Forest Ecology
and
Management
ELSEVIER
Forest Ecology and Management 129 (2000) 143-152
www.elsevier.comllocate/foreco
Site preparation effects on foliar Nand P use, retranslocation,
and transfer to litter in I5-years old Pinus taeda
Kathryn
B.
Piatek*,1,
H.
Lee Allen
Department of Forestry. North Carolina State University. Box 8008. Raleigh. NC 27695, USA
Received 8 August 1998; accepted 23 April 1999
Abstract
Intensive site preparation in loblolly pine
(Pinus taeda L.) plantations
may remove nutrients and lower site productivity. We
evaluated the effects of nutrient removal in site preparation on mid-rotation pine foliar production, and foliar N- and P-use,
retranslocation, and transfer to litter for two years. We also investigated changes in foliar nutrients one year after fertilization.
Site preparation treatments were: shear-pile-<lisk and chop-burn, used with or without vegetation control. Mid-rotation pines
were fertilized with
200 kg ha-I
N and
50 kg ha-I
p. or with
200 kg ha-I
N and
50 kg ha-I
P and micronutrients. Foliar
production was estimated from litter mass. N- and P-use was estimated from Nand P concentrations in green foliage and foliar
production. Retranslocation was the difference in Nand P between green foliage and litter, in percent. Nand P transfer to litter
was estimated from litter N and P concentration and litter mass. Nutrient removal in site preparation at plantation
establishment did not affect mid -rotation pine foliar production, foliar N- and P-use, retranslocation. or nutrient transfer to
litter. The lack of site preparation effects may be related to the length of time after treatment; the stage of decomposition of
organic matter that may be removed in site preparation may determine when nutrient supply will be affected. Competition
with hardwoods decreased pine foliar production by
56%, and N- and P-use by 55% and 52%, but not percent retranslocation.
On shear-pile-<lisk/herbicide, shear-pile-<lisklno-herbicide, and chop-burn/herbicide plots (none or small hardwood
component), average pine foliar production was
retranslocation was
63.7%
and
69.8%,
4365 kg ha-I year-I, N- and P-use was 53.2 and 4.5 kg ha-I year-I, Nand P
18.9 and 1.3 kg ha-I year-I. Based on a hypothetical N
N and P transfer to litter was
budget for the total stand, an N limitation may develop on those treatments that lost more nutrients in site preparation.
Fertilization increased foliage production by
© 2000
26%,
and N- and P-use both by
49%,
indicating some luxury consumption.
Elsevier Science B. V. All rights reserved.
Keywords: Pinus taeda; Nitrogen; Phosphorus; Retranslocation; Productivity; Plantation management; Fertilization
*Corresponding author. Tel.: +1-360-357-5204; fax: +1-360 35 7-9313. E-mail address:kpiateklr6pnw_olympia@fs.fed.us (K.B. Piatek). 1. Introduction
Olympia Forestry Sciences Laboratory, 3625 93rd Ave, SW,
Current forest management in loblolly pine (Pinus
taeda L.) plantations in the southeastern US targets
Olympia, WA 98512-9193, USA.
foliage production as a strategy to raise productivity
I
present address: USDA Pacific Northwest Research Station.
0378 -1127/001$ - see front matter © 2000 Elsevier Science B.V. All rights reserved.
PII: S 0 3 78-1127( 9 9 ) 0 0 1 5 0-4
144
K.B. Piatek, H.L. Allen/Forest Ecology and Management 129 (2000) 143-152
(Allen et a!., 1990). Foliar biomass and net above­
ground productivity are positively and linearly related
on a range of loblolly pine sites (Teskey et aI., 1987;
'
Vose and Allen, 1988).
Foliage is relatively nutrient-demanding, and
assimilates between 30% and 70% . of the total
nutrients used annually by an established forest
stand (S witzer and Nelson, 1972). Current-year
foliage in loblolly pine stands ages 13 to 25-year
1
old may use 50-83 kg ha- N, and 5-11 kg ha-1 P
(S witzer and Nelson, 1972; Wells and Jorgensen,
1975; Johnson and Lindberg, 1992). Pinus sylvestris,
up to 30-years old on a nutrient-poor site, used
27 kg ha-1 N -and 2 kg ha-I P in I-year old foliage
(Rode, 1993).
Primary sources of foliar nutrients are soil supply
and retranslocation from older foliage. Soils in the
southeastern US, where loblolly pine is widely
planted, are nutrient-limited (Allen, 1987; Binkley
et a!., 1995). Although N availability after clear­
cutting and site preparation can increase in the soil
to ca. 100 kg ha-I year-1 in both, loblolly pine in
the southeastern US and radiata pine in Australia
(V itousek and Matson, 1984, 1985; Vitousek et aI.,
1992; S methurst and Nambiar, 1995), it also
tends to decline within several years after site
preparation (Vitousek et aI., 1992; Piatek and
Allen, 1999) when nutrient demand of developing
forest stands is still increasing. The decline of N
availability may occur earlier or be more severe
after site preparation that removes organic matter
and large amounts of organic matter-bound nutrients.
Nutrient removal associated with mechanical site
preparation has raised widespread concerns over
future site productivity, especially on nutrient-limited
sites (Burger and Kluender, 1982; Neary et aI., 1984;
Morris and Lowery, 1988; Fox et a!., 1989; Powers
et a!., 1990; Thornley and Cannell, 1992; Munson
et a!., 1993).
