Nutrient dynamics in the litter fall and forest floor of an 18-year-old loblolly pine plantation

1986 ◽  
Vol 16 (5) ◽  
pp. 1109-1112 ◽  
Author(s):  
B. G. Lockaby ◽  
Jane Ellen Taylor-Boyd

Dry weight and N, P, K, Ca, and Mg concentrations were monitored in the litter fall and forest floor of a loblolly pine (Pinustaeda) plantation in north Louisiana for 2 years. Dry weights of both litter fall and forest floor were statistically stable during the sampling period, possibly indicating steady-state conditions. A comparison of litter fall with forest floor weights indicated rapid decomposition (floor turnover = 1.5 years) relative to that of other loblolly pine systems.

1997 ◽  
Vol 13 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Nicholas C. Songwe ◽  
F. E. Fasehun ◽  
D. U. U. Okali

ABSTRACTThe variations in macronutrient concentrations of the leaves of Terminalia superba and Pycanthus angolensis were studied and the concentrations of nutrients in leaves before abscission were compared with those after abscission. The amounts of nutrients returned to the forest floor were also computed from litter fall data at the start of maximum annual fall in the Reserve. With the exception of potassium in Pycanthus angolensis, there were significant variations in the nutrient concentrations of the two species with the time of year. With increasing leaf age the concentration of nitrogen, phosphorus, potassium and magnesium declined in Terminalia superba while magnesium concentration decreased in Pycanthus angolensis leaves. Furthermore, calcium showed an increasing concentration in Terminalia superba with increase in leaf age. The concentrations of nitrogen, phosphorus and potassium decreased before leaf fall. Estimated losses in nitrogen phosphorus and potassium before abscission were 44, 53 and 50%, respectively, whereas generally there was an increase (40%) in the concentration of calcium at leaf fall. Magnesium did not follow a definite pattern. The return of calcium through litter fall to the forest floor was the greatest of all the major elements. The distribution and variation of foliar nutrient concentrations in the leaves of Terminalia superba and Pycanthus angolensis and the importance of the amount of litter and the concentration of the various nutrients in the influencing soil fertility are discussed.


1987 ◽  
Vol 11 (2) ◽  
pp. 83-86 ◽  
Author(s):  
J. Melinda Slay ◽  
B. G. Lockaby ◽  
J. C. Adams ◽  
C. G. Vidrine

Abstract Competing vegetation, seedling survival, and growth of loblolly pine (Pinus taeda L.) were evaluated one year following four site-preparation techniques in north Louisiana. The treatments were chop and burn, windrow, fuelwood harvest, and fuelwood harvest followed by a herbicide. Physicalsoil properties were evaluated before and after treatment application. The study was designed as a randomized complete block and was installed on a Gore silt loam (Vertic Paleudalf) soil. Windrowing significantly increased surface bulk densities. Fuelwood had significantly higher bulk densityvalues for subsurface samples. In comparisons among treatments, surface bulk densities for the windrow treatment were significantly higher than both of the fuelwood treatments. The fuelwood treatment was significantly higher in competing vegetation while the fuelwood followed by a herbicidetreatment was significantly lowest. The fuelwood followed by a herbicide ranked significantly higher in seedling height, ground line diameter, and volume. Seedling growth was inversely related to competing vegetation dry weight. There were no significant differences among treatments in seedlingsurvival. South. J. Appl. For. 11(2):83-86.


1991 ◽  
Vol 21 (4) ◽  
pp. 462-468 ◽  
Author(s):  
I. K. Morrison

Litter fall and its content of N, P, K, Ca, Mg, S, Fe, Mn, Zn, and Cu were measured monthly over a 5-year period in an old-growth Acersaccharum Marsh, stand on a till site in central northern Ontario. Determined were the following: the amount, and the temporal and spatial distributions, of organic matter and elements deposited annually in the different litter fractions; the proportion of elements conserved within the tree phytomass through retranslocation versus that shed in the annual litter fall; and the residence time of litter-transported elements in the forest floor. Element transfer through the annual litter fall was also compared with that by other vectors of transport to the forest floor. Over the study period, total litter fall averaged 3730 kg•ha−1•year−1 (dry weight), with 78% consisting of leaves, 8% of flowers and fruits, and the remaining 14% mainly of twigs, branches, and bark slough. Annual element depositions (kg•ha−1) averaged as follows: N, 40.6; P, 1.8; K, 9.1; Ca, 37.6; Mg, 3.9; S, 3.0; Fe, 0.57; Mn, 2.67; Zn, 0.28; and Cu, 0.03. Turnover time of the forest floor was calculated as 7.4 years. Residence times (years) of elements in the forest floor were as follows: N, 18.3; P, 18.3; K, 1.5; Ca, 6.1; Mg, 6.8; S, 5.1; Fe, 257.2; Mn, 4.8; Zn, 18.1; and Cu, 5.8. Although the turnover time of forest-floor organic matter did not differ appreciably from values reported for A. saccharum forests elsewhere, residence times for elements suggested somewhat slower cycling, probably as a result of reduced uptake related to the advanced age of the stand. Potassium, followed by S, P, and N, were all conserved to a high degree by A. saccharum trees through retranslocation to the tree's perennial parts prior to leaf fall; Cu, Mn, and Mg were conserved to a lesser degree; Zn, Ca, and Fe were conserved very little. In comparing the leaching loss of elements from foliage with quantities conserved through retranslocation and quantities shed in the annual litter fall, the relative orders of magnitude do not give cause for concern that A. saccharum trees risk appreciable leaching losses of base cations, including K, from foliage as a result of acidified precipitation, at least at levels experienced in central northern Ontario during the early 1980s.


