Cation distribution, cycling, and removal from mineral soil in Douglas-fir and red alder forests

1992 ◽  
Vol 16 (2) ◽  
pp. 121-150 ◽  
Author(s):  
Peter S. Homann ◽  
Helga van Miegroet ◽  
Dale W. Cole ◽  
Gordon V. Wolfe
Keyword(s):  
Cation Distribution ◽  
Mineral Soil ◽  
Douglas Fir ◽  
Red Alder

Effect of the light environment on seed germination of red alder (Alnusrubra)

1993 ◽  
Vol 23 (7) ◽  
pp. 1487-1491 ◽  
Author(s):  
Sybille Haeussler ◽  
John C. Tappeiner II
Keyword(s):  
Leaf Litter ◽  
Red Light ◽  
Mineral Soil ◽  
Field Studies ◽  
Douglas Fir ◽  
Understory Vegetation ◽  
Light Conditions ◽  
Complete Darkness ◽  
Red Alder ◽  
Disturbed Habitats

Red alder (Alnusrubra Bong.) seed showing strong phytochrome activity in the laboratory was tested to determine whether the phytochrome effect could influence germination under light conditions experienced in the field. Seeds in sealed Petri dishes were placed beneath three types of overstory cover (clearcut (no overstory); Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) (coniferous evergreen overstory); and red alder (broad-leaved deciduous overstory)) and seven types of understory cover (control (complete darkness); uncovered; 1-cm mineral soil; leaf litter; moss; swordfern; and non-evergreen herbs). Germination was highest in clearcuts (68.6%), intermediate in Douglas-fir stands (47.4%), and lowest in red alder stands (11.7%). Covers of understory vegetation, leaf litter, and mineral soil significantly reduced germination, with the greatest reduction occurring where understory vegetation was dense enough to significantly reduce the ratio of red:far-red light. These findings concur with field studies of red alder seedling establishment and suggest that the phytochrome sensitivity of red alder seed plays an important role in this species' success on disturbed habitats.

Water chemistry profiles in an early- and a mid-successional forest in coastal British Columbia

1982 ◽  
Vol 12 (2) ◽  
pp. 240-248 ◽  
Author(s):  
Dan Binkley ◽  
J. P. Kimmins ◽  
M. C. Feller
Keyword(s):  
Water Chemistry ◽  
Forest Ecosystem ◽  
Stream Water ◽  
Mineral Soil ◽  
Douglas Fir ◽  
Mineral Weathering ◽  
Nutrient Concentrations ◽  
Saturated Zone ◽  
Red Alder ◽  
Zone Water

Water chemistry profiles of an 18-year-old forest ecosystem are compared with those of a 70- to 90-year-old forest ecosystem for a 9-month period. The younger ecosystem was dominated by Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and red alder (Alnusrubra Bong.) whereas western hemlock (Tsugaheterophylla (Raf.) Sarg.), Douglas-fir, and western red cedar (Thujaplicata Donn.) dominated the older ecosystem. Concentrations of nutrients and other chemicals were measured in throughfall, forest floor and mineral soil lecachates, saturated-zone water, and stream water. Concentrations of dissolved chemicals were much greater in the younger ecosystem than in the older ecosystem at intermediate stages in the profiles. However, stream water concentrations differed less between the two ecosystems for most of the chemicals investigated. Nitrate and silica were exceptional; stream water nitrate concentrations in the younger ecosystem averaged 16 times greater than those in the older ecosystem. This was probably a result of biological nitrogen fixation by red alder in the younger ecosystem, a process which would more than compensate for the higher nitrate losses. Silica concentrations in the younger ecosystem consistently exceeded levels in the older ecosystem by 40 to 100%. suggesting a possibility of a greater rate of mineral weathering in the younger ecosystem.Although nutrient concentrations were higher in the soil leachates of the younger ecosystem, these higher levels failed to persist through the saturated-zone water and stream water stages of the water chemistry profile. Consequently, the younger ecosystem appeared relatively more efficient at retaining dissolved nutrients than the older ecosystem. Stream water chemistry was relatively insensitive to the magnitudes of the differences in biogeochemical process rates of the two ecosystems.

