Effects of small aggregates of mature tree retention on adjacent planted coastal Douglas-fir growth and survival

2021 ◽  
Vol 480 ◽  
pp. 118613
Author(s):  
N.J. Smith ◽  
W.J. Beese
Keyword(s):  
Douglas Fir ◽  
Mature Tree ◽  
Growth And Survival ◽  
Tree Retention

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.

Effects of tree cover, understory vegetation, and litter on regeneration of Douglas-fir (Pseudotsuga menziesii) in southwestern Argentina

1998 ◽  
Vol 28 (5) ◽  
pp. 683-692 ◽  
Author(s):  
F D Caccia ◽  
C L Ballaré
Keyword(s):  
Seed Germination ◽  
Pseudotsuga Menziesii ◽  
Seedling Emergence ◽  
Canopy Cover ◽  
Douglas Fir ◽  
Understory Vegetation ◽  
Tree Cover ◽  
Growth And Survival ◽  
Thermal Environments ◽  
Seedling Predation

The factors and processes that regulate Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) natural regeneration in southwestern Argentina are unknown. We investigated (i) the germination responses of P. menziesii seeds to variations in the radiation and thermal environments imposed by canopy cover and litter, (ii) the effects of litter on seedling emergence, and (iii) the effects of understory vegetation on seedling performance and seed and seedling predation. Seed germination was high in darkness and under canopies. Under a combination of canopy types and litter covers, germination showed a negative correlation with temperature between 23 and 40°C. Germination was not altered by changes in red/far-red ratio. These results suggest that the presence of an overstory canopy promotes P. menziesii seed germination compared with a no-canopy situation (e.g., a clearcut). Litter inhibited seedling emergence by reducing water availability and by acting as a mechanical barrier. Understory vegetation (established saplings) reduced seedling growth and survival. However, our results suggest that direct competition between seedlings and understory vegetation is not the principal force regulating regeneration; indirect effects appear to be of paramount importance because P. menziesii seed and seedling consumption (presumably by rodents) is greatly encouraged by the presence of dense vegetation patches in the understory.

Effects of Environment on Growth and Survival of Douglas-fir Transplants

1974 ◽  
Vol 4 (2) ◽  
pp. 193-200
Author(s):  
E. B. Tregunna ◽  
M. Crown
Keyword(s):  
Storage Time ◽  
Water Status ◽  
Douglas Fir ◽  
Planting Date ◽  
Growth And Survival ◽  
Lower Elevation ◽  
Survival And Growth ◽  
And Storage ◽  
Root Treatment ◽  
Spring Planting

Variation in lifting date, planting date, planting site, seedling history, root treatment, and storage time were tested for their effects on Douglas-fir transplants. Survival, water status, types of damage, and both shoot and root growth were measured. Survival decreased with later spring planting date in the field, but this was partly offset by trends in browsing. Survival was greater at the lower elevation. Differences in seed lot, or conditions in the nursery, resulted in differences in tree size, which had some effects because the larger trees were browsed more. Survival and growth were not markedly different between root treatments. Cold storage increased survival of trees lifted late in the spring. The relative turgidity of leaves from bareroot trees in storage was related to lifting date and subsequent survival. Survival decreased severely as lifting date progressed through March.

scholarly journals Interactive Effects of Stock Type and Forest Vegetation Management Treatments on Douglas-Fir Seedling Growth and Survival—Ten-Year Results

Forests ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 1002 ◽  
Author(s):  
Wightman ◽  
Gonzalez-Benecke ◽  
Dinger
Keyword(s):  
Plant Cover ◽  
Growing Season ◽  
Vegetation Management ◽  
Action Control ◽  
Douglas Fir ◽  
Forest Vegetation ◽  
Shrub Cover ◽  
Growth And Survival ◽  
Stock Type ◽  
Forest Vegetation Management

