Evaluation of nonspatial approaches and equation forms used to predict tree crown recession

2004 ◽  
Vol 34 (10) ◽  
pp. 1993-2003 ◽  
Author(s):  
David W Hann ◽  
Mark L Hanus
Keyword(s):  
Growth Period ◽  
Allometric Equation ◽  
Douglas Fir ◽  
Tree Age ◽  
Permanent Plots ◽  
Stand Age ◽  
Tree Crown ◽  
Effective Age ◽  
The Difference ◽  
Modeling Data

Two nonspatial approaches for modeling tree crown recession (ΔHCB) were evaluated by using 5341 observations from Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). The first approach applies a static height-to-crown-base (HCB) equation at the start and end of the growth period and uses the difference in these predictions as an estimate of ΔHCB. This allometric method can be applied to species lacking ΔHCB data from permanent plots. The incremental method directly predicts ΔHCB from an equation developed from adequate permanent plot data. Two allometric and six incremental equation forms were examined. Also examined were three approaches for determining the end-of-growth-period tree and plot attributes used by the allometric method. Although the allometric method can produce unbiased estimates of ΔHCB, the best allometric equation forms explained about one-half of the variation explained by the best incremental equation form. The two best incremental equation forms were modifications of a nonlinear logistic equation form previously developed for Douglas-fir. The modifications included using measured stand age (BHA) or predicted tree growth effective age (GEA) instead of measured tree age. The best equation form used BHA, which limits its application to modeling data collected from just even-aged stands. The equation form using GEA could be applied to modeling data sets from both even- and uneven-aged stands.

Ten-year growth and mortality in young Douglas-fir stands experiencing a range in Swiss needle cast severity

2011 ◽  
Vol 41 (10) ◽  
pp. 2064-2076 ◽  
Author(s):  
Douglas A. Maguire ◽  
Douglas B. Mainwaring ◽  
Alan Kanaskie
Keyword(s):  
Disease Severity ◽  
Growth Period ◽  
Douglas Fir ◽  
Permanent Plots ◽  
Annual Increment ◽  
Needle Age ◽  
Needle Cast ◽  
Needle Retention ◽  
Swiss Needle Cast ◽  
Annual Mortality

Swiss needle cast, a foliar disease caused by the Ascomycete Phaeocryptopus gaeumannii (T. Rohde) Petr., continues to afflict Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) in north coastal Oregon. Permanent plots were installed in 1998 to assess growth impacts and monitor disease severity. Gross periodic annual increment was measured for three 2-year growth periods and one 4-year growth period and ranged from 0.37 to 31.74 m3·ha–1·year–1. Foliage retention, defined as the average number of annual needle age classes held by a tree, was also estimated as an index of disease severity. Assuming negligible losses in stands with maximum needle retention (approximately 3.9 years), growth losses in net periodic annual increment reached slightly over 50% in stands with the lowest needle retention (approximately 1 year). Mixed-effects regression models supported a consistent relationship between foliage retention and both gross and net periodic annual increment among the four growth periods. Periodic annual mortality ranged from 0 to 19.12 m3·ha–1·year–1 but was not significantly influenced by Swiss needle cast as measured by average foliage retention. Minimum and maximum foliage retention has fluctuated annually from 1998 to 2008 on the permanent plots, but growth losses at a given level of foliage retention appear to have remained stable. Estimated growth losses are similar to those reported for comparable levels of defoliation by other agents.

Nodulation and nitrogen fixation by red alder and Sitka alder on coal mine spoils

1982 ◽  
Vol 12 (4) ◽  
pp. 992-997 ◽  
Author(s):  
Paul Heilman ◽  
Gorden Ekuan
Keyword(s):  
Nitrogen Fixation ◽  
Nitrogenase Activity ◽  
Douglas Fir ◽  
Tree Age ◽  
Fixed Nitrogen ◽  
Red Alder ◽  
Mine Spoils ◽  
Nodule Number ◽  
Western Washington ◽  
The Difference

