Are forest floors in mid-rotation stands of loblolly pine (Pinus taeda) a sink for nitrogen and phosphorus?

2001 ◽  
Vol 31 (7) ◽  
pp. 1164-1174 ◽  
Author(s):  
Kathryn B Piatek ◽  
H Lee Allen
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
N Mineralization ◽  
Forest Floor ◽  
Nutrient Dynamics ◽  
Net N Mineralization ◽  
Litter Bags ◽  
Forest Floors ◽  
Fresh Litter

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.

Nitrogen availability in forest floors of three tree species on the same site: the role of litter quality

2000 ◽  
Vol 30 (11) ◽  
pp. 1698-1706 ◽  
Author(s):  
K D Thomas ◽  
C E Prescott
Keyword(s):  
Nitrogen Mineralization ◽  
Tree Species ◽  
N Mineralization ◽  
Forest Floor ◽  
Lodgepole Pine ◽  
Douglas Fir ◽  
Net N Mineralization ◽  
N Concentration ◽  
Paper Birch ◽  
Forest Floors

Forest floor samples from a 25-year-old plantation of three tree species (Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.), and paper birch (Betula papyrifera Marsh.)) growing on the same site were incubated (aerobically) in the laboratory for 29 days. Rates of N mineralization in the forest floors of Douglas-fir (165.1 µg/g) was significantly greater than either birch (72.9 µg/g) or lodgepole pine (51.2 µg/g). Douglas-fir forest floors also had the highest N concentration, lowest C/N ratio, and highest NH4-N concentrations, followed by paper birch and lodgepole pine. Douglas-fir forest floors also mineralized more N per unit of either N or C than the other species. There were no differences in rates of CO2-C mineralization in forest floors among the three species. Nitrogen mineralization rates were positively correlated with the N concentration of the forest floor (r2 = 0.81) and also with the C/N and NH4-N concentration of the forest floor. Nitrogen concentration, C/N, and lignin/N of foliar litter were poor predictors of N mineralization rates resulting from Douglas-fir litter having the lowest N concentrations in litter but the highest rates of net N mineralization in the forest floor. Nitrogen mineralization in the forest floor was negatively correlated (r2 = 0.67) with the lignin concentration in foliar litter. Douglas-fir litter had low lignin concentrations, which may allow more of the mineralized N to remain in inorganic forms rather than being bound in humus. Our results suggest that a component of Douglas-fir might improve N availability in coniferous forest floors.

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 Mid-Term Effects of Forest Thinning on N Mineralization in a Semi-Arid Aleppo Pine Forest

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1470
Author(s):  
Inmaculada Bautista ◽  
Luis Lado-Monserrat ◽  
Cristina Lull ◽  
Antonio Lidón
Keyword(s):  
N Mineralization ◽  
Nutrient Dynamics ◽  
Pinus Halepensis ◽  
Block Design ◽  
Plant Cover ◽  
Basal Area ◽  
Net N Mineralization ◽  
Mineral N ◽  
Silvicultural Treatments ◽  
Randomized Block Design

In order to assess the sustainability of silvicultural treatments in semiarid forests, it is necessary to know how they affect the nutrient dynamics in the forest. The objective of this paper is to study the effects of silvicultural treatments on the net N mineralization and the available mineral N content in the soil after 13 years following forest clearings. The treatments were carried out following a randomized block design, with four treatments and two blocks. The distance between the two blocks was less than 3 km; they were located in Chelva (CH) and Tuéjar (TU) in Valencia, Spain. Within each block, four experimental clearing treatments were carried out in 1998: T0 control; and T60, T75 and T100 where 60%, 75% and 100 of basal area was eliminated, respectively. Nitrogen dynamics were measured using the resin tube technique, with disturbed samples due to the high stoniness of the plots. Thirteen years after the experimental clearings, T100, T75 and T60 treatments showed a twofold increase in the net mineralization and nitrification rates with respect to T0 in both blocks (TU and CH). Within the plots, the highest mineralization was found in sites with no plant cover followed by those covered by undergrowth. These results can be explained in terms of the different litterfall qualities, which in turn are the result of the proportion of material originating from Pinus halepensis Mill. vs. more decomposable undergrowth residues.

Effect of landscape position on N mineralization and nitrification in a forested watershed in the Adirondack Mountains of New York

1999 ◽  
Vol 29 (4) ◽  
pp. 497-508 ◽  
Author(s):  
Kiyokazu Ohrui ◽  
Myron J Mitchell ◽  
Joseph M Bischoff
Keyword(s):  
New York ◽  
N Mineralization ◽  
Forest Floor ◽  
Landscape Position ◽  
Nitrification Rate ◽  
Forested Watershed ◽  
Net N Mineralization ◽  
Adirondack Mountains ◽  
Net Nitrification ◽  
Intermediate Rate

Within a forest ecosystem in the Adirondack Mountains of New York, net N mineralization and nitrification rates were measured at different landscape positions (zones). Net N mineralization rates (0-15 cm depth) were less (39 kg N·ha-1 per year) within a wetland without alder and with a coniferous overstory than an upland conifer zone (82 kg N·ha-1 per year) and an upland hardwood zone (107 kg N·ha-1 per year). Net N mineralization rates (39 to 82 kg N·ha-1 per year) and the forest floor N concentrations (2.3 to 2.5%) were higher than values reported (1.2-29 kg N·ha-1 and 1.1-2.12%, respectively) for other spruce forests. The net nitrification rates were higher at the upland hardwood zone (29 kg N·ha-1 per year) than the upland conifer zone (2 kg N·ha-1 per year). The wetland conifer zone without alders had an intermediate rate of net nitrification (13 kg N·ha-1 per year) compared with the upland zones. The presence of white alder (Alnus incana (L.) Moench) in the wetland increased the NO3- content and net nitrification rate of the soil.