In the Pacific Northwest, the use of forest vegetation management (FVM) and seedling stock type selection are important tools to ensure seedling establishment according to organizational objectives and state laws. Individually, these two reforestation decisions have been shown to increase growth and survival of Douglas-fir seedlings, however, the interaction between seedling stock type and level of vegetation control represents economic and ecologic tradeoffs that are less well understood. This study was designed to test the combined effects of three FVM regimes and three containerized stock types, one of which was experimental at the time, on Douglas-fir growth during the initial ten years of establishment on a site near Belfair, Washington (USA). When compared to the no-action control, FVM treatments reduced competitive plant cover below 20% during the year of application, and differences in vegetation cover persisted through the fifth growing season. Vegetation species diversity recovered quickly after FVM and there were no differences among the treatments by the third growing season. After ten growing seasons, trees in plots treated with FVM were 1.1 m taller with a mean diameter at breast height (DBH) 2.2 cm larger than those in the no-action control. Larger seedlings at the time of planting (styro-60) were 0.6 m taller with a mean DBH 1.1 cm larger than smaller seedlings (styro-8 and styro-15). The only significant stock type by FVM interaction in the experiment occurred with the survival of styro-60 seedlings growing in the no action control which had lower survival than all other treatment combinations (67% vs 91%). The long-term competitive impact of shrub cover was demonstrated by a strong non-linear relationship. Increasing cumulative shrub cover from 10% to 30% during the first two years of establishment reduced stand volume at year 10 by 79%.

scholarly journals Laminated Root Rot and Fumigant Injection Affect Survival and Growth of Douglas-Fir

2007 ◽  
Vol 22 (3) ◽  
pp. 220-227 ◽  
Author(s):  
Constance A. Harrington ◽  
Walter G. Thies
Keyword(s):  
Tree Growth ◽  
Growth Rates ◽  
Root Rot ◽  
Survival Rates ◽  
Height Growth ◽  
Douglas Fir ◽  
Infection Level ◽  
Growth And Survival ◽  
Growing Seasons ◽  
Tree Survival

Abstract Laminated root rot caused by Phellinus weirii is a significant disease of western conifers; it is important to understand the effects of the disease on tree growth and survival and, for some management objectives, to develop treatments that will reduce those effects. This study was conducted in a 47-year-old Douglas-fir (Pseudotsuga menziesii) stand in northwest Oregon. First, we evaluated the effects of root system infection on diameter and height growth. Growth rates were lowest in trees with high infection levels; root infection level affected diameter growth more than height growth. Second, we evaluated the effects of fumigation treatments on tree growth. The nine treatments were as follows: three dosages of methylisothiocyanate (MITC), four dosages of chloropicrin (trichloronitromethane), one dosage of Vorlex [20% MITC, 80% chlorinated C3 hydrocarbons (v/v)], and a control. The fumigants were applied by inserting them into holes drilled into the base of live trees. After nine growing seasons, all three of the treatments applying different dosages of MITC and the treatment applying the lowest dosage of chloropicrin had higher tree survival rates than the untreated control, and the growth rates in those four fumigation treatments were not significantly different from growth in the surviving control trees.

Ten-year growth and survival of Douglas-fir seedlings treated with plant growth regulating substances at transplant

2000 ◽  
Vol 30 (11) ◽  
pp. 1778-1787 ◽  
Author(s):  
C F Scagel ◽  
R G Linderman ◽  
R K Scagel
Keyword(s):  
Plant Growth ◽  
Root Growth ◽  
Douglas Fir ◽  
Growth Responses ◽  
Indole Butyric Acid ◽  
Growth And Survival ◽  
Growing Seasons ◽  
Tree Survival ◽  
Stock Types ◽  
The Cost

Commercially available plant growth regulators (PGRs) or moisture retention gels, applied to the roots of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) before planting, can modify indole-3-acetic acid (IAA) levels in roots, root growth responses, and tree survival. We treated two different 1+0 stock types (PSB313B and PSB323) of Douglas-fir with indole-butyric acid (IBA), ethephon (Ethrel®), alginate, or a combination of IBA and alginate. New root growth and IAA levels in roots were measured 2 weeks after planting, and aboveground growth and tree survival were monitored over 10 growing seasons after planting. Treatment with IBA or the combination of IBA and alginate increased IAA conjugate and free IAA levels in roots, root growth, and tree survival. Alginate treatment alone increased new root growth and tree survival, but did not increase free IAA levels in roots. Ethrel® treatment increased free IAA levels and root growth, but had no effect on IAA conjugates or tree survival. A cost analysis suggests that use of certain PGRs or alginate decreases the cost required to attain target stocking and increased tree size. Our results suggest that application of PGRs or other root-promoting materials to the roots of Douglas-fir before planting has the potential to be a cost-beneficial method for increasing root growth and tree survival.

scholarly journals The 1912 Douglas-Fir Heredity Study: Long-Term Effects of Climatic Transfer Distance on Growth and Survival