This study evaluated the effects of site pre­
paration at plantation establishment on mid­
rotation pine foliar production, N and P concentration,
N- and P-use, retranslocation, and transfer to litter,
and examined changes in these foliar nutrients
after mid-rotation fertilization. Our goal was to
determine if nutrient removal in site preparation
lowered loblolly pine foliar production and N- and
P-use.
2.
Methods
2.1. Study site
The study site was located near Henderson, Vance
County, North Carolina (36025' N, 78030' W) in the
physiographic region of the Piedmont. The average
temperature is 14.8°C and annual precipitation is
1133 mm, based on a 64-year record (National Cli­
matic Data Center, 1997). Soils on the site are kao­
linitic clays of the Cecil series classified as thermic,
kaolinitic, Typic Kanhapludults.
2.2. Treatments
The original study design has been described in
detail by Vitousek and Matson, 1984, 1985; and Tew
et aI., 1986. Briefly, two types of harvest (stem-only
and whole-tree removal) and two types of site
preparation (shear-pile-disk and chop-bum) were
implemented in a factorial design in 1981 to monitor
long-term site productivity under plantation manage­
ment. For the current study, we used only those plots
that were harvested as stem-only because previous
research showed no significant differences in growth
due to harvesting level (NCSFNC, 1995). Stem-only
harvest resulted in an estimated removal of 57 kg
N ha-1 , 5 kg P ha-t, 35 kg K ha-l, 51 kg Ca ha-1,
and 14 kg Mg ha -'. Site preparation using the shear­
pile-disk treatment resulted in an estimated removal
of 591 kg N ha-1, 34 kg P ha-1 , 92 kg K ha-1, 363 kg
Ca ha-1, and 64 kg Mg ha-1 (Tew et aI., 1986). In this
treatment, woody debris from harvesting and some
topsoil were pushed away from the planting site into
windrows 47 m apart. The area between the windrows
was disked to a depth of 7-12 cm (Gent et aI., 1984).
Site preparation using the chop-burn treatment
resulted in an estimated removal of 46 kg N ha-1,
and 0 kg ha-I, P, K, Ca, and Mg. In this treatment,
woody debris was fragmented with a roller drum
chopper and burned. Burning was light and patchy
(Tew et aI., 1986).
First-generation improved loblolly pine seedlings
were planted in 1982. Vegetation control (complete
herbicide for the first five years and no herbicide) was
added in a split-plot design to the main treatments. The
current study was initiated in April 1994 in plots in the
following treatment combinations: shear-pile-disk/
K.B. Piatek, H.L. Allell/ Forest Ecology and Management 129 (2000) 143-152
145
herbicide, shear-pile-disklno herbicide, chop-burnl
from the upper part of the crown in February each year
12 plots in three blocks.
maximum N and P concentration in loblolly pine
herbicide, and chop-burnlno herbicide, for a total of
from five trees per plot. Previous studies showed that
A fertilization trial was added at plantation age 14
foliage occurs in late wiiIter (Zhang and Allen,
each block in areas that were treated in 1981 with
is one-year old (produced in the previous year), and
surement
shear-pile-disklno-herbicide
foliar N and P concentrations were multiplied by
against which we tested the fertilizer effect. One of
the two fertilizer plots received 200 kg ha-I N and
use was not estimated because Nand P concentration
(mid-rotation). 1\vo new plots were established in
shear-pile-disklno herbicide, but never used as mea­
plots.
The
treatment (measurement plot) was used as control
50 kg ha-I P, and is referred to as the "N + P' treat­
ment. The other plot received, in kg ha -I, 200 N, 50 P,
100 K, 119 Ca, 100 S, 50 Mg, 20 Fe, 20 Mn, 7.5 Cu,
7.5 Zn, 1.5 B, and 0.5 Mo, and is referred to as the
'complete' treatment. Fertilizers were in the form of
urea, triple superphosphate, potassium chloride, gyp­
sum, dolomitic lime, epsom salts, sulfates of iron,
manganese, copper, zinc, borax, and sodium molyb­
date. Fertilizer was mixed in the field and spread
manually in the spring 1994.
2.3. Foliage production and nutrients
We collected pine foliar litter to estimate foliar
production. In April 1994, five fiberglass traps, each
with an area of 0.75 m2 and collectively covering
0.83% of the plot area, were systematically located
in each plot. Four traps were placed toward (but away
from) the plot comers and a fifth one in the middle of
the plot. Litter was collected bimonthly in early
1996), at the time when foliage present on branches
two-year-old foliage is already dropped. February
annual foliar production (annual litter mass) to esti­
mate foliar N- and P-use. Hardwood foliar N- and P­
in green hardwood leaves was not measured.
N and P retranslocation was estimated from the
difference in Nand P between green foliage and litter.
Percent N and P retranslocation in pine foliage was
defined as:
(green N and P content - litter N and P content/
green N and P content) x 100
Nand P transfer to litter was estimated from litter N
and P concentration and litter mass. Litter N and P
concentration was analyzed in each sample collection.
Litter (pine and hardwood separately) was mixed
thoroughly by hand. and subsamples were drawn.