Nodule number, nodule weight, and nitrogen fixation (nitrogenase activity by acetylene reduction) were determined for 3 years for red alder (Alnusrubra Bong.) and Sitka alder (Alnussinuata Reg. Rydb.) on three types of coal spoils in western Washington. Generally, the two species were similar in number and weight of nodules and in nitrogen-fixation rates when measured in June (these rates varied from 23 to 27 µmol•g−1•h−1). The type of coal spoil material influenced nodule number but not nodule weight. Topsoil covered subsoil had the highest number of nodules. Trees on unweathered subsoil had the lowest number, particularly for Sitka alder. Nodule weight (dry, ash free) varied from 68 kg•ha−1 for 5-year-old Sitka alder interplanted in a 1:1 mix with Douglas-fir (1790 alders•ha−1) to 188–200 kg•ha−1 for pure stands of both alder species at age 5 (5380 trees•ha−1). The difference in nodule weight between species was not significant. Both species fixed nitrogen at similar rates although in the last year of measurement red alder trees fixed 37% more nitrogen than Sitka alder. This difference was not significant, however. Nitrogen fixation per unit area depended on tree age and spacing, varying from 17 kg•ha−1•year−1 at age 3 with 1830 alders•ha−1 to 150 kg•ha−1•year−1 by both species at age 5 and a density of 5380 trees•ha−1. Fixation rates increased from age 3 to 5 years primarily because of increased nodule weight. Nitrogen fixation by the Sitka alder in mixture with Douglas-fir was relatively high and was encouraging for the concept of mixed plantings of these two species. However, response of Douglas-fir to mixed planting with Sitka alder has not been demonstrated.

Root rot damage in naturally regenerated stands of spruce and balsam fir in Ontario

1989 ◽  
Vol 19 (3) ◽  
pp. 295-308 ◽  
Author(s):  
R. D. Whitney
Keyword(s):  
Root Rot ◽  
Black Spruce ◽  
Basal Area ◽  
Ground Level ◽  
White Spruce ◽  
Balsam Fir ◽  
Tree Age ◽  
Stand Age ◽  
Root Decay ◽  
Forest Region

In an 11-year study in northern Ontario, root rot damage was heaviest in balsam fir, intermediate in black spruce, and least in white spruce. As a result of root rot, 16, 11, and 6%, respectively, of dominant or codominant trees of the three species were killed or experienced premature windfall. Butt rot, which resulted from the upward extension of root rot into the boles of living trees, led to a scaled cull of 17, 12, and 10%, respectively, of gross merchantable volume of the remaining living trees in the three species. The total volume of wood lost to rot was, therefore, 33, 23, and 16%, respectively. Of 1108 living dominant and codominant balsam fir, 1243 black spruce, and 501 white spruce in 165 stands, 87, 68, and 63%, respectively, exhibited some degree of advanced root decay. Losses resulting from root rot increased with tree age. Significant amounts of root decay and stain (>30% of root volume) first occurred at 60 years of age in balsam fir and 80 years in black spruce and white spruce. For the three species together, the proportion of trees that were dead and windfallen as a result of root rot increased from an average of 3% at 41–50 years to 13% at 71–80 years and 26% at 101–110 years. The root rot index, based on the number of dead and windfallen trees and estimated loss of merchantable volume, also increased, from an average of 17 at 41–50 years to 40 at 71–80 years and 53 at 101–110 years. Death and windfall of balsam fir and black spruce were more common in northwestern Ontario than in northeastern Ontario. Damage to balsam fir was greater in the Great Lakes–St. Lawrence Forest region than in the Boreal Forest region. In all three tree species, the degree of root rot (decay and stain) was highly correlated with the number of dead and windfallen trees, stand age, and root decay at ground level (as a percentage of basal area) for a 10-tree sample.

Distribution of epicormic branches and foliage on Douglas-fir as influenced by adjacent canopy gaps

2018 ◽  
Vol 48 (11) ◽  
pp. 1320-1330
Author(s):  
John W. Punches ◽  
Klaus J. Puettmann
Keyword(s):  
Branch Length ◽  
Canopy Gaps ◽  
Douglas Fir ◽  
Canopy Gap ◽  
Tree Age ◽  
Gap Size ◽  
Terminal Bud ◽  
Total Branch Length ◽  
A Minor ◽  
Epicormic Branches

