scholarly journals Growth of Young Douglas-Fir Plantations Across a Gradient in Swiss Needle Cast Severity

2002 ◽  
Vol 17 (2) ◽  
pp. 86-95 ◽  
Author(s):  
Douglas A. Maguire ◽  
Alan Kanaskie ◽  
William Voelker ◽  
Randy Johnson ◽  
Greg Johnson
Keyword(s):  
Volume Growth ◽  
Basal Area ◽  
Height Growth ◽  
Douglas Fir ◽  
Site Quality ◽  
North Coast ◽  
Needle Cast ◽  
Basal Area Growth ◽  
Area Growth ◽  
Swiss Needle Cast

Abstract During the past decade, Swiss needle cast (SNC) damage has intensified in many Douglas-fir plantations in the Coast Range of Oregon, particularly along the immediate north coast. In plantations with severe symptoms, growth losses and reduced tree vigor are evident, but the magnitude of growth losses associated with varying intensities of damage is not known. A growth impact study was conducted in 1997 to quantify retrospectively the relationship between growth losses and visual symptoms in 10- to 30-yr-old Douglas-fir plantations in coastal northwestern Oregon, a population totaling 75,700 ha. A random sample of 70 Douglas-fir plantations was selected from the population and evaluated for Swiss needle cast severity. One 0.02 ha plot was destructively sampled in each plantation to reconstruct past height and basal area growth trends and to characterize foliage loss and distribution. The SNC “effect” was assessed by comparing growth of plantations with varying degrees of Swiss needle cast to growth of those that retained maximal amounts of foliage, after correcting for initial stand density, Douglas-fir growing stock, age, and site index. Of numerous possible SNC indices, mean needle retention (yr) explained the largest amount of variation in both basal area and top height growth. Prior to 1990, top height growth was similar across all plantations after correcting for site quality and plantation age; but, by 1992, top height growth losses appeared and were proportional to apparent foliage losses. In 1996, top height growth was reduced by up to 25% relative to plantations with little or no SNC. Basal area growth reductions began to appear around 1990, and in 1996 basal area growth of the most heavily damaged plantations was 35% less than the growth that would be expected in absence of SNC damage. The inferred volume growth loss for 1996 averaged 23% for the 75,700 ha target population, but this loss averaged as high as 52% for the most severely impacted plantations. West. J. Appl. For. 17(2):86ߝ95.

Growth responses to commercial thinning in Douglas-fir stands with varying severity of Swiss needle cast in Oregon, USA

2005 ◽  
Vol 35 (10) ◽  
pp. 2394-2402 ◽  
Author(s):  
Douglas B Mainwaring ◽  
Douglas A Maguire ◽  
Alan Kanaskie ◽  
Jeff Brandt
Keyword(s):  
Basal Area ◽  
Douglas Fir ◽  
Growth Responses ◽  
Infection Level ◽  
Individual Tree ◽  
Needle Cast ◽  
Commercial Thinning ◽  
Basal Area Growth ◽  
Area Growth ◽  
Swiss Needle Cast

Concern has risen about the degree to which Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands with severe infections of Swiss needle cast (SNC) respond to thinning. A retrospective study was established in the fall of 2001 to assess the growth of Douglas-fir stands that were commercially thinned between 4 and 10 years ago. Current SNC infection levels in these stands ranged from severe to very light. Past volume and basal area growth declined with increasing severity of SNC, as measured by current foliage retention and crown length / sapwood ratio. As has been observed in many other studies, thinning to lower residual stock reduced stand level growth; however, individual tree growth increased with lower residual stand density. The ratio of growth in successive periods and analysis of annual basal area growth since thinning suggested that trees did respond to thinning, although less so as SNC increased. A positive response to thinning, regardless of infection level, was confirmed by an analysis of annual trends in basal area growth over the first 5 years after thinning.