After grinding to pass a 1 mm screen, subsamples
were dried. Aliquots (0.2 g) were digested in a sulfuric
acid/hYdrogen peroxide mix (parkinson and Allen,
1975). Ten percent sample duplication and a pine
standard tissue (Standard Reference Material 1575,
National Institute of Standards and Technology) were
summer, semi-monthly in fall, and monthly during
used as quality controls. Kjeldahl N and P (total
traps was composited per plot. On the no-herbicide
imetrically on a Lachat autoanalyzer (Lachat Quick­
litter in the field, and also composited by plot. Herbi­
N and P, respectively). Litter N and P content was
the rest of the year, for two years. Litter from the five
treatments, hardwood litter was separated from pine
cide plots contained pine litter only. Litter was oven­
dried for three days at 70°C and weighed to the nearest
gram. The sum of litter weights found between April
1994 and March 1995 represented the 1993 foliar
production (Vose and Allen, 1988), here referred to
as Year 1. Similarly, the April 1995 to March 1996
collections represented the 1994 foliar production, or
Year 2.
Pine foliar N- and P-use were estimated from N and
organic P and polyphosphates) were determined color­
chern; Methods 13-107-06-2-D and 13-115-01-1-B for
obtained by multiplying N and P concentrations for
each collection by the litter weight for that collection.
Annual N and P transfer to litter was estimated by
adding N and P contents from each collection for the
year.
2.4. Statistical analyses
Analysis of variance for split-plot design was used
P concentrations in green foliage and foliar produc­
to examine site preparation effects on mid-rotation
first flush of the previous growing season was sampled
duction, and N and P concentration, use, retransloca­
tion. For nutrient concentrations, pine foliage from the
pine and plot total (pine plus hardwood) foliar pro­
K.B. Piatek. H.L. Allell/Forest Ecology alld Mallagemellt 129 (2000) 143-152
146
tion, and transfer to litter. W hole-plot effects were
foliage in the chop-burn!no-herbicide plots, com­
those of site preparation, with subplots of vegetation
study in a randomized complete block design with
50% of total foliar weight in Year 1,
45% in Year 2. Hardwood foliage in the shear­
pile-disklno-herbicide plots comprised 17% of the
total foliar weight in Year 1, and 13% in Year 2.
Hardwoods were present in six plots (no-herbicide
3.2.
prised up to
and
. control. Fertilized plots were evaluated against the
shear-pile-disklno-herbicide treatments' of the main
three fertilizer regimes: none, N + P, and complete.
only) and were tested for the effect of site preparation
Foliar Nand P concentration, and N- and P-use
N concentration in green pine foliage did not differ
on leaf litter production. Year-to-year variation was
across treatments in Year
analyzed by analysis of covariance, by including a
variable 'year'. All treatment effects were considered
1. N concentration in Year 2
significant at p < 0.05.
was higher in herbicide plots than in no-herbicide
1
1
plots (Table 2). N-use ranged from 43 kg ha- year1
t
(average of Year 2) to 49 kg ha- year- (average of
3. Results
no-herbicide and highest on the chop-burnlherbicide
Year 1). N-use
in Year 1 was lowest on the chop-burn!
treatment, with a significant site preparation x vegeta­
3.1.
to
tion control interaction. N-use in Year 2 was
Foliar biomass production
Production of pine foliar biomass ranged from 1938
4875 kg ha-1 year-I on the non-fertilized plots.
plots, with a significant effect of vegetation control
(Table
was
Pine foliar production was lower on the chop-burn!
no-herbicide treatment than on any other treatment in
Year
pine foliar production (Tables
1 and 2). Hardwood
2). On average, N-use in year 1 pine foliage
6.1 kg ha-1 higher than in Year 2, and this
difference was significant.
1 and in Year 2, both treatment combinations
without vegetation control had significantly lower
43%
lower on the no-herbicide plots than on herbicide
P concentration in green pine foliage exhibited no
1 or 2. P-use ranged from 3.4
1
1
1) to 4.4 kg ha- year- (average of
treatment effects in Year
(average of Year
Table 1
Biomass production, N and P concentrations and use in pine foliage in a mid-rotation loblolly pine plantation under different silvicultural
treatments (A) and following fertilization (B)
(A) DIHR"
DI N Ob
CHHRc
CH N Od
SEg
(B)
N +P'
CompleteI'
SEg
Foliage production
(kg ha-I year-I)
N concentration
(g kg-I)
N-use
(kg ha-I year-I)
P concentration
(g kg-I)
P-use (kg ha-I year-I) 1993
1993
1994
1993
1994
1993
1994
1993
1994
4.5 1994
4727
4770
12.5
11.9
58.8
56.6
1.1
0.9
5.1
3891
3551
12.1
10.9
46.9
38.8
1.1
0,9
4.3
3.3
4875
4374
13.4
12.0
65.3
52.5
1.2
0.9
5.6
4.1
1938
1994
12.7
11.5
24.8
23.1
1.2
0.9
2.4
1.9
0,6
0.6
3.2
3.3
0.1
0.1
0.3
0.3
264.3
306.8
3912
5107
12.3
14.9
48.1
76
1.2
1.4
4.4
6.9
3920
4792
12.9
15.0
50.6
71
1.2
1.4
4.6
6.5
0.8
0.4
4.3
0.1
0.4
0.3
0.3
196.6
242.0
3.1
·Shear-pile-diskJherbicide. bShear-pile-disklno-herbicide. cChop-burnlherbicide. dChop-bum/no-herbicide. "ZOO N. 50 P (in kg ha-I). 1'200 N. 50 p. 100 K, 119 Ca, 100 S. 50 Mg. 20 Fe, 20 Mn. 7.5 Zn. 1.5 B and 0.5 Mo (in kg ha-I). gStandard error. 147
K.B. Piatek. H.L. Allen/Forest Ecology and Management 129 (2000) 143-152
Table 2
P -values for treatment effects on biomass, N and P concentration and use in pine foliage in a mid -rotation loblolly pine plantation under
different silvicultural treatments (A) and following fertilization (B)
(A)
Block
Site preparation
Vegetation control
Site preparation x vegetation control
(B)
Block
Fertilizer
Foliage production
N concentration
1993
1993
1994
N-use
1994
1993
P concentration
1994
1993
1994
P -use
1993
1994
0.849
0.811
0.387
0.159
0.516
0.680
0.133
0.024
0.274
0.353
0.208
0.267
0.376
0.250
0.352
0.327
0.411
0.527
0.361
0.219
0.002
0.004
0.453
0.005
0.001
0.002
0.511
0.678
0.003
0.003
0.017
0.132
0.857
0.167
0.011
0.152
10.00
0.781
0.Q25
0.115
0.278
0.448
0.673
0.846
0.562
0.385
0.063
0.170
0.371
0.704
0.994
0.022
0.747
0.003
0.827
0.002
0.752
0.004
0.803
0.002
was retranslocated
Year 2). Similar to N-use in year 1, P-use in year 1 was
with
no significant treatment
effects, but with a larger between-treatment variation.
