RESEARCH EXTENESION NOTE
NO. 7 – November 2012

Foliar nutrient concentrations and potential
limitations of white spruce (Picea glauca (Moench)
Voss) in Yukon, Canada.

By
Alyson Watt, Arthur L. Fredeen &
Paul T. Sanborn

Alyson Watt is a Masters student in the Natural Resources and Environmental
Studies Graduate Program at the University of Northern British Columbia, Prince
George, B.C., Canada. Dr. Art Fredeen and Dr. Paul Sanborn are faculty in the
Ecosystem Science and Management Program and members of the Natural
Resources and Environmental Studies Institute, University of Northern British
Columbia, Prince George, B.C., Canada.
The correct citation for this paper is:
Watt, A., Fredeen, A. L. and Sanborn, P. T. 2012. Foliar nutrient concentrations and
potential limitations of white spruce (Picea glauca (Moench) Voss) in Yukon, Canada.
Natural Resources and Environmental Studies Institute Research Extension Note No. 7,
University of Northern British Columbia, Prince George, B.C., Canada.

This paper can be downloaded without charge from
http://www.unbc.ca/nres/research_extension_notes.html

Watt, Fredeen & Sanborn  Foliar nutrient concentrations and limitations of white spruce

ii

The Natural Resources and Environmental Studies Institute (NRES Institute) is a
formal association of UNBC faculty and affiliates that promotes integrative research
to address natural resource systems and human uses of the environment, including
issues pertinent to northern regions.
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Phone: 250-960-5288
Email: nresi@unbc.ca
URL: www.unbc.ca/nres

iii

Research Extension Note No.7
Nov 2012

CONTENTS

Abstract ........................................................................................................................................... 2
Introduction ..................................................................................................................................... 3
Methods........................................................................................................................................... 3
Study Sites ...................................................................................................................................3
Foliage sampling and chemical analysis ......................................................................................4
Data analysis ................................................................................................................................6
Results and Discussion ................................................................................................................... 6
Macronutrients .............................................................................................................................6
Micronutrients ..............................................................................................................................9
Conclusion .................................................................................................................................... 11
References ..................................................................................................................................... 13

.

1

Research Extension Note No.7
Nov 2012

Abstract
Although nutrient deficiencies are not
uncommon in forests across the north, little is
known about these limitations in the Yukon,
and even less about how these limitations have
been and/or will be affected by climate. To
address existing edaphic limitations to forests
in the Yukon, an investigation of the nutrient
concentrations of white spruce (Picea glauca
(Moench) Voss) foliage was undertaken
throughout various regions of Yukon in 2009.
By
comparing
individual
nutrient
concentrations to critical values and reviewing
nutrient ratios, the results identified nitrogen
(N) as being commonly severely deficient.

Phosphorus (P) and sulphur (S) were also
commonly deficient, whereas magnesium
(Mg) and potassium (K) were mostly adequate
with few reports of slight deficiency levels. In
contrast, calcium (Ca) was adequate at all
locations. Of the micronutrients, zinc (Zn) and
manganese (Mn) were the only elements in
adequate supply at all sites while slight to
moderate deficiencies were commonly
indicated for all other micronutrients across
the study area. Nutrient limitations may
ultimately restrict the growth response of
white spruce to climate changes and/or
increasing atmospheric CO2.

Watt, Fredeen & Sanborn  Foliar nutrient concentrations and limitations of white spruce

