Terrestrial carbon in aquatic ecosystems: experimental tests of the

subsidy-stability hypothesis

Stuart E. Jones & Jay T. Lennon

Producer-DecomposersPhytoplankton-Bacterioplankton

Organic Carbon

Organic Nutrients

Inorganic Carbon

Inorganic Nutrients

Producer Decomposer

Subsidy

Terrestrial DOC is an increasing subsidy to aquatic ecosystems

Findlay 2005 Frontiers in Ecology and the Environment

Hudson River, Northeast USA

Water color ~ DOC

Allo

chth

ony

Carpenter et al. 2005; Jansson et al. 2007

Does terrestrial DOC influence aquatic metabolic stability?

Carbon Loading

Result of Manipulation

Water Color (m-1)

DOC (mg L-1)

0

5

10

15

20

25

30

0 50 100 150 200 250

C Loading (g C m -

DO

C a

nd

Wat

er C

olo

r

DOC isn’t just a subsidy…

0

10

20

30

40

50

60

70

7/7 7/27 8/16 9/5 9/25

Date

SR

P (

mic

rog

ram

s L

-1) High DOC

Low DOC

Next steps…

• Metabolism data• Microbial loop

coupling• ???