Tree species and soil nutrient profiles in old-growth forests of the Oregon Coast Range

2011 ◽  
Vol 41 (1) ◽  
pp. 195-210 ◽  
Author(s):  
Alison Cross ◽  
Steven S. Perakis
Keyword(s):  
Tree Species ◽  
Forest Floor ◽  
Mineral Soil ◽  
Soil Nutrient ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Coast Range ◽  
Old Growth ◽  
Oregon Coast Range ◽  
Old Growth Forests

Old-growth forests of the Pacific Northwest provide a unique opportunity to examine tree species – soil relationships in ecosystems that have developed without significant human disturbance. We characterized foliage, forest floor, and mineral soil nutrients associated with four canopy tree species (Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco), western hemlock (Tsuga heterophylla (Raf.) Sarg.), western redcedar (Thuja plicata Donn ex D. Don), and bigleaf maple (Acer macrophyllum Pursh)) in eight old-growth forests of the Oregon Coast Range. The greatest forest floor accumulations of C, N, P, Ca, Mg, and K occurred under Douglas-fir, primarily due to greater forest floor mass. In mineral soil, western hemlock exhibited significantly lower Ca concentration and sum of cations (Ca + Mg + K) than bigleaf maple, with intermediate values for Douglas-fir and western redcedar. Bigleaf maple explained most species-based differences in foliar nutrients, displaying high concentrations of N, P, Ca, Mg, and K. Foliar P and N:P variations largely reflected soil P variation across sites. The four tree species that we examined exhibited a number of individualistic effects on soil nutrient levels that contribute to biogeochemical heterogeneity in these ecosystems. Where fire suppression and long-term succession favor dominance by highly shade-tolerant western hemlock, our results suggest a potential for declines in both soil Ca availability and soil biogeochemical heterogeneity in old-growth forests.

scholarly journals Influence of forest age on forms of carbon in Douglas-fir soils in the Oregon Coast Range

1998 ◽  
Vol 28 (3) ◽  
pp. 390-395 ◽  
Author(s):  
James A Entry ◽  
William H Emmingham
Keyword(s):  
Organic Matter ◽  
Mineral Soil ◽  
Light Fraction ◽  
Coast Range ◽  
Old Growth ◽  
Oregon Coast Range ◽  
Soil C ◽  
Second Growth ◽  
Old Growth Forests ◽  
Young Growth

The amount and type of carbon (C) in a forest soil reflects the past balance between C accumulation and loss. In an old-growth forest soil, C is thought to be in dynamic equilibrium between accumulations and losses. Disturbance upsets this equilibrium by altering the microclimate, the amount and type of vegetation growing on a site, and properties that affect organic matter decomposition. We measured total C and forms of soil C in the L, F, and H layers and in the light fraction of soil organic matter in the 0-10 cm of mineral soil in old-, second-, and young-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) soils in the Oregon Coast Range. Total C in L, F, and H layers and in organic material in the top 10 cm of mineral soil in old-growth forests was higher than in young- or second-growth forests. Old-growth forests had a higher lignin concentration and lower concentrations of sugar, hemicellulose, and cellulose in the L, F, and H layers and in the light fraction of organic material than second- or young-growth forests. Old-growth forests had greater amounts of fats, waxes, and oils, sugar, cellulose, and lignin, in the L, F, and H layers per square hectare and greater amounts of hemicellulose, cellulose, and lignin in the light fraction of organic matter in the 0-10 cm of mineral soil per square hectare than young- and second-growth forests. Concentrations of fats, waxes, and oils, sugar, and tannin in the light fraction of organic matter in the 0-10 cm of mineral soil did not differ with forest age.

