Decomposition of logging residues in Douglas-fir, western hemlock, Pacific silver fir, and ponderosa pine ecosystems

1985 ◽  
Vol 15 (5) ◽  
pp. 914-921 ◽  
Author(s):  
Heather E. Erickson ◽  
R. L. Edmonds ◽  
C. E. Peterson
Keyword(s):  
Ponderosa Pine ◽  
Small Diameter ◽  
Soil Surface ◽  
Douglas Fir ◽  
Dry Season ◽  
Western Hemlock ◽  
Dominant Factor ◽  
Silver Fir ◽  
Decomposition Rates ◽  
Residue Decomposition

Logging residue decomposition rates were determined in four conifer forest ecosystems in the State of Washington, U.S.A. (coastal western hemlock, Puget lowland Douglas-fir, high-elevation Pacific silver fir, and eastern Cascade ponderosa pine), by examining wood density changes in a series of south-facing harvest areas with residues of different ages. Decomposition rates were determined for two diameter classes (1–2 and 8–12 cm) and two vertical locations (on and >20 cm above the soil surface). Pacific silver fir and ponderosa pine ecosystems had the lowest k values (0.005 and 0.010 year−1, respectively) followed by Douglas-fir (range, 0.004–0.037 year−1) and western hemlock (range, 0.010–0.030 year−1). Small-diameter residues decomposed at rates significantly slower than large-diameter residues in Douglas-fir and western hemlock ecosystems; this relationship was also implied in the other ecosystems. In all four ecosystems, dry season moisture contents were lower in smaller-diameter residues. Moisture levels associated with small-diameter residues were too low for significant decomposition to occur during the dry summer period and probably contributed to the slow annual decay rates. Residues located above the soil surface decomposed significantly slower than residues on the soil surface only in the Douglas-fir ecosystem. Dry season residue moisture, rather than initial lignin concentration, appeared to be the dominant factor determining residue decomposition rates on exposed harvested areas.

Decomposition of Douglas-fir and red alder wood in clear-cuttings

1986 ◽  
Vol 16 (4) ◽  
pp. 822-831 ◽  
Author(s):  
Robert L. Edmonds ◽  
Daniel J. Vogt ◽  
David H. Sandberg ◽  
Charles H. Driver
Keyword(s):  
Small Diameter ◽  
Soil Surface ◽  
Douglas Fir ◽  
Dominant Factor ◽  
Minor Role ◽  
Wood Decomposition ◽  
Decomposition Rates ◽  
Red Alder ◽  
A Minor ◽  
The University

Decomposition rates of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and red alder (Alnusrubra Bong.) wood (simulating logging residues) were determined in clear-cuttings at the Charles Lathrop Pack Experimental Forest of the University of Washington, which is located approximately 120 km south of Seattle, WA. The influence of diameter (1–2, 4–6, and 8–12 cm), vertical location (buried, on the soil surface, and elevated), season of logging (summer and winter), aspect (north and south), and wood temperature, moisture, and chemistry on wood decomposition rates were determined. Red alder wood decomposed faster (k = 0.035–0.517 year−1) than Douglas-fir wood (k = 0.006–0.205 year−1). In general, buried wood decomposed faster than surface wood, which decomposed faster than elevated wood. Small diameter wood generally decomposed faster than larger diameter wood. Aspect and season of logging had little influence on decomposition rates. Moisture and temperature were the dominant factors related to Douglas-fir wood decomposition, with initial chemistry playing a minor role. Initial wood chemistry, particularly soda solubility, was the dominant factor related to red alder wood decomposition.

Decomposition and nutrient release from green needles of western hemlock and Pacific silver fir in an old-growth temperate rain forest9 Olympic National Park, Washington

1995 ◽  
Vol 25 (7) ◽  
pp. 1049-1057 ◽  
Author(s):  
Robert L. Edmonds ◽  
Ted B. Thomas
Keyword(s):  
Mass Loss ◽  
National Park ◽  
Nutrient Dynamics ◽  
Western Hemlock ◽  
Dominant Factor ◽  
Silver Fir ◽  
Decomposition Rates ◽  
Old Growth ◽  
Olympic National Park ◽  
Significant Difference