2

Introduction
Research has suggested that boreal forests
may be able to take advantage of the
increasing CO2 concentrations through
enhanced photosynthesis (Chapin 1991a,
Perry 1994, Reich et al. 2006). However, the
ability of plants to capitalize on increased CO2
concentrations in the atmosphere will depend
on nutrient availability (Perry 1994, Reich et
al. 2006). While nutrient concentrations are a
function of soil attributes such as active layer
depth and weathering rate of parent material,
soil richness is also dictated by environmental
stresses (Chapin 1991b), e.g., when soil
temperatures are below 0°C, soil microbial
activity decreases restricting nutrient turn-over
rates (Jefferies et al. 2010). The ability of a
tree to photosynthesize is affected by the
nutrients it has available to it (Miller 1995)
and when nutrient availability is limiting,
growth rates are limited (Kozlowski and
Pallardy 1997).
Information about the nutrient status of stands
and its effects on tree growth is important not
only to improve understanding of forest
productivity, but also for forest managers who
are making management decisions (Wang and
Klinka 1997, Yarie and Van Cleve 2010). A
common method for evaluating tree nutritional
status
is
measuring
foliar
nutrient
concentrations (Ballard and Carter 1986).
Foliar sampling and elemental analysis are a
relatively simple way to investigate nutritional
health of trees and identify severe deficiencies
(Carter 1992).
The purpose of this
exploratory study was to investigate the
current foliar nutrient status of white spruce
(Picea glauca (Moench) Voss) trees located in
central and southern Yukon in order to gain

3

insight into the potential
limitations in this species.

for

growth

Methods
Study Sites
Twenty sites were sampled throughout the
Boreal Cordillera eco-zone of Yukon (Figure
1). The sites were all located at mesic
locations with southern exposures. Summary
characteristics of the site locations are
provided in Table 1. The Boreal Cordillera
eco-zone is found in the midsection of the
western cordilleran system of Canada and
extends from northern British Columbia into
the southern and central Yukon.
It is
composed of mountains, valleys and lowlands
and
experiences
moderating
effects
influencing the climate because of the close
proximity to the Pacific Ocean. Mean annual
temperatures range from 1.5-5°C, winters are
long and cold, while summers are short and
warm. This climate allows for widespread
permafrost in alpine and northern areas. The
forests grow only in the valleys and lowlands
and are dominated by white spruce; subdominant species include lodgepole pine
(Pinus contorta Dougl. ex Loud. var. latifolia
Engelm), subalpine fir (Abies lasiocarpa
(Hook.) Nutt.), trembling aspen (Populus
tremuloides Michx.), black spruce (Picea
mariana (Mill.) BSP), balsam poplar (Populus
balsamifera L.), and paper birch (Betula
papyrifera Marsh.) (Smith et al. 2004).

Research Extension Note No.7
Nov 2012

Figure 1. Spatial distribution of the 2009 white spruce foliar nutrient sampling sites across
the eco-regions of the Boreal Cordillera eco-zone in Yukon, Canada.

Foliage sampling and chemical
analysis
All foliar sampling procedures were
conducted in accordance with Brockley
(2001). Foliar samples were collected in mid
to late August in 2009, after trees had gone
into dormancy. Four dominant trees were
selected at each site to be sampled. For
nutrient assessment work often more trees
(10+) are sampled at each site. The intention
of this work, however, was to conduct an
initial investigation of available nutrients
throughout white spruce stands. Therefore
emphasis was put on sampling more sites

instead of more trees per site. Budget and time
were additional constraints in this study.
Foliage from each of the 4 trees at each site
were sampled using a shotgun (Winchester
Marine 12 gauge with 12 gauge - 2 ¾ inch - 1
1/8oz, 4 shot). This sampling approach was
necessary as the height of the trees did not
allow for the use of a ladder or extending pole
pruner. Four field assistants observed the
impacts of the shot, as well as the foliage
falling to the ground, assuring that the samples
were taken from the top third of the canopy of
the intended tree. Multiple samples were
collected from each tree to create a composite

Watt, Fredeen & Sanborn  Foliar nutrient concentrations and limitations of white spruce

4

Table 1: Location, elevation and eco-region of white spruce foliar nutrient research plots
within Yukon, Canada.
Site Location