Fungal and arboreal biomass in a western Oregon Douglas-fir ecosystem: distribution patterns and turnover

1979 ◽  
Vol 9 (2) ◽  
pp. 245-256 ◽  
Author(s):  
Robert Fogel ◽  
Gary Hunt
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Forest Floor ◽  
Distribution Patterns ◽  
Turnover Time ◽  
Douglas Fir ◽  
Coast Range ◽  
Oregon Coast Range ◽  
Second Growth ◽  
Soil Hyphae

The allocation of biomass and the turnover time of various components were measured from August 1976 to August 1977 in a young, second-growth Douglas-fir stand in the Oregon Coast Range. Allocation of biomass among the tree components was 14 732 kg foliage ha−1, 30 455 kg branches ha−1, 212 941 kg boles ha−1, 49 289 kg nonmycorrhizal roots ha−1, and 15 015 kg host portion of mycorrhizae ha−1. Biomass allocation of fungal components was 10 009 kg mycorrhizal mantles ha−1, 2785 kg Cenococcumgeophilum sclerotia ha−1, 65 kg sporocarps ha−1, 369 kg litter hyphae ha−1, and 6666 kg soil hyphae ha−1. The forest floor was composed of 6970 kg fine (<2 mm) litter ha−1, 6564 kg coarse (2–25 mm) litter ha−1, and 5500 kg log (>25 mm) litter ha−1. Soil organic matter (<0.494 mm) was 87 600 kg ha−1. Total annual stand throughput was 30 324 kg ha−1, excluding soil organic matter throughput. Of this total, 50.5% was accounted for by fungal throughput, 39.5% by tree throughput, and 10.0% by forest floor throughput.

Effects of bigleaf maple on soils in Douglas-fir forests

1990 ◽  
Vol 20 (3) ◽  
pp. 259-266 ◽  
Author(s):  
Jeremy S. Fried ◽  
James R. Boyle ◽  
John C. Tappeiner II ◽  
Kermit Cromack Jr.
Keyword(s):  
Forest Floor ◽  
Mineral Soil ◽  
Nutrient Content ◽  
Douglas Fir ◽  
Organic Carbon Content ◽  
Coast Range ◽  
Litter Fall ◽  
Turnover Rates ◽  
Calcium Magnesium ◽  
Forest Floors

Soil chemical and physical properties, forest floor weights, nutrient content and turnover rates, and litter fall weights and nutrient content under bigleaf maple (Acermacrophyllum Pursh) and Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco var. menziesii) were compared on five sites on the eastern margin of the Oregon Coast Range. Litter fall weight and nutrient content were significantly greater under maple on every site for every macronutrient and for most micronutrients. Forest floor biomass and nutrient content were extremely variable, much more so than litter fall, and there were no consistent differences between the two species. However, turnover rates for forest floor biomass and nutrients were significantly faster under maple for every nutrient at every site. Bulk density of mineral soil was also highly variable with significant differences at only two sites. Soil under maple was consistently higher in nitrogen, and less consistently, in potassium. There were no consistent trends in amounts of calcium, magnesium, or phosphorus. Soil organic carbon content under maple was significantly greater than under Douglas-fir on four of five sites. These differences may result from the more rapid turnover of forest floors under maple trees.

Multi-decadal establishment for single-cohort Douglas-fir forests

2014 ◽  
Vol 44 (9) ◽  
pp. 1068-1078 ◽  
Author(s):  
James A. Freund ◽  
Jerry F. Franklin ◽  
Andrew J. Larson ◽  
James A. Lutz
Keyword(s):  
Pseudotsuga Menziesii ◽  
Temporal Patterns ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Old Growth ◽  
Old Growth Forests ◽  
Western Washington ◽  
Century Development ◽  
Single Cohort

The rate at which trees regenerate following stand-replacing wildfire is an important but poorly understood process in the multi-century development of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) forests. Temporal patterns of Douglas-fir establishment reconstructed from old-growth forests (>450 year) have generated contradictory models of either rapid (<25 year) or prolonged (>100 year) periods of establishment, while patterns of tree establishment in mid-aged (100 to 350 year) forests remains largely unknown. To determine temporal patterns of Douglas-fir establishment following stand-replacing fire, increment cores were obtained from 1455 trees in 18 mature and early old-growth forests in western Washington and northwestern Oregon, USA. Each of the stands showed continuous regeneration of Douglas-fir for many decades following initiating fire. The establishment period averaged 60 years (range: 32–99 years). These results contrast both with the view of rapid (one- to two-decade) regeneration of Douglas-fir promoted in the early forestry literature and with reports of establishment periods exceeding 100 years in older (>400 year) Douglas-fir–western hemlock stands. These results have important implications for management designed to create and promote early-seral forest characteristics.