Decomposition rates and nutrient dynamics (for N, P, K, Ca, Mg, Mn, and Na) were determined for green needles of western hemlock (Tsugaheterophylla (Raf.) Sarg.) and Pacific silver fir (Abiesamabilis (Dougl.) Forb.) in an old-growth forested watershed (58 ha West Twin Creek) in the Hoh River valley, Olympic National Park, Washington. The influence of temperature and substrate chemistry on decomposition was determined. Temperature was the dominant factor controlling decomposition rates in the first year in this watershed, with the fastest decomposition at an elevation of 275 m (lower watershed) and the slowest decomposition at 725 m (upper watershed). After 12 months mass loss averaged 36% in the lower watershed and 28% in the upper watershed. There was no significant difference in decomposition rates between species. Substrate chemistry, i.e., the lignin/N ratio, became a more important factor than temperature as decomposition proceeded. After 37 months mass loss for needles averaged 61% for western hemlock and 50% for Pacific silver fir, with no difference by watershed location. After 61 months both types of substrates appeared to be approaching similar substrate chemistry and similar decomposition rates and there were no significant differences by species or watershed location. Decomposition constants (k values) after 61 months were 0.26 and 0.20 year−1 for western hemlock needles in the lower and upper watershed, respectively, and 0.22 and 0.19 year−1 for Pacific silver fir needles in the lower and upper watershed, respectively. Nitrogen was immobilized during the first 12 months of decomposition in needles of both species and then released. No other elements were immobilized during the initial (0- to 12-month) decomposition period, except for Ca in Pacific silver fir needles. However, in the 37- to 61-month period there was a considerable immobilization of Mg and Na in both species in the upper and lower watershed and K and Mn in both species in the upper watershed.

Forest fire history of Desolation Peak, Washington

1990 ◽  
Vol 20 (3) ◽  
pp. 350-356 ◽  
Author(s):  
James K. Agee ◽  
Mark Finney ◽  
Roland De Gouvenain
Keyword(s):  
Ponderosa Pine ◽  
Fire History ◽  
Forest Type ◽  
Douglas Fir ◽  
Forest Community ◽  
Western Hemlock ◽  
Silver Fir ◽  
Forest Types ◽  
Natural Fire ◽  
Interior Forest

Forests in the vicinity of Desolation Peak, Washington, are of special ecological interest because of their transitional nature between coastal and interior forest types. The area is west of the Cascade Mountain crest but in the rainshadow of mountains farther to the west. Fire return intervals were hypothesized to be shorter than typical for coastal forest types, such as those dominated by western hemlock and Pacific silver fir, and longer than typical for interior forest types, such as ponderosa pine, owing to the close juxtaposition of these types at Desolation Peak. Seven forest community types were defined, and a 400-year fire history was developed for this 3500-ha area. The average natural fire rotation was 100 years; this varied by a factor of two by century and by topographic aspect. Forest types typical of coastal regions, such as Douglas-fir, – western hemlock and mountain hemlock – Pacific silver fir, had mean fire return intervals (108–137 years) much lower than in other western Washington areas. The most interior forest type, ponderosa pine – Douglas-fir, had a higher mean fire return interval (52 years) than reported for similar forest types east of the Cascades. Historically, fire has created structural and landscape diversity on Desolation Peak and may be an important process in the maintenance of such diversity into the future.

Coarse woody debris and forest floor respiration in an old-growth coniferous forest on the Olympic Peninsula, Washington, USA

1994 ◽  
Vol 24 (9) ◽  
pp. 1811-1817 ◽  
Author(s):  
James L. Marra ◽  
Robert L. Edmonds
Keyword(s):  
Coarse Woody Debris ◽  
Forest Floor ◽  
Woody Debris ◽  
Large Diameter ◽  
Small Diameter ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Respiration Rates ◽  
Decay Class ◽  
Class 1

