Responses of western hemlock, Pacific silver fir, and western red cedar plantations on northern Vancouver Island to applications of sewage sludge and inorganic fertilizer

1993 ◽  
Vol 23 (9) ◽  
pp. 1815-1820 ◽  
Author(s):  
G.F. Weetman ◽  
M.A. McDonald ◽  
C.E. Prescott ◽  
J.P. Kimmins

A field experiment was designed to determine whether or not municipal sewage sludge would be effective for fertilization for chlorotic and checked plantations of western hemlock (Tsugaheterophylla (Raf.) Sarg.), Pacific silver fir (Abiesamabilis (Dougl.) Forbes), and western red cedar (Thujaplicata Donn ex. D. Don) already shown to be responsive to conventional nitrogen and phosphorus fertilization. Sewage sludge was applied at an estimated rate of 500 kg N/ha and 133 kg P/ha and ammonium nitrate and triple superphosphate were applied at 225 kg N/ha and 75 kg P/ha to plots planted 8 years earlier on a cutover of old-growth cedar–hemlock forest. Current-year leader growth and foliar vector analyses showed that the trees responded to both treatments during the first growing season with a doubling or tripling of growth rates and improved nutrition. The apparent problem of insufficient sulphur following nitrogen and phosphorus fertilization was not seen in trees treated with sludge. There were no apparent problems in micronutrient supply in these plantations. The extensive area of checked plantations on northern Vancouver Island present an opportunity for the disposal of sewage sludge.

1994 ◽  
Vol 24 (2) ◽  
pp. 297-301 ◽  
Author(s):  
M.A. McDonald ◽  
B.J. Hawkins ◽  
C.E. Prescott ◽  
J.P. Kimmins

The fertilizer efficacy of a variety of organic wastes was tested in a 9-year-old plantation of western red cedar (Thujaplicata Donn ex D. Don) growing on a cutover of cedar–hemlock (Tsugaheterophylla (Raf.) Sarg.) forest on northern Vancouver Island. Seven treatments were compared: municipal sewage sludge, sewage sludge plus pulp sludge, fish silage and wood ash, silage and ash plus pulp sludge, wood ash alone, ammonium nitrate with triple super phosphate, and control (untreated). Each treatment was replicated three times. Rates of application were 225 kg N•ha−1 in the inorganic fertilizer and about 500 kg N•ha−1 in the organic wastes (except wood ash). The height and diameter of the cedar trees 2 years after fertilization were greatest in the plots treated with inorganic fertilizer (average height was 274 cm, vs. 211 cm in control plots; average diameter at 30 cm was 49 mm, vs. 34 mm in control plots). Smaller but significant growth responses were achieved with sewage sludge and fish silage plus ash. Mixtures of sewage sludge or silage with pulp sludge produced smaller height growth responses, but did not affect diameter growth. Wood ash alone had no effect on tree growth. All treatments except wood ash increased the concentrations of macronutrients in foliage. Foliar N concentrations were greatest in trees treated with fish silage or inorganic fertilizer. Stagnated plantations of western red cedar appear to provide an opportunity for recycling these organic wastes.


1993 ◽  
Vol 23 (6) ◽  
pp. 1052-1059 ◽  
Author(s):  
Rodney J. Keenan ◽  
Cindy E. Prescott ◽  
J.P. Hamish Kimmins

Biomass and C, N, P, and K contents of woody debris and the forest floor were surveyed in adjacent stands of old-growth western red cedar (Thujaplicata Donn)–western hemlock (Tsugaheterophylla (Raf.) Sarg.) (CH type), and 85-year-old, windstorm-derived, second-growth western hemlock–amabilis fir (Abiesamabilis (Dougl.) Forbes) (HA type) at three sites on northern Vancouver Island. Carbon concentrations were relatively constant across all detrital categories (mean = 556.8 mg/g); concentrations of N and P generally increased, and K generally decreased, with increasing degree of decomposition. The mean mass of woody debris was 363 Mg/ha in the CH and 226 Mg/ha in the HA type. The mean forest floor mass was 280 Mg/ha in the CH and 211 Mg/ha in the HA stands. Approximately 60% of the forest floor mass in each forest type was decaying wood. Dead woody material above and within the forest floor represented a significant store of biomass and nutrients in both forest types, containing 82% of the aboveground detrital biomass, 51–59% of the N, and 58–61% of the detrital P. Forest floors in the CH and HA types contained similar total quantities of N, suggesting that the lower N availability in CH forests is not caused by greater immobilization in detritus. The large accumulation of forest floor and woody debris in this region is attributed to slow decomposition in the cool, wet climate, high rates of detrital input following windstorms, and the large size and decay resistance of western red cedar boles.