Nutrient concentrations and nitrogen mineralization in forest floors of single species conifer plantations in coastal British Columbia

2000 ◽  
Vol 30 (9) ◽  
pp. 1341-1352 ◽  
Author(s):  
C E Prescott ◽  
L Vesterdal ◽  
J Pratt ◽  
K H Venner ◽  
L M de Montigny ◽  
...  
Keyword(s):  
Nitrogen Mineralization ◽  
Tree Species ◽  
N Mineralization ◽  
Single Species ◽  
Douglas Fir ◽  
Picea Sitchensis ◽  
Slope Position ◽  
Nutrient Concentrations ◽  
Net N Mineralization ◽  
Forest Floors

We examined the extent to which nutrient concentrations and C and N mineralization rates in forests floors under different tree species are predictable from the chemistry of foliar litter and its rate of decomposition. We studied replicated single species plantations of western redcedar (Thuja plicata Donn ex D. Don), western hemlock (Tsuga heterophylla (Raf.) Sarg.), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), and Sitka spruce (Picea sitchensis (Bong.) Carr.) at four locations. Nutrient concentrations in forest floors correlated poorly with litter nutrient concentrations; the only significant relationships were for Ca and K. Nitrogen mineralization correlated weakly with forest floor C/N ratio, and differed more among sites than among species. None of the litter chemistry parameters were related to net N mineralization rates. Decomposition was fastest in hemlock litter, intermediate in Douglas-fir litter and lowest in cedar litter. Litter also decomposed more rapidly on hemlock forest floors than on cedar forest floors. Rates of N mineralization in the forest floors were not related to rates of decomposition of foliar litter. Differences among sites in N mineralization rates were related to the understory vegetation composition, particularly the amount of the ericaceous shrub salal, which in turn was related to slope position. These site factors appeared to override the effect of tree species on rates of N mineralization.

scholarly journals Monthly alterations in macromolecular contents of in situ ovules excised from Georgian Pinus taeda L.

2014 ◽  
Vol 57 (4) ◽  
pp. 555-562
Author(s):  
Deneke H. Mariam ◽  
David L. Bramlett ◽  
John E. Mayfield ◽  
William V. Dashek
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Total Protein ◽  
Uv Spectroscopy ◽  
Southeastern United States ◽  
Time Dependent ◽  
Vitro Fertilization ◽  
Pinus Taeda L

<em>Pinus taeda</em> L. (loblolly pine), a commercial timber three of the Southeastern United States, provides a major component of the region's forest resources. We cultured loblolly ovules for in vitro fertilization. This procedure was assisted by quantifying time-dependent alterations of in situ ovular RNA, DNA and total protein (Jan-Aug, 1985) contents for ovules (yr 2 of reproductive cycle). Cold-hot, TCA extracted macromolecules were quantified by colorimetry and UV spectroscopy. Total protein was about 0.4 µg per 100 ovules x 10<sup>4</sup> (Jan-Apr) and except for July increased to 3.6 µg per 100 ovules x 10<sup>4</sup> by August. In contrast, RNA "dropped" from 3 to about I µg per 100 ovules x 10<sup>2</sup> (Jan-Mar) and then rose to 7 µg per 100 ovules x 10<sup>2</sup> by July. The DNA climbed from about I to above 8 µg per 100 ovules x 10<sup>2</sup> (Jan-Mar) and then plummeted to I µg per 100 ovules x 10<sup>2</sup> (Apr-June). The observed alterations may reflect ovule morphogenesis.

Nitrogen mineralization dynamics following the establishment of a loblolly pine plantation

2003 ◽  
Vol 33 (2) ◽  
pp. 364-374 ◽  
Author(s):  
Qingchao Li ◽  
H Lee Allen ◽  
Carlos A Wilson
Keyword(s):  
Organic Matter ◽  
Loblolly Pine ◽  
Soil Type ◽  
N Mineralization ◽  
The United States ◽  
Net N Mineralization ◽  
Soil Core ◽  
Organic C ◽  
Organic Matter Removal ◽  
Vegetation Control

The USDA Forest Service initiated a national study in the early 1990s to examine the effects of organic matter removal, compaction, and vegetation control on tree growth and soil processes at several locations across the United States and Canada. Our study was undertaken on the Lower Coastal Plain of North Carolina installation during the second and the fifth growing seasons following loblolly pine (Pinus taeda L.) plantation establishment. We used the in situ soil core incubation method to assess net N mineralization, and collections were conducted monthly from March to December in 1993 and 1996. The largest differences in N mineralization resulted from soil type differences between blocks. Organic matter removal did not affect N mineralization in either year; however, compaction reduced N mineralization during both years. Vegetation control had a pronounced positive effect on N mineralization and was only slightly less important as compared with soil type. Mineralization rates in year 5 were 80% less than in year 2. We hypothesized that the high N mineralization rates in year 2 may be related to a decrease in the input of soluble organic C following harvest (reducing immobilization), a quick mineralization of microbial N, fluctuating soil temperature and water conditions, and fine roots and litter biomass input following harvest.