2019 ◽  
Vol 118 (1) ◽  
pp. 1-13 ◽  
Author(s):  
J Bradley St. Clair ◽  
Glenn T Howe ◽  
Jennifer G Kling
Keyword(s):  
Pacific Northwest ◽  
Douglas Fir ◽  
Future Climate Change ◽  
Long Term Effects ◽  
Term Survival ◽  
Growth And Survival ◽  
Seed Sources ◽  
The Pacific ◽  
Near Term

Abstract The 1912 Douglas-Fir Heredity Study is one of the first studies undertaken by the US Forest Service, and one of the first forest genetics studies in North America. The study considers provenance variation of 120 parent trees from 13 seed sources planted at five test sites in the Pacific Northwest. The unique, long-term nature of the study makes it valuable to revisit and consider its biological and historical significance. This analysis considers how far climatically Douglas-fir populations may be moved without incurring unacceptable declines in growth and survival. Results indicate that Douglas-fir seed sources may be moved at least 2° C cooler or warmer and still retain good long-term survival and productivity. However, projected future climate change beyond 2° C may lead to lower survival and productivity. One option to address these concerns is assisted migration; however, if seed sources are moved beyond 2–3° C to a cooler climate in anticipation of warming, or from a more continental to a maritime climate, we are likely to see increased mortality and associated losses in productivity in the near-term. Lessons from this study include: (1) pay attention to good experimental design; we were able to overcome limitations from the design by using new statistical approaches; (2) maladaptation may take time to develop; poorer survival was not evident until more than two decades after planting; and (3) long-term studies may have value for addressing new, unforeseen issues in the future.

scholarly journals Partial Retention of Legacy Trees Protect Mycorrhizal Inoculum Potential, Biodiversity, and Soil Resources While Promoting Natural Regeneration of Interior Douglas-Fir

2021 ◽  
Vol 3 ◽  
Author(s):  
Suzanne W. Simard ◽  
W. Jean Roach ◽  
Jacob Beauregard ◽  
Julia Burkart ◽  
Dominique Cook ◽  
...  
Keyword(s):  
Resource Availability ◽  
Forest Floor ◽  
Douglas Fir ◽  
Inoculum Potential ◽  
Soil Resources ◽  
Mycorrhizal Inoculum Potential ◽  
Tree Retention ◽  
Harvesting Intensity ◽  
Overstory Trees ◽  
Partial Retention

Clearcutting reduces proximity to seed sources and mycorrhizal inoculum potential for regenerating seedlings. Partial retention of legacy trees and protection of refuge plants, as well as preservation of the forest floor, can maintain mycorrhizal networks that colonize germinants and improve nutrient supply. However, little is known of overstory retention levels that best protect mycorrhizal inoculum while also providing sufficient light and soil resources for seedling establishment. To quantify the effect of tree retention on seedling regeneration, refuge plants, and resource availability, we compared five harvesting methods with increasing retention of overstory trees (clearcutting (0% retention), seed tree (10% retention), 30% patch retention, 60% patch retention, and 100% retention in uncut controls) in an interior Douglas-fir-dominated forest in British Columbia. Regeneration increased with proximity to legacy trees in partially cut forests, with increasing densities of interior Douglas-fir, western redcedar, grand fir, and western hemlock seedlings with overstory tree retention. Clearcutting reduced cover of ectomycorrhizal refuge plants (from 80 to 5%) while promoting arbuscular mycorrhizal plants the year after harvest. Richness of shrubs, herbs, and mosses declined with increasing harvesting intensity, but tree richness remained at control levels. The presence of legacy trees in all partially cut treatments mitigated these losses. Light availability declined with increasing overstory cover and proximity to leave trees, but it still exceeded 1,000 W m−2 in the clearcut, seed tree and 30% retention treatments. Increasing harvesting intensity reduced aboveground and belowground C stocks, particularly in live trees and the forest floor, although forest floor losses were also substantial where thinning took place in the 60% retention treatment. The loss of forest floor carbon, along with understory plant richness with intense harvesting was likely associated with a loss of ectomycorrhizal inoculum potential. This study suggests that dispersed retention of overstory trees where seed trees are spaced ~10–20 m apart, and aggregated retention where openings are &lt;60 m (2 tree-lengths) in width, will result in an optimal balance of seed source proximity, inoculum potential, and resource availability where seedling regeneration, plant biodiversity, and carbon stocks are protected.

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