Pteridium caudatum (L.) Maxon Behaves as a Potassium Plant and Accumulates Aluminum in the Subterranean Organs

2007·9.1 MB·English

by  Elizabeth Olivares

American
Fern
Journal 97(2):81-94
(2007)
Maxon
caudatum
Pteridium
Behaves
as
(L.)
Aluminum
Potassium and Accumulates
a Plant
in the
Subterranean Organs
Elizabeth Olivares 1 Eder Pena, and Malfy Benitez
,
Centro de Ecologia, Instituto Venezolano de Investigaciones Cientificas, Apartado 21827,
Caracas 1020A, Venezuela
—
Abstract. The purpose study was
of this to investigate the nutritional status of Pteridium
caudatum
(bracken fern) in a Neotropical region where this species occurs in acid leached soils. In
this region there is a high availability of Al in soluble toxic forms, rendering P. caudatum an
weed
important associated with wildfire regimes. Water-soluble Ca, exchangeable Ca fraction, Ca
bound to pectate + phosphate, and bound to oxalate were evaluated from P. caudatum sampled
from a burned parcel of land 94 and 270 days after an accidental as well as from an unburned
fire,
control parcel. Both sites were located in a tropical secondary savanna community in a successional
mosaic of a cloud forest. The concentrations of total Ca, N, P, K, Mg, Fe, Mn, Zn, Cu, Ni and Al, and
their distribution in the plant organs were investigated. The study addressed the hypothesis
thai
show
shoots should low concentrations of Ca because a low cation capacity exchange has been
We
reported in roots of Pteridium. expected a low water-soluble Ca fraction because bracken has
been defined in the literature as a non-calcicole plant. The exchangeable fraction and pectate +
phosphate bound Ca constituted 60 to 85% of the total Ca in pinnae and rhizomes, while the
bound Ca 14%
oxalate constituted only 3 to of the total Ca. Concentrations of Al as high as
-1
-1
248.3 mmol kg were found in roots. Pinnae showed only 84.53 mmol Ca kg and 5.62 mmol Al
-1
kg and their Ca/Al ratio was 15 mol mol contrasting with aquilinum from temperate regions
P.
'
,
-1
We
where Ca/Al was 1440 mol mol however Ca/P was mol mol" 1
the 2 in both species.
,
conclude that P. caudatum behaves as a potassium plant (soluble K/Ca >>1) such as the grass-like
families Poaceae and Cyperaceae and accumulates Al in the subterranean organs.
Bracken ferns of the world-wide genus Pteridium appear in the Neotropics
human
on land exposed intervention where primary cloud have been
to forests
converted montane savannas (Alonso-Amelot and
into Rodulfo-Baechler,
The
montane
1996). basic characteristics of tropical cloud forests are that
they capture water from clouds, have low evapotranspiration and add
rates
water to the hydrologic system. These forests are threatened by anthropogenic
fire usually associated with grazing, agricultural interventions and hunting
(Hamilton et ah, 1995). Pteridium occurs especially widely in burned
fire
habitats and, unusually, has the ability to pioneer ash-burn surfaces of high
potash levels and highly alkaline pH, metamorphosing become an
to
acidophilus plant once rhizomes penetrate beyond the ash surface
its initial
layers (Page, 2004).
is important to understand the mineral nutrition of bracken because this
It
weed
perennial causes problems for agriculture, forestry, conservation and
1 Author correspondence: 58-212-5041088
for [email protected];
fax:
VOLUME NUMHER
AMERICAN KERN JOURNAL:
97
(2007)
82 2
many
animal health, despite attempts to develop control strategies (Papavla-
Kuhn
The Pteridium aquilinum has
sopoulos, 2003). nutritional status of (L.)
(Thompson
been studied temperate climates aL, 1997; Skre aL, 1998)
in et et
caudatum
and there are several studies of the Neotropical bracken fern, P. (L.)
