Effect of forest floor on growth and nutrition of Douglas-fir and western hemlock seedlings with and without fertilizer

1992 ◽  
Vol 22 (9) ◽  
pp. 1222-1229 ◽  
Author(s):  
M.A. Radwan
Keyword(s):  
Seedling Growth ◽  
Forest Floor ◽  
Dry Weight ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Seed Sources ◽  
Shoot Dry Weight ◽  
Growth And Nutrition ◽  
Forest Floors ◽  
P Fertilizers

Experiments were conducted to determine the effects of four different forest soils on growth and shoot nutrients of potted Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and western hemlock (Tsugaheterophylla (Raf.) Sarg.) seedlings, in absence and in presence of forest floor, and with and without N and P fertilizers. Nine-month-old seedlings from low-elevation seed sources were used, and seedlings were grown for 2 years in a roofed lathhouse. Soils were of the Klone, Vesta, Bunker, and Shelton series; Klone and Vesta soils, and Bunker and Shelton soils, were collected from western hemlock and Douglas-fir stands, respectively. The fertilizers ammonium nitrate at 100 kg N/ha and triple superphosphate at 226 kg P/ha were tested. The forest floor, at 70 g/7.6-L pot, and the N and P fertilizers were added to the top of the planting pots without mixing. The forest floors and mineral soils differed by source in many of the chemical characteristics determined. Overall, seedling growth of Douglas-fir and western hemlock was better in the Klone and Shelton soils than in the Bunker and Vesta soils. Seedlings, especially those of western hemlock, grew better with than without forest floor. The N fertilizer reduced seedling growth of both species and, in some soils, reductions were more with than without forest floor. The P fertilizer improved seedling growth of both species in all soils and, with one exception, growth was much greater in the presence than in the absence of the forest floor. With both species, soil, forest-floor, and fertilization treatments affected concentrations and contents of the various shoot nutrients determined. The nutritional changes observed varied by nutrient and reflected differences in uptake of native and fertilizer nutrients, as well as changes in shoot dry weight. The results demonstrate the importance of the forest floor to growth and nutrition of Douglas-fir and western hemlock seedlings, especially when fertilizers are used.

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.

Nitrogen mineralization and decomposition in forest floors in adjacent plantations of western red cedar, western hemlock, and Douglas-fir

1994 ◽  
Vol 24 (12) ◽  
pp. 2424-2431 ◽  
Author(s):  
C.E. Prescott ◽  
C.M. Preston
Keyword(s):  
Mass Loss ◽  
N Mineralization ◽  
Forest Floor ◽  
Douglas Fir ◽  
Western Hemlock ◽  
N Availability ◽  
Net N Mineralization ◽  
Red Cedar ◽  
Western Red Cedar ◽  
Forest Floors

To determine if western red cedar (Thujaplicata Donn) litter contributes to low N availability in cedar–hemlock forests, we measured concentrations of N and rates of net N mineralization in forest floors from single-species plantations of cedar, western hemlock (Tsugaheterophylla (Raf.) Sarg.), and Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) on the same site in coastal British Columbia. Concentrations of total and extractable N and rates of net N mineralization during laboratory incubations were lowest in the cedar forest floor and highest in Douglas-fir. Less C was mineralized in the cedar forest floor during incubation, and the amount of N mineralized per unit C was least in cedar. Rates of mass loss of foliar litter of the three species were similar during the first 50 weeks of a 70-week laboratory incubation, but cedar lost mass more quickly during the final 20 weeks. Rates of net N mineralization in the forest floors were significantly correlated with the initial percent N, C/N, % Klason lignin, and lignin/N of foliar litter. Foliar litter of cedar had lower concentrations of N and greater proportions of alkyl C (based on 13C NMR spectroscopy) than Douglas-fir litter. These characteristics of cedar litter may contribute to low N availability in cedar–hemlock forest floors. Concentrations of alkyl C (waxes and cutin) may be better than lignin for predicting rates of mass loss and N mineralization from litter.

scholarly journals Exogenous Antioxidants Enhance Seedling Growth and Yield of Artificially Aged Cabbage and Lettuce Seeds

