Conifer seed predation in harvested and burned dry Douglas-fir forests in southern British Columbia

2009 ◽  
Vol 39 (8) ◽  
pp. 1548-1556 ◽  
Author(s):  
David J. Huggard ◽  
André Arsenault
Keyword(s):  
Pinus Ponderosa ◽  
Seed Predation ◽  
Ponderosa Pine ◽  
Natural Regeneration ◽  
Woody Debris ◽  
Survival Rates ◽  
Forest Litter ◽  
Douglas Fir ◽  
Burned Area ◽  
Clear Cut

Consumption of seeds of Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) and ponderosa pine ( Pinus ponderosa Dougl. ex P. & C. Laws.) was measured in dry Douglas-fir forest at the Opax Mountain Silvicultural Systems site and a nearby burned area as one component of understanding limited natural regeneration in these sites. Seeds were placed in plots surrounded by a physical barrier to invertebrates, enclosed in mesh impermeable to small mammals, covered by litter, or unprotected in clear-cut, partially harvested, uncut, and burned areas and monitored for three several-day sessions in 2 years. Daily survival rates of unprotected seeds of both species were equally low: 0.63 in uncut forest, 0.45 in partially harvested and clear-cut sites, and 0.03 in the burned area. Experimental reductions of coarse woody debris reduced seed predation moderately in patch cuts but not in uncut forest. Litter cover or selective exclosure of ground-dwelling invertebrates reduced seed losses only slightly, whereas small mammal exclosures eliminated most seed loss. Deer mice ( Peromyscus maniculatus Wagner) are likely the most important seed predators. High rates of seed predation in dry Douglas-fir forests likely limit natural regeneration in harvested and burned stands.

Multicentury history of western spruce budworm outbreaks in interior Douglas-fir forests near Kamloops, British Columbia

2006 ◽  
Vol 36 (7) ◽  
pp. 1758-1769 ◽  
Author(s):  
Rochelle Campbell ◽  
Dan J Smith ◽  
André Arsenault
Keyword(s):  
British Columbia ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Survival Rates ◽  
Spruce Budworm ◽  
Douglas Fir ◽  
Western Spruce Budworm ◽  
Air Temperatures ◽  
Forest Sites ◽  
History Of

Western spruce budworm (Choristoneura occidentalis Freeman) is a native defoliator of forests in the interior Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) forests of British Columbia, Canada. Dendrochronological techniques and the software program OUTBREAK were used to reconstruct a defoliation history of Douglas-fir for 19 forest sites near Kamloops in central British Columbia. By comparing the radial-growth response of ponderosa pine (Pinus ponderosa Dougl. ex P. Laws. & C. Laws.) with that of Douglas-fir growing in nearby but separate stands, eight western spruce budworm outbreaks over the past 300 years were distinguished. Although there is considerable variation in the timing and duration of these western spruce budworm events at the stand level, synchronous outbreaks have occurred in approximately 30- to 43-year cycles. Spectral analyses of a composite time series from all stands showed similar and consistent intervals between outbreaks. Climatic variation appears to have been important to budworm outbreaks in the 20th century. Notable outbreaks tended to occur during years with average spring air temperatures following winters with less than average precipitation. Based on this finding, it is proposed that with high over-winter survival rates and a longer growing season, the duration of outbreaks may increase in the future.

A field experiment informs expected patterns of conifer regeneration after disturbance under changing climate conditions

2015 ◽  
Vol 45 (11) ◽  
pp. 1607-1616 ◽  
Author(s):  
Monica T. Rother ◽  
Thomas T. Veblen ◽  
Luke G. Furman
Keyword(s):  
Field Experiment ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Douglas Fir ◽  
Tree Regeneration ◽  
Colorado Front Range ◽  
Front Range ◽  
Average Growth ◽  
Growth And Survival ◽  
Treatment Type

Climate change may inhibit tree regeneration following disturbances such as wildfire, altering post-disturbance vegetation trajectories. We implemented a field experiment to examine the effects of manipulations of temperature and water on ponderosa pine (Pinus ponderosa Douglas ex P. Lawson & C. Lawson) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings planted in a low-elevation, recently disturbed setting of the Colorado Front Range. We implemented four treatments: warmed only (Wm), watered only (Wt), warmed and watered (WmWt), and control (Co). We found that measures of growth and survival varied significantly by treatment type. Average growth and survival was highest in the Wt plots, followed by the Co, WmWt, and Wm plots, respectively. This general trend was observed for both conifer species, although average growth and survival was generally higher in ponderosa pine than in Douglas-fir. Our findings suggest that warming temperatures and associated drought are likely to inhibit post-disturbance regeneration of ponderosa pine and Douglas-fir in low-elevation forests of the Colorado Front Range and that future vegetation composition and structure may differ notably from historic patterns in some areas. Our findings are relevant to other forested ecosystems in which a warming climate may similarly inhibit regeneration by dominant tree species.