Carbon dioxide evolution rates for downed logs (coarse woody debris) and the forest floor were measured in a temperate, old-growth rain forest in Olympic National Park, Washington, using the soda lime trap method. Measurements were taken every 4 weeks from October 22, 1991, to November 19, 1992. Respiration rates for Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and western hemlock (Tsugaheterophylla (Raf.) Sarg.), logs were determined for decay classes 1–2, 3, and 5 in two diameter classes. Overall, western hemlock logs respired at a rate 35% higher (4.37 g CO2•m−2•day−1) than Douglas-fir logs (3.23 g CO2•m−2•day−1). Respiration rates for decay class 1–2 logs of both species were similar to decay class 5 logs (4.46 and 4.07 g CO2•m−2•day−1, respectively), but decay class 3 logs respired at a lower rate (3.23 g CO2•m−2•day−1). Seasonal patterns of respiration rates occurred, particularly for decay class 1 and 2 western hemlock logs where monthly averages ranged from a low of 2.67 g CO2•m−2•day−1 in February 1992 to a high of 8.30 g CO2•m−2•day−1 in September 1992. Rates for decay class 1–2 western hemlock logs were greater than those from the forest floor, which ranged from 3.42 to 7.13 g CO2•m−2•day−1. Respiration rates were depressed in late July and August compared with fall and spring owing to the summer drought characteristic of the Pacific Northwest. Large-diameter western hemlock logs in decay class 1–2 had higher respiration rates than small-diameter logs, whereas large-diameter decay class 3 western hemlock logs had lower respiration rates than small-diameter logs.

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%.

Use of the ectomycorrhizal fungus Laccarialaccata in forestry. I. Consistency between isolates in effective colonization of containerized conifer seedlings

1982 ◽  
Vol 12 (3) ◽  
pp. 469-473 ◽  
Author(s):  
Randy Molina
Keyword(s):  
Seedling Growth ◽  
Ponderosa Pine ◽  
Dry Weight ◽  
Sitka Spruce ◽  
Ectomycorrhizal Fungus ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Conifer Species ◽  
Colonization Success ◽  
Inoculation Treatment

Four isolates of the ectomycorrhizal fungus Laccarialaccata (Scop. ex Fr.) Berk and Br. were inoculated singly onto containerized Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), ponderosa pine (Pinusponderosa Dougl. ex Laws.), Sitka spruce (Piceasitchensis (Bong.) Carr.), and western hemlock (Tsugaheterophylla (Raf.) Sarg.) seedlings to detect ecotypic variation in colonization success and effects on seedling growth. All isolates formed well-developed ectomycorrhizae on all inoculated seedlings. Abundance ratings of short roots colonized did not differ between the four isolates for any conifer species; most inoculated seedlings developed ectomycorrhizae on over 80% of their short roots. There were also no differences between isolates in affecting seedling height, stem diameter, and dry weight of tops and roots for all conifer species. Inoculations did not improve seedling growth over uninoculated controls. Uninoculated controls of Douglas-fir and ponderosa pine had significantly greater dry weight than their inoculated seedlings; growth of Sitka spruce and western hemlock seedlings was not affected by any inoculation treatment. Laccarialaccata vigorously colonized the entire container rooting substrate and appears a prime candidate for artificial ectomycorrhizal inoculation of containerized western conifers.

Litter decomposition and nutrient release in Douglas-fir, red alder, western hemlock, and Pacific silver fir ecosystems in western Washington

1980 ◽  
Vol 10 (3) ◽  
pp. 327-337 ◽  
Author(s):  
Robert L. Edmonds
Keyword(s):  
Weight Loss ◽  
Nutrient Release ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Silver Fir ◽  
Rapid Weight Loss ◽  
Red Alder ◽  
Cellulose Decomposition ◽  
The Pacific ◽  
Western Washington

Decomposition rates and changes in the nutrient content of needle and leaf litter were examined in Douglas-fir (Pseudotsugamenziesii Mirb. Franco), western hemlock (Tsugaheterophylla (Raf.) Sarg.), Pacific silver fir (Abiesamabilis (Dougl.) Forbes), and red alder (Alnusrubra Bong.) ecosystems in western Washington, U.S.A. Nylon litterbags (1-mm mesh) were placed in the stands in November and December 1974. Bags were collected after 3, 6, 12, and 24 months and weighed, except in the Pacific silver fir stand when bags were collected after 6, 9, 14, and 24 months. Litter was analyzed for C, N, P, K, Ca, Mg, Mn, lignin, and cellulose. Decomposition constants (k values) were determined. Fastest decomposition after 2 years occurred in red alder leaves, followed by Douglas-fir, western hemlock, and Pacific silver fir needles. There were significant differences in weight loss among species after 1 year, but no significant differences were evident after 2 years. Red alder leaves showed rapid weight loss in the 1st year but decomposed little in the 2nd year. Decomposition constants were highly positively correlated with minimum air temperatures and negatively correlated with C:N ratios. Low litter moisture tended to reduce decomposition in summer, particularly in the Pacific silver fir stand. Decomposition proceeded under snow in this ecosystem. The pattern of loss of elements from litterbags after 2 years varied from ecosystem to ecosystem, particularly for N. The following element mobility series resulted for the four ecosystems: red alder (K > Mg > Ca > P > N > Mn), Douglas-fir (K > P > Ca > Mg > Mn > N), western hemlock (K > Ca > Mg > N > Mn > P), and Pacific silver fir (K > Mg > Ca > Mn > P > N).