lowest on the chop-burnlno-herbicide and highest on
In Year 2, percent N retranslocation was lower than in
the chop-bum/herbicide treatment, with a significant
site preparation x vegetation control interaction. In
Year I, at 59% of maximum green N content, with no
plots than on herbicide plots, with a significant effect
in Year 2, with a significant effect of vegetation
treatment effects. Percent P retranslocation was 62%
Year 2, P-use was 40% lower on the no-herbicide
control; herbicide plots retranslocated P at rates
of vegetation control. The difference in foliar P-use
1 and 2 was significant at 0.9 kg ha-I
11% higher than no-herbicide plots (Table 3).
between years
(Tables
1 and 2).
3.4.
3.3.
Nand P transfer to litter
Nand P retranslocation
litter in Year 2 retranslocated 68% of its maximum N­
The amount of N returned to the forest floor in pine
foliar litter varied from a low of 7.4 kg ha -I year- Iin
Year 1 to a high of 23.4 kg ha-I year-I in Year 2
Additionally, 77% of the maximum green P content
control interaction was significant; pine foliage in
Pine foliage produced in Year
1 and dropped as
content regardless of treatment (Tables
3 and 4).
(Table 4). In Year
1, site preparation x vegetation
Table 3
Treatment means for percent N and P retranslocation, and amounts of N and P lost in pine foliar litter
N retrans1ocation
P retranslocation
(%)
N transfer to litter
(%)
(kg ha-l year-I)
P transfer to litter
(kg ha-1 year-I)
1994
1993
1993
1994
1993
1994
1993
1994
DIHRa
68.9
58.6
78.1
62.9
18.2
23.4
1.11
1.66
DINOb
673
56.3
72.2
58.7
14.9
16.9
1.17
1.35
CHHRc
68.6
62.5
79.0
67.6
20.5
19.7
1.19
1.34
CHNOd
68.7
58.9
79.3
58.2
7.4
9.5
0.48
0.81
2.1
1.4
1.8
2.4
0.9
1.8
0.07
0.12
SEe
Shear-pile-disklherbicide.
Shear-pile-disklno-herbicide.
C Chop-burn/herbicide.
d Chop-burn/no-herbicide.
C Standard error.
n
b
K.B. Piatek. H.L Allen/Forest Ecology and Management 129 (2000) 143-152
148
Table 4
P values for treatment effects on pine foliar retranslocation and nutrient transfer to litter
N retranslocation
Block
Site preparation
Vegetation control
Site preparation x vegetation control
P retranslocation
P transfer to litter
1993
1994
1993
1994
1993
1994
1993
1994
0.126
0.155
0.297
0.109
0.840
0.967
0.540
0.259
0.837
0.145
0.190
0.073
0.405
0.254
0.744
0.113
0.190
0.049
0.010
0.022
0.707
0.670
0.150
0.350
0.001
0.006
0.028
0.010
0.006
Note: Error a for bloc and site preparation is bloc
x
0.348
0.142
0.393
site preparation.
1
the chop-burnJherbicide plots lost 13.1 kg ha1
year- more N in litter than in the chop-burnlno­
herbicide plots. In Year
N transfer to litter
2, vegetation control was
significant, and foliage in the herbicide plots lost
8 A kg ha-1 year-1 more N in litter than no-herbicide
-
1982; Neary et aI., 1984; Morris and Lowery, 1988;
1989; Powers et aI., 1990; Thomley and
Cannell, 1992; Munson et aI., 1993). Reductions in
Fox et aI.,
tree growth associated with nutrient loss after site
preparation have been reported on some nutrient-poor
3 and 4). P tmnsfer to litter ranged from a
1
1
low of 0.5 kg ha- year- in Year 1 to a high of
1
1
1.7 kg ha- year- in Year 2 (Table 3). In Year 1,
1986; Graham et aI.,
1989), but not on other sites (Munson et a!., 1993), and
have not been observed at this site (NCSFNC, 1995).
