Yin ◽  
Derong Xu ◽  
Kun Tian ◽  
Derong Xiao ◽  
Weiguo Zhang ◽  
...  

Climate change has an inevitable impact on tree radial growth, particularly at mountain timeberlines. To understand climate effects on conifer radial growth in the central Hengduan Mountains, and the potential impacts of future climate change on conifer forests, we studied the growth responses to climate variables in Abies georgei, the major tree species of conifer forest in the Hengduan Mountains. We collected tree ring samples from four sites near the timberlines and analyzed the relationship between principle components (PC#1) of four chronologies and climatic variables (monthly mean temperature and monthly total precipitation) by using response function analysis (RFA), redundancy analysis (RDA), and moving interval analysis (MIA). A. georgei growth was affected by both temperature (positive effects) and precipitation (negative effects). Specifically, the radial growth of A. georgei was significantly and positively correlated with current July (by 6.1%) and previous November temperature (by 17.3%) (detected by both RFA and RDA), while precipitation of current June (by 6.6%) and September (by 11.7%) inhibited tree growth (detected by RDA). More rapid warming in the most recent 20 years (1990–2010) clearly enhanced growth responses to July and November temperature, whereas the relationship was weakened for June and September precipitation, according to MIA. Under the climate trend of the study area, if the increasing temperature could offset the negative effects of excessive precipitation, A. georgei radial growth would likely benefit from warming.


Author(s):  
Dingcai Yin ◽  
Derong Xu ◽  
Kun Tian ◽  
Derong Xiao ◽  
Weiguo Zhang ◽  
...  

Climate change has a inevitable impacts on tree radial growth, particularly at mountain timeberlines. To understand climate effects on conifer radial growth in the central Hengduan Mountains and potential impacts of future climate change on conifer forest, we studied growth responses to climate variables in Abies georgei, the major tree species of conifer forest in Hengduan Mountains. We collected tree ring samples from four sites near the timberlines and analyzed the relationship between principle components (PC#1) of four chronologies and climatic variables by using response function analysis (RFA), redundancy analysis (RDA) and moving interval analysis (MIA). A. georgei growth was affected by both temperature (positive effects) and precipitation (negative effects). Specifically, the radial growth of A. georgei was significantly and positively correlated with current July and previous November temperature (detected by both RFA and RDA), while precipitation of current June and September inhibited tree growth (detected by RDA). More rapid warming in recent 20 years (1990–2010) clearly enhanced growth responses to July and November temperature, whereas the relationship was weaken for June and September precipitation according to MIA. Under the climate trend of the study area, if the increasing temperature could offset the negative effects of excessive precipitation, A. georgei radial growth would likely benefit from warming, the dynamics of conifer forest should also consider indirect impacts of climate change.


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