Post on 21-Jan-2016
description
Determining carbon sources of eroded sediment in low order Sierra Nevada
catchments
Emma McCorkle
2
Method overview
StreamSoils
Crest Bksl Dep
Forest Floor
Bank Bed
Sediment
Low
-5 -4 -3 -2 -1 0 1 2 3-29
-28
-27
-26
-25
-24
-23
3
13C and 15N High
-5 -4 -3 -2 -1 0 1 2 3-29
-28
-27
-26
-25
-24
-23
δ15N (‰) δ15N (‰)
δ13C
(‰)
High Low
4
Low
Soil depth (cm)
0 10 20 30 40 50 60
Fraction m
odern
0.6
0.7
0.8
0.9
1.0
1.1
1.2High
Soil depth (cm)
0 10 20 30 40 50 60
Fraction m
odern
0.6
0.7
0.8
0.9
1.0
1.1
1.2
Soil radiocarbon
5
Sediment radiocarbon
Sediment Water Year
2008 2009 2010 2011 2012 2013 2014
Fraction m
odern
0.90
0.95
1.00
1.05
1.10
1.15
1.20
Recap
• Eroded sediment is dominated by surface material and gully erosion from established stream channels
• Deeper upland soils are more stable than shallow
• Bull has much older SOM in banks and soils than Providence– Radiocarbon bolsters stable isotope findings
6