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 Canopy gap edge determination and the importance of gap edges for plant diversity

Web Ecology ◽  
2002 ◽  
Vol 3 (1) ◽  
pp. 1-5 ◽  
Author(s):  
D. Salvador-Van Eysenrode ◽  
F. Kockelbergh ◽  
J. Bogaert ◽  
I. Impens ◽  
P. Van Hecke
Keyword(s):  
Fagus Sylvatica ◽  
Plant Diversity ◽  
Forest Cover ◽  
Beech Forest ◽  
Canopy Gaps ◽  
Canopy Gap ◽  
Structural Elements ◽  
Forest Patch ◽  
Young Forest ◽  
Maintenance Of Diversity

Abstract. Canopy gaps, i.e. openings in the forest cover caused by the fall of structural elements, are considered to be important for the maintenance of diversity and for the forest cycle. A gap can be considered as a young forest patch in the forest matrix, composed of interior surrounded by an edge, both enclosed by a perimeter. Much of the attention has been focused on the gap interior. However, at gap edges the spectrum of regeneration opportunities for plants may be larger than in the interior. Although definitions of gap are still discussed, any definition can describe it in an acceptable way, if justified, but defining edges is complicated and appropriate descriptors should be used. A method to determine gap interior and edge, using light as a descriptor, is presented with an example of gaps from a beech forest (Fagus sylvatica) in Belgium. Also, the relevance and implications of gap edges for plant diversity and calculation of forest turnover is discussed.

Selection of flood-resistant and susceptible seedlings of Populustrichocarpa Torr. & Gray

1988 ◽  
Vol 18 (2) ◽  
pp. 271-275 ◽  
Author(s):  
Barbara A. Smit
Keyword(s):  
Leaf Area ◽  
Marked Reduction ◽  
Branch Length ◽  
Stomatal Resistance ◽  
Growth And Survival ◽  
Seed Collection ◽  
Individual Leaf ◽  
Total Branch Length ◽  
Collection Sites ◽  
Selection Of

To identify Populustrichocarpa plants with contrasting levels of resistance to flooding, seedlings from five diverse riparian sites were evaluated for growth and survival under flooding conditions. All seedlings survived 6 or 8 weeks of flooding. Total branch length and leaf number were reduced in all flooded plants relative to nonflooded controls. There was also a marked reduction in individual leaf area and increased stomatal resistance of flooded plants compared with nonflooded controls. Growth of flooded and nonflooded plants was highly variable within populations and no significant trends were found among populations. Therefore differential responses to flooding can be selected for within any of the seed collection sites. Plants that were rated as particularly resistant or susceptible fo flooding were selected for further study.

OVERWINTERING SPRUCE BUDWORM ON BLACK SPRUCE: SAMPLE-UNIT SIZE AND POPULATION DISTRIBUTION

1985 ◽  
Vol 117 (4) ◽  
pp. 395-399 ◽  
Author(s):  
Daniel J. Robison ◽  
Lawrence P. Abrahamson ◽  
Miroslaw M. Czapowskyj ◽  
Edwin H. White ◽  
Douglas C. Allen
Keyword(s):  
Population Distribution ◽  
Black Spruce ◽  
Branch Length ◽  
Spruce Budworm ◽  
Unit Size ◽  
Optimum Size ◽  
Sample Unit ◽  
Larval Distribution ◽  
Total Branch Length ◽  
Branch Distribution

AbstractOptimum size of a sample unit and within-branch distribution of overwintering spruce budworm were determined for black spruce in northern Maine. No significant differences in sample reliability were found between whole-branch and 45-cm branch-tip samples. Larval distribution on branches varied with total branch length and a model was developed to estimate the whole-branch population from a 45-cm branch tip. Use of a 45-cm branch-tip sample unit is recommended because it is biologically and statistically valid and reduces sampling costs.