1977 ◽  
Vol 25 (1) ◽  
pp. 47
Author(s):  
RW Rogers ◽  
WE Westman

The plant components and chemical composition of litter fall and the litter layer in a forest growing on deep, nutrient-poor sands were examined on North Stradbroke Island, south-eastern Queensland. The seasonal distribution of litter fall was examined over a 26-month period. While the total litter fall was greatest during summer months, the dominant tree species differed in their individual patterns of litter fall. Eucalyptus signata showed a single summer peak for leaf fall while E. umbra exhibited one peak in early summer and another in autumn. The possibility is discussed that these and other temporal differences are evolutionary expressions of niche differentiatibn to reduce competition between species in the ecosystem. The total litter fall averaged 640 g m-1 yr-1 and the accumulated forest floor mass totalled 2700 g m-2. Total nutrient pools and nutrient inputs in litter fall are presented. A litter half-life of 2.9 years is estimated, a figure close to the half-life of most of the nutrients in the litter. Manganese appears to be markedly concentrated in eucalypt leaves before they fall. Only sodium, potassium, copper and chloride appear to be leached easily from leaves slashed from trees and left on the forest floor. Patterns of litter production and decay in this subtropical forest fit within trends extrapolated from temperate Eucalyptus-dominated communities studied to date.


2001 ◽  
Vol 31 (7) ◽  
pp. 1164-1174 ◽  
Author(s):  
Kathryn B Piatek ◽  
H Lee Allen

We examined decomposition and nutrient dynamics in fresh litter and net N mineralization in old litter to determine (i) if forest floor is a source of available nutrients in mid-rotation loblolly pine (Pinus taeda L.) stands and (ii) the effect of site preparation and vegetation control on forest floor nutrient dynamics. Four types of fresh litter were decomposed in situ in mesh bags: two containing only pine (differing by history of stand management) and two pine–hardwood mixes (ratios 1:5 and 5:1). Litter bags were recovered every May and October for 26 months. Litter type, in particular the presence and amount of leaves, affected decomposition and nutrient dynamics in fresh litter. After 26 months, all fresh litters lost 55% of mass; decay rate constants were 0.43 (needles) to 0.60 year–1 (leaves). Pine (1) and pine (2) and needles in mix 1:5 immobilized N. Almost all fresh litters also immobilized P. After 26 months of decay, N and P pools suggested an accumulation in the needles of 0.7–2.7 kg N·ha–1 and 0.2–0.5 kg P·ha–1 and mineralization of 1.1–3.7 kg N·ha–1 in mix 5:1 needles and mix 1:5 leaves. All fresh litters mineralized K, Ca, and Mg. Old litter was incubated in situ in capped polyvinyl chloride containers from May to November. Monthly rates of net N mineralization in old litter were determined in KCl extracts of NH4+ and NO3–. Net N mineralization in old litter was 0.75–1.5 kg N·ha–1 per 6 months and was attributed to mineralization in mineral soil. We conclude that forest floors in these stands are not a source of available N or P. Instead, forest floors appear to be sinks for N and probably P.


1987 ◽  
Vol 17 (12) ◽  
pp. 1496-1506 ◽  
Author(s):  
M. G. Weber

Decomposition, litter fall, and nutrient and organic matter turnover rates were determined in five eastern Ontario jack pine (Pinusbanksiana Lamb.) stands having various burning histories, including wildfire. The stands included a 65-year-old age-class (stand No. 1), two stands within this age-class that were treated with nonlethal understorey fires in 1962 and 1963 (stand Nos. 2 and 3, respectively), a 21-year-old age-class (stand No. 4), and an 8-year-old age-class (stand No. 5) created by experimental burning plots within the 21-year-old age-class. Overstorey and understorey litter decomposition was assessed separately using the litterbag (1-mm mesh size) technique over a 2-year period. Overstorey litter weight loss did not vary among stands and understorey litter lost significantly more weight (P < 0.05) in the older age-classes (stands 1,2, and 3) compared with the younger stands (stands 4 and 5). Litterbag nutrient dynamics between overstorey and understorey were significantly different (P < 0.05) for P, K, and Cain all stands. Magnesium and N dynamics were the same in both litter types on all treatments, as was Fe, except in the 65-year-old stand where significantly more Fe was accumulated in understorey litter (P < 0.04) at the end of the litterbag exposure period. Three-year averages of annual litter fall ranged from 119 kg•ha−1•year−1 in the 8-year-old age-class to 4182 kg•ha−1•year−1 in the older stands. Nutrient inputs through litter fall reflect the developmental stage occupied by the younger stands along a continuum leading to equilibrium conditions of the 65-year-old age-class. Forest floor nutrient and organic matter residence times (or annual fractional turnover) were longest (least amount cycled) in the 8-year-old stand (57.6 years for organic matter), indicating harsh environmental controls over nutrient dynamics. Recovery for the 21-year-old age-class to turnover rates approaching equilibrium conditions (10-year residence time for organic matter) was rapid, demonstrating ecosystem stability in its interaction with fire. Detrimental effects on ecosystem processes can be expected if a stand-replacing fire recurs during early stages of jack pine ecosystem development.


2005 ◽  
Vol 11 (3) ◽  
pp. 421-434 ◽  
Author(s):  
S. Palmroth ◽  
C. A. Maier ◽  
H. R. McCarthy ◽  
A. C. Oishi ◽  
H.-S. Kim ◽  
...  

2009 ◽  
Vol 73 (2) ◽  
pp. 630-637 ◽  
Author(s):  
D.E. Kissel ◽  
M.L. Cabrera ◽  
N. Vaio ◽  
J.R. Craig ◽  
J.A. Rema ◽  
...  

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