Latitude

Teslin 1

60 17' 21.0" N

Jake1

60 20' 43.2" N

Teslin 3

60 7' 34.706" N

Ranch 1

60 4' 29.0" N

Ranch 3

60 10' 11.0" N

Junction 1

60 1' 44.5" N

Dempster

64 14’12.8” N

Dawson 2

64 04’10.4” N

Dawson 4

64 07’27.7” N

Dawson 5

64 09’08.7” N

Klondike 1

63 57’27.0” N

Klondike 2

63 55’32.7” N

Klondike 3

63 35’11.9” N

Keno 2

63 56’41.9” N

Duncan 1

63 44’15.5” N

Mayo 2

63 35’27.2” N

Stewart 2

63 25’39.2” N

Pelly 1

63 00’20.6” N

Twin 1

61 50’19.9” N

Fox 2

61 13’24.2” N

Longitude

o

132 58'54" W

o

134 2'3.7" W

o

132 35'53.6" W

Elevation (m) Eco-region

o

745

YSL

o

755

YSL

o

761

YSL

o

1030

LB

o

847

LB

o

665

LB

o

739

YPN

o

715

KP

o

1072

KP

o

1140

KP

o

460

KP

o

538

KP

o

454

YPN

o

870

YPN

o

665

YPN

o

562

YPN

o

503

YPN

o

688

YPC

o

590

YPC

o

810

YPC

o

130 53'6.3" W

o

130 9'44.6" W

o

129 0'13.3" W

o

138 31’33.7” W

o

139 30’54.9” W

o

139 42’51.5” W

o

139 45’58.6” W

o

138 41’37.1” W

o

138 32’50.1” W

o

137 28’22.8” W

o

135 23’04.2” W

o

135 50’38.7” W

o

136 00’18.2” W

o

136 30’23.3” W

o

136 29’08.6” W

o

136 05’37.1” W

o

135 25’59.0” W

1

1

YSL-Yukon Southern Lakes, LB-Liard Basin, YPN-Yukon Plateau North, KP- Klondike Plateau,
YPC-Yukon Plateau Central

sample from the current year foliage. The
sampled foliage was placed directly into prelabelled sealable plastic bags that were stored
in a cooler on ice (1-5°C).

5

In the laboratory, samples were dried in a
drying oven at 70°C for a 24-hour period or
until samples were oven-dried, needles
separated from twigs and then needles ground
to a fine powder using a stainless steel electric
Research Extension Note No.7
Nov 2012

coffee grinder. Ground samples were sent to
the Ministry of Forest and Range lab in
Victoria, BC, Canada, for analysis of total
carbon (C), nitrogen (N), phosphorus (P),
potassium (K), calcium (Ca), zinc (Zn), iron
(Fe), magnesium (Mg), boron (B), manganese
(Mn), aluminum (Al), copper (Cu), sulphur
(S), and sulphate-S (SO4-S). Foliage samples
were digested in a very strong oxidizing acid
mix in a closed vessel microwave digestion
process (Questron QLab 6000) for analysis of
P, K, Ca, Mg, Zn, Fe, Mn, B, Al, and Cu
(Kalra and Maynard 1991). Nutrients were
analyzed using a Teledyne/Leeman Prodigy
dual-view Inductively Coupled Plasma (ICP)
spectrometer. For the processing of total C, N
and S, ground samples were combusted in tin
capsules. This process converted all elements
of interest into oxide gases that were measured
using gas chromatography and mass
spectrometry (Fisons NA-1500, Carlo-Erba;
Kalra and Maynard 1991).
SO4-S was
extracted by boiling ground material in 0.01M
HCl, and quantified using a Waters Ion
Chromatography System with a Grace/Vydac
302IC column (Lambert (1989; as outlined in
Kalra and Maynard 1991).