Nitrogen content, decay rates, and decompositional dynamics of hollow versus solid hardwood logs in hardwood forests of Minnesota, U.S.A.

1998 ◽  
Vol 28 (9) ◽  
pp. 1276-1285 ◽  
Author(s):  
Cindy M Hale ◽  
John Pastor
Keyword(s):  
Residence Time ◽  
N Mineralization ◽  
Nutrient Dynamics ◽  
Hardwood Forests ◽  
Decay Rates ◽  
Net N Mineralization ◽  
Residence Times ◽  
Decay Class ◽  
Class 1 ◽  
Decay Parameters

Decay rates and nutrient dynamics of hardwood logs have been quantified in only a few studies over the last two decades. This study quantified and compared the nitrogen dynamics, residence times, and decay rates of hollow and solid maple and oak logs in decay classes 1 through 4. Decay parameters were not correlated with log age but did correlate with decay class. Hollow logs generally had lower percent original density and higher %N than did solid logs in each decay class. The point of maximum net immobilization of N and initial net N mineralization occurred late in decay class 1 or early in decay class 2. Residence time of logs in each decay class was low in decay class 1 (2 years), high in decay class 2 (17 years), and low in decay classes 3 and 4 (3 and 4 years, respectively). Decay rates varied by decay class, being low in decay classes 1 and 2 and high in decay classes 3 and 4.

Studies on In situ Net N Mineralization in Soils from Mathura Tea Garden and Cultivated Land of North Bengal

2016 ◽  
Vol 9 (6) ◽  
pp. 1023
Author(s):  
Bisweswar Mahato ◽  
Parimal Panda ◽  
Bappa Paramanik ◽  
Parijat De ◽  
Ranajit Panda Anarul Hoque ◽  
...  
Keyword(s):  
N Mineralization ◽  
Net N Mineralization ◽  
Cultivated Land ◽  
Tea Garden ◽  
North Bengal

scholarly journals The bi-directional exchange of oxygenated VOCs between a loblolly pine (<I>Pinus taeda</I>) plantation and the atmosphere

2005 ◽  
Vol 5 (11) ◽  
pp. 3015-3031 ◽  
Author(s):  
T. Karl ◽  
P. Harley ◽  
A. Guenther ◽  
R. Rasmussen ◽  
B. Baker ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Pinus Taeda ◽  
Loblolly Pine ◽  
Vapor Pressures ◽  
Oxygenated Compounds ◽  
Leaf Surfaces ◽  
Leaf Level ◽  
Ambient Concentrations ◽  
Biogenic Compounds

Abstract. Using new in-situ field observations of the most abundant oxygenated VOCs (methanol, acetaldehyde, acetone, C3/C4 carbonyls, MVK+MAC and acetic acid) we were able to constrain emission and deposition patterns above and within a loblolly pine (Pinus taeda) plantation with a sweetgum (Liquidambar styraciflua) understory. During the day canopy scale measurements showed significant emission of methanol and acetone, while methyl vinyl ketone and methacrolein, acetaldehyde and acetic acid were mainly deposited during the day. All oxygenated compounds exhibited strong losses during the night that could not be explained by conventional dry deposition parameterizations. Accompanying leaf level measurements indicated substantial methanol and acetone emissions from loblolly pine. The exchange of acetaldehyde was more complex. Laboratory measurements made on loblolly pine needles indicated that acetaldehyde may be either emitted or taken up depending on ambient concentrations, with the compensation point increasing exponentially with temperature, and that mature needles tended to emit more acetaldehyde than younger needles. Canopy scale measurements suggested mostly deposition. Short-term (approx. 2 h) ozone fumigation in the laboratory had no detectable impact on post-exposure emissions of methanol and acetone, but decreased the exchange rates of acetaldehyde. The emission of a variety of oxygenated compounds (e.g. carbonyls and alcohols) was triggered or significantly enhanced during laboratory ozone fumigation experiments. These results suggest that higher ambient ozone levels in the future might enhance the biogenic contribution of some oxygenated compounds. Those with sufficiently low vapor pressures may potentially influence secondary organic aerosol growth. Compounds recently hypothesized to be primarily produced in the canopy atmosphere via ozone plus terpenoid-type reactions can also originate from the oxidation reaction of ozone with leaf surfaces and inside the leaf. This needs to be taken into account when scaling up very reactive biogenic compounds.

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