scholarly journals Root Volume and Growth of Ponderosa Pine and Douglas-Fir Seedlings: A Summary of Eight Growing Seasons

1997 ◽  
Vol 12 (3) ◽  
pp. 69-73 ◽  
Author(s):  
R. Rose ◽  
D. L. Haase ◽  
F. Kroiher ◽  
T. Sabin
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Douglas Fir ◽  
Stem Volume ◽  
Coast Range ◽  
Root Volume ◽  
Growth And Survival ◽  
Growing Seasons ◽  
Early Results

Abstract This is the final summary of two studies on the relationship between root volume and seedling growth; early results were published previously. Survival, growth, and stem volume were determined for 2+0 ponderosa pine (Pinus ponderosa) and Douglas-fir (Pseudotsuga menziesii) seedlings after 8 growing seasons. For each species, seedlings from three seedlots were assigned to one of three root-volume categories [<4.5 cm3 (RV1), 4.5-7 cm3 (RV2), and >7 cm3 (RV3) for ponderosa pine; <9 cm3 (RV1), 9-13 cm3 (RV2), and >13 cm3 (RV3) for Douglas-fir]. On a dry harsh ponderosa pine site on the eastern slopes of Mt. Hood in Oregon, where gopher and cattle damage decreased the number of seedlings, more seedlings in the highest root-volume category survived (70%) than in the smaller root-volume categories (62% and 50%). Douglas-fir on a good site in the Coast Range of Oregon showed significantly greater height and stem volume for the largest root-volume category, whereas annual shoot growth and survival did not differ. Root volume is one of several potentially useful criteria for predicting long-term growth and survival after outplanting. West. J. Appl. For. 12(3):69-73.

Diversity and host specificity of ectomycorrhizal fungi retrieved from three adjacent forest sites by five host species

1999 ◽  
Vol 77 (8) ◽  
pp. 1053-1076 ◽  
Author(s):  
H B Massicotte ◽  
R Molina ◽  
L E Tackaberry ◽  
J E Smith ◽  
M P Amaranthus
Keyword(s):  
Pseudotsuga Menziesii ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Host Species ◽  
Ectomycorrhizal Fungus ◽  
Douglas Fir ◽  
Abies Grandis ◽  
Forest Sites ◽  
Fungal Propagules ◽  
Arbutus Menziesii

Seedlings of Abies grandis (Dougl.) Lindl. (grand fir), Lithocarpus densiflora (Hook. & Arn.) Rehd. (tanoak), Pinus ponderosa Dougl. ex Laws. (ponderosa pine), Pseudotsuga menziesii (Mirb.) Franco (Douglas-fir), and Arbutus menziesii Pursh (madrone) were planted in mixture and monoculture in soil collected from three adjacent forest sites in southwestern Oregon (a clearcut area, a 25-year-old Douglas-fir plantation, and a mature 90- to 160-year-old Douglas-fir - pine forest) to determine the effect of host tree diversity on retrieval of ectomycorrhizal morphotypes. In this greenhouse bioassay, 18 morphotypes of mycorrhizae were recognized overall from all soils with a total of 55 host-fungus combinations: 14 types with ponderosa pine, 14 with Douglas-fir, 10 with tanoak, 10 with grand fir, and 7 for madrone. Four genus-specific morphotypes were retrieved (three on ponderosa pine and one on Douglas-fir), even in mixture situations, demonstrating selectivity of some fungal propagules by their respective host. Five types were detected on all hosts, but not necessarily in soils from all sites. The remaining nine types were associated with two, three, or four hosts, which indicates a wide potential for interspecific hyphal linkages between trees. More morphotypes were retrieved from the monoculture treatments compared with the mixture treatments, although the differences were not significant. Several examples of acropetal replacement of one fungus by another (interpreted as succession) were recorded on all hosts during the course of the experiment. These results illustrate the importance of different host species in maintaining ectomycorrhizal fungus diversity, especially fungi with restricted host range, and the strong potential for fungal linkages between trees in forest ecosystems.Key words: fungal succession, fungal communities, compatibility, Arbutus menziesii, Pseudotsuga menziesii, Pinus ponderosa, Abies grandis, Lithocarpus densiflora.