Horticulturae ◽  
2021 ◽  
Vol 7 (9) ◽  
pp. 274
Author(s):  
Ademola Adetunji ◽  
Sershen ◽  
Boby Varghese ◽  
Norman Pammenter
Keyword(s):  
Leaf Area ◽  
Seedling Growth ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Growth And Yield ◽  
Seed Vigour ◽  
Beneficial Effects ◽  
Shoot Dry Weight ◽  
Antioxidant Defence System ◽  
Aged Seeds

Aged seeds exhibit compromised vigour in terms of germination, seedling emergence and growth, but this can to some extent be alleviated by invigoration treatments before sowing. This study aimed to investigate ageing rates and patterns in cabbage (Brassica oleraceae) and lettuce (Lactuca sativa) seeds and whether the beneficial effects of invigorating aged seeds with exogenous antioxidants translate to enhanced seedling performance. Seeds were artificially aged to 25% viability before soaking in 0.4 mM glycerol, 0.6 mM GSH and 0.2 mM trolox for cabbage, and 0.6 mM glycerol, GSH and trolox for lettuce; deionised water served as a control. After 14 days of sowing, seedling emergence percentage, mean emergence time, mean daily emergence, and time taken to 25% emergence were computed. Seedling vigour index, root and shoot dry weight, root:shoot ratio, leaf area, leaf area ratio, and leaf chlorophyll content were assessed 6 weeks after sowing. Furthermore, the photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (E), and chlorophyll fluorescence were measured 6 weeks after sowing. Notably, ageing resulted in the loss of seed vigour and viability at higher rates in lettuce than cabbage. Seed pretreatment with glycerol promoted seedling growth in both species and shoot dry weight in lettuce, while glycerol and GSH enhanced Pn, Gs and E in lettuce. Trolox also enhanced Pn and E in lettuce. The beneficial effects of the antioxidant treatments are thought to be associated with the protection of photosystems from oxidative stress and/or stimulation of enzymes involved in photosynthesis, possibly through an enhanced antioxidant defence system during the early development stages when seedlings are particularly vulnerable to stress.

Availability of N and P in the forest floors of adjacent stands of western red cedar–western hemlock and western hemlock–amabilis fir on northern Vancouver Island

1993 ◽  
Vol 23 (4) ◽  
pp. 605-610 ◽  
Author(s):  
C. E. Prescott ◽  
M.A. McDonald ◽  
G.F. Weetman
Keyword(s):  
Forest Floor ◽  
Forest Type ◽  
Western Hemlock ◽  
Red Cedar ◽  
Floor Layer ◽  
Second Growth ◽  
Extractable P ◽  
Western Red Cedar ◽  
Forest Floors ◽  
Floor Material

Availability of N and P was compared in the forest floors of old-growth forests of western red cedar (Thujaplicata Donn)and western hemlock (Tsugaheterophylla (Raf.) Sarg.) (CH forests), and second-growth forests of western hemlock and amabilis fir (Abiesamabilis (Dougl.) Forbes) (HA forests) of windthrow origin. Five samples of each forest floor layer (litter, fermentation (woody and nonwoody), and humus (woody and nonwoody)) were collected from three forests of each type (CH and HA). All layers of CH forest floors had smaller concentrations of total and extractable N and mineralized less N during 40-day aerobic incubations in the laboratory. Total and extractable P was lower in the litter layer of CH forest floors. Seedlings of western red cedar, Sitka spruce (Piceasitchensis (Bong.) Carr.), western hemlock, and amabilis fir grown from seed in forest floor material from CH forests grew more slowly and took up less N and P than did seedlings grown in HA forest floor material. The low supply of N and P in CH forest floors may contribute to the nutrient supply problems encountered by regenerating trees on cutovers of this forest type.

Patterns of log decay in old-growth Douglas-fir forests

1987 ◽  
Vol 17 (12) ◽  
pp. 1585-1595 ◽  
Author(s):  
Phillip Sollins ◽  
Steven P. Cline ◽  
Thomas Verhoeven ◽  
Donald Sachs ◽  
Gody Spycher
Keyword(s):  
C:N Ratio ◽  
Dry Weight ◽  
Douglas Fir ◽  
Time Span ◽  
Western Hemlock ◽  
Tissue Type ◽  
Old Growth ◽  
Total N ◽  
Red Cedar ◽  
Western Red Cedar