cant; P transfer to litter in the chop--burnJherbicide
1
1
plots was 0.7 kg ha- year- more than in the chop-­
nutrient removal with site preparation at plantation
plots (Tables
the site preparation x vegetation control was signifi­
or drought-prone sites (Minore,
In this study, we also did not find evidence that
establishment decreased pine foliage production at
was significant, and foliage in the herbicide plots lost
mid-rotation (age 15 years). At an average of
4687 kg ha-1 year-I on plots without hardwoods,
cide plots.
was comparable to that reported in other studies
Fertilization effects on pine foliar biomass, N
and P concentration and use
Foliage production is important to forest management
burnlno herbicide plots. In Year
2, vegetation control
0042 kg ha-1 year-1 more P in litter than in no-herbi­
pine foliar production on these eroded Piedmont soils
(Wells and Jorgensen,
3.5.
1975; Lockaby et aI., 1995).
in loblolly pine plantations because it has been shown
that net aboveground productivity increases linearly
Before fertilization
(1993), pine foliar production
and nutrient concentrations were not significantly
different between plots destined for fertilization and
the control plots (shear-pile--disklno-herbicide). One
year after fertilizing
(1994), the fertilizer effect was
significant for all measurements but percent retranslo­
cation. The two fertilizer regimes (N + P, and com­
plete)
did not differ from each other (Table
Fertilizing
increased pine
foliage
production
2).
by
26% over the control, and N- and P-use by 49%
each.
with foliar biomass (Teskey et
Allen,
aI., 1987; Vose and
1988).
Foliar N- and P-use strongly reflected treatment
differences in foliage production. Avemge N- and
P-use by pine foliage on this site was similar to that
reported in other studies (Wells and Jorgensen,
1975;
Johnson and Lindberg, 1992). Also, pine foliage in the
1
previous rotation at this site used 46 kg N ha- and
1
3.9 kg P ha- at age 22 (Tew et aI., 1986), an amount
comparable to the averages observed in this study on
plots without hardwoods. At the current level of foliar
biomass, the removal of nutrients in site preparation
14-15 years earlier did not diminish the ability of this
4. Discussion
Mechanical site prepamtion may remove site nutri­
ents and reduce productivity (Burger and Kluender,
site to supply nutrients needed in foliage at mid­
rotation.
N and P removed in harvest (stem-only) and shear­
pile--disk site preparation constituted
14% N and
K.B. Piatek. H.L. Allen/Forest Ecology alld Management 129 (2000) 143-152
149
60% of ecosystem P (aboveground vegetation,
0-60 cm depth
included) (data from Tew et aI., 1986). Chop-burn
site preparation removed 2% of total ecosystem N and
7.6% of total ecosystem P. Yet neither N nor P in pine
from retranslocationYear 2). Soil N supply was needed
I
16.0 kg N ha- year-I on the shear-pile-diskl
I
I
herbicide, 6.8 kg N ha- year - on shear-pile-diskl
I
I
no-herbicide, 7.7 kg N ha- year- on chop-burn/
I
I
herbicide, and 5.8 kg N ha- year- on chop-burnl
foliage at mid-rotation were affected by site prepara­
no-herbicide treatments for the Year
tion alone. The state of organic matter decomposition
actual net N mineralization in mineral soil at 0-15 cm
was probably more important to whether nutrient
depth that year was 28.1, 19.1, 29.8, and 34.3 kg N
I
ha -I year- on the above treatments (Piatek and Allen,
almost
forest floor, and mineral soil from
supply was affected
15 years after treatment than
the absolute amount of organic matter or its nutrient
content. Coarse woody debris, for example, may need
at
2 foliage. The
1999), sufficient to close the budget for foliar N-use.
Foliar nutrients make up 30% to 70% of the total
decades and possibly centuries (Tyrell and Crow,
stand nutrient use in established stands (Switzer and
1994) to mineralize, and its removal would most likely
not be reflected in soil nutrient supply only 15 years
Nelson,
1972). Root, branch, and stem wood produc­
tion, which were not assessed in this study, make up
later. This does not change the immediate importance
the remainder. Assuming that foliar nutrient use was
of coarse woody debris to other ecosystem functions,
physical properties. Since P was removed at a sub­
70% of the total (the best case scenario), a hypothe­
tical total stand N-use would be 80.9, 55.4, 75.0, and
33.0 kg N ha­ Iyear-Ion the above treatments. After
stantially higher rate relative to ecosystem P capital,
subtracting N from retranslocation, soil N supply for
we would expect treatment differences in
the hypothetical stand would have to be 40 kg
I
I
N ha- year- on shear-pile-disklherbicide, 24 kg
I
I
N ha- yearon
shear-pile-disklno-herbicide,
30 kg N ha-Iyear-I on chop-burnlherbicide, and
16 kg N ha-Iyear-Ion chop-burnlno-herbicide treat­
such as moisture retention, wildlife habitat, or soil
foliar
P rather than N. One explanation for the lack of
apparent effect of substantial P removal on subsequent
foliar P may be that N supply limits the amount of
foliar biomass to below the level, in which P may
become limiting. Such interaction of N and
l' in
loblolly pine foliage was observed by Zhang and
Allen
(1996).
