Stand development following precommercial thinning and fertilization treatments in a western redcedar (Thuja plicata) dominated forest

2011 ◽  
Vol 41 (1) ◽  
pp. 151-164 ◽  
Author(s):  
Constance A. Harrington ◽  
Warren D. Devine

Western redcedar (Thuja plicata Donn ex D. Don.) is an important North American tree species, but little information is available on its long-term responses to silvicultural treatments. Stand responses (mortality, ingrowth, basal area and volume growth, and distributions of trees by diameter and height classes) were followed for 25 years after thinning and fertilization treatments (alone and in combination) were applied to a naturally regenerated, low site quality western redcedar stand on the Olympic Peninsula in western Washington, USA. Mortality was low overall, but the densest stands experienced competition-related mortality. Thinning resulted in additional stem recruitment; after 25 years, the number of ingrowth trees exceeded the number of trees in the cohort left after thinning. Fertilization (with nitrogen and phosphorus) flattened size distributions and skewed them to larger size classes. Thinning plus fertilization resulted in the largest individual trees and the most large trees, but also many trees in a wide range of diameter classes. The recruitment of a second cohort did not result in a two-storied stand. Fertilization without thinning resulted in the greatest stand basal area and volume, as well as trees with fewer live lower branches.

1991 ◽  
Vol 21 (4) ◽  
pp. 516-521 ◽  
Author(s):  
K. A. Stegemoeller ◽  
H. N. Chappell

Fertilization of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stands generally increased both basal area and volume growth for at least 8 years. Thinning tended to have an even greater effect than fertilization on basal area and volume growth, increasing both on an individual-tree basis. On a land-area basis, however, the removal of growing stock by thinning caused volume growth to be less than that of the control. The magnitude and duration of this negative response was dependent on the level of thinning and the site quality. A significant positive interaction between fertilization and thinning exists. The combined treatment resulted in the greatest absolute basal area and volume increments, and the response became greater than that to fertilizer alone in the 3rd and 4th years, and remained so through at least 8 years.


1997 ◽  
Vol 21 (4) ◽  
pp. 168-174
Author(s):  
Michael G. Shelton ◽  
Paul A. Murphy

Abstract Growth was monitored for 4 yr in a thinned stand in southern Arkansas with three pine basal areas (70, 85, and 100 ft2/ac) and three hardwood basal areas (0, 15, and 30 ft2/ac); pretreatment basal areas averaged 119 and 33 ft2/ac for pines and hardwoods, respectively. Treatments were arranged in a 3 X 3 factorial randomized complete block design with three replicates, yielding 27 permanent 0.20 ac plots. Growth variables were regressed with residual pine and hardwood basal areas. Pine basal area and volume growth increased with the pine stocking level after thinning and decreased with the level of retained hardwoods. For basal area and merchantable volume, hardwood growth largely compensated for losses in the pine component, and thus, hardwood retention had little net effect on the total growth of the stand. The greatest impact of hardwood retention was on the stand's sawtimber growth, because hardwoods did not contribute to this product class. Each 1 ft2/ac of retained hardwood basal area reduced pine sawtimber growth by 6 to 10 bd ft Doyle/ac/yr, depending on the pine stocking. Because large differences existed in the value of timber products, retaining 15 and 30 ft2/ac of hardwoods reduced the value of timber production by 13 and 24%, respectively, at 4 yr after thinning. South. J. Appl. For. 21(4):168-174.


2001 ◽  
Vol 31 (6) ◽  
pp. 978-987 ◽  
Author(s):  
J M Kranabetter ◽  
P Kroeger

We examined epigeous ectomycorrhizal mushroom richness and productivity after partial cutting in a western hemlock (Tsuga heterophylla (Raf.) Sarg.) - western redcedar (Thuja plicata Donn ex D. Don in Lamb.) forest of northwestern British Columbia. Mushrooms were collected throughout the fruiting season (July to October) for 3 years, starting 5 years after partial cutting, from plots with mesic soil conditions and residual basal areas ranging from 23 to 69 m2/ha for western hemlock and 0 to 26 m2/ha for western redcedar. Partial cutting had no apparent effect on mushroom phenology over the 3 years. Significant block interactions demonstrated that reductions in basal area of western hemlock could lead to positive, neutral, and negative responses in mushroom richness, biomass, and number of fruiting bodies. These responses were related to stand structure and the potential differences in tree vigour after partial cutting. In addition, there was weak evidence that western redcedar, a host for vesicular-arbuscular mycorrhiza, had a negative effect on average taxon richness. The study demonstrated that partial-cutting systems could allow some timber removal without necessarily reducing ectomycorrhizal mushroom communities.