Maxon, concerning xenobiotic materials such as phenolics, tannins, the
and which from
cyanogenic glycoside prunasin, illudanes, protect the plant
herbivores (Alonso-Amelot and Avendaiio, 2002; Alonso-Amelot aL, 2001;
et
we
2004). However, as far as know, bracken's nutritional status in tropical
environments been
has not investigated.
There variation in the shoot Ca content of angiosperms (Broadley et aL,
is
commelinoid monocots
2003), the lowest values corresponding to orders of
According Broadley aL
cereals, maize, bananas). to et (2003) root cation-
(rice,
We
may
exchange capacity (CEC), pectin and Ca shoot content be correlated.
CEC
expect lower Ca content bracken than dicots based on the low
a in in
CEC
Koedam The
found by et aL (1992) in P. aquilinum roots. root is located in
the apoplast and attributed to the free carboxyl groups of galacturonic acids
is
of cell wall pectins in he middle lamella. The pectin contents of shoot cell
I
walls are comparable to those of root cell walls (Broadley et aL, 2003).
According White and Broadley plants with low soluble Ca
to (2003) a
K/Ca
concentration include the potassium plants, characterized by high shoot
quotients, and the oxalate plants, which have high tissue oxalate concentra-
tions. Plants that accumulate oxalate can be subdivided into species that
and which
contain soluble oxalate those in Ca-oxalate precipitated, lljin in
is
which
1936-1944 (Kinzel, 1983) designated the term calciotrophic to plants
amounts
contain appreciable of water-soluble Ca. This physiological termi-
nology only Ca metabolism and different from the geobotanical label
refers to
is
calcicole, which refers to the flora observed on calcareous soils. In such a flora,
nutrient acquisition and ecological success depend not only on Ca, but also on
other factors such as their root development, microorganism associations,
rhizosphere pH, root exudates,
etc.
The Ca potassium
physiotypes oxalate
three distinct for nutrition, plants,
and angiosperm
plants calciotrophes, are characteristic of particular families
K/Ca and
(White, 2005), therefore is interesting to investigate the ratio (lie
it
Ca Venezolano de
total fractionation in a fern. In acid soils of the Institute)
such
Investigaciones Cientificas (IVIC) calciotrophes, as Clusia multiflora, are
-1
mmol
present with Ca concentration of 244 kg and water-soluble Ca
a total
,
6%
77%
representing of the total Ca, while oxalate comprises only of the total,
found where was found
but this species also in dry calcareous forests to
is it
mmol
have Ca concentrations of 403 kg" 1 (Olivares and Aguiar, 1999). Bracken
has been defined an acidiphilous pteridophyte (Koedan 1992; Pago,
as et
a/..
we may
usually does grow on calcareous and expect low
2004); not soils a
it
Ca because advantageous an osmotic
water-soluble fraction this fraction as
is
which
counter ion xerophytic, calcareous environments, the opposite of
in
is
bracken Therefore bracken predicted have the phvsiotype of
habitat. to
is
The
a potassium or oxalate plant. Ca phvsiotype of plants genotica
is
Un-
determined and phylogenetic information has been used identify crops with
to
CAUDATUM
OLIVARKS ET PTERIDIUM BEHAVES AS A POTASSIUM PLANT
AL.: 83
humans
higher Ca content to address Ca malnutrition in (White, 2005). can
It
weed shows and
also be useful to identify the a high oxalate fraction able
if is
Ca and under behaves
to survive excessive in calcareous soils liming, or if as
it
plants in the Poales with a high K/Ca due to lower requirements of Ca than
dicots.
we
In the present study sampled P. caudatum in a tropical secondary
community where montane
savanna Venezuela, cloud
in in a tropical
site
forest has given way in some areas to secondary savannas due to recurrent
human-related fires in the last two centuries. The site is characterized by acid
The
and Marulanda,
(Garcfa-Miragaya Herrera, 1971; 1998). objectives of
soils
To measure Ca pinnae and rhizomes
this study are: 1) concentrations in of P.