ments. Because net N mineralization was assessed in
deposition at a rate of
Retranslocation may meet a substantial portion of
1999), atmospheric
I
1O kg N ha- year-I(Richter
closed tubes (Piatek and Allen,
and Markewitz,
1996) must be added to find out the
the foliar nutrient needs, ranging from 18% of foliar N
total soil N supply. Again, comparing soil N supply to
in Abies amabilis in the Pacific Northwest (Keenan et
the hypothetical stand N-use from above results in a
I
I
deficit of -2 kg N ha- year- on shear-pile-diskl
I
I
herbicide, and a surplus of +5 kg N ha- year- on
1
1
shear-pile-disklno-herbicide, +9 kg N ha- yearI
I
on chop-burnlherbicide, and +28 kg N ha- year-
1995),44% in Larix laricina in Minnesota (Tilton,
1977) to 79% in Larix laricina in Alaska (Chapin and
Kedrowski, 1983). Loblolly pine retranslocated 43%
of foliar N and 65% of foliar P in Tennessee (Grizzard
et aI., 1976), and 75% N and 73% P in the Georgia
Piedmont (Zhang and Allen, 1996). Contribution of
aI.,
retranslocation to foliar N- and P-use in our study can
on chop-burnlno-herbicide treatments. These calcula­
tions may indirectly suggest that despite no evidence
of declining foliar production or foliar nutrient use at
be estimated by subtracting N-useYear2 from N retran­
this time, N limitation may be developing on the
slocatedYear
shear-pile-disk treatments,
1>
and assuming that the retranslocated
nutrients were used for foliar production only. Thus,
I
I
retranslocation
contributed
40.6 kg ha- year­
(71.6%) to foliar N on shear-pile-disklherbicide,
I
32.0 kg ha-Iyear- (81.3%) on shear-pile-disklno­
I
I
herbicide, 44.8 kg ha- year(85.3%) on chop­
I
I
burnlherbicide, and 17.4 kg ha- year- (73.8%) on
the chop-burnlno-herbicide treatments.
Soil N supply needed for pine foliage may now be
estimated by another subtraction (N-useYear 2 - N
where
organic matter
was removed before plantation establishment. The
estimated deficit
would be more striking, if the
hypothetical stand N-use were estimated based on
foliar N-use as
30% of the total. However, relative
to soil N supply, more N was returned in litter on the
shear-pile-disklno-herbicide treatment In the next
rotation,
a higher litter N
content may actually
increase the forest floor N turnover and N mineraliza­
tion
in the mineral soil. In general, pine foliage in the
K.B. Piarek, H.L Allen/Forest Ecology and Management 129 (2000) 143-152
150
herbicide plots lost more nutrients to litter than in the
strated in conifers, including Picea abies and Pseu­
no-herbicide plots. N transfer to litter was positively
dotsuga menziesii (Bray and Gorham, 1964).
related to soil N availability in other studies (V itousek
et ai.,
As shown by other studies in this region, mid­
1982; Pastor et al., 1 984).
Retranslocation also supplied 88.5,94.0, 1 07.9, and
1 00.2% of P used in the Year 2 pine foliage on the
and Allen,
shear-pile-disklherbicide,
potential for growing foliage can
shear-pile-disklno-herbi­
rotation fertilization increases nutrient availability,
and may increase foliage and stand production (Vose
1988; Allen et al., 1990). This site's
be increased by
cide, chop-burnlherbicide, and chop-burnlno-herbi­
adding nutrients. Fertilization boosted pine foliar
cide treatments, respectively. Numbers above
100%
were possible because pine foliar biomass in Year 1
production, and N- and P-use over non-fertilized.
was higher than in Year 2. Because more P was
to growth, at least that year, because the complete
Nutrients other than N or P did not seem to
be limiting
1 than used
fertilizer treatment did not result in any more growth
in foliage in Year 2, factors other than P nutrition may
or nutrient uptake than N + P alone. Some storage
have affected foliage production and its P-use. Again,
consumption may have occurred following fertiliza­
available from retranslocation from Year
an insufficient N supply seems to be a plausible
tion because biomass did not increase any further
explanation.
with increasing N and P concentration. This apparent
Loblolly pine foliage production can be drastically
luxury consumption may result in further foliar
reduced in competition with hardwoods. In this study,
biomass
pine foliage production was lowest on the chop-burn/
greater amounts of nutrients will be available for
no-herbicide plots where hardwood leaves made up to
retranslocation.
increase
in
subsequent
years
because
50% of the total plot litter. By comparison. the shear­
pile-disk treatment had only 1 3- 17% of hardwood
litter. These differences resulted because the chop­
Acknowledgements
bum treatment allowed hardwood root systems from
the previous rotation to persist, and root sprouts
This study was supported by the Forest Nutrition
occupied the site quickly. By contrast, in the shear­
Cooperative at North Carolina State University and
pile-disk treatment, stumps were sheared, and any
conducted on land owned by Champion InternationaL
hardwoods present today seeded in over time from
The reviews by M. Barbercheck, D. Richter, S. Shafer,
adjacent stands. Hardwoods proliferated
in the no­
herbicide subplots of both site preparation treatments.
T. Wentworth, and two anonymous reviewers are
gratefully acknowledged.