scholarly journals On Asymptotics of the Beta Coalescents

2014 ◽  
Vol 46 (2) ◽  
pp. 496-515 ◽  
Author(s):  
Alexander Gnedin ◽  
Alexander Iksanov ◽  
Alexander Marynych ◽  
Martin Möhle
Keyword(s):  
Asymptotic Expansions ◽  
Branch Length ◽  
Wasserstein Distance ◽  
Stable Limit ◽  
Initial Number ◽  
Stable Law ◽  
Total Branch Length ◽  
Coalescent Tree ◽  
Number Of Particles

We show that the total number of collisions in the exchangeable coalescent process driven by the beta (1, b) measure converges in distribution to a 1-stable law, as the initial number of particles goes to ∞. The stable limit law is also shown for the total branch length of the coalescent tree. These results were known previously for the instance b = 1, which corresponds to the Bolthausen-Sznitman coalescent. The approach we take is based on estimating the quality of a renewal approximation to the coalescent in terms of a suitable Wasserstein distance. Application of the method to beta (a, b)-coalescents with 0 < a < 1 leads to a simplified derivation of the known (2 - a)-stable limit. We furthermore derive asymptotic expansions for the moments of the number of collisions and of the total branch length for the beta (1, b)-coalescent by exploiting the method of sequential approximations.

STUDIES IN FOREST PATHOLOGY: XIV. DECAY OF DOUGLAS FIR IN THE COASTAL REGION OF BRITISH COLUMBIA

1954 ◽  
Vol 32 (5) ◽  
pp. 630-653 ◽  
Author(s):  
G. P. Thomas ◽  
R. W. Thomas
Keyword(s):  
British Columbia ◽  
Coastal Region ◽  
Douglas Fir ◽  
Tree Age ◽  
Separate Analysis ◽  
Average Amount ◽  
Old Growth ◽  
Dead Trees ◽  
Select Group ◽  
Coastal British Columbia

An investigation of Douglas fir, Pseudotsuga taxifolia (Poir.) Britton, in coastal British Columbia has shown that decay losses in old-growth stands are low, amounting to 2.6 and 7.3% of the gross volume of living and combined living and dead trees respectively. Twenty-five decay-producing fungi were isolated from living trees and 29 from dead trees. The most important of these were Fomes pini (Thore) Lloyd, Polyporus schweinitzii Fries, and Fomes pinicola (Sw.) Cke. Certain irregularities in the occurrence of decay-producing fungi and the amounts of decay associated with them were traced to the influences of site, tree age or size, latitude, and stand history. Root infections were the most frequent but branch-stub infections caused the greatest average amount of decay. An examination of tree abnormalities showed that a select group of them, sporophores and swollen knots of Fomes pini in particular, are useful indicators of hidden decay. A separate analysis of dead trees has shown that they occasion ally form a high proportion of Douglas fir stands and that much of the wood in such trees is sound.

Canopy gaps affect the shape of Douglas-fir crowns in the western Cascades, Oregon

2016 ◽  
Vol 363 ◽  
pp. 31-38 ◽  
Author(s):  
Dominik Seidel ◽  
Kenneth J. Ruzicka ◽  
Klaus Puettmann
Keyword(s):  
Canopy Gaps ◽  
Douglas Fir

Neighborhood predictors of interspecific competition in young Douglas-fir plantations

1991 ◽  
Vol 21 (6) ◽  
pp. 821-828 ◽  
Author(s):  
Robert G. Wagner ◽  
Steven R. Radosevich
Keyword(s):  
Interspecific Competition ◽  
Woody Plants ◽  
Woody Species ◽  
Spatial Arrangement ◽  
Douglas Fir ◽  
Stem Diameter ◽  
Tree Age ◽  
Percent Cover ◽  
Competition Index ◽  
Neighborhood Models

