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.

Decomposition and nutrient dynamics of ponderosa pine needles in a Mediterranean-type climate

1992 ◽  
Vol 22 (3) ◽  
pp. 306-314 ◽  
Author(s):  
Stephen C. Hart ◽  
Mary K. Firestone ◽  
Eldor A. Paul
Keyword(s):  
Sierra Nevada ◽  
Ponderosa Pine ◽  
Nutrient Dynamics ◽  
Decay Rates ◽  
Litter Fall ◽  
Decomposition Rates ◽  
Old Growth ◽  
Old Growth Forest ◽  
Significant Difference ◽  
Young Growth

A litter-bag technique was used to measure decay rates and assess changes in organic and inorganic constituents of ponderosa pine (Pinusponderosa Laws.) needle litter during decomposition over a 2-year period in old- and young-growth forests in the Sierra Nevada of California. Rates of mass loss were among the lowest reported for temperate and boreal forests, with annual decomposition constants of about 0.08 and 0.18 year−1 for the old- and young-growth forests, respectively. Apparently, the temporal separation of warm temperatures and moist conditions found in Mediterranean-type climates severely limits decomposition in these coniferous forests. In the old-growth forest, comparison of estimates of tree nutrient uptake with net releases of nutrients from fine litter during their 1st year of decomposition suggests that recent litter fall potentially acts as a significant source of P, Mg, and K for tree uptake in this forest; in contrast, recently fallen litter acts as a net sink for N, S, and Ca. Despite initially lower indices of litter quality for litter originating from the old–growth relative to the young–growth forest, no significant difference in decomposition rates of these two litter age-classes was found when placed at either site. This result does not support the hypothesis that decreases in decomposition rates during forest development are driven by decreases in the quality of litter fall.

Diversity, production, and nutrient dynamics of fungal sporocarps on logs in an old-growth temperate rain forest, Olympic National Park, Washington

1998 ◽  
Vol 28 (5) ◽  
pp. 665-673 ◽  
Author(s):  
Robert L Edmonds ◽  
David S Lebo
Keyword(s):  
Forest Floor ◽  
National Park ◽  
Nutrient Dynamics ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Common Type ◽  
Fruiting Bodies ◽  
Old Growth ◽  
Olympic National Park ◽  
Temperate Rain Forest

Fungal sporocarps were sampled on 47 logs in six 0.1-ha plots in an old-growth Sitka spruce (Picea sitchensis (Bong.) Carr.) - western hemlock (Tsuga heterophylla (Raf.) Sarg.) forest in the Hoh River Valley, Olympic National Park, Washington, from October 1993 to May 1994. Log biomass averaged 205 Mg/ha and the surface area of plots occupied by logs was 9.8%. Most fungal fruiting occurred on decay class 3 logs, the most common type on a scale from 1 (least decayed) to 5 (most decayed). Eighty-two taxa of fleshy fungi (63 saprophytic, 18 mycorrhizal, and one pathogenic) and six taxa of large annual or perennial fungi occurred on logs. Most fungi were basidiomycetes. Highest fleshy sporocarp production occurred in fall (456 g/ha) rather than spring (40 g/ha). Ischnoderma resinosum had the highest annual production (88 g/ha). Concentrations of N, P, K, Ca, Mg, Mn, Na, Fe, Zn, Al, B, and Cu in fruiting bodies were determined. Lower N concentrations occurred in perennial fungi (0.45%) than mycorrhizal (4.33%) and fleshy saprophytic species (3.30%). Only a small fraction of the nutrient capital in the logs was exported to the forest floor in fungal sporophores.

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.

Overstory litter inputs and nutrient returns in an old-growth temperate forest ecosystem, Olympic National Park, Washington

2002 ◽  
Vol 32 (4) ◽  
pp. 742-750 ◽  
Author(s):  
Robert L Edmonds ◽  
Georgia LD Murray
Keyword(s):  
National Park ◽  
Woody Debris ◽  
Basal Area ◽  
Tsuga Heterophylla ◽  
Old Growth ◽  
Olympic National Park ◽  
Shade Tolerant Species ◽  
Woody Litter ◽  
Fine Wood ◽  
Temperate Forest Ecosystem

Overstory litterfall rates and nutrient returns were determined in an old-growth temperate rainforest watershed in the Hoh River valley, Olympic National Park, Washington. Litter was sorted into green needles, senescent needles, fine wood, reproductive, and miscellaneous litter (mostly arboreal lichens and mosses). Understory and coarse woody debris inputs were not determined. Total annual overstory litterfall averaged 3594 kg·ha–1 and varied among the six plant communities in the watershed. There was a trend for litterfall to be higher in the upper watershed; elevations ranged from 180 to 850 m. Needles provided the greatest amount of litterfall (60%) with woody litter and other material averaging 18 and 22%, respectively. Highest senescent needle litterfall occurred from July to October, but highest woody litterfall was from January to April. Green needles provided only 3% of annual needle litterfall. Green and senescent needle litterfall were related to western hemlock (Tsuga heterophylla (Raf.) Sarg.) basal area, suggesting that this shade-tolerant species was the greatest contributor to needle litterfall. The following quantities (kg·ha–1) of nutrients were returned to the forest floor annually: Ca, 26.8; N, 24.6; K, 4.0; Mg, 3.0; P, 2.9; Mn, 1.7; and Na, 1.2.