Total foliar production in the chop-burnlno-herbicide
treatment was significantly lower than in any other
treatment, suggesting that the site's capacity to pro­
duce foliage in general was impeded by the presence
of a large hardwood component, despite a higher
current N mineralization rate
(piatek and Allen,
1 999). This was probably because hardwood species
are more nutrient-demanding than conifers (Nadel­
hoffer et ai.,
1983; Nadelhoffer et al., 1984; Rode,
1993).
The year-to-year variation in foliar nutrition seemed
to be related to variation in pine foliar production, in
that N- and P-use was lower when foliar production
decreased in Year
2. Annual variation in foliar pro­
in this study,
duction itself, although not significant
may be related to climate variations; climatic data
were not taken in this study. Large annual variations in
litter production due to climatic factors were demon­
References
Allen, H.L., 1987. Forest fertilizers: nutrient amendment, stand productivity, and environmental impact. J. For. 85, 37-46. Allen, H.L., Dougherty, P.M., Campbell, R.G., 1990. Manipulation of water and nutrients-practice and opportunity in southern
U.S. pine forests. For. Ecol. Manage. 30, 437-453.
Binkley, D., Carter, R., Allen, H.L., 1995. Nitrogen fertilization
practices in forestry. In: Bacon, P.E. (Ed.), Nitrogen Fertiliza­
tion in the Environment. Marcel Dekker Inc., New York. pp.
608.
Bray, J.R., Gorham, E., 1964. Litter production in forests of the
world. Adv. Ecol. Res. 2, 101-158.
Burger, J .A., Kluender, R.A., 1982. Site preparation-Piedmont.
Symposium on loblolly pine ecosystem. December 8-10, 1982,
Raleigh, NC.
Chapin III, F.S., Kedrowski, R.A" 1983. Seasonal changes in
nitrogen and phosphorus fractions and autumn retranslocation
in evergreen deciduous taiga trees. Ecology 64, 376-391.
151
K.B. Piatek. H.L. Allen/Forest Ecology and Management 129 (2000) 143-152
Fox. T.R.. MOrris. L.A.. Maimone. R.A.. 1989. The impact of
Parkinson. J.A.. Allen. S.E.• 1975. A wet oxidation procedure
windrowing on the productivity of a rotation age loblolly pine
suitable for the detennination of nitrogen and mineral nutrients
plantation. In: Miller. I.H. (Compiler). Proc. Fifth Bienniai
in biological materials. Commun. Soil Sci. Plant Anal. 6.
Southern Silvicultural Research Conference., Memphis, TN.
USDA Forest Service Gen. Tech. Rep. SO·74. pp. 133-140.
Gent Jr.• J.A.. Ballard. R .• Hassan. A.E.• Cassel. D.K.. 1984. The
1-11.
Pastor. J . • Aber. J.D., McClaugherty. C.A.. Melillo, J.M .• 1984.
Aboveground production and N and P cycling along a nitrogen
impact of harvesting and site preparation on the physical
mineralization gradient on Blackhawk Island. Wisconsin.
properties of Piedmont forest soils. Soil Sci. Soc. Am. J. 48.
Ecology 65.256-268.
Powers.R.E. Alban, D.H .• Miller.R.E.• Tiarks.A.E .• Wells. C.G.•
173-177.
Graham.R.T.. Harvey. A.E. • Jurgensen. M.E.1989. Effect of site
Avers.P.E .• Cline.R.G .• Fitzgerald.R.O .• Loftus Jr.• N.S .• 1990.
preparation on survival and growth of Douglas-fir (Pseudotsuga
Sustaining site productivity
menziesii (Mirb.) Franco) seedlings. New For. 3. 89-98.
problems and prospects. In: Gessel.S.P.• Lacate. D.S .• Weet­
in North
American forests:
Grizzard.T .• Henderson. G.S..Clebsch. E.C .• Reichle.D.E .. 1976.
man. G.P..Powers. R.E (Eds.).Sustained Productivity of Forest
Seasonal nutrient dynamics of foliage and litterfall on Walker
Soils. Proc. 7th N. Am. Forests Soils Conf. July 1988.
Branch watershed. a deciduous forest ecosystem. Publication
814.Oak Ridge National Laboratory. Environmental Science
plantation fifteen years after harvesting and site preparation.
Division. Oak Ridge. TN. USA.
Johnson D.W .• Lindberg, S.E. (Eds.), 1992. Atmospheric Deposi­
tion and Forest Nutrient Cycling. A Synthesis of the Integrated
and nutrient resorption in western red cedar and western
forests on northern
Vancouver Island,
Soil Sci. Soc. Am. J. (accepted 1999).
Richter. D.D., Markewitz. D .• 1996. Atmospheric deposition and
soil resources of the southern pine forest. In: Fox. S .• R.A.
Forest Study. Springer-Verlag.New York. pp. 707.
Keenan, R.J .• Prescott. C.E.• Kimmins. J.P. • 1995. Litter production
hemlock
Vancouver. Canada. pp. 49-78.
Piatek. K.B .• Allen. H.L.. Nitrogen mineralization in a pine
British
Columbia. Can. J. For. Res. 25. 1850-1857.
Lockaby. B.G.• Miller. I.H.• Clawson. R.G.• 1995. Influences of
community composition on biogeochemistry of loblolly pine
systems. Am. Mid!. Nat. 134.176-184.
Minore, D .• 1986. Effects of site preparation on seedling growth: a
preliminary comparison of broadcast burning and pile burning.
Mickler (Eds.). Impact of Air Pollutants on Southern Pine
Forests. Springer-Verlag, New York. pp. 315-336.