Data analysis
Assessment of foliar concentrations involved
relating them to published critical values,
defined as concentrations minimally adequate
for growth of a given tree species (Brockley
2001). The nutrient status of white spruce
trees sampled throughout Yukon were
analysed using critical values for white spruce
from Carter (1992), except for S and SO4-S
where values from Ballard and Carter (1986)
were used. The diagnosis of each essential

element was averaged at each site before
being compared to the critical value. Foliar
nutrient concentrations are expressed as
percent
(macronutrients)
or
ppm
(micronutrients) concentrations on an oven
dry mass basis.
Critical ranges are ratios that are used as a
diagnostic tool to investigate the interactions
between nutrients (i.e., N/S or N/P) and help
to further identify which, if either, of the
nutrients are in deficient concentrations at a
site (Koerselman and Meuleman 1996, Zhang
et al. 2010). The critical ranges of these
nutrient ratios were also compared to values
from Ballard and Carter (1986).
The
classification scheme for these critical ranges
is the same: deficient, possibly deficient and
adequate.

Results and Discussion
Macronutrients
The prevalence of macronutrient deficiencies
in white spruce across all 20 sites in Yukon
are listed in Table 2 and illustrated in Figure
2. Eighteen sites showed severe N deficiency
(<1.05%) and two sites moderate N deficiency
(1.05-1.25%). Nitrogen deficiencies in boreal
forests are common (Boonstra et al. 2008),
thus finding 18 of 20 sites N deficient was not
unexpected. Phosphorus was adequate at only
site, but was less deficient overall than N, with
19 sites exhibiting moderate to slight
deficiencies.
White spruce has been
considered to be a more nutrient demanding
conifer and requires higher concentrations of
P than other boreal conifers (Wilde 1966). In
previous work, widespread P deficiencies in

Watt, Fredeen & Sanborn  Foliar nutrient concentrations and limitations of white spruce

6

Table 2: Summary of the macronutrients analysis from 80 white spruce trees sampled across 20
sites throughout Yukon, Canada. The concentrations were compared with critical values from
Carter 1992 with exception of S-ICP (Inductive coupled plasma is a spectrometer used in
laboratories to determine total S in an extract) and SO4-S, which are compared to critical values
from Ballard and Carter (1986). Ballard and Carter (1986) do not classify nutrient levels as
severe, moderate, slight and adequate, therefore, severe for S and SO4-S is merely indicating
deficiency versus adequate concentrations.

Foliar
Nutrient

Macronutrient
Concentrations (%)
Range

Mean (SD)

No. of plots diagnosed as deficient
Severe

Moderately

Slight

Adequate

N

0.569-1.304

0.835 (0.146)

18

2

0

0

P

0.088-0.202

0.134 (0.022)

0

14

5

1

K

0.307-1.004

0.520 (0.120)

0

0

5

15

Ca

0.234-1.096

0.522 (0.163)

0

0

0

20

Mg

0.109-0.128

0.098 (0.019)

0

4

16

0

S-ICP
SO4-S

0.036-0.086

0.061 (0.011)

19

0

0

1

0.300-154.400

73.770 (39.567)

9

0

0

11

white spruce have been observed in eastern
Canada (Quesnel et al. 2006).
There are several probable explanations why
some sites reported deficient concentrations of
P. Phosphorus leaching may have occurred if
sites were located on old weathered soils or in
areas with coarse or sandy soils (Alfaro et al.
2004). Weathered soils may be the cause of
deficiencies found in the sites (Dawson 2,
Dawson 4, Dawson 5, Klondike 1 and
Klondike 2) located in the Klondike plateau
eco-region. Areas of this eco-region known as
the Beringia have not experienced recent
glaciation, which has allowed soils to weather
to a greater degree than surrounding glaciated
soils (Bond and Sanborn 2006). Another
potential explanation may lie in decreased soil
microbial activity (Jefferies et al. 2010) and/or
decreased mineral P weathering rates in cold
and/or drier soils with short growing seasons
(Mengel and Kirby 2001). In either case, will