May
caudatum three and nine months after an accidental in and
fire,
November, and with growing
to contrast these data control plants in
We
unburned Ca burned due
a parcel. expect higher in parcels to the effect
Ca from burned and
of ash fertilization. Similar values of in plants control
To
parcels will indicate leaching of nutrients during the experimental time.
2)
compare the shoot Ca concentration the pteridophyte with monocots and
in
dicots reported in the literature, considering that remarkable differences have
CEC
been found probably consequence and pectin
as a of their different
To by K/Ca
contents in the cell wall. define the physiotype the soluble ratio,
3)
related to acidiphily, and to evaluate the proportion of soluble,
its
it
To
exchangeable pectate + phosphate and Ca-oxalate. evaluate the
4)
distribution of mineral elements in the plant organs.
Materials and Methods
—
Plant material and sampling. Pteridium caudatum [= Pteridium
field
aquilinum caudatum Dominj, supported in the specific rank by
var. (L.)
Thomson and Alonso-Amelot was sampled within the grounds of the
(2002),
Instituto Venezolano de Investigaciones Cientificas (IVIC), located in Altos de
m
66° 58'W, 1380 above The predominant
Pipe (10° 24'N, sea
level).
vegetation IVIC primary cloud surrounded by secondary forests
at forest,
is
and grasslands. Occasionally take place during the dry season in the
fires
secondary vegetation units. Disturbed areas between the forest and grassland
dominated by The were sampled secondary
are ferns. plants in a tropical
mm
savanna community. The 10-yr average annual precipitation of 1100
is
two months
throughout with only
relatively well distributed the year,
The was
(February and March) of dry season (Sanhueza et ah, 2000). study
performed the rainy season (May and November). Soil profiles from Altos de
in
pH
showed and
Pipe a water of 4.7 to 5.2 (Carcia-Miragaya Herrera, 1971).
m
m
and
Five relatively small plants (< 0.3 tall) five larger plants (> 1 tall),
May
were burned
denoted as or respectively, collected in a parcel (B) in
s
/,
and November 94 and 270 days an accidental that occurred on
after fire
where
February 2003. Sampling was also carried out in a control parcel (C)
14,
and
did not take place. Plants are defined here as fronds attached
fire
X X and
underground excavated from holes 50 50 20 cm. Small large
parts
AMERICAN FERN VOLUME NUMBER
JOURNAL:
»4
2 (2007)
1)7
plants were present in the second sampling in November, but small plants
May
were found
not in in the control parcel. This indicated that vegetative
May
sprouting after in the control parcel can be attributed to the fact that there
were no monitored disturbances of this region. This different from the
is fire
burned region in which, presumably, there had been activity of small wild
herbivores humans, such walking The each was
or as or clearing. area of parcel
m
approximately 400 and they were separated from each other by Km. The
1
distance between the samplings was m. Sporophytes were
at least 5 sterile at
both harvest times and had fronds with three nine pinnae. The excavated
to
were and underground were
plants transported the laboratory the organs
to
washed
with tap water. Aerial and underground organs were dried constant
to
weight in a ventilated oven for approximately 78 h 60" C and then ground
at
Thomas
with a Wiley mill (3383-L10, Scientific, U.S.A.). The aerial biomass,
given by the dry mass of pinnae (green tissue) and rachis + petioles was
we
The was
measured. biomass not calculated because were not sure
total
if
we
rhizome X X
collected the entire length in the explored soil area (50 50
20 cm). Mineral analysis and underground organs was performed and
in aerial
expressed by dry mass.
—
Chemical analyses. The Ca fractionation methodology of Kostytschew and
was
Berg described in Kinzel (1989) used: Hot water-soluble Ca, originally
was
included in the vacuoles, obtained by heating ground plant material in
mg G
a proportion of 200 dry mass to 5 niL water. After centrifugation 4.6 for
at
was and
10 min, the liquid collected the residue treated with the next
extracting solution. Calcium adsorbed electrostatically on the walls or on
cell
10%
polyanions in the vacuoles was extracted by means of hot NaCl solution.