Four-year Basal Area Growth Response of a 25-year-old Douglas-fir Stand to Thinning and Urea Fertilization

1974 ◽  
Vol 4 (4) ◽  
pp. 568-571 ◽  
Author(s):  
Y. Jim Lee
Keyword(s):  
Nitrogen Fertilization ◽  
Growth Response ◽  
Basal Area ◽  
Douglas Fir ◽  
Site Quality ◽  
Growing Period ◽  
Basal Area Growth ◽  
Area Growth ◽  
Four Levels ◽  
Urea Fertilization

Four-year growth response to nitrogen fertilization and thinning is reported for an experiment established in a 25-year-old Douglas-fir stand of medium site quality. Four levels of nitrogen (0, 112, 224, and 336 kg N/ha), in the form of urea, were tested at two thinning levels in a randomized 4 × 2 × 2 factorial design replicated in 2 Blocks. Fertilizer was applied in spring or fall. Basal area growth per hectare in the thinned stand significantly surpassed that of the unthinned stand in the fourth growing period. Increased rate of nitrogen fertilization resulted in increased growth 1 year after fertilization. Urea applied in the fall resulted in greater growth response than that applied in the spring for the first growing period and over a 4-year period. Increased rate of fertilization increased mortality significantly in the fourth growing period, but had no prior effect. Thinning decreased mortality in all four growing periods.

Long-term patterns of diameter and basal area growth of old-growth Douglas-fir trees in western Oregon

2002 ◽  
Vol 32 (7) ◽  
pp. 1232-1243 ◽  
Author(s):  
Nathan J Poage ◽  
John C Tappeiner, II
Keyword(s):  
Large Diameter ◽  
Basal Area ◽  
Douglas Fir ◽  
Slope Aspect ◽  
Site Factors ◽  
Old Growth ◽  
Site Class ◽  
Basal Area Growth ◽  
Area Growth ◽  
Age Range

Diameter growth and age data collected from stumps of 505 recently cut old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees at 28 sample locations in western Oregon (U.S.A.) indicated that rapid early and sustained growth of old Douglas-fir trees were extremely important in terms of attaining large diameters at ages 100–300 years. The diameters of the trees at ages 100–300 years (D100–D300) were strongly, positively, and linearly related to their diameters and basal area growth rates at age 50 years. Average periodic basal area increments (PAIBA) of all trees increased for the first 30–40 years and then plateaued, remaining relatively high and constant from age 50 to 300 years. Average PAIBA of the largest trees at ages 100–300 years were significantly greater by age 20 years than were those of smaller trees at ages 100–300 years. The site factors province, site class, slope, aspect, elevation, and establishment year accounted for little of the variation observed in basal area growth at age 50 years and D100–D300. The mean age range for old-growth Douglas-fir at the sample locations was wide (174 years). The hypothesis that large-diameter old-growth Douglas-fir developed at low stand densities was supported by these observations.

Different nitrogen sources for fertilizing western hemlock in western Washington

1984 ◽  
Vol 14 (2) ◽  
pp. 155-162 ◽  
Author(s):  
M. A. Radwan ◽  
D. S. DeBell ◽  
S. R. Webster ◽  
S. P. Gessel
Keyword(s):  
Forest Floor ◽  
Mineral Soil ◽  
Volume Growth ◽  
Basal Area ◽  
N Fertilization ◽  
Height Growth ◽  
Growth Responses ◽  
Total N ◽  
Area Growth ◽  
Western Washington

Effects of different sources of fertilizer N on selected chemical characteristics of soils and foliage, and on growth of western hemlock (Tsugaheterophylla (Raf.) Sarg.) were compared at three different sites in western Washington. Treatments were the following: untreated control (O), ammonium nitrate (AN), ammonium sulfate (AS), calcium nitrate (CN), urea (U), and urea – ammonium sulfate (US). Fertilizers were applied in the spring (April–May) at 224 kg N/ha. Forest floor and mineral soil, to a depth of 5 cm, and foliage were sampled periodically for 2 years. Height and diameter of selected trees were measured periodically for 4 years. Results are reported mostly for two sites, one in the Cascade Range and one in the coastal zone in western Washington. The pH of forest floor and mineral soil varied by treatment, and the two urea fertilizers caused substantial initial rise. Effects on soil and foliar nutrients varied by fertilizer, sampling date, and location. In general, all fertilizers increased NH4 N, N03 N, and total N in the forest floor and mineral soil, and total N in the foliage. Also, with some exceptions, especially with foliar P in the Cascade site, fertilization reduced foliar content of important nutrients. At the Cascade site, 4-year growth responses in height, basal area, and volume averaged over all fertilizers were 30, 34, and 32%, respectively. AN, AS, CN, and urea resulted in height growth significantly (P < 0.20) higher than that of the control. Significant basal area growth and volume-growth responses were produced by AN, CN, and US. No significant height-growth response to any fertilizer occurred in the coastal stand; basal area growth and volume-growth responses averaged 27 and 21%, respectively, and best response occurred with urea. These results suggest that the low and inconsistent response of hemlock to N fertilization cannot be improved by applying some N fertilizer other than urea. Factors limiting response to N fertilization may be associated with availability of native N and other nutrients or other characteristics of hemlock sites and stands.

