Effects of aminocarb and fenitrothion formulations on decomposition rate of balsam fir foliage in litterbags on the forest floor

1986 ◽  
Vol 16 (1) ◽  
pp. 145-146
Author(s):  
D. C. Eidt ◽  
C. A. A. Weaver

Aminocarb with Atlox®, aminocarb with Triton® X-114, and fenitrothion with Tritox® X-114, all inacqueous formulations at the conventional aerial spray double emission rate and 10 times that rate, had no effect on decomposition rate of balsam fir, Abiesbalsamea (L.) Mill., foliage, as indicated by weight loss.

1985 ◽  
Vol 15 (1) ◽  
pp. 174-176
Author(s):  
D. C. Eidt ◽  
C. A. A. Weaver

Fenitrothion in oil and water-based formulations at the conventional aerial emission rate and 10 times that rate, and adjuvants alone at 10 times the aerial emission rate, had no effect on the decomposition rate of white spruce foliage, as indicated by weight loss.


1974 ◽  
Vol 4 (3) ◽  
pp. 327-334
Author(s):  
Denis Lachance

In a balsam fir stand, two different humus moisture conditions were artificially produced and maintained for 2 years by covering the forest floor with polythene sheets on two out of four plots. In the two covered sample plots the water saturation of the humus layer was 30% lower and the moisture contents of root-wood was 35% lower than those of uncovered plots. Roots in covered plots, inoculated with Odontiabicolor, showed 51.4% infection as compared to 57.7% for those growing in control plots. Similarly, trunk inoculations yielded infection levels of 35.8% and 44.5%, respectively. Statistical tests show no significant difference in infection percentages between wetter and drier conditions for roots and trunks, and a significantly greater susceptibility to infection of the roots by O. bicolor as compared to the trunks. Growth rates of the fungus toward the trunk (in the roots) or up the trunks of 4.4–5.8 cm per year was 25–44% greater than growth in the opposite direction. Root and trunk sizes had no definite influence on infection percentages and growth rate, but the latter was always faster in trunk wood than in root wood.


1986 ◽  
Vol 16 (2) ◽  
pp. 293-302 ◽  
Author(s):  
E. S. Wallace ◽  
B. Freedman

A postclear-cutting chronosequence of hardwood stands in Nova Scotia was examined for patterns of forest floor weight, concentration of selected nutrients, rate of potential insitu litter decomposition (litterbags), and potential lab ammonification and nitrification. Some evidence was found that the forest floor experiences weight loss following clear-cutting. However, the large weight losses and clear pattern of recovery described by others for New Hampshire hardwood chronosequences were not observed. The lack of close agreement may have been a result of intra- and inter-stand variation in forest floor weight in our study. This spatial variation was greater than any effect as a result of clear-cutting. There was no significant relationship between insitu weight loss of leaves or twigs with stand age. No clear-cutting effect was observed in the laboratory for potential ammonification, which occurred readily in all stands (three clear-cuttings, three mature stands). Limed materials produced significantly more mineralized N (nitrate N + ammonium N) than did unlimed materials. Concentrations of ammonium N in F and H horizon field material were significantly higher on clear-cuttings than in mature stands. However, since this measurement reflects net rather than total production, it is not evidence that higher rates of ammonification occurred on clear-cuttings. Potential nitrification was not an important process in F and H horizon materials at their natural pH. Nitrification occurred readily in limed materials, but there were no significant differences among different aged stands. Concentrations of nitrate N in field F and H horizon material were low for all stands, with a mean of 9 ± 7 ppm (n = 350). However, in 7% of field samples, nitrate N ≥ 15 ppm was found; in 2%, ≥30 ppm was found.


1978 ◽  
Vol 56 (21) ◽  
pp. 2730-2749 ◽  
Author(s):  
David A. MacLean ◽  
Ross W. Wein