The Ca-phosphate + was by means
pectate fraction extracted of hot acid
acetic:
mM).
In each case the extraction mixture was heated the boiling point of
(2 to
the solution. Finally, Ca bound oxalate was extracted overnight with HC1
to
mM)
The
ambient
temperature. by
at extraction efficiency, calculated the
(2
sum
linear regression of the of fractions versus the Ca, was 95%.
total
K
The soluble hot water was measured and K/Ca
in extracts the
ratio in
pinnae and rhizomes was The Ca and K
calculated. concentration of the
in
water extract and Ca in other extracts were determined on an atomic
absorption spectrometer (SpectrAA 55B, Varian Techtron,
Victoria, Australia).
Rhizomes were used instead of roots for the fractionation because the dry mass
was
of roots per plant too small for analysis, but concentrations of total Ca, K,
Mg, Fe, Al, Mn, Ni, Zn and Cu, were determined from the organs
all in nitric-
perchloric acid digestions
(Miller, 1998).
Total nitrogen concentration was determined by the Kjeldhal method
(Tecator Kjeltec Systems from Foss Tecator, Hoganas, Sweden) digestion
after
of the ground dry plant material with sulfuric acid. Phosphorus was measured
(Murphy and means
colorimetrically Riley, 1962) in the digested material by of
Amersham
UV/visible spectrophotometer (Ultrospec 2000, Pharmacia, Cam-
Ash was
bridge, England). content determined by heating biomass samples
to
510 °C for 8 hours in a muffle furnace (Thermolyne, Iowa, U.S.A.).
A
OLIVARES ET PTERIDIUM CAUDATUM BEHAVES AS A POTASSIUM PLANT
AL.: 85
Molar ratios (mol N/mol P) for the mineral elements instead of mass ratios
(g
common
N/g P) are shown in the present work because they are more in
physiological research, as they reflect the actual stoichiometric relationships.
common
They by For comparative purposes mass
differ a factor of 2.21. ratios,
were molar
in the literature, recalculated to ratios.
—
Standard used sampling
Statistical analysis. errors are as indicators of
The shown
error rather than treatment values from the seven categories
effects.
in Table 1 (May-Bs, B/, CI and November-Bs, B/, Cs, CI) were pooled to get the
shown
average Table For organs and rhizomes chemical analyses
in aerial
2.
=
were X X
duplicated plants 7 categories 2 chemical analyses but for
(5 70),
=
mass was
roots the dry insufficient for replicate chemical analyses (n
35).
Results
—
Ca caudatum and
Total concentration
in P. of different size fire history.
clear difference in total Ca concentrations between plants of different size from
burned and was Calcium
the control parcels not observed. concentration in
pinnae was higher than that measured in rhizomes and the highest Ca
May
concentration was found in plants from the control parcel sampled in
(Table
1).
—
Ca and K/Ca The exchangeable
fractionation soluble fraction
ratio.
62%
represented up to of the total Ca in rhizomes from small plants and up
53%
+ phosphate pinnae from both
to in the pectate fraction in large plants,
sampled burned November The exchangeable and
in the parcel in (Table
1).
85%
phosphate + pectate fractions taken together contributed 60 to of the total
Ca in pinnae and rhizomes. The exchangeable fraction was higher than, or
nearly equal the pectate + phosphate fraction, except in pinnae from the
to,
burned November. The same low was found
parcel in pattern of oxalate-Ca in
pinnae and rhizomes. Water-soluble Ca contributed to the total Ca in a lower
proportion in rhizomes than in pinnae and the highest value of this fraction
28%
was in pinnae from small plants from the burned plot in November.
K
Pinnae had higher soluble concentrations than rhizomes. The highest
K
and K/Ca were found pinnae from
concentration of soluble ratio in the
burned
parcel.