1983 ◽  
Vol 13 (1) ◽  
pp. 126-136 ◽  
Author(s):  
Chadwick Dearing Oliver ◽  
Marshall D. Murray

A Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) thinning study was established in 1959 in a stand begun after logging in 1930. Thinnings to set basal area densities were done in 1959, 1962, 1966, and 1970. On each plot both large and small trees were removed since average basal area per tree was kept constant before and after thinning. Volume growth varied greatly between plots of the same age, initial basal area, and site because of differences in stand structure. Large trees on a plot grew more per tree and per basal area than small trees. Stand basal area, stand volume, number of stems, or number of dominant and codominant trees were not closely related to volume growth per hectare, although density indexes giving weight to larger trees showed the closest relation. The lack of close relation between stand density indexes and growth found here and elsewhere probably means the indexes do not uniquely define stand structures; it does not necessarily mean that thinning will not increase volume growth per hectare. Volume growth per hectare after thinning to a given basal area density will be greater and probably more consistent if larger trees are left and enough time is allowed for the stand to recover following thinning.


2016 ◽  
Vol 46 (5) ◽  
pp. 645-655 ◽  
Author(s):  
Justin L. Pszwaro ◽  
Anthony W. D’Amato ◽  
Thomas E. Burk ◽  
Matthew B. Russell ◽  
Brian J. Palik ◽  
...  

Red maple (Acer rubrum L.), historically a common but not abundant tree species in North America, has increased in abundance throughout its range over the last several decades; however, it has received little attention in growth and yield studies. The objectives of this study were to (i) evaluate the effects of stocking level and stand density on overall patterns of red maple stand productivity and (ii) quantify these relationships across a wide range of stand age, site quality, geographic location, and climatic conditions. We used long-term measurements from 52 sites in Wisconsin and Michigan to examine growth responses of even-aged red maple stands to various levels of thinning. Using linear, mixed-effects modeling, future stand-level red maple basal area was modeled as a function of stand and plot characteristics and climatic variables. Growing season precipitation and its interaction with initial red maple basal area were significant predictors; however, they only collectively reduced the mean squared error by 2.1% relative to a base model containing solely stand and plot factors. Model projections indicated there was little difference in predicted future basal area for the range of climate conditions experienced by these stands highlighting red maple’s wide tolerance of environmental conditions across the region.


2007 ◽  
Vol 37 (12) ◽  
pp. 2587-2599 ◽  
Author(s):  
R. W. Negrave ◽  
C. E. Prescott ◽  
J. E. Barker

A factorial trial was established to examine the effects of planting density and fertilization on the growth of western redcedar ( Thuja plicata Donn ex D. Don) and western hemlock ( Tsuga heterophylla (Raf.) Sarg.) on nutrient-poor (CH) sites and nutrient-medium (HA) sites. Two levels of NPK fertilization were crossed with three levels of planting density (500, 1500, and 2500 stems/ha). Fifteen years after establishment and 10 years after the last fertilizer application, height, individual stem volume increment, stand volume, 5 year periodic annual increment (PAI), and 5 year periodic height increment were all increased by fertilization. Fertilization of CH sites increased annual stand volume increment by 753%–2552% and 122%–209% for hemlock and cedar, respectively; fertilization of HA sites increased PAI by 94%–264%. Volume growth response to fertilization was greater on HA than on CH sites. Increasing stand density reduced height growth on CH sites but not on HA sites. These results suggest that competition for nutrients can be a significant growth-limiting factor even before canopy closure occurs and that treatment of ericaceous sites may not be justified by productivity increases.