7

continued
global
warming
induced
enhancement of tree growth outpace any
associated
improvements
in
soil
P
availability?
Further work is needed to
address this and all other potential tree
nutrient limitations in Yukon in the face of
continued warming.
N and P are commonly limiting nutrients for
plants, as they are required in large amounts
(both are macronutrients) and are very
important for plant growth and development
(Chapin et al. 1986, Koerselman and
Meuleman 1996, Zhang et al. 2010). The ratio
of N/P is also an important diagnostic tool
when investigating the relative importance of
these nutrient limitations (Koerselman and
Meuleman 1996, Zhang et al. 2010). For
example, the ratio between N and P is often a
better tool for identifying their relative
limitations of N or P to plant growth
(Koerselman and Meuleman 1996). The N/P
Research Extension Note No.7
Nov 2012

Figure 2. Map showing the reported macro-nutrient concentrations from the foliage of white spruce
trees at each research site in Yukon, Canada. The nutrients read from left to right at all sites; N, P,
K, Ca and Mg. Circles of various sizes and colors indicate foliar nutrient concentrations ranked
according to the ‘critical level’ classification scheme for the macro-nutrients: severely deficient,
moderately deficient, possible deficient or adequate, according to Carter (1992).

ratios from these data suggest that none of
these sites were experiencing a true P
limitation (Figure 3) or that because of the
limiting N, the nutrients are in balance. For
example, if N were to become more available
in these areas (with improved environmental
conditions and warmer soils) it is unknown if
there would be enough P in the soils to
maintain a balance.
Of the cationic macronutrients, Mg was the
most deficient; slightly (0.08-0.12%, 16 sites)
or moderately (0.05-0.08%, 4 sites) at all of

the sites. K levels were mostly found to be
adequate (>0.50%, 15 sites) with a minority of
sites showing slight deficiencies (0.30-0.50%,
5 sites). By contrast, Ca was the only
macronutrient present in adequate amounts at
every location with concentrations ranging
from 0.23-1.10%.
S concentrations were identified as deficient at
all except one site. These results are
comparable to findings of Wang and Klinka
(1997)
where
similar
macronutrient
deficiencies occurred in hybrid spruce in the

Watt, Fredeen & Sanborn  Foliar nutrient concentrations and limitations of white spruce

8

Figure 3. Summary of the P and N/P ratio from the white spruce foliage sampled from 20
research sites throughout Yukon, Canada. Circle size is as defined in Figure 2.

Sub-Boreal Spruce (SBS) bio-geoclimatic
zone of BC.
These S results are also
consistent with widespread S deficiencies
identified in lodgepole pine foliage within the
SBS zone (Sanborn et al. 2005). These
similarities are potentially highlighting a trend
of limiting S concentrations occurring from
central BC to southern and central Yukon.
There was some discrepancy between total S,
N/S ratio and SO4-S determinations of S
deficiency (Figure 4). Although total S levels
indicated S-deficiencies occurred in 19 of 20
sites, N/S ratios suggested that only 11 sites
were S-deficient and SO4-S analyses indicated
9 of the 20 sites were S-deficient. All
analyses indicated that Teslin 3, Klondike 3
and Dawson 2 sites had the most deficient

9

levels of S and Duncan 1 was uniformly Ssufficient. Research has identified SO4-S as
being a good indicator of N and S deficiencies
within trees and it is accepted that if SO4-S
concentrations are insufficient, it will affect
the ability of a tree to acquire N (Brockley
2000, Sanborn et al. 2005). This suggests that
sites Teslin 3, Klondike 2 and Dawson 2,
which had severely deficient levels of SO4-S,
will be predisposed to N-deficiency.