P and caudatum and
Biomass, N, ash content
in P. of different size
—
history. Aerial biomass appears to be higher in non-burned plots samples
fire
The caudatum was found
(Table highest value of ash content in P. in
2).
rhizomes. Pinnae from burned and control parcels were similar in ash content,
showed
but rhizomes from the burned parcel higher ash percent of dry mass.
a
Contents of P were higher in burned plot samples of pinnae and rhizomes.
May
Large plants sampled in in the non-burned plot had the lowest contents of
N
and P found work
pinnae.
in this for
and
Distribution of metals in the plant organs ratio of total mineral elements
—
Underground showed
in pinnae. organs higher concentrations of Al, Fe, Zn,
Cu and Ni than aerial ones, and roots showed higher concentrations of these
Mn
The was
metals than the rhizomes (Table concentration of higher in
3).
3
AMERICAN FERN JOURNAL: VOLUME NUMHIiR
80 97 (2007)
2
Table Total Ca concentration and fractions of Ca, expressed in per cent of total, extracted with
1.
hot water (water-soluble), hot NaCl solution (exchangeable), hot acetic acid (Ca-phosphate and Ca-
peotate) and HC1 (Ca-oxalate), water-soluble K and soluble K/Ca ratio in relatively small and
(s)
larger P. caudatum from a burned field, 04 and 270 days after fire, and from a control
(13) ((])
(/)
means SE
plot. For each category values given are (n
5).
Calcium
water- hot hot
NaCl HC1 K K/Oa
total soluble acetic Sol. Sol.
m m
mmol
mol
( ) I
kg' 1 (% total Ca) kg mol '
'
PINNAE
May, 94 days
after fire
Bs 54 12 16 42 34 431 38 10 9 9
8
1
80 6 18 36 38 8 419 29 41
Jl
)
0/ 116 48 29 309 37 22
9 18 5 2
November, 270 days
after fire
±17
±
101 12 28 23 37 12 514 92 37
13s
59 ± 4 21 23 53 3 740 ± 4 83 ± 21
1
110 12 22 50 21 6 269 2 2
( )s 1
C/ 71 10 13 52 27 9 260 20 44 15
lUirned (n 20) 73 21 3 31 5 40 ± 4 8 ± 2 532 ± 35 67 ± 10
±16
±
Control (n 15) 99 7 18 3 50 -+- 26 2 6 1 279 26 5
1
RHIZOMES
May
Bs 49 6 18 46 27 9 273 ± 20 29 ± 5
35 3 17 44 29 10 217 16 31 3
13/
±
C/ 30 4 12 51 24 14 202 9 42
3
November
Bs 40 3 6 62 24 9 75 10 33 4
Bl 26 3 7 53 30 10 111 ± 8 63 ± 5
±16
32 9 10 38 43 9 163 40 ± 4
C.s-
c/ 25 2 3 46 32 9 144 10 43 6
1
±4
Burned (n 20) 37 3 12 3 51 28 ± 9 ± 167 ± 15 39 ± 3
1
± ± ±
lontrol (n 15) 29 2 12 45 4 33 6 11 170 8 42
1 3
( 1
rachis + petioles and rhizomes than pinnae and The quotients
in roots.
calculated with the average of the element concentrations in shoots are given
Table comparison with
in 3 for the literature.
Discussion
—
Total Ca concentration caudatum and
in P. of different size history.
fire
The highest Ca concentration was found in large plants from the control parcel
mmol
(116 ± 9 kg Table which low compared with the range (25 to
1) is
;
-
mmol
Thompson
1249 kg found in higher plants (Marschner, 1995).
et al.
)
mmol
found Ca concentration 142 kg" 1 pinnae aquilinum
(1997) a of in of P. in
England
(Table In adult dry leaves of tropical plants, values of up
to
3).
mmol i
955 kg~ Ca have been and Zohlen and
reported (Olivares Aguiar, 1999).