Weight loss and nutrient (N, P, K, Ca, Mg) changes with decomposition were examined over a 2-year period fora variety of kinds of litter on five forest sites. Litter types included pine needles, leaves of four deciduous species (red maple, pin cherry, trembling aspen, and white birch), branches of pine and four deciduous species, understory vegetation, and partially decomposed forest floor material, while the study sites consisted of jack pine stands aged 16, 29, and 57 years and mixed hardwood stands aged 7 and 29 years. Statistically significant differences in rate of weight loss were found to occur, with understory and leaf litter significantly faster on the hardwood stands than on the pine stands, understory litter faster on the 7-year-old hardwood stand than on the 29-year-old stand, and forest floor material faster on the 29-year-old pine stand than on the 57-year-old pine stand. Among the four deciduous species examined, significant differences in leaf weight loss also occurred, but differences among branch litter were nonsignificant. The mass of N in samples generally decreased with decomposition, with increases occurring in a few cases (i.e., pine understory and needle litter). Phosphorus mass generally increased on the pine sites and decreased on the hardwood sites; this appeared to be largely a function of the low initial P concentrations of litter on the pine sites. In general, the mass of K, Ca, and Mg decreased in the various samples with decomposition; the loss of K from deciduous leaves in this study was particularly fast and was greater than other values from the literature.


1983 ◽  
Vol 13 (5) ◽  
pp. 789-794 ◽  
Author(s):  
John F. Fox ◽  
Keith Van Cleve

Forest-floor decomposition is compared among 16 Alaskan taiga forest stands. These include black spruce (Piceamariana (Mill.) B.S.P.), white spruce (Piceaglauca (Moench) Voss), and birch (Betulapapyrifera Marsh.), aspen {Populustremuloides Michx.), and balsam poplar (Populusbalsamifera L.) types, spanning a wide range in decomposition rates, forest-floor microclimates, and litter quality. Jenny's index of decomposition rate, k, is reasonably well correlated with annual cellulose (filter-paper) decomposition differences among stands. Both estimates of decomposition rate are correlated with forest-floor heat sum and forest-floor nitrogen concentration. These between-site correlations support inferences based upon experimental work claiming that temperature and forest-floor chemical quality have a major influence upon the level of decomposition in a particular stand. Inferences about the factors regulating decomposition rate around an average level within one stand cannot legitimately be made from the same correlations. Moisture has not been considered in this analysis, but could also be important to between-stand differences in decomposition rate.


2020 ◽  
Vol 30 (1) ◽  
pp. 32-38
Author(s):  
S. Bhattarai ◽  
B. Bhatta

Leaf-litter decomposition in terrestrial ecosystems has a major role in recycling the nutrients to the soil. Nutrient dynamics is the way nutrients cycle in an ecosystem. The present study was conducted for five selected tropical tree species viz. Shorea robusta, Ficus hookeri, Mallotus philippensis, Artocarpus lakoocha and Dillenia pentagyna at Hetauda, Makawanpur. This paper aims to determine the litter decomposition rate-constant and nutrient mineralization pattern of the selected species. The litter-bag method was used to assess the decomposition and nutrient dynamics for one year. Both decomposition rate-constant and weight loss were highest for M. philippensis (% weight loss = 73.49; k = 0.33) and lowest for S. robusta (% weight loss = 54.01; k = 0.18). In general, weight remaining showed a strong negative correlation with N and P concentration but a slightly negative with K. However, the remaining weight of litter showed a strong positive correlation with C : N ratio, thus indicating a good predictor of mass loss and mineralization. The study showed that there was no net release of nitrogen during the one-year study period; however, the net P release was found to be highest for S. robusta followed by D. pentagyna and the net K release was highest in F. hookeri followed by A. lakoocha.


2000 ◽  
Vol 80 (3) ◽  
pp. 507-514 ◽  
Author(s):  
Sylvain St-Laurent ◽  
Rock Ouimet ◽  
Sylvie Tremblay ◽  
Louis Archambault

Following the Rio and Kyoto protocols, forest sequestration of organic C (Corg) appears to be among the measures to reduce atmospheric C. In this context, we assessed the evolution of soils' reserves of Corg after complete whole-tree forest harvesting in the balsam fir–yellow birch forest of eastern Quebec. The experimental design consisted of eight plots in mature stands, and 10 plots in 7-, 12-, and 22-yr-old clearcuts in the "Seigneurie du Lac Métis", located 80 km south-east of Rimouski, Quebec, Canada. The soil type was an Orthic Humo-ferric Podzol. Major Corg losses occured in the forest floor of the 7-, 12- and 22-yr-old harvested plots compared with mature stands. The FH horizon of harvested plots showed a loss of 44% (−30.5 t ha−1) in dry weight and 13.5% (−62.1 g kg–1) in Corg content between 7 and 22-yr-old harvested plots. More than half the Corg content of the forest floor was lost in that time (−52% or −16.6 t ha−1). The Corg stock of the L horizon were lowered only for the 7-yr-old treatment (2.5 t ha−1) compared with mature stands (4.9 t ha−1). No significant differences in the Corg stocked in the first 30 m of the mineral soil were found between treatments. It appears that the forest floor of balsam fir–yellow birch stands has become a source of Corg for at least 22 yr after forest harvesting. Key words: Forest harvesting, soil, organic carbon, forest floor