The influence of adjacent canopy gaps on spatial distribution of epicormic branches and delayed foliage (originating from dormant buds) was investigated in 65-year-old coastal Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco). Sample trees were selected across a broad range of local densities (adjacent canopy gap sizes) from a repeatedly thinned stand in which gaps had been created 12 years prior to our study. Lengths and stem locations of original and epicormic branches were measured within the south-facing crown quadrant, along with extents to which branches were occupied by sequential (produced in association with terminal bud elongation) and (or) delayed foliage. Epicormic branches, while prevalent throughout crowns, contributed only 10% of total branch length and 2% of total foliage mass. In contrast, delayed foliage occupied over 75% of total branch length, accounted for nearly 39% of total foliage mass, and often overlapped with sequential foliage. Canopy gap size did not influence original or epicormic branch length or location. On original branches, larger gaps may have modestly negatively influenced the relative extent of sequential foliage on branches and (or) slightly positively influenced delayed foliage mass. Delayed foliage appears to contribute substantially to Douglas-fir crown maintenance at this tree age, but canopy gap size had a minor influence, at least in the short term.

scholarly journals Stand-Level Components of a Growth and Yield Model for Nothofagus Mixed Forests from Southern Chile

Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 810
Author(s):  
Sebastian Palmas ◽  
Paulo C. Moreno ◽  
Wendel P. Cropper ◽  
Alicia Ortega ◽  
Salvador A. Gezan
Keyword(s):  
Forest Type ◽  
Geographical Area ◽  
Basal Area ◽  
Forest Growth ◽  
Model Systems ◽  
Growth And Yield ◽  
Permanent Plots ◽  
Stand Age ◽  
Yield Model ◽  
Mixed Forests

Reliable information on stand dynamics and development is needed to improve management decisions on mixed forests, and essential tools for this purpose are forest growth and yield (G&Y) models. In this study, stand-level G&Y models were built for cohorts within the natural mixed second-growth Nothofagus-dominated forests in Chile. All currently available (but limited) data, consisting of a series of stratified temporary and permanent plots established in the complete range of this forest type, were used to fit and validate these models. Linear and nonlinear models were considered, where dominant stand age, number of trees, and the proportion of basal area of Nothofagus species resulted in significant predictors to project future values of stand basal area for the different cohorts (with R2 > 0.51 for the validation datasets). Mortality was successfully modeled (R2 = 0.79), based on a small set of permanent plots, using the concept of self-thinning with a proposed model defined by the idea that, as stands get closer to a maximum density, they experience higher levels of mortality. The evaluation of these models indicated that they adequately represent the current understanding of dynamics of basal area and mortality of Nothofagus and companion species in these forests. These are the first models fitted over a large geographical area that consider the dynamics of these mixed forests. It is suggested that the proposed models should constitute the main components of future implementations of G&Y model systems.

Electric Vehicle Forecasting for China from 2011 to 2050 Based on Scenario Analysis

2011 ◽  
Vol 128-129 ◽  
pp. 846-849
Author(s):  
Shi Jun Fu ◽  
Yu Long Ren
Keyword(s):  
Climate Change ◽  
Internal Combustion Engine ◽  
Electric Vehicle ◽  
Growth Model ◽  
Electric Vehicles ◽  
Scenario Analysis ◽  
Combustion Engine ◽  
Growth Period ◽  
The Difference ◽  
New Industry

With climate change being growing concerns, the development of EV (Electric Vehicles) has taken on an accelerated pace. This paper is to forecast China’s EV stock from 2011 to 2050 based on the double species growth model. We elaborate two orbits according to two scenarios: with vehicle stock being 200 and 300 per thousand people at 2050. These orbits reveals that, China’s EVs development has a golden stage which will last 10 to 11 years; And before this booming stage, there is a slowly growth period which will last 7 to 8 years. Furthermore, under each scenario, the difference between EVs and ICEVs (Internal Combustion Engine Vehicles) stock at 2030 is 4.69% to 6.77%, which confirms that China’s ambitious EVs program may be realized if government sets strong policy supports on this new industry persistently.

scholarly journals Correlations among Tree Quality, Stand Characteristics, and Site Characteristics in Plantation Teak in Mountainous Areas of Lao PDR

Forests ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 777
Author(s):  
Simone Vongkhamho ◽  
Akihiro Imaya ◽  
Chisato Takenaka ◽  
Kazukiyo Yamamoto ◽  
Hiroyuki Yamamoto
Keyword(s):  
Lao Pdr ◽  
Quality Characteristics ◽  
Present Condition ◽  
Tree Age ◽  
Stand Age ◽  
Site Characteristics ◽  
Stem Straightness ◽  
Tree Quality ◽  
Plantation Teak ◽  
Stand Characteristics