CAUDATUM A POTASSIUM PLANT
BEHAVES AS
PTERIDIUM 87
OLIVARES ET
AL.:
Table Aerial (pinnae + rachis) and rhizomes biomass. The pinnae contribution in the aerial
2.
biomass indicated. Total N and P concentration and ash content in the same plants of Table 1.
is
Biomass
N
Ash
P
mass
clrv
(g
-1 -1
-1
%
Pinnae (mmol kg (mmol kg (% dry mass)
plant
) ) )
PINNAE
May
58 1646 149 53 8 6.9 0.2
Bs 8 2
±
59 ± 77 1260 51 24 3 5.9 0.4
B/ 6
a
52 82 899 27 4 1 5.5 0.8
7
November
Bs 32 4 70 1395 118 49 11 8.7 0.9
62 9 68 1369 19 61 4 6.7 0.2
B/
36 88 1590 57 33 3 8.0 0.9
7
C.s-
a
±
84 1439 76 35 6 5.7 0.2
91 12
±
Burned 40 13 68 ± 4 1425 77 47 8 7.1 0.4
(n 20)
Control (n 15) 60 16 85 2 1309 210 24 10 6.4 0.5
RHIZOMES
May
274 28 12 2 15.2 3.0
Bs 13
1
±
316 16 10 10.9 0.9
B7 9 2 1
a
11 296 20 9 1 7.5 0.5
2
November
±
431 27 16 4 10.3 1.9
Bs 9 2
363 33 13 2 5.5 0.6
B/ 7 3
Cs 603 21 10 2 9.2 0.7
5 1
432 30 6.8 1.7
CI 8 1 5 1
346 34 13 10.5 1.2
Burned 10 1
(n 20) 1
444 89 8 2 7.8 0.6
Control 8 2
(n 15)
Sweden
mmol x from
Ca herbs
reported 179 299 kg in calcifuge
Tyler (2004) to
-1
mmol
Ca
growing on acid and 74 to 142 kg in calcifuge grasses.
soils,
growth and
up Ca than adequate
Monocots of the Poaceae take less dicots tor
shows low
bracken Ca.
also
which on
occur acid
have plant species into calcifuges,
Ecologists classified
and
with low Ca, and calcicoles, which grow on calcareous soil (White
soils
and
was by Chodat 1913
term nology introduced in
The
Salisbury in 1920 respectively (Kinzel, 1983). response of calcifuges to
understanding
and calcareous important in their ability to
acidic soils
is
have
compete and survive (Zohlen and Tyler, 2004) because calcifuge plants
low exudation
a low capacity to solubilize soil P and this is related to root rates
Phosphate
of and tricarboxylic organic acids, in particular oxalic acid. in
di-
may
may
Ca-phosphate
causing precipitation of in their tissues.
place in calcifuges,
have lower
Zohlen and Tyler (2004) reported calcifuge herbs not only
compared with
and P leaves
concentrations of soluble inorganic total in their
when
P grown on
calcicoles, but also a lower relative proportion of soluble
CC
Tabi.i: 3. Mineral element concentrations in organs of P. caudatum (mean ± SE): pinnae, rachis + rhizomes and = compared
petioles, roots (n with
35),
=
pinnae aquilinum Thompson
of from
P. (n 30)
et (1997).
al.
caudatum
P. aquilinum a
P.