scholarly journals First Report of Swiss Needle Cast Caused by Phaeocryptopus gaeumannii on Douglas-Fir in Turkey

Plant Disease ◽  
2003 ◽  
Vol 87 (12) ◽  
pp. 1536-1536 ◽  
Author(s):  
F. Temel ◽  
J. K. Stone ◽  
G. R. Johnson
Keyword(s):  
North America ◽  
Volume Growth ◽  
Douglas Fir ◽  
State University ◽  
Western North America ◽  
Needle Cast ◽  
First Report ◽  
Western Asia ◽  
Swiss Needle Cast ◽  
Natural Range

Two 15-year-old Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) test plantations at Artvin, in the eastern Black Sea Coast Region of Turkey, were inspected in July 2003. Trees in both plantations had yellow-to-brown foliage, and most trees retained only the current year's needles, resulting in sparse tree crowns. Numerous minute, black fruit bodies were present along the rows of stomata on the lower surfaces of needles from both plantations. Laboratory examination revealed that the fruiting bodies that emerged through the stomata were those of Phaeocryptopus gaeumannii [Rohde] Petrak, the causal agent of Swiss needle cast (SNC). Although low infection levels are relatively harmless, heavily infected trees lose all but the current year's foliage, with resulting average volume growth reductions of 23 to 52% (2,3). The pathogen occurs throughout the natural range of Douglas-fir in western North America, where it is native, as well as in eastern North America, Europe, Australia, and New Zealand, where both host and fungus have been introduced (1,2). The pathway of introduction of the pathogen to Turkey is unknown. Douglas-fir is the only known host of P. gaeumannii, and the pathogen is not known to be seedborne. Where P. gaeumannii has been introduced outside of western North America, infected nursery stock has been considered the most probable source (1). However, the affected Artvin plantations were established with seedlings produced in Turkey by using seed obtained from various sources. Earlier Douglas-fir plantations in Turkey date from 1953 and were established by using seed originating from France. The possibility that the pathogen could have arrived with untracked Douglas-fir seedlings from outside Turkey imported by arboreta or private nurseries cannot be excluded. Alternatively, scattered Douglas-fir plantations could have served as links between the Artvin infestation and known infested areas in central and eastern Europe, with spread occurring via windborne ascospores, similar to the spread of the pathogen to Denmark from the British Isles (ca. 1930) (1). Presence of severe SNC infections in Douglas-fir test sites at Artvin could hamper efforts to use this species in operational forestry in Turkey. To our knowledge, this is the first report of the occurrence of Swiss needle cast on Douglas-fir in western Asia. Voucher specimens have been deposited in the Oregon State University herbarium (OSC 106394-106403). References: (1) J. S. Boyce. Phytopathology 30:649, 1940. (2) E. M. Hansen et al. Plant Dis. 84:773, 2000. (3) D. Maguire et al. West. J. Appl. For. 17:86, 2002.

scholarly journals Assessing Differences in Competitive Effects Among Tree Species in Central British Columbia, Canada

Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 167
Author(s):  
Stella Britwum Acquah ◽  
Peter L. Marshall
Keyword(s):  
Tree Species ◽  
Lodgepole Pine ◽  
Basal Area ◽  
Douglas Fir ◽  
Competitive Effects ◽  
Basal Area Growth ◽  
Interior Spruce ◽  
Area Growth ◽  
Different Levels ◽  
Over Time