Decomposition rates and nutrient dynamics in small-diameter woody litter in four forest ecosystems in Washington, U.S.A.

1987 ◽  
Vol 17 (6) ◽  
pp. 499-509 ◽  
Author(s):  
Robert L. Edmonds
Keyword(s):  
Nutrient Dynamics ◽  
Forest Ecosystems ◽  
Small Diameter ◽  
High Elevation ◽  
Silver Fir ◽  
Decomposition Rates ◽  
Red Alder ◽  
N Release ◽  
Woody Litter ◽  
Western Washington

Decomposition rates and nutrient dynamics in small-diameter woody litter (twigs, cones, and branches) were studied in four ecosystems in western Washington: high elevation Pacific silver fir (Abiesamabilis (Dougl.) Forbes) and low elevation Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), western hemlock (Tsugaheterophylla (Raf.) Sarg.), and red alder (Alnusrubra Bong.). Conifer twigs decomposed faster (k = 0.14–0.24 year−1) than cones (k = 0.09–0.12 year−1) and branches (k = 0.03–0.11 year−1). Decomposition constants were related better to initial lignin/initial N ratios (r = −0.64) than initial lignin concentrations. N was generally the least mobile nutrient while K was the most mobile. Many nutrients were strongly immobilized in conifer fine woody litter, including N, Mg, Mn, and Ca. There was little immobilization of N in red alder branches. N release from decomposing woody litter appears to be controlled by a critical C/N ratio. This critical C/N ratio, however, was not constant and increased as the substrate decomposition rate increased.

Spatial and population characteristics of dwarf mistletoe infected trees in an old-growth Douglas-fir – western hemlock forest

2005 ◽  
Vol 35 (4) ◽  
pp. 990-1001 ◽  
Author(s):  
David C Shaw ◽  
Jiquan Chen ◽  
Elizabeth A Freeman ◽  
David M Braun
Keyword(s):  
Nearest Neighbor ◽  
Positive Association ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Negative Association ◽  
Population Characteristics ◽  
Western Hemlock ◽  
Silver Fir ◽  
Dwarf Mistletoe ◽  
Old Growth

We investigated the distribution and severity of trees infected with western hemlock dwarf mistletoe (Arceuthobium tsugense (Rosendahl) G.N. Jones subsp. tsugense) in an old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) – western hemlock (Tsuga heterophylla (Raf.) Sarg.) forest. With the use of Hawksworth six-class dwarf mistletoe rating system, infection status was assessed for 3516 hemlock and true firs ≥5 cm diameter on a 12-ha stem-mapped plot located in the Cascade Mountains of southwest Washington State. Within the plot, 33% of the area had some level of infection and 25% (719) of western hemlocks, 2.2% (12) of Pacific silver fir (Abies amabilis (Dougl.) Forbes), and 29% (2) of noble fir (Abies procera Rehd.) trees were infected. Infected trees are larger than uninfected trees, on average, and within the infected tree population, the severely infected trees averaged larger than lightly infected trees. Abundant dwarf mistletoe in larger trees definitely positions the dwarf mistletoe population for future spread. Ripley's K analysis indicates a negative association between infected and uninfected hemlock trees, confirming that the infected trees form distinct dwarf mistletoe infection centers. The infection centers are actively spreading at their margins, which was confirmed by nearest neighbor analysis. Heavily infected trees had a negative association with uninfected trees, while lightly infected trees had a positive association with uninfected trees.

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