Comparing site productivity of mature fire-origin and post-harvest juvenile lodgepole pine stands in Alberta

2004 ◽  
Vol 34 (6) ◽  
pp. 1181-1191 ◽  
Author(s):  
Shongming Huang ◽  
Robert A Monserud ◽  
Thomas Braun ◽  
Hugh Lougheed ◽  
Olenka Bakowsky

Twenty-two paired-plot sample locations were revisited to re-examine the site indices of mature fire-origin and adjacent post-harvest juvenile lodgepole pine (Pinus contorta var. latifolia Engelm.) stands occurring on the same physiographic sites. The post-harvest juvenile stands followed harvesting and drag scarification, whereas the mature fire-origin stands received no stand treatment. Results showed that the site index of post-harvest juvenile stands was 27% to 35% higher than that of the mature fire-origin stands. Calculation of the rate of change in site index indicated that the site index estimates of post-harvest stands were stable after 5 years breast height age was reached. This suggests that the increase in site index in post-harvest stands is not a short-term artifact, but a sustained gain that will be maintained over time. Simulations of post-harvest yield based on the Alberta growth and yield projection system (GYPSY) for lodgepole pine suggested that the increase in post-harvest site index will likely result in substantial gains in the mean annual increment and total yield of post-harvest lodgepole pine stands in the study area. The results of this study indicate that post-harvest lodgepole pine stands are growing significantly faster than their fire-origin counterparts on equivalent sites.

1991 ◽  
Vol 15 (4) ◽  
pp. 213-216 ◽  
Author(s):  
Quang V. Cao ◽  
Kenneth M. Durand

Abstract A compatible growth and yield model was developed based on remeasurement data collected from 183 plots on unthinned improved eastern cottonwood (Populus deltoides Bartr.) plantations in the lower Mississippi Delta. The Sullivan and Clutter (1972) equation form was selected for predicting cubic-foot volume yield and projecting volume from site index and initial age and basal area. Yield equations explained 97% and 94%, respectively, of the variations in total outside bark and merchantable inside bark volumes. Mean annual increment of merchantable volume culminated between 8 and 15 years, depending on site index and initial basal area. South. J. Appl. For. 15(4):213-216.


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.


2021 ◽  
Vol 97 (01) ◽  
pp. 65-77
Author(s):  
W. Richard Dempster ◽  
Sharon Meredith

Changes in the structure and dynamics of lodgepole pine stands following the 2006 outbreak of mountain pine beetle in western Alberta were investigated by monitoring attacked permanent sample plots over the following decade and projecting future stand development with locally validated growth models. Results suggest that a wide range in growth and yield of attacked stands is likely, with projected impacts varying from minor and inconsequential modifications to full stand replacement. Severely disturbed stands are unlikely to naturally regenerate to pine. The degree to which timber production is naturally restored in such stands will depend to a large extent on the amount and composition of non-pine advance growth and regeneration. Variation in attack severity and tree species composition will, in the absence of clearcutting following disturbance, result in increased diversity in stand and forest structure. Recommendations are made for scheduling salvage and restoration operations to ameliorate losses in timber supply.


2005 ◽  
Vol 20 (1) ◽  
pp. 64-68 ◽  
Author(s):  
Oscar García ◽  
Adrian Batho

Abstract Top height definitions are often based on the heights of a certain number of the largest trees per unit area, such as the largest 100/ha. Recognizing that results vary with the extent of the reference area, this area is specified in the British Columbia definition, basing top height on the largest tree in a 0.01-ha plot. The problem is how to estimate top height when data is available for larger plots, without the information needed to subdivide them into 0.01-ha subplots. The usual largest 100/ha overestimates the correct value, and we find that the bias can be substantial. We evaluate two alternatives for natural lodgepole pine stands, using data from 0.04- and 0.08-ha sample plots. The improved estimators considerably reduce bias, although some bias due to spatial size autocorrelations remains. Autocorrelation was found to be predominantly positive, and some implications for growth and yield prediction are mentioned. West. J. Appl. For. 20(1):64–68.


1986 ◽  
Vol 16 (5) ◽  
pp. 875-879
Author(s):  
Dennis M. Cole

Relationships for representing relative thinning response potential among overstocked lodgepole pine stands were investigated with data from 31 stands in four National Forests of Idaho. The common logarithm of mean 10-year cross-sectional increment of dominant and codominant trees on stand edges created by clearing was the dependent variable selected for examining relationships with a large number of tree, stand, and site variables. A linear regression model explained nearly 60% of the variance in the response variable. The model included variables representing mean 10-year periodic cross-sectional increment prior to clearing, site index, and quadratic mean stand diameter. As a predictor of edge-tree response to clearing, the model represents relative thinning response differences to be expected among overstocked lodgepole pine stands and thus reflects relative stand vigor.


1987 ◽  
Vol 63 (1) ◽  
pp. 28-31 ◽  
Author(s):  
R. P. Brockley ◽  
E. Elmes

A survey was undertaken to assess the incidence and magnitude of barking injuries by red squirrels in juvenile stands of spaced lodgeppole pine in south-central British Columbia. Eleven of the 40 stands surveyed (27.5%) showed evidence of squirrel damage. Within damaged stands, an average of 51% of lodgepole pine crop trees exhibited barking injuries (ranging from 6 to 90%).The average diameter (6.8 cm) of damaged stands was significantly greater than that of undamaged stands (3.9 cm). Sixty-seven percent of stands with average diameters greater than 6 cm showed evidence of barking injuries, while only 11% of stands with average diameters less than 6 cm had been damaged. Squirrels preferentially attacked the larger-diameter stems in damaged stands. Data indicate that fire-origin stands are more susceptible to barking damage than stands naturally regenerated following harvesting.Inability to accurately assess either squirrel damage potential or its impact on growth and yield indicates that a conservative approach is necessary in spacing juvenile lodgepole pine in areas susceptible to squirrel attack. A two-step spacing strategy may be the most practical method of minimizing the impact of squirrel barking injuries. Key words: lodgepole pine, juvenile-spacing, red squirrels.


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