Research Highlights: We investigated the competitive interactions among three tree species (interior Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco), interior spruce (Picea glauca [Moench] Voss × Picea engelmannii Engelm.), and lodgepole pine (Pinus contorta Dougl. Ex Loud. var. latifolia Englem.)) in multi-aged stands in central British Columbia, Canada. Background and Objectives: Understanding competitive interactions among tree species in mixed-species stands is fundamental to supporting silvicultural decision-making in such stands. Using the periodic annual basal area increment for single trees as our dependent variable, we investigated whether neighboring trees competed with subject trees independently of species identity. We also examined the differences in single-tree basal area growth among the three conifer species over time under different levels of competition. Materials and Methods: We developed several spatially explicit, single-tree basal area growth models for interior Douglas-fir, interior spruce, and lodgepole pine using data from 16 plots in two blocks of a long-term study (five measurements over a 21-year period) on the response to pre-commercial thinning. We compared these equations to assess whether intraspecific or interspecific competition predominated. We also examined the differences in basal area growth among the three conifer species over time under different levels of competition. Results: We found asymmetrical relationships between the conifer trees and their neighbors for all species, indicating that the main driver limiting growth in these stands is aboveground competition for light. There was evidence of higher intraspecific competition for small (<10.0 cm DBH) interior Douglas-fir in one block. However, there was no general pattern among larger subject trees with respect to the identity of neighborhood competitive effects and the equivalence of neighbors. We observed a higher level of basal area growth over time for interior Douglas-fir than for lodgepole pine and interior spruce, irrespective of the competition intensity and, not surprisingly, the growth rate declined with increasing competition levels for the three species. Conclusions: Our results provide an understanding of how interior Douglas-fir stands will develop over time and information on species interactions that could help forest managers explore different silvicultural options and their effects on individual tree growth in these complex stands.

Basal Area and Volume Development of Natural Even-Aged Shortleaf Pine Stands in the Ouachita Mountains

1992 ◽  
Vol 16 (1) ◽  
pp. 30-34 ◽  
Author(s):  
Paul A. Murphy ◽  
Edwin R. Lawson ◽  
Thomas B. Lynch
Keyword(s):  
Initial Conditions ◽  
Volume Growth ◽  
Basal Area ◽  
Pinus Echinata ◽  
Shortleaf Pine ◽  
Ouachita Mountains ◽  
Annual Increment ◽  
Basal Area Growth ◽  
Area Growth ◽  
Mean Annual Increment

Abstract Shortleaf pine (Pinus echinata Mill.) stands, average age 41 years, were thinned to different density levels (45 to 125 ft² of basal area in increments of 20 ft²). The stands received no further thinning. Equations for projected volumes and basal area per acre given initial conditions were formulated and fitted. The following trends were observed using the equations. Over a 24-year period, total basal area growth per acre started out over 2 ft² and had declined to less than 2 ft² by the end. Annual basal area growth had already culminated by age 41. Total annual cubic-foot volume growth per acre depended largely on initial stocking. The initial stocking and subsequent growth of the sawtimber portion were not related to the thinning treatments. Although sawtimber periodic annual cubic-foot growth culminated during the period under study, board-foot growth did not, indicating that mean annual increment for board-foot volumes had not culminated by age 64. South. J. Appl. For. 16(1):30-34.

scholarly journals EVALUATING THE COMPETITIVE ENVIRONMENT FOR WILD PISTACHIO (Pistacia atlantica Desf.) SEEDLINGS IN THE CENTRAL FORESTS OF IRAN

2018 ◽  
Vol 42 (6) ◽  
Author(s):  
Bahman Kiani ◽  
Asma Amiri
Keyword(s):  
Basal Area ◽  
Height Growth ◽  
Good Precision ◽  
Pistacia Atlantica ◽  
Basal Area Growth ◽  
Area Growth ◽  
Amygdalus Scoparia ◽  
The Relationship ◽  
Area Development ◽  
Competition Indices

ABSTRACT Wild pistachio (Pistacia atlantica Desf.) is an important tree species from dry forests of Eurasia. Seedlings must usually compete with other tree and shrub species in the dry harsh environment of mountain forests. In this study, we identified the main competitor species and evaluated some widely used competition indices, including distance-dependent and distance-independent ones, to quantify the relationship between the reference seedlings and their neighbors. The results indicated that the main competitors are mountain almond (Amygdalus scoparia Spach.), thorny almond (Amygdalus lycioides Spach.), montpellier maple (Acer monspessulanum subsp. cinerascens Boiss.) and other wild pistachio seedlings. We found that competition increases the height growth but reduces the diameter, basal area growth and crown development of wild pistachio seedlings. Some competition indices had a noticeable correlation with seedling growth, indicating that competition does exist. A combination of log-transformed indices could explain 85% of the diameter growth variations, 46% of height growth, 76% of basal area growth and 72% of crown area development with a good precision.

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