Micronutrients
Micro-nutrient deficiencies are depicted in
Table 3 and demonstrate variable levels of
deficiency across the sites (Figure 5). B was
likely deficient (<5ppm, 19 sites) at all
Research Extension Note No.7
Nov 2012

Figure 4. Summary of the S, SO4-S (SS) and N/S ratios diagnosed from white spruce foliage
sampled from 20 research sites throughout Yukon, Canada. Circle size is as defined in Figure
2, but the threshold used were deficient, possibly deficient, and adequate (Ballard and Carter
1986).

locations except the Dawson 5 site where
possibly deficiency (5-12 ppm, 1 site) was
reported. Because the intake of B is reliant on
mass flow and water availability in the soil
horizon (Mengel and Kirby 2001), these B
deficiencies might be attributed to well
drained soils and/or low precipitation or
periodic drought. All sites showed a possible
moderate deficiency (1-2 ppm, 5 sites) and
possible deficiency in Cu (2-3 ppm, 15 sites).
Only 1 site had an adequate level of Fe (>50
ppm) with the remaining sites showing
possible (25-50 ppm) and likely deficiency
(<25 ppm) levels at 13 and 6 sites
respectively. Iron deficiencies are normally

associated with calcareous soils because it
becomes insoluble at higher soil pH levels
(Van Dijk and Bienfait 1993, Mengel and
Kirby 2001). The variability and reported
deficiencies of Fe for these sites in the boreal
forest, where soils normally have lower pH’s
(Ste-Marie and Paré 1999), were not expected.
Research involving Fe and white spruce is
limited; one study by Ballard (1985) identified
Fe deficiency in white spruce that were
located in cut blocks that had been burned for
site preparation before the seedlings were
planted. Adequate levels of Zn and Mn were
identified at all 20 sites with concentrations of
Zn and Mn ranging from 21.5-76.3 ppm and

Watt, Fredeen & Sanborn  Foliar nutrient concentrations and limitations of white spruce

10

Figure 5. Map showing the reported micro-nutrient concentrations identified from the
foliage of white spruce at each research site in the Yukon, Canada. The nutrients read from
left to right at all sites; B, Cu, Fe, Zn and Mn. Circle size is as in Figure 2 but micro
nutrients the thresholds were: severe deficiency, possible moderate deficiency, possible
deficiency or no deficiency (adequate).

33.5-731.3 ppm respectively.
Zinc
deficiencies, like Fe, arise with increasing soil
pH’s (Mengel and Kirby 2001), which is
likely why there were no Zn deficiencies
reported from any of the sites.

Conclusion
Seasonal patterns of temperature and
precipitation are changing over this northern
landscape. The predictions of continued and
amplified warming and drying at these

11

latitudes are expected to impose significant
impacts on these ecosystems (Spittlehouse and
Stewart 2003, IPCC 2007).
Both positive
(enhanced growth) and negative impacts
(increased natural disturbance occurrence and
severity) are expected to occur (Nitschke
2009). The prediction that boreal forests will
grow better under warmer and drier climates
(Chapin 1991a, Perry 1994, Reich et al. 2006)
could be questioned given the high potential
for nutrient limitations indicated by this study.
With the exception of Ca and K, all of the
macronutrients were found in deficient levels
Research Extension Note No.7
Nov 2012

Table 3. Summary of the micronutrients analyses from 80 white spruce trees sampled across 20
sites throughout Yukon, Canada. The concentrations were compared with critical values from
Carter (1992).
Micronutrients (ppm)
Foliar
Nutrient

Concentration

No. of plots diagnosed as deficient

Range

Mean (SD)

Severely
deficient

Moderately
deficient

Mildly
deficient

Adequate

B

3.8-14.8

8.0 (2.5)

1

19

0

0

Cu

1.3-5.5

2.1 (0.6)

0

5

15

0

Fe

15.2-128.2

30.0 (24.3)

0

13

6

1

Mn

33.5-731.3

238.8 (133.6)

0

0

0

20

Zn

21.5-76.3

37.1 (11.9)

0

0

0

20

at most of the sites. Nitrogen and S, both of
which are important macronutrients for
protein
synthesis
and
photosynthesis
exclusively fell in the severely deficient and
deficient range at all sites sampled across
Yukon. Phosphorus, a major macronutrient,
and B and Fe, major micro-nutrients, all
exhibited lower deficiencies, but are still
possibly in inadequate supply at many sites.
Knowing that nutrient concentrations and
availability are one of the most important

resources that will help to define plant
communities and productivity (Koerselman
and Meuleman 1996), the common nutrient
deficiencies reported in this study could
suggest that the white spruce in the sampled
areas may not be capable of taking full
advantage of improved local climatic
conditions such as warming (Miller 1995) if
nutrient limitations ‘bottleneck’ growth (Yarie
and Van Cleve 2010).