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.

scholarly journals Western redcedar population dynamics in old-growth forests: Contrasting ecological paradigms using tree rings

2003 ◽  
Vol 79 (3) ◽  
pp. 517-530 ◽  
Author(s):  
Lori D Daniels
Keyword(s):  
British Columbia ◽  
Population Dynamics ◽  
Western Hemlock ◽  
Thuja Plicata ◽  
Silver Fir ◽  
Old Growth ◽  
Western Redcedar ◽  
Old Growth Forests ◽  
Gap Phase ◽  
Coastal British Columbia

In coastal British Columbia, late-successional forests dominated by western redcedar (Thuja plicata Donn ex D. Don) are structurally complex, with deep multi-layered canopies, large trees that are > 250 years old, and abundant coarse woody debris (CWD). These forests are presumed to be "old-growth" forests in which fine-scale gaps are the dominant disturbance regime, accounting for their structural diversity. In this study, I have used tree-ring analyses to investigate western redcedar regeneration dynamics in these old-growth forests. Western redcedar dominates canopies of many stands, but is rare in the understorey although it tolerates shade. The traditional interpretation is that western redcedar depends on catastrophic disturbance to regenerate and that it is replaced through succession by western hemlock (Tsuga heterophylla (Raf.) Sarg.) and Pacific silver fir (Abies amabilis (Dougl. ex Loud.) Dougl. ex J. Forbes), which are abundant in the understorey. Dominant trees are perceived to represent an even-aged, post-disturbance cohort and the lack of regeneration indicates a population decline in the absence of catastrophic disturbances. In this paper, I investigate four assumptions underlying this interpretation: (1) Tree size indicates age. (2) Populations establish as even-aged, post-disturbance cohorts. (3) Abundant CWD represents recent mortality. (4) Regeneration is insufficient to maintain canopy dominance. Using tree-ring evidence, I show that population dynamics of western redcedar are a combination of gap-phase establishment and a continuous mode of recruitment from the sub-canopy to the canopy. Specifically, size is a poor surrogate for tree age. Age distributions from 15 sites revealed uneven-aged populations, rather than single post-disturbance cohorts. Both logs and snags of western redcedar may persist more than 270 years; they do not represent recent mortality that is disproportionate to the number of live western redcedar in canopy. The regeneration niches of western redcedar and western hemlock overlap. For both species, gap-phase disturbances result in substrate suitable for successful seedling establishment. Preliminary results from dendroecological analysis of radial growth rates of trees in the subcanopy and canopy strata suggest that western hemlock and Pacific silver fir depend on gaps to recruit to the upper canopy, but recruitment of western redcedar may be independent of canopy gaps. I propose that differences in mode of recruitment to the canopy may explain the differences in population structures between western redcedar, western hemlock, and Pacific silver fir in the old-growth forest. These results provide an ecological precedent for use of a range of silvicultural systems, including clearcuts through single-tree harvesting and protection forests, when managing western redcedar in coastal British Columbia. Key words: Coastal British Columbia, disturbance regimes, regeneration dynamics, Thuja plicata, variable retention silviculture

Understory patch dynamics and ungulate herbivory in old-growth forests of Olympic National Park, Washington

1996 ◽  
Vol 26 (2) ◽  
pp. 255-265 ◽  
Author(s):  
Edward G. Schreiner ◽  
Kirsten A. Krueger ◽  
Douglas B. Houston ◽  
Patricia J. Happe
Keyword(s):  
Species Richness ◽  
Standing Crop ◽  
National Park ◽  
Patch Dynamics ◽  
Percent Cover ◽  
Old Growth ◽  
Patch Type ◽  
Ungulate Herbivory ◽  
Olympic National Park ◽  
Old Growth Forests

The relationship between native ungulates (mainly Roosevelt elk, Cervuselaphus L.) and the occurrence of three patch types in an old-growth (220- to 260-year-old) Sitka spruce (Piceasitchensis (Bong.) Carrière)–western hemlock (Tsugaheterophylla (Raf.) Sarg.) temperate coniferous rain forest was investigated on the South Fork Hoh River in Olympic National Park. The distribution, frequency, and size of two understory patches (grass, moss) and patches where shrubs had escaped herbivory (refugia) were sampled along transects. Vegetation standing crop, percent cover, species richness, and equitability along transects were compared with conditions in two 8-year-old 0.5-ha ungulate exclosures. Ungulate herbivory profoundly affected the distribution and abundance of understory patch types. Grass-dominated patches disappeared following 8 years of protection from ungulate herbivory. Ungulates maintained a reduced standing crop, increased forb species richness, and determined the distribution, morphology, and reproductive performance of several shrub species. There is clearly a dynamic relationship between patch type, tree fall, and ungulate herbivory in these old-growth forests. Our results show that ungulate herbivory is a driving force shaping vegetation patterns in coastal coniferous forests.

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