Models for describing basal diameter and vertical distribution of primary branches in young Douglas-fir

1994 ◽  
Vol 63 (1) ◽  
pp. 23-55 ◽  
Author(s):  
D.A. Maguire ◽  
M. Moeur ◽  
W.S. Bennett
Keyword(s):  
Vertical Distribution ◽  
Douglas Fir ◽  
Basal Diameter

scholarly journals Shifts in Foliage Biomass and Its Vertical Distribution in Response to Operational Nitrogen Fertilization of Douglas-Fir in Western Oregon

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 511 ◽  
Author(s):  
Jacob D. Putney ◽  
Douglas A. Maguire
Keyword(s):  
Vertical Distribution ◽  
Nitrogen Fertilization ◽  
N Fertilization ◽  
Douglas Fir ◽  
Tree Level ◽  
Stem Volume ◽  
Parameter Estimates ◽  
Growth Responses ◽  
Basal Diameter ◽  
Dormant Season

Nitrogen (N) fertilization is a commonly applied silvicultural treatment in intensively managed coast Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) plantations. Field trials were established in a randomized complete block design by Stimson Lumber Company (Gaston, Oregon), to test the economic viability of N fertilization on their ownership and to better understand Douglas-fir growth responses. The 23 stands comprising the trials were Douglas-fir dominated, had a total age of 16–24 years, had been precommercially thinned, and had a density of 386–1021 trees ha−1. Fertilizer was applied aerially at a rate of 224 kg N ha−1 as urea during the 2009–2010 dormant season. In the dormant season of 2016–2017, seven growing seasons following application, 40 trees were felled and measured with the objective of assessing crown attributes and aboveground allometrics. Branch-level foliage mass equations were developed from 267 subsampled branches and were applied to the 40 felled sample trees on which the basal diameter and height of all live branches were measured, allowing estimation of both the total amount of foliage and its vertical distribution. A right-truncated Weibull distribution was fitted to data, with the truncation point specified as the base of live tree crown. The resulting tree-level parameter estimates were modeled as functions of tree-level variables. Stand-level factors not explicitly measured were captured through the use of linear and nonlinear mixed-effects models with random stand effects. Fertilization resulted in more total crown foliage mass in the middle crown-third and caused a downward shift in the vertical distribution of foliage, with implications for feedback responses in crown development and photosynthetic capacity. Defining the morphological responses of Douglas-fir crowns to nitrogen fertilization provides a framework for studying influences on stand dynamics and should ultimately facilitate improved site-specific predictions of stem-volume growth.

Influence of Swiss needle cast on foliage age-class structure and vertical foliage distribution in Douglas-fir plantations in north coastal Oregon

2006 ◽  
Vol 36 (6) ◽  
pp. 1497-1508 ◽  
Author(s):  
Aaron R Weiskittel ◽  
Douglas A Maguire ◽  
Sean M Garber ◽  
Alan Kanaskie
Keyword(s):  
Vertical Distribution ◽  
Douglas Fir ◽  
Parameter Estimates ◽  
Class Structure ◽  
Needle Cast ◽  
Age Class ◽  
Relative Contribution ◽  
Crown Structure ◽  
Growth Decline ◽  
Swiss Needle Cast

Swiss needle cast (SNC) causes premature loss of foliage and subsequent growth decline in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). Although the mechanisms leading to this growth decline include loss of photosynthetic surface area and physiological disruption of surviving foliage, estimating the relative contribution of these two primary sources requires precise quantification of SNC effects on total foliage mass, foliage age-class structure, and vertical foliage distribution. The effect of SNC severity on these crown structural attributes was tested across a range of stand densities and site qualities in 10- to 60-year-old plantations in north coastal Oregon. Foliage mass in each age-class was sampled at the branch level, and the resulting equations were applied to all live branches on intensively measured sample trees. Vertical distribution of each foliage age-class was described by a beta distribution fitted to each sample tree, and sources of variation in vertical distribution were tested by regressing beta parameter estimates on SNC intensity and other covariates representing tree, stand, and site attributes. Distribution of foliage mass by age-class and by relative height in the crown was significantly affected by SNC severity, in addition to other covariates such as crown size and tree social position. SNC caused a reduction in the amount of foliage in each age-class and greater relative representation of younger needles. SNC also shifted the mode of relative vertical distribution toward the top of the tree for the three youngest foliage age-classes, but toward the base of the crown for 4- and 5-year-old foliage. Quantification of foliage age-class structure and vertical distribution across a range of SNC severity has helped to establish diagnostic criteria for assessing changes in crown structure that precede declines in growth and vigor. The induced changes in crown structure will also help to identify the relative contribution of several mechanisms causing growth losses in diseased trees.

