Download Mean difference in mineral soil C concentration in g kg

Soil Series Changes in Mineral Soil C and N after
a Thirty-year Interval L. Chris Kiser, J. Michael Kelly, and P. Alan Mays
Virginia Tech Department of Forestry and Tennessee Valley Authority
based on bootstrap analysis. Error bars represent bootstrap derived 95%
confidence interval. For a comparison to be significant (*), confidence interval
values must be either strictly positive or strictly negative.
1976 to 2006 based on bootstrap analysis. Error bars represent bootstrap
derived 95% confidence interval. For a comparison to be significant (*),
confidence interval values must be either strictly positive or strictly negative.
4.0
 94 hectare aggrading oak forest
3.0
 73 permanent sampling points
 Comparison of 1976 and 2006
mineral soil C concentration in
the 0 to 10 cm depth
 Archived samples from 1976
re-analyzed along with samples
from 2006 with Vario MAX CNS
analyzer
2.0
Mean difference C g kg
Methods
Clifty: fine-silty, mixed, mesic
Fluventic Dystrochrept - upland
stream courses
Sequoia: clayey, mixed, mesic
Typic Hapludult - gently sloping
uplands
Wallen/Ramsey: loamy-skeletal,
siliceous, mesic Typic
Dystrochrept - loamy, siliceous,
mesic Lithic Dystrochrept - steep
side-slopes – Kalmia latifolia L.
understory
0.0
*
*
-1.0
*
*
*
*
Clarkrange
-2.0
Lily
Wallen/Ramsey
-3.0
Clifty
Atkins
-5.0
-6.0
1.0
Beersheba
0.5
0.0
Clarkrange tax
*
-0.5
* Clarkrange
*
*
Sequoia
-1.0
Lily
-1.5
-2.0
Wallen/Ramsey
-2.5
-3.0
Clifty
Atkins
-3.5
Soil Series
Soil Series
Fig.2 - Mean difference in mineral soil total-N concentration in g kg-1 from 1976 to
2006 based on bootstrap analysis. Error bars represent bootstrap derived 95%
confidence interval. For a comparison to be significant (*), confidence interval values
must be either strictly positive or strictly negative.
Conclusions
Changes in C and N were distinct to each of the 8 soil series.
Increases in mineral soil C were associated with increases in
the C/total-N ratio and decreases in mineral soil C were
associated with decreases in the ratio of C/total-N.
0.3
Mean difference total-N g kg
Clarkrange: fine-silty, siliceous,
mesic Typic Fragiudult - broad,
smooth plateaus and hilltops
Sequoia
Although both increases and decreases in mineral soil C
-1
Beersheba and Lily: fine-loamy,
siliceous, mesic Typic Hapludult
- gentle slopes, narrow ridges,
and benches
Clarkrange tax
1.0
-4.0
Soil Series
Atkins: fine-loamy, mixed, mesic
Typic Fluvaquent - floodplains
Beersheba
-1
established at the intersections
of a 100 by 100 m grid
1.5
Mean difference C/total-N ratio g kg /g kg
State Park on the Cumberland
Plateau in central Tennessee
Fig.3 - Mean difference in mineral soil C/total-N ratio in g kg-1/g kg-1 from
-1
 Located within Fall Creek Falls
Fig.1 - Mean difference in mineral soil C concentration in g kg-1 from 1976 to 2006
-1
Camp Branch
Watershed
Wallen/Ramsey
0.2
Beersheba
Sequoia
0.1
-0.1
Clarkrange tax
Clifty
Atkins
*
*
*
Clarkrange
-0.2
Soil Series
Lily
were observed after a 30-year interval, mineral soil C storage
in Atkins, Clifty, and Wallen/Ramsey soils was greater than or
equal to the remaining soil series in both 1976 and 2006
suggesting mineral soil C storage will be greater in these
soils over the long term (mesic sites and sites with Kalmia
latifolia L. understory).
*
Acknowledgements: Funding for this research was
provided by the National Council for Air and Stream
Improvement, Inc. (NCASI), the Tennessee Valley
Authority (TVA), and Virginia Tech.