1989 ◽  
Vol 19 (4) ◽  
pp. 524-526 ◽  
Author(s):  
I. D. Thompson ◽  
A. U. Mallik

We collected forest floor organic matter at two sites where exclosures had been established 12 years previously. The exclosures allowed examination of the effects of moose (Alcesalces) herbivory on the growth of balsam fir (Abiesbalsamea). The areas supported an understory with Kalmiaangustifolia, which has been shown to affect seedling growth of black spruce (Piceamariana). Balsam fir seedlings grown in the laboratory in soil from outside the exclosures showed a significant reduction in fresh weight of the primary root compared with plants grown in washed sand. Treatment soils also showed a previously known growth inhibition effect on roots of black spruce. Exclusion of moose browsing resulted in a higher density of balsam fir inside the exclosures, while Kalmia, which was not browsed, was more dense outside the exclosures. We postulate that moose browsing reduces the extent to which balsam fir shades Kalmia, and can result in a higher density of the latter species, with consequent inhibitory effects on regenerating coniferous species.


1964 ◽  
Vol 96 (6) ◽  
pp. 894-909 ◽  
Author(s):  
C. J. Sanders

AbstractThirty-five colonies of three species of carpenter ant were examined: 25 of Camponotus herculeanus, 9 of C. noveboracensis, and 1 of C. pennsylvanicus. Workings were examined in about 150 trees. No major differences were noticed in the biology of the first two species.All individuals were taken from two overwintering, torpid, C. herculeanus colonies; the larger contained 6,000 workers, 550 winged forms, and 6,500 larvae. Larvae were of two sizes and it is thought that the life cycle covers two years in New Brunswick. Frequency curves of worker head widths show that there are majors and minors, the minors being more numerous, especially in small colonies.Each colony typically occupied several trees, only one of which contained the brood; the others had less extensive workings. Entrances were underground and led to tunnels connecting the trees within each colony. Surplus wood chips were buried in the ground. Ant activity in the tunnels was continuous through the day and night; few ants were seen on the forest floor.Woodpeckers are important enemies and had attacked one third of the brood trees.The workings frequently assist wind breakage and damage butt logs. From the roots they extend to a height of 4-6 ft., occasionally higher. 1% of the spruce, and 2-4% of the balsam fir examined had been attacked. This may lead to loss of 10% of merchantable volume, and possibly a higher figure for eastern white cedar.


2005 ◽  
Vol 35 (3) ◽  
pp. 667-673 ◽  
Author(s):  
G. Geoff Wang ◽  
Kevin J Kemball

Experimental seeding of balsam fir (Abies balsamea (L.) Mill.) and white spruce (Picea glauca (Moench) Voss) was implemented in three mature trembling aspen (Populus tremuloides Michx.) stands in southeastern Manitoba to test (i) the effect of vegetation (light) competition and seedbed type (undisturbed forest floor, exposed mineral soil, and rotten logs) on seedling recruitment over the first 2 years and (ii) the effect of broadleaf litter exclusion on seedling mortality during the first winter. The study indicated that, with adequate seed supply, seedbed type was the most important factor limiting seedling recruitment, especially the recruitment of white spruce, in trembling aspen stands. Seedling recruitment on the best and the worst seedbeds differed by 1.8 times for balsam fir but by 19 times for white spruce. Significant differences in soil moisture and temperature were found between seedbed types. Broadleaf litter exclusion also facilitated the recruitment of balsam fir and white spruce, but only on undisturbed forest floor. Vegetation (light) competition, however, did not limit seedling recruitment. On the contrary, the presence of understory vegetation benefited seedling recruitment on rotten logs. Compared with white spruce, balsam fir is better adapted to regenerate in trembling aspen stands. Balsam fir was about 4, 12, and 36 times better than white spruce when regenerating on exposed mineral soil, rotten log, and undisturbed forest floor, respectively.


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