Rode, M.W .• 1993. Leaf-nutrient accumulation and turnover at
three stages of succession from heathland to forest. J. Veg. Sci.
4.263-268.
Smethurst.P.J..Nambiar. E.K.S.• 1995. Changes in soil carbon and
nitrogen during establishment of a second crop of Pinus
radiata. For. Eco!. Manage. 73. 145-155.
Switzer. G.L .• Nelson. L.E .• 1972. Nutrient accumulation and
Research Note PNW-RN-452. Portland.OR. Pacific Northwest
cycling in loblolly pine (Pinus taeda L.) plimtation ecosystems:
Research Station. USDA Forest Service.
the first twenty years. Soil Sci. Soc. Am. J. 36.143-147.
Morris. L.A.• Lowery.R.F.. 1988. Influence of site preparation on
Teskey. R.O .• Bongarten. B.C.. Cregg. B.M .• Dougherty. P.M.•
soil conditions affecting stand establishment and tree growth.
Hennessey.T.C.. 1987. Physiology and genetics of tree growth
South. J. App!. For. 12.170-178.
response to moisture and temperature stress: an examination of
Munson. A.D., Margolis. H.A.• Brand. D.G.. 1993. Intensive
silvicultural treatment: impacts on soil fertility and planted
conifer response. Soil Sci. Soc. Am. J. 57.246-255.
the characteristics of loblolly pine (Pinus taeda L.). Tree
Physiol. 3. 41-61.
Tew. D.T.• Morris. L.A.. Allen. H.L.. Wells. C.G .• 1986. Estimates
Nadelhoffer. K.J., Aber. J.D .• Melillo. J.M .• 1983. Leaf-litter and
of nutrient removal. displacement and loss resulting from
soil organic matter dynamics along a nitrogen-availability
harvest and site preparation of a Pinus taeda plantation in
gradient in southern Wisconsin (USA). Can. J. For. Res. 13.
the Piedmont of North Carolina. For. Eco!. Manage. 15,
12-21.
257-267.
Nadelhoffer. KJ., Aber. J.D .• Melillo, J.M., 1984. Seasonal patterns
Thomley. J.H.M .• Cannell. M.G.R.. 1992. Nitrogen relations in a
of ammonium and nitrate uptake in nine temperate forest
forest plantation-soil organic matter ecosystem model. Ann.
ecosystems. Plant and Soil 80. 321-335.
Bot. 70, 137-151.
National Climatic Data Center. 1997. The State Clima:te Office of
Tilton. D.L.. 1977. Seasonal growth and foliar nutrients of Larix
North Carolina. Southeastern Regional Oimate Center. Ra­
laricina in three wetland ecosystems. Can. J. Bot. 55, 1291­
leigh.NC.
1298.
Neary. D.G .• Morris, L.A .• Swindel.B.E.1984. Site preparation
Tyrell. L.E., Crow, T.R..1994. Dynamics of dead wood in old­
and nutrient management in southern pine forests. In: Stone.
growth hemlock-hardwood forests of northern Wisconsin and
E.L. (Ed.), Forest Soils and Treatment Impacts. Proc. 6th
North Am. Forest Soils Conf. Knoxville. TN. June 1983.
pp. 121-144.
NCSFNC. 1995. Effects of harvest utilization.site preparation and
vegetation control on growth of loblolly pine on a Piedmont
site. North Carolina State Forest Nutrition Cooperative
northern Michigan. Can. J. For. Res. 24. 1672-1683.
Vitousek. P.M .• Gosz. J.R .• Grier. C.C.• Melillo. I.M.. Reiners.
W.A.. 1982. A comparative analysis of potential nitrification
and nitrate mobility in forest ecosystems. Eco!. Monogr. 52,
155-177.
Vitousek. P.M.• Matson, P.A.• 1984. Mechanisms of nitrogen
Research Note No. 11. NCSFNC. Dept. of Forestry. North
retention in forest ecosystems: a field experiment. Science 225.
Carolina State University, Raleigh.
51-52.
152
K.B. Piatek. H.L Allen/Forest Ecology and Management 129 (2000) 143-152
Vitousek, P.M., Matson, P.A., 1985. Disturbance, nitrogen avail­
ability and nitrogen losses in an intensively managed loblolly
pine plantation. Ecology 66, 1360-1376.
Vitousek, P.M. . Andariese, S.W., Matson, P.A., Ml,lrris, L., Sanford,
R.L., 1992. Effects of harvest intensity, site preparation and
herbicide use on soil nitrogen transformations in a young
loblolly pine plantation. For. Ecol. Manage. 49, 277-292.
Vose. J.M.• Allen, H.L.. 1988. Leaf area. stemwood growth and
nutrition relationships in loblolly pine. For. Sci. 34, 547-563.
Wells, C.G., Jorgensen, J.M., 1975. Nutrient cycling in loblolly
pine plantations. In: Bernier, B., Winget, C.H. (Eds.), Forest
Soils and Forest Land Management. Proc. 4th North American
Forest Soils Conference, Laval University, Quebec, Canada. pp.
137-158. Zhang, S., Allen, H.L. . 1996. Foliar nutrient dynamics of l l-year­
old loblolly pine (Pinus taeda L.) following nitrogen fertiliza­
tion. Can. J. For. Res. 26, 1426-1439.