Fallen boles (logs) of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), western hemlock (Tsugaheterophylla (Raf.) Sarg.), and western red cedar (Thujaplicata Donn) in old-growth stands of the Cascade Range of western Oregon and Washington were compared with regard to their physical structure, chemistry, and levels of microbial activity. Western hemlock and western red cedar logs disappeared faster than Douglas-fir logs, although decay rate constants based on density change alone were 0.010/year for Douglas-fir, 0.016/year for western hemlock, and 0.009/year for western red cedar. We were unable to locate hemlock or red cedar logs older than 100 years on the ground, but found Douglas-fir logs that had persisted up to nearly 200 years. Wood density decreased to about 0.15 g/cm3 after 60–80 years on the ground, depending on species, then remained nearly constant. Moisture content of logs increased during the first 80 years on the ground, then remained roughly constant at about 250% (dry-weight basis) in summer and at 350% in winter. After logs had lain on the ground for about 80 years, amounts of N, P, and Mg per unit volume exceeded the amount present initially. Amounts of Ca, K, and Na remained fairly constant throughout the 200-year time span that was studied (100-year time span for Na). N:P ratios converged toward 20, irrespective of tree species or wood tissue type. C:N ratios dropped to about 100 in the most decayed logs; net N was mineralized during anaerobic incubation of most samples with a C:N ratio below 250. The ratio of mineralized N to total N increased with advancing decay. Asymbiotic bacteria in fallen logs fixed about 1 kg N ha−1 year−1, a substantial amount relative to system N input from precipitation and dry deposition (2–3 kg ha−1 year−1).

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.

scholarly journals Effect of Nitrogen, Gibberellic Acid, Triadimefon, and Kinetin on the Seedling Growth of Sapodilla (Achras sapota) and Tamarind (Tamarindus indica)

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 437C-437
Author(s):  
J.P. Morales-Payan ◽  
B.M. Santos
Keyword(s):  
Gibberellic Acid ◽  
Seedling Growth ◽  
Dry Weight ◽  
Internode Length ◽  
Tamarindus Indica ◽  
Loamy Soil ◽  
Shoot Dry Weight ◽  
Achras Sapota ◽  
Nitrogen Rates ◽  
Plastic Containers

Container experiments were conducted in the Dominican Republic to determine the effects of nitrogen, gibberellic acid, triadimefon, and kinetin on the seedling growth of sapodilla (Achras sapota) and tamarind (Tamarindus indica). Plants were started from seeds on cylindrical plastic containers (20 × 20 cm) filled with an artificial a 1:1 mixture of sand and loamy soil, allowing the growth of only one plant per container. Nitrogen rates (0.5, 0.75, and 1.0 g N per plant, applied as ammonium sulfate) were factorially combined with the rates (0, 25, 50, 75, and 100 ppm each) of the regulators. When the plants had three true leaves, nitrogen was applied to the growing mixture, whereas the growth regulators were applied foliarly. Plants were allowed to grow during 60 days after treatment. There were no nitrogen and regulator interactions. Kinetin treatments did not significantly influence shoot dry weight and height in either species. Both species responded with linearly increased height, internode length, and dry weight to increasing GA3 concentrations. Increasing rates of the growth retardant triadimefon significantly reduced the internode length and total height of sapodilla and tamarind seedlings. These results suggest that gibberellin and triadimefon could be effectively used as a means to stimulate or retard, respectively, the growth of sapodilla and tamarind.

The effect of wrenching on morphology and field performance of Douglas fir and loblolly pine seedlings

1976 ◽  
Vol 6 (4) ◽  
pp. 453-458 ◽  
Author(s):  
Yasuomi Tanaka ◽  
J. D. Walstad ◽  
J. E. Borrecco
Keyword(s):  
Loblolly Pine ◽  
Lateral Roots ◽  
Field Performance ◽  
Dry Weight ◽  
Douglas Fir ◽  
Shoot Dry Weight ◽  
Percentage Points ◽  
Pine Seedlings ◽  
Nursery Stock ◽  
Second Year

Second-year Douglas fir and 1st-year loblolly pine nursery stock were undercut and wrenched while actively growing in nursery beds. Their morphology and field performance were compared with Douglas fir seedlings that had been undercut only and with loblolly pine seedlings that had been left intact.The treatment produced shorter, thinner-stemmed loblolly pine seedlings with reduced shoot dry weight. Height, diameter, and shoot dry weight of Douglas fir seedlings were virtually unaffected, but root dry weight was increased substantially. Development of fibrous lateral roots was stimulated in both species. As a consequence, shoot–root ratios were considerably improved, and the seedlings were better conditioned to withstand outplanting. On droughty sites, field survival of Douglas fir was increased by 20 percentage points and loblolly pine by 30 percentage points. Wrenching also extended by several weeks the fall and spring planting periods for loblolly pine and the fall planting period for Douglas fir.