Vertical fine root distributions of western redcedar, western hemlock, and salal in old-growth cedar–hemlock forests on northern Vancouver Island

2002 ◽  
Vol 32 (7) ◽  
pp. 1208-1216 ◽  
Author(s):  
Jennifer N Bennett ◽  
Ben Andrew ◽  
Cindy E Prescott
Keyword(s):  
Forest Floor ◽  
Fine Roots ◽  
Fine Root ◽  
Mineral Soil ◽  
Vancouver Island ◽  
Western Hemlock ◽  
Old Growth ◽  
Total N ◽  
Western Redcedar ◽  
Vertical Distributions

The vertical distributions of fine roots of western hemlock (Tsuga heterophylla (Raf.) Sarg.) western redcedar (Thuja plicata Donn ex D. Don), and salal (Gaultheria shallon Pursh) were characterized in old-growth cedar–hemlock forests on northern Vancouver Island. Total biomasses of cedar, hemlock, and salal roots in the forest floor and upper mineral soil were 817, 620, and 187 g·m–2, respectively. Hemlock and salal fine roots were concentrated in the upper forest floor, while cedar fine roots were evenly distributed through the profile. Salal and hemlock fine root densities (g·m–3) in the forest floor and mineral soil were positively correlated, as were salal and cedar root biomass distributions (g·m–2). Only salal and hemlock root densities were significantly correlated with N concentrations. Hemlock root densities were negatively correlated with total N, and salal root densities were negatively correlated with total N and soluble organic N. Based on fine root densities, hemlock and salal probably compete for resources in the upper forest floor, whereas cedar accesses resources in the lower organic and mineral soil horizons. The differences in the vertical distributions of cedar, hemlock, and salal fine roots may partly explain the co-occurrence and different productivities of the three species in cedar-hemlock forests.

Relationships between soil organic matter and forest productivity in western Oregon and Washington

1994 ◽  
Vol 24 (6) ◽  
pp. 1101-1106 ◽  
Author(s):  
R.L. Edmonds ◽  
H.N. Chappell
Keyword(s):  
Forest Floor ◽  
Mineral Soil ◽  
Puget Sound ◽  
Site Index ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Soil N ◽  
Soil C ◽  
C And N ◽  
Washington Cascades

Mineral soil and forest floor C and N contents were determined in 154 Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and western hemlock (Tsugaheterophylla (Raf.) Sarg.) stands in western Oregon and Washington ranging in age from 16 to 64 years. Relationships between site index and mineral soil and forest floor C, N, and C/N ratios were examined. Douglas-fir data were analyzed by geographic province (Puget Sound, Washington Cascades, Oregon Cascades, coastal Washington, coastal Oregon, and southwest Oregon). Average mineral soil C in Douglas-fir stands ranged from 102 Mg/ha to 177 Mg/ha in Puget Sound and Washington Cascades provinces, respectively. Soil N ranged from 3708 kg/ha in Puget Sound province to 9268 kg/ha in the Washington Cascade province. Western hemlock data were analyzed in three provinces (Washington Cascades, coastal Washington, and coastal Oregon). Average mineral soil C in western hemlock stands ranged from 241 Mg/ha in the Washington Cascades to 309 Mg/ha in coastal Washington and was higher than Douglas-fir mineral soil C. Western hemlock mineral soil N was also higher than Douglas-fir mineral soil N ranging from 10 495 kg/ha in the Washington Cascades to 15 216 kg/ha in coastal Oregon. Forest floor C and N contents were also higher in western hemlock than Douglas-fir stands. Nonlinear regression analysis revealed a weak positive relationship between site index and total mineral soil C in Douglas-fir (r2 = 0.19). A similar relationship was observed between Douglas-fir site index and total soil N (r2 = 0.19). Relationships were weak because of the large variability in mineral soil C and N within as well as across provinces. Maximum Douglas-fir site indexes occurred across a broad plateau of mineral soil and forest floor C/N ratios ranging from 15–25 and 35–45, respectively. Minimum site indexes also occurred in these C/N ranges. No increase in Douglas-fir productivity occurred above mineral soil C levels of 125 Mg/ha. There were no relationships between site index and mineral soil C and N or C/N ratios in western hemlock stands.