Effects of fuel morphology on ember generation characteristics at the tree scale

2020 ◽  
Vol 29 (11) ◽  
pp. 1042
Author(s):  
Tyler R. Hudson ◽  
Ryan B. Bray ◽  
David L. Blunck ◽  
Wesley Page ◽  
Bret Butler
Keyword(s):  
Mass Loss ◽  
Pseudotsuga Menziesii ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Douglas Fir ◽  
Biological Factors ◽  
Abies Grandis ◽  
Western Juniper ◽  
Juniperus Occidentalis ◽  
Spot Fires

This work reports characteristics of embers generated by torching trees and seeks to identify the important physical and biological factors involved. The size of embers, number flux and propensity to ignite spot fires (i.e. number flux of ‘hot’ embers) are reported for several tree species under different combinations of number (one, three or five) and moisture content (11–193%). Douglas-fir (Pseudotsuga menziesii), grand fir (Abies grandis), western juniper (Juniperus occidentalis) and ponderosa pine (Pinus ponderosa) trees were evaluated. Embers were collected on an array of fire-resistant fabric panels and trays filled with water. Douglas-fir trees generated the highest average ember flux per kilogram of mass loss during torching, whereas grand fir trees generated the highest ‘hot’ ember flux per kilogram of mass loss. Western juniper produced the largest fraction of ‘hot’ embers, with ~30% of the embers generated being hot enough to leave char marks. In contrast, only 6% of the embers generated by ponderosa pine were hot enough to leave char marks. Results from this study can be used to help understand the propensity of different species of tree to produce embers and the portion of embers that may be hot enough to start a spot fire.

Woody debris and tree regeneration dynamics following severe wildfires in Arizona ponderosa pine forests

2012 ◽  
Vol 42 (3) ◽  
pp. 593-604 ◽  
Author(s):  
John P. Roccaforte ◽  
Peter Z. Fulé ◽  
W. Walker Chancellor ◽  
Daniel C. Laughlin
Keyword(s):  
Pinus Ponderosa ◽  
Forest Fires ◽  
Ponderosa Pine ◽  
Woody Debris ◽  
Climatic Conditions ◽  
Pine Forest ◽  
Tree Regeneration ◽  
Forest Recovery ◽  
Regeneration Dynamics ◽  
Ponderosa Pine Forests

Severe forest fires worldwide leave behind large quantities of dead woody debris and regenerating trees that can affect future ecosystem trajectories. We studied a chronosequence of severe fires in Arizona, USA, spanning 1 to 18 years after burning to investigate postfire woody debris and regeneration dynamics. Snag densities varied over time, with predominantly recent snags in recent fires and broken or fallen snags in older fires. Coarse woody debris peaked at > 60 Mg/ha in the time period 6–12 years after fire, a value higher than previously reported in postfire fuel assessments in this region. However, debris loadings on fires older than 12 years were within the range of recommended management values (11.2–44.8 Mg/ha). Overstory and regeneration were most commonly dominated by sprouting deciduous species. Ponderosa pine ( Pinus ponderosa C. Lawson var. scopulorum Engelm.) overstory and regeneration were completely lacking in 50% and 57% of the sites, respectively, indicating that many sites were likely to experience extended periods as shrublands or grasslands rather than returning rapidly to pine forest. More time is needed to see whether these patterns will remain stable, but there are substantial obstacles to pine forest recovery: competition with sprouting species and (or) grasses, lack of seed sources, and the forecast of warmer, drier climatic conditions for coming decades.

Water stress and survival of three species of conifer seedlings planted on a high elevation south-facing clear-cut

1987 ◽  
Vol 17 (9) ◽  
pp. 1115-1123 ◽  
Author(s):  
N. J. Livingston ◽  
T. A. Black
Keyword(s):  
Survival Rates ◽  
High Elevation ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Silver Fir ◽  
High Survival ◽  
High Survival Rate ◽  
Poor Survival ◽  
Tolerance Mechanisms ◽  
Clear Cut

Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), western hemlock (Tsugaheterophylla (Raf.) Sarg.), and Pacific silver fir (Abiesamabilis (Dougl.) Forbes) container-grown 1-0 seedlings were spring planted on a south-facing high elevation clear-cut located on Mount Arrowsmith, Vancouver Island, British Columbia. Treatments, which included inclining seedlings to the southwest, provision of shade cards, irrigation, and irrigation and shade cards combined, were applied to determine whether modification of seedling microclimate would increase survival. Highest survival rates, regardless of treatment, were shown by Douglas-fir. By April 1984, 72 and 82% of untreated Douglas-fir seedlings planted in 1981 and 1982, respectively, survived, whereas survival of treated seedlings ranged from 81 to 95%. The high survival rate in Douglas-fir appeared to be due to their high drought tolerance. The osmotic potential of unirrigated Douglas-fir seedlings declined by over 1.1 MPa during the course of the 1982 growing season in response to decreasing soil water potentials and consequently turgor was maintained in the foliage. Transpiration rates of these seedlings were never less than 50% of those that were irrigated. Western hemlock and Pacific silver fir seedlings exhibited very poor survival, possibly owing to the lack of stress avoidance and tolerance mechanisms. Survival rates of the two species were increased by shade cards and irrigation but never exceeded 64%.