Variance in response of pole-size trees and seedlings of Douglas-fir and western hemlock to nitrogen and phosphorus fertilizers

1991 ◽  
Vol 21 (10) ◽  
pp. 1431-1438 ◽  
Author(s):  
M. A. Radwan ◽  
J. S. Shumway ◽  
D. S. DeBell ◽  
J. M. Kraft
Keyword(s):  
Plant Tissue ◽  
Basal Area ◽  
Douglas Fir ◽  
Nitrogen Fertilizers ◽  
Western Hemlock ◽  
Triple Superphosphate ◽  
Nitrogen And Phosphorus ◽  
P Fertilizer ◽  
Closed Canopy ◽  
P Fertilizers

Three experiments were conducted to determine effects of N and P fertilizers on growth and levels of plant-tissue nutrients of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and western hemlock (Tsugaheterophylla (Raf.) Sarg.). Both pole-size trees in closed-canopy stands and potted seedlings were used. Soil series were Bunker for Douglas-fir and Klone for western hemlock in experiments 1 and 3, and Vesta in experiment 2. For each species in experiments 1 and 2, P and N fertilizers were tested in six or eight treatments using factorial design. In experiment 3, N and P fertilizers were individually tested on seedlings, at one rate of application each. Nitrogen fertilizers used were urea in experiment 1 and ammonium nitrate in the other two experiments; P was applied as triple superphosphate in all three experiments. In general, fertilization changed levels of some plant-tissue nutrients of the pole-size trees and potted seedlings. Neither height nor basal-area growth of the trees was significantly affected by any of the fertilization treatments in the first two experiments. Seedling growth of both Douglas-fir and western hemlock was dramatically improved by the P fertilizer, but was negatively affected by the N fertilizer. Results clearly show differences between pole-size trees and seedlings in response to N and P fertilizers. They also suggest that N not be applied where soils are high in N and low in P and that P applications be confined to sites with low-P soils, when trees are young, before canopy closure.

Trifluralin and Triallate Retention by Imbibed Tame Oat (Avena sativa) Caryopses

Weed Science ◽  
1984 ◽  
Vol 32 (2) ◽  
pp. 251-257 ◽  
Author(s):  
Martin C. Heath ◽  
Ross Ashford ◽  
Robert B. McKercher
Keyword(s):  
Seedling Growth ◽  
Avena Sativa ◽  
Shoot Growth ◽  
Residual Activity ◽  
Dry Weight ◽  
Distilled Water ◽  
Coleoptile Length ◽  
Seed Imbibition ◽  
Shoot Dry Weight ◽  
Phytotoxic Effect

The effect of exposing tame oat (Avena sativaL. ‘Hudson’) to trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) and triallate [S-(2,3,3-trichloroallyl) diisopropylthiocarbamate] during seed imbibition was investigated in a growth cabinet at 21 C in the absence of light. Caryopses were imbibed in 0.0, 1.5, and 3.0 ppmv aqueous dilutions of trifluralin and triallate for up to 10 h, after which germination was continued in distilled water. Germination was not affected following imbibition in either herbicide. Both herbicides produced distinct visual symptoms of herbicide injury during subsequent seedling growth. Coleoptile length of 5-day-old seedlings was reduced following imbibition in a 1.5-ppmv dilution of either herbicide. Triallate at 1.5 ppmv resulted in a reduction in shoot dry weight. Both herbicides were largely excluded from embryos of imbibing caryopses. Seedlings were unaffected when cultured from embryos excised from caryopses imbibed in trifluralin and triallate dilutions. Seedling phytotoxic effects resulted from residual activity of trifluralin and triallate retained by the pericarp and testa of imbibed caryopses. Presence of the hull during imbibition decreased the phytotoxic effect of both herbicides on shoot growth. These findings suggest that germinating seedlings ofAvenaspp. may be affected by trifluralin and triallate at an earlier stage than previously realized.

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