1988 ◽  
Vol 18 (7) ◽  
pp. 859-866 ◽  
Author(s):  
K. L. O'Hara

The growth of individual trees from four thinning treatments in a 64-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stand was analyzed to determine desirable residual stand structures after thinning. Dominant and codominant trees had the highest individual tree stem volume growth rates over the previous 5 years, and accounted for most stand volume growth in thinned and unthinned stands. Two measures of growing space, crown projection area and sapwood basal area (a surrogate for leaf area), were used to measure how efficiently individual trees used their growing space. Crown classes were useful in characterizing growing space efficiency (volume growth per unit of growing space) only in the unthinned treatment. In thinned treatments, tall trees with medium-sized crowns were most efficient, while in the unthinned treatment, tall trees with relatively large crowns were most efficient. A large crown in an unthinned stand was comparable in size to a medium-sized crown in a thinned stand. Results suggest growing space is not limiting individual tree growth in thinned stands and that thinning to a particular stand structure is more appropriate than thinning to a particular level of stand density.


2014 ◽  
Vol 44 (8) ◽  
pp. 977-985 ◽  
Author(s):  
Dale G. Brockway ◽  
Edward F. Loewenstein ◽  
Kenneth W. Outcalt

Proportional basal area (Pro-B) was developed as an accurate, easy-to-use method for making uneven-aged silviculture a practical management option. Following less than 3 h of training, forest staff from a range of professional backgrounds used Pro-B in an operational-scale field study to apply single-tree selection and group selection systems in longleaf pine (Pinus palustris Mill.) stands. Field crews achieved precision levels often within 3%–5% of the 11.5 m2·ha−1 target residual basal area. By aggregating many diameter classes into only three diameter-class groups, Pro-B improves efficiency by requiring tree markers to remember only three fractions, while making a single pass through the stand. Trees of large size, specific species and with good form, broad crowns and cavities can be retained, while adjusting spacing to release residuals. Systematic quantification of marking trees for removal enables different individuals to obtain similar results. Early observations revealed encouraging levels of pine regeneration and stand development, along with continuing good volume growth rates of 3% per year. Although less certain until one or more cutting cycles are completed, these early tests indicate that a stable mature forest structure should develop, which is characterized by the presence of large trees and natural regeneration.


1991 ◽  
Vol 6 (4) ◽  
pp. 94-98 ◽  
Author(s):  
James A. Moore ◽  
Peter G. Mika ◽  
James L. Vander Ploeg

Abstract Response to nitrogen fertilization treatments in Rocky Mountain Douglas-fir (Pseudotsuga menziesii var. glauca) differed significantly among geographic regions within the inland northwest. Gross basal area and volume growth on fertilized plots were significantly greater than growth on controls for all geographic regions, but only in northern Idaho and central Washington was gross response significantly greater on 400 lb/ac N plots than on 200 lb N plots. Net basal area and volume growth on treated plots in Montana, central Idaho, and northeast Oregon were not significantly greater than the controls for either nitrogen treatment. Analysis of 2-year periodic basal area increment indicated that, while response did decline through time, treated plots continued to produce more gross growth than control plots 6 years after treatment. Similar operational nitrogen treatments applied to the Douglas-fir population sampled in this study should produce gross responses exceeding 10% after 6 years three out of four times. West. J. Appl. For. 6(4):94-98.


1998 ◽  
Vol 15 (2) ◽  
pp. 98-105 ◽  
Author(s):  
Graham R. Hillman ◽  
Sam K. Takyi

Abstract A split-plot design experiment replicated in four blocks was established to determine the effects of thinning (main plots) and fertilization (subplots) on growth of a 50- to 60-yr-old stagnant stand of black spruce on a shallow peatland (swamp) in Alberta drained in the previous year in a large-scale experimental project to convert it to a future merchantable stand. The thinning treatments were selective hand-spacing to 1600 trees ha-1 and no thinning. The hand-broadcast fertilizer treatments were: no fertilizer, nitrogen (N), phosphorus (P), potassium (K), NP, PK, NK, and NPK. Nitrogen as NH4NO3 was applied at 200 kg ha-1, P as triplesuperphosphate at 100 kg ha-1, and K as potassium chloride at 100 kg ha-1. After six growing seasons, diameter at breast height, basal area, and volume growth were significantly greater in the thinned treatment than for the same number of large (dominant and codominant) trees in the unthinned treatment. Thinning had no significant effect on height growth. Nitrogen significantly increased dbh, height, basal area, and volume growth, and NP increased the basal area and volume growth. P, K, and PK treatments showed little effects on growth, and P applied alone tended to reduce growth. The results indicated it will be beneficial to supplement drainage with thinning or fertilization with N and N-containing fertilizers or with both shortly after drainage, particularly when other researchers have indicated black spruce may take several years to respond to drainage. North. J. Appl. For. 15(2):98-105.


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