Watt, Fredeen & Sanborn  Foliar nutrient concentrations and limitations of white spruce

12

References
Alfaro, M.A., S.C. Jarvis, and P.J. Gregory. 2004. Factors affecting potassium leaching in
different soils. Soil Use Management 20: 182-189.
Ballard, T.M. 1985. Nutritional demands of planted spruce. pp. 1-16 in Proceedings of the.
Interior Spruce Seedling Performance-State of the Art. Prince George, B.C. Feb. 5-6, 1985.
Northern Silviculture Committee.
Ballard, T.M., and R.E. Carter. 1986. Evaluating Forest Stand Nutrient Status. Province of
British Columbia, Information Service Branch, Ministry of Forests, Victoria, BC, Canada,
45 pp.
Bond, J. D, and P. T. Sanborn. 2006. Morphology and geochemistry of soils formed on
colluviated weathered bedrock case studies from unglaciated upland slopes in west-central
Yukon. YGS Open File Report 2006-19. Yukon Geological Survey, Whitehorse, Yukon.
70pp
Boonstra, R., L. Desantis, C.J. Krebs, and D.S. Hik. 2008. Climate and nutrient influences on
the growth of white spruce trees in the boreal forest of the Yukon. Climate Research. 36:
123-130.
Brockley, R.P. 2000. Using foliar variables to predict the response of lodgepole pine to nitrogen
and sulphur fertilization. Canadian Journal of Forest Research 30: 1389–1399.
Brockley, R.P. 2001. Foliar sampling guidelines and Nutrient Interpretative Criteria for Lodge
pole Pine. Extension Note No. 52. British Columbia Ministry of Forests and Range.
Carter, R.E. 1992. Diagnosis and interpretation of forest stand nutrient status. pp 90-97 in
Forest fertilization: sustaining and improving nutrition and growth of western forests. H.N.
Chappell, G.F. Weetman, and R.E. Miller (ed), College of Forest Resources Contribution
#73, University of Washington, Seattle.
Chapin III, F.S. 1991a. Integrated response of plants to stress: a centralized system of
physiological responses. Bioscience 41: 29-36.
Chapin III, F.S. 1991b. Effects of multiple environmental stresses on nutrient availability and
use. pp. 67-88. in Response of plants to multiple stresses, H.A. Mooney, W.E. Winner, and
A.J. Pel (ed.)San Diego, California: Academic Press, Inc.
Chapin III, F.S., P.M. Vitousek, and K. Van Cleve. 1986. The nature of nutrient limitation in
plant communities. American Naturalist 127: 48-58.
Intergovernmental Panel on Climate Change (IPCC). 2007. WGI fourth assessment report: the
physical basis. Summary report for policy makers. Available at: www.ipcc.ch/