Douglas-fir soil C and N properties a decade after termination of urea fertilization

2001 ◽  
Vol 31 (12) ◽  
pp. 2225-2236 ◽  
Author(s):  
Peter S Homann ◽  
Bruce A Caldwell ◽  
H N Chappell ◽  
Phillip Sollins ◽  
Chris W Swanston
Keyword(s):  
Mineral Soil ◽  
Cellulase Activity ◽  
Douglas Fir ◽  
Soil Organic C ◽  
Total N ◽  
Organic C ◽  
Soil C ◽  
Second Growth ◽  
Heavy Fractions ◽  
Urea Fertilization

Chemical and microbial soil properties were assessed in paired unfertilized and urea fertilized (>89 g N·m–2) plots in 13 second-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands distributed throughout western Washington and Oregon. A decade following the termination of fertilization, fertilized plots averaged 28% higher total N in the O layer than unfertilized plots, 24% higher total N in surface (0–5 cm) mineral soil, and up to four times the amount of extractable ammonium and nitrate. Decreased pH (0.2 pH units) caused by fertilization may have been due to nitrification or enhanced cation uptake. In some soil layers, fertilization decreased cellulase activity and soil respiration but increased wood decomposition. There was no effect of fertilization on concentrations of light and heavy fractions, labile carbohydrates, and phosphatase and xylanase activities. No increase in soil organic C was detected, although variability precluded observing an increase of less than ~15%. Lack of a regionwide fertilization influence on soil organic C contrasts with several site-specific forest and agricultural studies that have shown C increases resulting from fertilization. Overall, the results indicate a substantial residual influence on soil N a decade after urea fertilization but much more limited influence on soil C processes and pools.

Germination, survival, and early growth of red alder seedlings in the central Coast Range of Oregon

1995 ◽  
Vol 25 (10) ◽  
pp. 1639-1651 ◽  
Author(s):  
Sybille Haeussler ◽  
John C. Tappeiner II ◽  
Brian J. Greber
Keyword(s):  
Soil Moisture ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
Mineral Soil ◽  
Survival Rates ◽  
Moisture Stress ◽  
Coast Range ◽  
Seedling Mortality ◽  
Central Coast ◽  
Red Alder

Effects of forest disturbance and soil moisture levels on establishment of red alder (Alnusrubra Bong.) seedlings were studied at four sites representing a climatic moisture gradient within the central Coast Range of Oregon. On average, there was no difference in seedling emergence between recent clearcuts and second-growth forests, but emergence was much higher on mineral soil than on organic seedbeds. Emergence, on both types of seedbed, was positively correlated with spring soil moisture conditions (R2 = 0.60). Seedling survival, on the other hand, differed greatly between clearcut and forest. In clearcuts, heat and drought injuries were the primary causes of seedling mortality. In the forest, seedlings had poor vigour and quickly succumbed to pathogens, herbivores, and rain splash. First-year survival rates were strongly correlated with minimum summer soil moisture levels (R2 = 0.71). Height growth of seedlings on clearcuts (2–5 cm after 1 year; 8–23 cm after 2 years) was much slower than rates typically described for red alder. Best establishment occurred on skid trails and landings, suggesting that young seedlings may suffer less from heat or moisture stress on these heavily disturbed microenvironments.