Pinnae
Rachis+petioles Rhizomes
Roots Pinnae caudatum
aquilinum
P. P. 1
>
Element (mmol kg a
Quotients in pinnae (mol mol
) *)
N
13 74.49 41.64) 458.11 ± 16.75) 389.97 15.98) 527.92 24.45) 2084.67 (± 16.94) N/P 37 24
n
P ±
37.41 2.84) 11.45 1.05) 10.71 0.68) 7.47 0.89) 87.17 (± 1.18) Ca/P >
2 2
Z
K
384.90 14.94) 244.22 ± 17.03) 155.44 6.40) 65.00 9.83) 555.02 (± 4.67) Ca/Mg
1 1
Ca
84.53 4.58) 24.27 ± 1.45) 33.71 1.70) 57.94 5.02) 142.22 (± K/Ca
1.82) 4
5
Mo
73.39 2.31) 21.09 ± 1.61) 33.73 2.04) 24.62 2.78) 98.75 (± 0.75) Ca/Al 15 1440 Z
Fe 2.17 ±
0.25) 0.95 0.16) 15.41 1.26) 49.54 7.02) 3.58 (± 0.03) Al/Fe 0.03 o
3
Al 5.62 0.49) 1.59 ± 0.17) 65.94 5.51) 248.30 28.95 0.10 (± 0.00) Fe/Mn c
3
1
Mn
0.85 0.08) 3.08 ± 0.32) 1.18 0.08) 1.48 0.29) 4.00 (± 0.13) Mn/Zn 28 Z
7
>
Ni 0.06 ±
0.01) 0.03 0.00) 0.09 0.01) 0.11 0.02) nd Mn/Cu
12
7
Zn
0.13 0.01) 0.04 ± 0.01) 0.07 0.01) 0.96 0.11) 0.14 (± 0.00) Mn/Ni 14 nd
Cu O
0.07 0.01) 0.04 ± 0.00) 0.05 0.01) 0.14 0.04) 0.56 (±
0.00)
a
H
Mineral element concentrations aquilinum from Thompson
in P.
et al. (1997), in http://www.shef.ac.uk/uni/academic/N-Q/nuocpe/ucpe/nutrient.txt,
were recalculated from mass molar
to units.
CD
z
E
re
*<1
CAUDATUM BEHAVES AS A POTASSIUM PLANT
PTERIDIUM 89
OLIVARES ET
AL.:
importance photosynthesis, growth,
calcareous This of to their
a soil. is
Koedam found
competition and final survival. et al. (1992) that the soil
am
Germany
Luxemburg and
ium, France,
pH and they did not detect calcium carbonate in the substrate, therefore
4.00)
and was
they considered bracken not to be a calcicole it labeled as
acidiphilous.
—
caudatum exchangeable
the
In
P.
fi
phosphate
Ca and the pectate + fraction
fraction the largest of the fractions,
is
simi
J
/c
These contrast those of the calciotrophes in
fractions are in to
1989).
66%
Brassicaceae with 49 to of the total Ca in the water-soluble fraction, or
91%
with Ballota nigra (Lamiaceae), with in the oxalate
the oxalate plant,
caudatum correspond
The physiotype does not to
of
fraction (Kinzel, 1989). P.
calciotrophe according to the soluble K/Ca ratio (Table 1) nor to oxalate
a
plants as they showed a low acid soluble fraction (Table 1). Therefore, the
um
740
mmol found
± 41 kg \ which are lower values than those in typical
K
potassium plants such as Carex pendula (Poales) with soluble concentra-
1-1
,„~^„
mmol (CTAWTlh ^^^r^r^
<2000 1 kg" 1 -i.-
tions
and
P caudatum
and size
Biomass, N, ash content in P. of different
by uni
history.—-When biomass data from Table 2 are recalculated area
fire
-2
m
±
the aerial biomass from plants in the burned parcel is 161 51 g
-2
m
however rhizomes
± "in
with 239 65 control parcels,
contrasting
g
We
m" 2
Dom ± ±
lmiiar oiomass iinn both pnaarrcceellss,. 36 3 and 32 7 g resnectivelv.
: . ,
cm
mlv sampled depth of 20
to a
m
2
and
Alonso-Amelot and Rodulfo-Baechler (1996) reported 53
izome. g
m" 2 datum
lzomes
m who maximum
found ash
that found by Skre et (1998), a
to al.
l i
m
percentage of 7.2 ± 1.1 in non-green plant tissue of P. aquilinum pla
± from
burned parcel, contrasting with a lower value of 3.7 0.5 in plants
a
unburned However, they reported that the ash percentage of green leaves
site.
were
from burned parcel and control similar.
a a site
mmol
kg
mmol
mpared with the range 194 kg ^ found in higher
to
(3
N
was
899
plants (Wright et 2004). The concentration of in shoots to
al.,
-1
mmol
1646 mmol kg and the range found in higher plants 143 to 456!