13

Research Extension Note No.7
Nov 2012

Jefferies, R.L., A.N. Walker, K.A. Edwards, and J. Dainty. 2010. Is the decline of soil microbial
biomass in late winter coupled to changes in the physical state of cold soils? Soil Biology
and Biochemistry 42: 129-135.
Kalra, Y.P., and D.G. Maynard. 1991. Methods Manual for Forest Soil and Plant Analysis,
Forestry Canada, Northwest Region, Northern Forest Centre, Edmonton, Alberta
Information Report NOR-X-319. 116pp.
Koerselman, W., and A.F.M. Meuleman. 1996. The vegetation N:P ratio: a new tool to detect
the nature of nutrient limitation. Journal of Applied Ecology 33: 1441-1450.
Kozlowski, T.T., and S.G. Pallardy. 1997. Physiology of Woody Plants, 2nd Edition. Academic
Press, Inc. San Diego, California, U.S.A. 411 pp.
Lambert, M.J. 1989. Methods for chemical analysis of forest soils, plant material and waters.
Forestry Commission of NSW Technical Paper No. 25, 3rd ed., 187 pp.
Mengel, K., and E.A. Kirby. 2001. Principles of Plant Nutrition, 5th Edition. Kluwer Academic
Publishers. Norwell, MA, U.S.A. 851 pp.
Miller, H.G. 1995. The influence of stand development on nutrient demand, growth and
allocation. Plant and Soil 168-169: 225-232.
Nistchke, C.R. 2009. Vulnerability and adaptive capacity of Yukon tree species to climate
change. Technical Report RC08-1698Mankovska B. 1997. Variations in sulphur and
nitrogen foliar concentration of deciduous and conifer vegetation in Slovakia. Water, Air &
Soil Pollution 96: 329-345.
Perry, D.A.1994. Forest Ecosystems. The John Hopkins University Press, Baltimore, Maryland,
USA. 649 pp.
Quesnel, P.O., B. Cote, J.W. Fyles, and A.D. Munson. 2006. Optimum nutrient concentrations
and CND scores of mature white spruce determined using a boundary-line approach and
spatial variation of tree growth and nutrition. Journal of Plant Nutrition 29:1999-2018.
Reich, P.B., S.E. Hobbie, T. Lee, D.S. Ellsworth, J.B. West, T. Johannes, M.H. Knops, S.
Naeem, and J. Trost. 2006. Nitrogen limitation constrains sustainability of ecosystem
response to CO2. Nature. 440: 922-925.
Sanborn, P., R.P. Brockley, B. Mayer, M. Yun, and J. Prietzel. 2005. Sulphur fertilization of
lodgepole pine: a stable isotope tracer study (E.P. 886.15): establishment report. B.C. Min.
For., Res.Br. Victoria B.C. Tech. Rep. 020. 52pp
Smith, C.A.S., J.C. Meikle, and C.F. Roots. 2004. Ecoregions of the Yukon
Territory:Biophysical properties of Yukon landscapes. pp. 157-249 in Ecoregions of the
Yukon Territory: Biophysical properties of Yukon landscapes, C. A. S. Smith, J. C. Meikle,
Watt, Fredeen & Sanborn  Foliar nutrient concentrations and limitations of white spruce

14

and C. F. Roots (ed.). Agriculture and Agri-Food Canada, PARC Technical Bulletin No. 0401, Summerland, British Columbia.
Spittlehouse, D.L., and R.B. Stewart. 2003. Adaptation to climate change in forest management.
BC Journal of Ecosystems and Management 4: 1-11.
Ste-Marie, C., and D. Paré. 1999. Soil, pH and N availability effects on net nitrification in the
forest floors of a range of boreal forest stands. Soil Biology and Biochemistry. 31:15791589.
Van Dijk, H.F.G., and H.F. Bienfait. 1993. Iron-deficiency chlorosis in Scots pine growing on
acid soils. Plant and Soil 153: 255-263.
Wang, G.G., and K. Klinka. 1997. White spruce foliar nutrient concentrations in relation to tree
growth and soil nutrient amounts. Forest Ecology and Management. 98: 89-99.
Wilde, S.A. 1966. Soil standards for planting Wisconsin conifers. Journal of Forestry. 64: 389–
391.
Yarie, J., and K. Van Cleve. 2010. Long-term monitoring of climatic and nutritional effects on
tree growth in interior Alaska. Canadian Journal of Forestry and Research 40: 1325-1335.
Zhang, F., J. Niu, W. Zhang, X. Chen, C. Li, L. Yuan, and J. Xie. 2010. Potassium nutrition of
crops under varied regimes of nitrogen supply. Plant and Soil. 335: 21-34.

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Research Extension Note No.7
Nov 2012