Overstory and understory development in thinned and underplanted Oregon Coast Range Douglas-fir stands

2006 ◽  
Vol 36 (10) ◽  
pp. 2696-2711 ◽  
Author(s):  
Samuel S Chan ◽  
David J Larson ◽  
Kathleen G Maas-Hebner ◽  
William H Emmingham ◽  
Stuart R Johnston ◽  
...  
Keyword(s):  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Coast Range ◽  
Old Growth ◽  
Shrub Species ◽  
Oregon Coast Range ◽  
Oregon Coast ◽  
Crown Length ◽  
Accelerate Development ◽  
Understory Plant

Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forests managed for timber in western Oregon frequently lack structure and diversity associated with old-growth forests. We examined thinning effects on overstory and understory development for 8 years after treatment. Three 30- to 33-year-old Oregon Coast Range plantations were partitioned into four overstory treatments: unthinned (~550 trees/ha) and lightly (~250 trees/ha), moderately (~150 trees/ha), and heavily (~75 trees/ha) thinned. Within each overstory treatment, two understory treatments were established: underplanted with Douglas-fir and western hemlock (Tsuga heterophylla (Raf.) Sarg.) or not underplanted. Thinning increased overstory stem growth, crown expansion, and retained crown length. Thinned overstory canopies began to close rapidly the third year after thinning, decreasing % skylight by approximately 2%/year, whereas % skylight in unthinned stands increased slightly. All seedlings planted in unthinned stands died, whereas eighth year survival in thinned stands averaged 88%. Natural regeneration densities and distributions were highly variable. Understory shrub cover was reduced by harvesting disturbance but recovered by the fifth year. Thinning increased understory plant species diversity, and no shrub species were lost. Thinning to low densities and underplanting has the potential to accelerate development of multilayered stands characteristic of old-growth Douglas-fir forests.

Influence of forest age on nutrient availability and storage in coniferous soils of the Oregon Coast Range

1995 ◽  
Vol 25 (1) ◽  
pp. 114-120 ◽  
Author(s):  
James A. Entry ◽  
William H. Emmingham
Keyword(s):  
Mineral Soil ◽  
Forest Litter ◽  
Coast Range ◽  
Litter Layer ◽  
Forest Age ◽  
Nutrient Storage ◽  
Old Growth ◽  
Oregon Coast Range ◽  
Old Growth Forest ◽  
Young Growth

A substantial fraction of the organic matter and plant essential nutrients in forest ecosystems are contained in the soil. The role of soils in nutrient storage and availability is an essential component of ecosystem function and stability. The top 10 cm of soil contains the highest concentration of nutrients. To determine the influence of forest age on nutrient storage and availability in riparian soils, we compared concentrations, storage, and extractability of plant nutrients in the litter layer and top 10 cm of mineral soil in old-, second-, and young-growth riparian forests. The analysis of variance for nutrient concentration, nutrient storage, or nutrients extracted in both the litter layer and top 10 cm of mineral soil showed no significant differences among sites or seasons for any nutrient; only differences among forest ages will be discussed. Concentrations of N, P, Mg, Mn, and Cu in forest litter did not differ by forest age, but concentrations of K, Ca, and B were significantly higher in old-growth forest litter than in the litter of second-or young-growth forests. In mineral soil, the concentrations of all nutrients were statistically equal for all forest ages. Old-growth forests stored significantly (P ≤ 0.05) greater amounts of all nutrients measured in the litter layer, and greater amounts of N, P, and K in the mineral soil, than were stored in second- or young-growth forests. Greater amounts of P, B, and Zn were extracted from old-growth forest litter than from either second- or young-growth forest litter, and greater amounts of P, K, Mn, B, and Zn were extracted from old-growth mineral soil than from second- or young-growth mineral soil. The amount of each nutrient stored in the litter layer of the different-aged forests correlated curvilinearly with the amount of C in the litter layer of these forests; r2 ranged from 0.60 to 0.83. Also, the amount of N, K, and Ca stored in the mineral soil correlated curvilinearly with the amount of C in the soil; r2 ranged from 0.50 to 0.76.

Sign in / Sign up

Export Citation Format

Share Document