Influence of Particle Size on Decomposition of Red Alder and Douglas Fir Sawdust in Soil

Nature ◽  
1965 ◽  
Vol 205 (4975) ◽  
pp. 991-993 ◽  
Author(s):  
J. L. NEAL ◽  
W. B. BOLLEN ◽  
K. C. LU
Keyword(s):  
Particle Size ◽  
Douglas Fir ◽  
Red Alder

Crop Rotation of Douglas-Fir and Red Alder: A Preliminary Biological and Economic Assessment

1979 ◽  
Vol 140 ◽  
pp. S102-S107 ◽  
Author(s):  
W. A. Atkinson ◽  
B. T. Bormann ◽  
D. S. de Bell
Keyword(s):  
Crop Rotation ◽  
Economic Assessment ◽  
Douglas Fir ◽  
Red Alder

Biomass and nutrient content of Douglas-fir logs and other detrital pools in an old-growth forest, Oregon, U.S.A.

1992 ◽  
Vol 22 (10) ◽  
pp. 1536-1546 ◽  
Author(s):  
Joseph E. Means ◽  
Paul C. MacMillan ◽  
Kermit Cromack Jr.
Keyword(s):  
Forest Floor ◽  
Soluble Fraction ◽  
Close Association ◽  
C:N Ratio ◽  
Mineral Soil ◽  
Nutrient Content ◽  
Douglas Fir ◽  
Area Index ◽  
Old Growth Forest ◽  
N Release

Logs, forest floor, and mineral soil were sampled and measured, and snags were measured, in a 450-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stand on the H.J. Andrews Experimental Forest, Oregon. Logs, some still identifiable after 300 years on the forest floor, contained large amounts of organic matter (222 Mg/ha), C (100 Mg/ha), water (559–10 700 L/log), N (183 kg/ha), and Ca (141 kg/ha), and smaller amounts of P (5.5 kg/ha), K (22 kg/ha), Mg (14 kg/ha), and Na (3.7 kg/ha). Logs and snags covered about 17% of the forest floor and had an all-sided area index of 0.69 m2/m2. Through mineralization, C, N, and K were lost through time; Ca and Mg increased; and P and Na increased then decreased, showing no net change. Also through mineralization, cellulose and hot acid detergent soluble fraction decreased more rapidly than lignin. Lignin was apparently not lost until the later stages of decay, when N was also lost in significant amounts. This parallels the shift from initial dominance by white rots that degraded cellulose and lignin to later dominance by brown rots that preferentially degraded cellulose. Lignin and cellulose were eventually lost at more similar rates in later decay stages. This may have been due in part to a close association between the remaining cellulose and lignin in later decay stages. Lignin was a better predictor of the onset of N release than was the C:N ratio.

The economics of Douglas-fir and red alder management with stochastic price trends

1993 ◽  
Vol 23 (8) ◽  
pp. 1695-1703 ◽  
Author(s):  
Robert G. Haight
Keyword(s):  
Pacific Northwest ◽  
Financial Analysis ◽  
Probability Distributions ◽  
Low Cost ◽  
The United States ◽  
Douglas Fir ◽  
Mixed Species ◽  
Red Alder ◽  
Commercial Thinning ◽  
Price Trends

A financial analysis of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and red alder (Alnusrubra Bong.) management is conducted using yield projections from the Stand Projection Simulator for the Pacific Northwest region of the United States. The analysis includes uncertainty in the price trends and stocking levels of both species following reforestation. Results from a case study in which Douglas-fir price is likely to increase faster than red alder price show that (i) on more productive sites, greater regeneration investment is justified to increase the likelihood of Douglas-fir establishment; (ii) on less productive sites, low-cost regeneration options that produce mixed-species stands have expected present values close to or greater than a high-cost Douglas-fir regeneration effort; (iii) optimal precommercial removal of red alder depends on midrotation prices and regeneration success, and in many cases growing a mixed-species stand to maturity produces the highest economic return; (iv) commercial thinning of Douglas-fir increases the expected present value of the most intensive regeneration option by up to 10%. The low-cost regeneration options have relatively high expected returns because of low initial investments and the presence of two species that may have high values in the future. The sensitivity of these results to changes in the probability distributions of regeneration success and price trends is discussed.

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