1972 ◽  
Vol 2 (2) ◽  
pp. 111-120 ◽  
Author(s):  
S. Eis

Many trees in stands of Douglas fir, western hemlock and western red cedar on Vancouver Island were joined by functional grafts. In a partially cut stand, 45% of the stumps showed evidence of continued growth and half of these (23%) were still growing vigorously more than 22 years after logging. On experimentally detopped trees, growth extended several meters up the bole. Dominant trees usually supported the growth of the root system and lower boles of grafted suppressed trees.Translocation through grafts may partially explain the frequent stagnation and slow recovery of stands after thinning from above, and may be involved in the usually rapid increase of growth after thinning from below. It is probably a contributing factor in establishing dominance and determining mortality in overtopped trees. In species that graft freely, the use of silvicides in spacing and thinning treatments should be restricted to young stands before grafts are established.


Recycling ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 52
Author(s):  
Ali Saud ◽  
Jouni Havukainen ◽  
Petteri Peltola ◽  
Mika Horttanainen

Based on mass and energy balance calculations, this work investigates the possibility of recovering heat and nutrients (nitrogen and phosphorus) from municipal sewage sludge using pyrolysis or combustion in combination with a gas scrubbing technology. Considering a wastewater treatment plant (WWTP) with 65,000 t/a of mechanically dewatered digestate (29% total solids), 550 t/a nitrogen and 500 t/a phosphorus were recovered from the 4900 t/a total nitrogen and 600 t/a total phosphorus that entered the WWTP. Overall, 3600 t/a (73%) of total nitrogen was lost to the air (as N2) and clean water, while 90 t/a (15%) of total phosphorus was lost to clean water released by the WWTP. Both in combustion and in pyrolysis, the nitrogen (3%) released within thermal drying fumes was recovered through condensate stripping and subsequent gas scrubbing, and together with the recovery of nitrogen from WWTP reject water, a total of 3500 t/a of ammonium sulfate fertilizer can be produced. Furthermore, 120 GWh/a of district heat and 9700 t/a of ash with 500 t/a phosphorus were obtained in the combustion scenario and 12,000 t/a of biochar with 500 t/a phosphorus was obtained in the pyrolysis scenario. The addition of a stripper and a scrubber for nitrogen recovery increases the total electricity consumption in both scenarios. According to an approximate cost estimation, combustion and pyrolysis require annual investment costs of 2–4 M EUR/a and 2–3 M EUR/a, respectively, while 3–5 M EUR/a and 3–3.5 M EUR/a will be generated as revenues from the products.


1993 ◽  
Vol 23 (3) ◽  
pp. 512-519 ◽  
Author(s):  
Robert L. Edmonds ◽  
Ted B. Thomas ◽  
Kathleen P. Maybury

Tree population dynamics, growth, and mortality were determined in old-growth forested watersheds in the Hoh River valley, Olympic Peninsula, Washington: West Twin Creek (elevation 180–850 m) and Hoh Lake (elevation 1250–1525 m). Principal tree species at West Twin Creek are Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), western hemlock (Tsugaheterophylla (Raf.) Sarg.), Pacific silver fir (Abiesamabilis (Dougl.) Forb.), western red cedar (Thujaplicata D. Don), and Sitka spruce (Piceasitchensis (Bong.) Carr.). At Hoh Lake they are Pacific silver fir, mountain hemlock (Tsugamertensiana (Bong.) Carr.), and Alaska cedar (Chamaecyparisnootkatensis (D. Don) Spach). In 1985 stem densities for trees >5 cm DBH averaged 476 and 489 ha−1 in the upper and lower West Twin Creek watershed, respectively, and 508 ha−1 at Hoh Lake watershed. Stem densities at both sites declined 3–5% from 1985 to 1990. Western hemlock and Pacific silver fir were the dominant species at West Twin Creek and Hoh Lake, respectively. From 1985 to 1990 the annual mortality rate was 0.8% at West Twin Creek and 0.9% at Hoh Lake. Pacific silver fir had the highest mortality rate. No Douglas-fir or western red cedar trees died. The primary causes of mortality were as follows: suppression–unknown, diseases, insects, and windthrow. In 1985 basal areas were 77, 87, and 94 m2•ha−1 in the lower and upper West Twin Creek watershed and Hoh Lake watershed, respectively. There was a 5% increase and a 1% decrease in basal area from 1985 to 1990 in the lower and upper West Twin Creek watershed, respectively, and a 4% decrease at Hoh Lake. Western red cedar, Douglas-fir, and western hemlock increased in basal area, while the other species declined.


Agronomie ◽  
2001 ◽  
Vol 21 (2) ◽  
pp. 169-178 ◽  
Author(s):  
Giovanni Gigliotti ◽  
Pier Lodovico Giusquiani ◽  
Daniela Businelli

Sign in / Sign up

Export Citation Format

Share Document