is
,
N
-1
Thompson found P and
(1997) a
kg (Wright et 2004). et al.
al.,
mmol
mmol 1 pinnae
87 kg" 1 and 2085 kg" respectively in
concentration of
N
and non-burned
and P burned
aquilinum England. Differences in in
of in
P.
sam
Norway
aquilinum from burned parcel and a control site in did not
parts of P. a
™ m
-1 __J OfO mmo
AC 1,„-1
~l
mmol
show 284 ± 58 kg and 258 _.-
significant differences,
90 AMERICAN FERN JOURNAL: VOLUME NUMHER
97
2 (2007)
The same was ± mmol
respectively. observed for N, 1785 428 kg and 1499
1-1 '
mmol
M-!
214A
1 kg
metals the plant organs and
in ratio
of
— )f
in pinnae. Very high concentrations of Al and Fe were found underground
in
compared
organs
to aerial organs (Table Johnson-Maynard
et (1997)
3). al.
pH
reported lower and
a higher exchangeable Al invaded
in a 30 years
site for
by bracken
fern than in an undisturbed forest and suggested that the
establishment bracken
of fern responsible subsequent
the
is for alteration of
which
soil properties, can have significant implications growth
for the of other
Higher C and
species.
organic: a repartitioning of secondary Al and Fe from
compounds
inorganic
into organic complexes characterize supporting
soils
bracken
fern.
The N/P
high caudatum may
ratios in P. (Table suggest a P-limited
3)
biomass
production; however,
experiments
fertilization are necessary
to
confirm
this hypothesis. Giisewell (2004) studied the variation and functional
N/P
significance of and
ratios in terrestrial plants reported
that often, but not
N/P <22 >44
always, and mol mol" 1
ratios correspond N- and
to P- limited
biomass
production. was
Intraspecific variation reported be more important
to
than N/P
interspecific variation, with
ratio variation of individual species
of
N
response
fifty-fold in to natural or experimental variations in and P supply.
Han N
found
et al. (2005) that higher and P concentrations occurred seed
in
plants than in ferns, suggesting that these phylogenic groups
differed
in leaf
Thompson N
chemistry.
et al. (1997) reported higher P and concentrations and
N/P
lower
aquilinum um
ratio in P. (Table than found here caudal
3) for P.
growing Han
acid
in soil. et (2005) studied aquilinum China and
al. P. in
mmol
reported 914 kg" 1 N, 27 mmol kg" 1 P and an N/P mol mol
ratio of 34
'.
The
Ca/P
quotient found in shoots of caudatum was mol mol
P. 2 '
(Table Zohlen and
Tyler (2004) reported Ca/P mol mol
3). a ratio of 2 8
- in
'
-1
which
grasses, is lower than that found in herbs (4-51 mol mol They found
).
the highest value Ca/P
of in calcifuge herbs in calcareous Calcifuge herbs
soils.
with low
oxalate exudation by and low
roots oxalate precipitation
in their
may
tissues not be able to survive calcareous conditions because
of the
precipitation of phosphate-Ca and
in soils tissues resulting in low inorganic P
necessary
that metabolism, and
is for its but calcifuge calcicole grasses did not
much
Ca
differ in the ratio of to total P (Zohlen and Tyler, 2004).
Ca/M
/M
They
studied 117 species from 24 orders and one unassigned
family
of
angiosperms grown
hydroponically and
81 species from 20
orders
of
angiosperms
reported an Thompson
in ecological survey by
et (1997).
al.
They
found
that if they excluded seven species from the order Caryophy
Hales,
which Mg
have
higher
relatively contents
in their shoots than the other
Mg
Ca and
species, concentration regressed significantly and Ca/Mg was
ratio
-1
1
mol mol"
7.7 gg 4.6
( ).
The
differences in Ca/Al and Al/Fe ratios between caudatum and
P.
P.
aquilinum
remarkable
are (Table because Al
concentration aquilinum
3) in P.