changes in phosphorus fractions during primary succession in lake michigan sand dunes, usa
DESCRIPTION
Changes in Phosphorus Fractions During Primary Succession in Lake Michigan Sand Dunes, USA. Scott Bridgham 1 and E. Ryan Murray, Univ. of Notre Dame, IN USA R. G. (Jerry) Qualls and Julia Lilienfen Univ. of Nevada, Reno, NV USA 1 As of Jan. 1, Univ. of Oregon. g P / unit area profile. - PowerPoint PPT PresentationTRANSCRIPT
Changes in Phosphorus Fractions During Primary Succession
in Lake Michigan Sand Dunes, USA
Scott Bridgham1 and E. Ryan Murray,
Univ. of Notre Dame, IN USA
R. G. (Jerry) Qualls and Julia Lilienfen
Univ. of Nevada, Reno, NV USA
1As of Jan. 1, Univ. of Oregon
Piapatite
Pioccluded
Pinon-occluded
Po
Ptotal
Time
g P
/ u
nit
are
a p
rofi
le
From Walker and Syers 1976
Modified Hedley Sequential P Fractions
0.5 g sample
Anion-Exchange Membrane (Pi)
0.5 M NaHCO3 (Pi + Po)
Chloroform + 0.5 M NaHCO3 (Pt)
0.1 M NaOH (Pi + Po)
1 M HCl (Pi)
Conc. HCl (Pi + Po)
Digest in conc. H2SO4 and 30% H2O2 (Pt)
0.5 g sample
Anion-Exchange Membrane (Pi)
Set A Set B Fraction
Pi = Readily availablePo = labile organic
Microbial P
Pi = Non-occluded + occluded Fe-Al phosphates and sesquioxidesPo = stable organic
Sonicate + 0.1 M NaOH (Pi + Po)
Stable Ca-bound Pi
Highly recalcitrant Pi + Po
Residual P
0
100
200
300
400
500
600
700
800
Ent Incp Arid Vert Moll Spod Alf Ult Ox
P Fractions as a Function of Soil Order
Resin + Bicarb
NaOH + Sonic
1 M HCl
Residual
Total Organic
ug P
/g s
oil
AGEFrom Cross & Schlesinger (1995)
0
20
40
60
80
100
120
Ent Incp Arid Vert Moll Spod Alf Ult Ox
P Fractions (as %) as a Function of Soil Order
%Resin + Bicarb
%NaOH + Sonic
%1 M HCl%
%Residual
%Organic%
To
tal P
AGEFrom Cross & Schlesinger (1995)
~ 50-year old site
~50- year old site.No A-horizon, little soil development.
400-year old site.~10-cm A horizon, Stained ‘B’ horizon
900-year old site.~10-cm A horizon, Stained ‘B’ horizon
8,000-year old site.~10-cm A horizon, Stained ‘B’ horizon
12,000-year old site.~10-cm A horizon, Stained ‘B’ horizon
0
20
40
60
80
100
120
140
1605 5.5 6 6.5 7 7.5 8 8.5
50 yr400 yr900 yr8,000 yr12,000 yr
Dep
th
pH
50
100
150
200
250
300
350
100 1000 10000
Indiana DunesTotal P
A horizonB horizonC horizon
ug P
/ g
so
il
Age
0
100
200
300
400
500
600
700
800
Ent Incp Arid Vert Moll Spod Alf Ult Ox
P Fractions as a Function of Soil Order
Resin + Bicarb
NaOH + Sonic
1 M HCl
Residual
Total Organic
ug P
/g s
oil
AGEFrom Cross & Schlesinger (1995)
0
50
100
150
200
100 1000 10000
Indiana Dunes
A horizon Pi
A horizon Po
B horizon Pi
B horizon Po
C horizon Pi
C horizon Po
ug P
/ g
so
il
Age
0
20
40
60
80
100
120
50 400 900 8000 12000
Dunes -- % of Total PA-Horizon
Resin + Bicarb Pi
NaOH + Sonic Pi
1 M HCl Pi
Conc. HCl Pi
ResidualTotal Organic
% T
otal
P
AGE
0
20
40
60
80
100
120
50 400 900 8000 12000
Dunes -- % of Total PB-Horizon
Resin + Bicarb Pi
NaOH + Sonic Pi
1 M HCl Pi
Conc. HCl Pi
ResidualTotal Organic
% T
ota
l P
AGE
0
20
40
60
80
100
120
50 400 900 8000 12000
Dunes -- % of Total PC-Horizon
Resin + Bicarb Pi
NaOH + Sonic Pi
1 M HCl Pi
Conc. HCl Pi
ResidualTotal Organic
% T
ota
l P
AGE
Conclusions
• As opposed to classic ecosystem successional theory, total P increases over time in Lake Michigan sand dunes due to very low initial concentrations.
• Changes in individual P fractions as a percentage of the total P more closely follow classical theory.
• % total Pi decreases with age and increases with depth. The opposite trends occur for % total Po.
• % readily available Pi increases with age.
• % Fe and Al-associated Pi increase with age.
• Ca-associated Pi decreases with age.
• Both recalcitrant and available Po fractions increase with time, with the majority of Po in recalcitrant fractions.
• While this study and others have demonstrated the general applicability of classical successional theory for soil P retention, differences in initial soil substrata can lead to important differences in the trajectories of both total P and the individual P fractions.