Patterns in vertical distribution of foliage in young coastal Douglas-fir

1996 ◽  
Vol 26 (11) ◽  
pp. 1991-2005 ◽  
Author(s):  
Douglas A. Maguire ◽  
William S. Bennett
Keyword(s):  
Vertical Distribution ◽  
Leaf Area ◽  
Stand Structure ◽  
Douglas Fir ◽  
Parameter Estimates ◽  
Relative Height ◽  
Structure Variation ◽  
Sapwood Area ◽  
Forest Stand Structure ◽  
Wide Range

Total amount and vertical distribution of foliage represent important aspects of forest stand structure and its influence on dry matter productivity, forest microclimate, watershed properties, and habitat structure. Variation in foliage distribution was analyzed on trees and plots in a series of even-aged Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stands scheduled for management under a wide range of silvicultural regimes. Branch-level foliage mass and foliage area equations were developed from a sample of 138 branches. These equations were applied to 27 trees on which the diameter and height of all live primary branches were measured, allowing estimation of both the total amount of foliage and its vertical distribution. A β-distribution was fitted to data describing the vertical distribution of foliage on each tree, and the resulting parameter estimates were modelled as functions of tree height, diameter at breast height, crown length, and relative height in the stand. Foliage area distribution tended to be shifted downward relative to foliage mass because of the expected increase in specific leaf area with depth into the crown. Similarly, the relative foliage distribution in terms of both mass and area was shifted downward as the tree became more dominant, or as relative height in the stand increased. In contrast, foliage on trees of similar relative height was shifted upward in response to the lower stand densities imposed by precommercial thinning. On the stand level, relative vertical distribution of foliage in the canopy was more peaked than would be implied by assuming a constant leaf area/sapwood area ratio throughout the composite tree crowns. Between-stand variation in vertical foliage distribution was dictated by differences in stand top height, height to crown base, and number of trees per hectare.

Slashburning effects on stocking, growth, and nutrition of young Douglas-fir plantations in salal-dominated ecosystems of eastern Vancouver Island

1988 ◽  
Vol 18 (6) ◽  
pp. 718-722 ◽  
Author(s):  
R. E. Vihnanek ◽  
T. M. Ballard
Keyword(s):  
Vancouver Island ◽  
Height Growth ◽  
Douglas Fir ◽  
Diameter Growth ◽  
Basal Diameter ◽  
Nutrient Levels ◽  
Growth And Nutrition ◽  
Foliar Nutrient ◽  
Foliar Concentrations ◽  
Mn Concentrations

Stocking, height growth, basal diameter growth, and foliar nutrient levels of 5- to 15-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were evaluated on burned and unburned areas within each of 20 sites on eastern Vancouver Island, which were characterized by ecosystems dominated by salal (Gaultheriashallon Pursh). Burning significantly reduced salal height and cover (P < 0.01). Douglas-fir stocking, height growth, and basal diameter were significantly increased (P < 0.05) as a result of burning. Douglas-fir foliar P, K, Ca, Fe, and B concentrations were significantly increased (P < 0.05) as a result of burning, but foliar concentrations of N, Mg, S, Zn, and Cu were not significantly affected, even at P = 0.10. Foliar Mn concentrations were significantly reduced but remained very far above the deficiency threshold.

Competitive interactions of whiteleaf manzanita, herbs, Douglas-fir, and ponderosa pine in southwest Oregon

1989 ◽  
Vol 19 (2) ◽  
pp. 232-238 ◽  
Author(s):  
Diane E. White ◽  
Michael Newton
Keyword(s):  
Leaf Area ◽  
Ponderosa Pine ◽  
Canopy Cover ◽  
Douglas Fir ◽  
Stem Volume ◽  
Density Level ◽  
Mixed Stands ◽  
Area Index ◽  
Basal Diameter ◽  
Canopy Volume

Whiteleaf manzanita (Arctostaphylosviscida Parry) was established on three sites at densities ranging from 0 to 27 000 seedlings/ha in 2-year-old mixed stands of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and ponderosa pine (Pinusponderosa Dougl. ex Laws.). Invading herbs were controlled by spraying all plots, except one at each site at the 13 500 manzanita/ha density level. Intraspecific manzanita competition reduced individual shrub basal diameter, leaf area, biomass, and canopy volume by the 3rd year of our study. In contrast, these variables increased at the highest density in the manzanita stand. Stem volume of 5-year-old conifers was reduced in relation to manzanita density, biomass, leaf area index, and canopy cover. The presence of herbaceous vegetation reduced both manzanita and conifer growth by the 3rd year.