Canopy characteristics and growth rates of ponderosa pine and Douglas-fir at long-established forest edges

2007 ◽  
Vol 37 (11) ◽  
pp. 2096-2105 ◽  
Author(s):  
Kelsey Sherich ◽  
Amy Pocewicz ◽  
Penelope Morgan
Keyword(s):  
Leaf Area ◽  
Pinus Ponderosa ◽  
Growth Rates ◽  
Ponderosa Pine ◽  
Stand Density ◽  
Growth Efficiency ◽  
Forest Edge ◽  
Douglas Fir ◽  
Forest Edges ◽  
Sapwood Area

Trees respond to edge-to-interior microclimate differences in fragmented forests. To better understand tree physiological responses to fragmentation, we measured ponderosa pine ( Pinus ponderosa Dougl. ex P. & C. Laws) and Douglas-fir ( Pseudotsuga menziesii (Mirbel) Franco) leaf area, crown ratios, sapwood area, basal area (BA) growth rates, and BA growth efficiency at 23 long-established (>50 year) forest edges in northern Idaho. Trees located at forest edges had more leaf area, deeper crowns, higher BA growth rates, and more sapwood area at breast height than interior trees. Ponderosa pine had significantly higher BA growth efficiency at forest edges than interiors, but Douglas-fir BA growth efficiency did not differ, which may relate to differences in photosynthetic capacity and drought and shade tolerance. Edge orientation affected BA growth efficiency, with higher values at northeast-facing edges for both species. Edge effects were significant even after accounting for variation in stand density, which did not differ between the forest edge and interior. Although edge trees had significantly greater canopy depth on their edge-facing than forest-facing side, sapwood area was evenly distributed. We found no evidence that growing conditions at the forest edge were currently subjecting trees to stress, but higher leaf area and deeper crowns could result in lower tolerance to future drought conditions.

Symptom expression in conifers infected with Armillaria ostoyae and Heterobasidion annosum

2004 ◽  
Vol 34 (6) ◽  
pp. 1210-1219 ◽  
Author(s):  
Daniel W Omdal ◽  
Charles G Shaw, III ◽  
William R Jacobi
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Lateral Roots ◽  
Douglas Fir ◽  
Root Disease ◽  
Heterobasidion Annosum ◽  
Armillaria Ostoyae ◽  
White Fir ◽  
Pine Trees ◽  
Old Trees

Crown symptoms and other aboveground variables were examined on 36 Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco.) (40–209 years old), 46 white fir (Abies concolor (Gord. & Glend.) Lindl.) (36–165 years old), and 97 ponderosa pine (Pinus ponderosa Dougl. ex Laws.) (64–220 years old) trees in northern New Mexico and southern Colorado. Root systems of all trees were excavated to determine extent of root disease. Symptoms observed on infected trees, including reductions in height growth, changes in foliage characteristics, and crown dieback, worsened as the number of infected roots increased. Trees with aboveground symptoms had a significantly higher (p < 0.05) number of infected lateral roots than trees without symptoms. In mixed conifer stands on the Archuleta Mesa, Colo., four qualitative crown symptoms were used to accurately detect Armillaria ostoyae (Romagn.) Herink and (or) Heterobasidion annosum (Fr.) Bref. infection of Douglas-fir (21/22, or 95%) and white fir (19/28, or 68%). Similarly, 61% (48/79) of the A. ostoyae infected ponderosa pine trees on the Jemez site, N.M., were detected using the qualitative Thomson vigor rating system. Discriminate analysis, using more thorough variables and analysis, resulted in correct infection classifications of 82%, 85%, and 78% for Douglas-fir, white fir, and ponderosa pine, respectively, suggesting that aboveground variables are reasonable indicators of root disease.

scholarly journals Growth of Douglas-Fir and Ponderosa Pine Seedlings with Foliar Applications of Methanol and Ethanol

1999 ◽  
Vol 14 (4) ◽  
pp. 183-185
Author(s):  
Gladwin Joseph ◽  
Rick G. Kelsey
Keyword(s):  
Pseudotsuga Menziesii ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Growing Season ◽  
Douglas Fir ◽  
Pine Seedlings

Abstract To test whether methanol or ethanol stimulated growth of coast Douglas-fir (Pseudotsuga menziesii vat. menziesii) or ponderosa pine (Pinus ponderosa) seedlings, we sprayed concentrations of 1 to 10% (v/v) on the foliage twice a week for 13 wk during the growing season. Foliar applications of methanol and ethanol neither significantly stimulated nor inhibited growth, and signs of damage at these concentrations were lacking. West. J. Appl. For. 14(4):183-185.

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