Neighborhood models describing the effect of interspecific competition on the height and stem diameter of 4- to 9-year-old saplings of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were developed from site-preparation experiments in the Oregon Coast Range. The influence of abundance measures, height, distance, arid spatial arrangement of nonconiferous woody plants surrounding individual saplings was examined. Optimum neighborhood heights and radii were defined. The best interspecific competition index for predicting Douglas-fir height and stem diameter was total percent cover for all woody species within a 2.1-m radius. Visual estimates of neighbor cover were superior to objective measures of crown area. The cover of woody species equalling or exceeding the height of the tree provided the best prediction for tree height. Woody species cover equalling or exceeding one-half the height of the tree provided the best index for predicting stem diameter. Accounting for the spatial arrangement of neighboring woody plants did not improve the competition index. Interaction between the competition index and tree age indicated that the negative effect of interspecific competition on Douglas-fir size increased with time. The age-adjusted competition index accounted for 11% of the variation in height and 19% of the variation in stem diameter. Douglas-fir stem diameter was more sensitive to neighboring woody plants than was height.

Interaction between gibberellin A4/7 and root-pruning on the reproductive and vegetative processes in Douglas-fir. III. Effects on anatomy of shoot elongation and terminal bud development

1985 ◽  
Vol 15 (2) ◽  
pp. 354-364 ◽  
Author(s):  
J. N. Owens ◽  
J. E. Webber ◽  
S. D. Ross ◽  
R. P. Pharis
Keyword(s):  
Shoot Elongation ◽  
Douglas Fir ◽  
Apical Growth ◽  
Root Pruning ◽  
Bud Development ◽  
Leaf Initiation ◽  
Terminal Bud ◽  
Terminal Buds ◽  
Effective Cone ◽  
Vegetative Bud

The relative importance of cell division and cell elongation to shoot elongation and the anatomical changes in vegetative terminal apices were assessed for 9- and 10-year-old seedlings of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) in response to two effective cone-induction treatments, gibberellin A4/7 (GA4/7) and root-pruning (RP). Root-pruning was done in mid-April at the start of vegetative bud swelling and GA treatments were begun at vegetative bud flushing in mid-May and continued until early July. Shoot elongation before flushing resulted primarily from cell divisions and was not affected by the RP treatment. Shoot elongation after flushing resulted primarily from cell expansion which was reduced by RP treatments. Root-pruning significantly slowed mitotic activity, apical growth, and development of vegetative terminal buds from mid-June through mid-July. Apical growth then resumed during leaf initiation and the final number of leaf primordia initiated was not affected. This resulted in a delay of 2 to 4 weeks in the transition from bud-scale to leaf initiation. Retarded terminal vegetative apices anatomically resembled latent axillary apices but were never completely inhibited. GA + RP had the same effect as RP. GA4/7 alone had no effect on shoot or apical development. These results show that RP and GA + RP significantly retard shoot elongation and terminal bud development but still allow normal development of vegetative terminal buds. Retardation of bud development by a few weeks shifts the critical morphogenetic phase of transition from bud scale to leaf initiation to a later time when endogenous and environmental conditions may differ from the normal.

Forest Dynamics with Canopy Gap Expansion and Stochastic Ising Model

Fractals ◽  
1998 ◽  
Vol 06 (01) ◽  
pp. 81-86 ◽  
Author(s):  
Makoto Katori ◽  
Shinya Kizaki ◽  
Youichi Terui ◽  
Takuya Kubo
Keyword(s):  
Ising Model ◽  
Forest Dynamics ◽  
Ecological Study ◽  
Gibbs State ◽  
Canopy Gap ◽  
Barro Colorado Island ◽  
Gap Size ◽  
Stochastic Ising Model ◽  
Neotropical Forest ◽  
Gap Creation

Importance of the influence of neighboring canopy gaps upon new gap creation has been clarified by the ecological study of a neotropical forest on Barro Colorado Island (BCI), Panama. A stochastic lattice model for the forest dynamics with interacting canopy gap expansion was introduced by Kubo et al. We give a theorem showing a condition that this model can be regarded as a stochastic Ising model, and that its stationary state is exactly given by a Gibbs state. Using this theorem, we obtain a Gibbs state which remarkably well approximates the real gap-size distribution in BCI.

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