Modelling number, vertical distribution, and size of live branches on coniferous tree species in British Columbia

2012 ◽  
Vol 42 (6) ◽  
pp. 1072-1090 ◽  
Author(s):  
Amanda F. Linnell Nemec ◽  
Roberta Parish ◽  
James W. Goudie
Keyword(s):  
Vertical Distribution ◽  
Poisson Process ◽  
Pseudotsuga Menziesii ◽  
Tree Species ◽  
Lodgepole Pine ◽  
Douglas Fir ◽  
Nonhomogeneous Poisson Process ◽  
Coniferous Tree ◽  
Mixed Effect ◽  
Coniferous Tree Species

A compound, nonhomogeneous Poisson process was used to model the number, vertical distribution, and size of branches on four coniferous tree species: 134 western hemlock ( Tsuga heterophylla (Raf.) Sarg.) on six sites, 45 amabilis fir ( Abies amabilis Douglas ex J. Forbes) (three sites), 60 lodgepole pine ( Pinus contorta var. latifolia Engelm. ex S. Watson) (six sites), and 60 white spruce ( Picea glauca (Moench) Voss) trees (five sites) and two varieties: 66 coastal Douglas-fir ( Pseudotsuga menziesii var. menziesii (Mirb.) Franco) (five sites) and 50 interior Douglas-fir ( Pseudotsuga menziesii var. glauca (Mayr) Franco) (four sites). Branches of these species are typically more or less clustered and have a characteristic, nonuniform vertical distribution along annual shoots. Total number and relative positions of clusters varied with shoot age. Clustering patterns in three of four species and two varieties appeared to scale proportionally with shoot length. However, in lodgepole pine, which has fewer clusters per metre and more branches per cluster, the vertical distribution of clusters along shoots ≤5 years old was consistent with a gamma-Poisson model but converged to a nonhomogeneous Poisson process model in shoots >5 years old. Separate mixed-effect regression models were developed for each species relating length and diameter of live branches to tree (crown), shoot, and branch (cluster) predictor variables.

scholarly journals Influence of Ash Substrate Proximity on Growth and Survival of Planted Mixed-Conifer Seedlings

2009 ◽  
Vol 24 (3) ◽  
pp. 117-123 ◽  
Author(s):  
Robert A. York ◽  
Zachary Thomas ◽  
Joseph Restaino
Keyword(s):  
Sierra Nevada ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Douglas Fir ◽  
Mixed Conifer ◽  
Basal Diameter ◽  
Growth And Survival ◽  
Sugar Pine ◽  
Giant Sequoia ◽  
Height Gain

Abstract To address uncertainty in the performance of seedlings planted in and around postburn substrates, we systematically planted seedlings in the center of, on the edge of, and outside ash substrate footprints following burning of logging residue piles and monitored growth and survival for a decade. Five species (Douglas-fir [Pseudotsuga menziesii], giant sequoia [Sequoiadendron giganteum], incense-cedar [Calocedrus decurrens], sugar pine [Pinus lambertiana], and ponderosa pine [Pinus ponderosa]) were planted in a regenerating mixed-conifer stand in the Sierra Nevada range of California. There was a positive effect of ash substrate proximity on growth that was immediate and persisted for 10 years for every species except incense-cedar. Seedlings planted in the centers of ash substrates consistently outgrew (in both height and basal diameter) seedlings that were planted either on the edges of or outside ash substrates. Douglas-fir had the greatest height gain (+47%), followed by giant sequoia (+28%), sugar pine (+23%), and ponderosa pine (+17%). Basal diameter differences were similar. No effect of ash proximity on survival was detected. Planting seedlings in the centers of ash substrates led to exceptionally larger trees by the time the stand had developed enough to apply a precommercial thin, a relevant milestone for managed stands.

Vertical Distribution of Xiphinemabakeri Nematodes in Soil in a Douglas-fir Nursery

1974 ◽  
Vol 4 (2) ◽  
pp. 175-178
Author(s):  
Jack R. Sutherland
Keyword(s):  
Moisture Content ◽  
Vertical Distribution ◽  
Distribution Pattern ◽  
Seasonal Changes ◽  
Root Distribution ◽  
Pore Space ◽  
Douglas Fir ◽  
Soil Samples ◽  
Nematode Control ◽  
The Vertical Distribution

Soil samples were collected throughout the year to determine the vertical distribution of Xiphinemabakeri nematodes in soil in a Douglas-fir [Pseudotsugamenziesii (Mirb.) Franco] nursery and to monitor seasonal changes in nematode distribution pattern. Root distribution, moisture content, available pore space, and osmotic pressure were also determined for soil samples taken at various depths to see if they were related to nematode distribution. More than 90% of the nematodes were present in the upper 20 cm of soil, especially from 0 to 10 cm, and this percentage did not change with season. Nematode distribution was related only to root distribution. The significance of the results for nematode control practices is discussed.

Branch surface area and its vertical distribution in coastal Douglas-fir

Trees ◽  
2006 ◽  
Vol 20 (6) ◽  
pp. 657-667 ◽  
Author(s):  
Aaron R. Weiskittel ◽  
Douglas A. Maguire
Keyword(s):  
Vertical Distribution ◽  
Surface Area ◽  
Douglas Fir
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