Teak (Tectona grandis Linn. f) is a globally valuable hardwood tree species whose growth performance and tree quality characteristics are controlled by various factors. Teak tree quality characteristics such as stem straightness, buttressing, and protuberant buds/knots are important in the sawing process, and directly affect timber yield, timber grade, recovery, and cost. In this study, we assessed the relationships among tree quality characteristics, stand characteristics, and site characteristics in plantation teak in the Luang Prabang province of the Lao PDR. We established 53 sample plots (20 × 20 m) and measured a total of 2149 sample trees. The stand-level tree age ranged from 10 to 31 years, and the trees were distributed in various modes of topography. The altitude ranged from 287 to 867 masl. The results of Spearman’s partial rank correlation analysis among the parameters revealed the present condition of the teak plantation forest in the region. The altitude was related to stand age and was correlated with tree quality characteristics such as epicormic shoots, mode of branching, and branch size. The correlation results suggest that higher-density plantation at the higher altitude sites might be suitable for teak plantations in this area. In addition, we found that a longer rotation in forest management might degrade tree quality.

Black Bears Prefer Urea-Fertilized Trees

1989 ◽  
Vol 4 (1) ◽  
pp. 13-15 ◽  
Author(s):  
E. E. Nelson
Keyword(s):  
Pseudotsuga Menziesii ◽  
Dominant Species ◽  
Tree Mortality ◽  
Ursus Americanus ◽  
Douglas Fir ◽  
Black Bears ◽  
National Forest ◽  
Feeding Damage ◽  
Mount Hood ◽  
The Difference

Abstract Feeding damage by black bears (Ursus americanus) to urea-fertilized 25-yr-old Douglas-firs (Pseudotsuga menziesii) in the Mount Hood National Forest, Oregon, resulted in tree mortality four times as severe as among unfertilized trees. Damage was most apparent following application of urea at 448 kg N/ha in 1972, and 224 kg N/ha in 1977. Only Douglas-fir, the dominant species in the stand, was attacked. Attacked trees were somewhat larger than the stand average, but the difference was not significant. Bears appeared to be attracted to the more vigorous trees, which were on fertilized plots. West. J. Appl. For. 4(1):13-15, January 1989.

scholarly journals Succession of mycorrhizae: a matter of tree age or stand age?

1989 ◽  
Vol 46 (Supplement) ◽  
pp. 758s-761s ◽  
Author(s):  
D. Blasius ◽  
F. Oberwinkler
Keyword(s):  
Tree Age ◽  
Stand Age

Factors controlling epiphytic lichen biomass during postfire succession in black spruce boreal forests

2009 ◽  
Vol 39 (11) ◽  
pp. 2168-2179 ◽  
Author(s):  
Catherine Boudreault ◽  
Yves Bergeron ◽  
Darwyn Coxson
Keyword(s):  
Boreal Forests ◽  
Stand Structure ◽  
Black Spruce ◽  
Tree Age ◽  
Stand Age ◽  
Epiphytic Lichens ◽  
Dominant Group ◽  
Epiphytic Lichen ◽  
Structure Tree ◽  
Species Groups

Alectorioid lichens are the dominant group of epiphytic lichens in boreal forests. Epiphytic lichen richness and abundance generally increase with stand age and within-stand heterogeneity. The objective of this study was to evaluate the importance of time elapsed since the last fire, stand structure, tree size, tree age, and branch height for epiphytic lichen biomass of the boreal forest of western Quebec. We sampled 12 sites belonging to four forest age classes (from 50 to >200 years). We assessed epiphytic lichen biomass of three species groups ( Bryoria , Evernia , and Usnea ) on 12 trees in each site. Our results showed that biomass of Bryoria and Usnea was higher in intermediate stages (between 101 and 200 years) compared with younger (50–100 years) and older (>200 years) stages. Biomass of the three species groups was greater on larger diameter trees (>16 cm) compared with smaller ones (<16 cm). These results indicate that the protection of postfire stands aged between 101 and 200 year should be prioritized to maintain the functional role of epiphytic lichens in managed landscapes.

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