QUERCC and JULES

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QUERCC and JULES

Ian Woodward

NERC Centre for Terrestrial Carbon Dynamics

Department of Animal & Plant Sciences

University of Sheffield


QUERCC: QUantifying

Ecosystem

Roles in the Carbon

Cycle

Overall objective: – NERC-speak.

To quantify the contemporary terrestrial carbon cycle using new combinations of

data and models.

This will be achieved through 4 work packages

Overall objective: – reality?.

Change/replace TRIFFID components to include a nitrogen cycle, a wider range of

functional types and more ecologically realistic sub-grid scale dynamics.


TRIFFID

Schematic showing

TRIFFID carbon flows for

each vegetation type.

Processes above the

dotted line are fluxes

calculated in the MOSES2

land surface scheme

every atmospheric model

time step (≈ 30 minutes).

In dynamic mode,

TRIFFID updates the

vegetation and soil carbon

every 10 days using timeaverages

of these fluxes.


TRIFFID and GCM coupling.

Changes in the distribution and

structure of five functional types

feedback to climate via two routes.

1. Vegetation determines the

biophysical parameters which

affect fluxes of heat, water and

momentum.

2. Changes in the carbon stored in

vegetation and soil ( NEP) also

change atmospheric CO 2

and

climate.

Nitrogen deposition is also shown as

a driver for vegetation change, but

this version of TRIFFID does not

include an interactive nitrogen

cycle.


QUERCC: QUantifying

Ecosystem

Roles in the Carbon

Cycle

Work package objectives

WP1. Develop new calibrated models of soil chemistry and nutrients that influence

the carbon cycle, with particular emphasis on the N cycle.

WP2. Develop, expand and validate descriptions of plant function.

WP3. Create model(s) to capture sub-grid scale dynamics of vegetation behaviour.

WP4. Combine the above models into the JULES structure and apply globally.


QUERCC: QUantifying

Ecosystem

Roles in the Carbon

Cycle

Observational data base

Leeds

Aberdeen

WP1

Soil N,P

WP2

Functional types

(FTs)

Sheffield

WP3

Sub-grid cell

dynamics

Simulations data base

CEH/Exeter

WP4

Input to JULES


Work Package 1

How to represent nutrient availability in

models

1. Temporal compartmentalisation of soil C cycling.

2. Identify the role of soil nutrient availability (N

and P) on rapid and slow cycling.


Work Package 1

Hypothesis –

Organic matter pool turnover regulated by nutrient driven

feedbacks in the short and long term

Connect the soil and

vegetation models

Wardle et al. (2004) Science


WP1

The Nitrogen cycle

Atmosphere

N 2

N 2

O

N 2

N 2

fixation

Photosynthesis

Organic

matter

Bacterial

degradation

NH 4

+

Nitrification

NO 2

NO 3

Aerobic conditions

N 2

O

Detrital

organic

matter

Bacterial

degradation

NH 4

+

Denitrification

N 2

N 2

O

Anaerobic conditions

After Wollast (1981)


Work Package 2

GLC 2000 vegetation map

Key regions


Wright et al.: Major axis of leaf variation

• Major axis of

variation from fast

to slow living

plants.

• Also correlated:

– N content,

10

100

1,000

10,000

– P content

– Assimilation

capacity,

– Dark respiration


Change in leaf longevity of dominant

vegetation (months)

• Black = Outside Climatic range


Work Package 3

Sub-grid scale activity


Work Package 3

TRIFFID/MOSES land surface scheme

Existing JULES model

NLeaf

tree

BLeaf

tree

C3 grass

C4 grass

• Grid cell divided into tiles.

• Each tile is one PFT

• Size of tile determined by

empirical dominance hierarchy

• Tendency for a single

vegetation type to dominate

Bare Gd

Shrub

• E.g. LPJ (Smith et al 2001)

NPP

NL

BL

BL

NL


Work Package 3

Ecosystem Demography Model (ED)

Moorcroft et al. (2001)

“Size and age structured

approximation of an

individual based model”

NLeaf

tree

C3 grass

61 y.o.

28 y.o.

BLeaf

tree

C4 grass

14 y.o.

94 y.o.

Bare Gd

Shrub

0 y.o. 5 y.o.


TRIFFID

ED

2 years

= PFT1

= PFT2

= PFT3

= PFT4

5 years

30 years

150 years

Area

Area


Simulating succession in ED

Leaf cost vs. mortality trade off

Cheap leaves

High mortality

Expensive leaves

Low mortality


Work Package 4

WP3: Sub-grid cell dynamics

WP4: Combine new knowledge into JULES structure

snow

radiation

phenology

Surface exchange

Canopy conductance

hydrology

soil

Dynamic vegetation

“Newer” processes for land surface modelling

WP1: N cycle and P response

WP2: Improved characterisation of PFTs


Soil Nutrient regulated Ecosystem Carbon

Cycle

CO 2

Vegetation

C

Nutrient availability (N:P content) Fast C Slow C

Can N and P availability be used as a predictor of Carbon cycling?

Slide from Nick Ostle, CEH Lancaster


INPUTS

CH 4 CO 2 NPP

CO 2

CH 4

LU Type

Soil

level

RPM

DPM

Methane

Oxidation

Water

level

Meth.

Oxid.

BIO Decomposition

HUM IOM

INPUTS

Max.Water

level

Rain,PET

Water

Module

Module

Temperature

Temperature

MoistureTexture

Decomposition

Drivers

Oxygen

Texture

Module

Oxygen

Module

INPUTS

Soil

Parameters

INPUTS

Air Temp

pH

pH Module

DOC

Slide from Peter Smith, Aberdeen


Work Package 3

Leaf life span change from fixed per FT to Wright et al

variable relationship with temperature and precipitation

Months


WP1

Soil model evaluation and improved process description

100

90

80

% C Remaining

70

60

50

40

30

a)

RMSE

25

20

Testing models

15

10

a

b

b

b

a a a a a

20

5

10

0

0 1 2 3 4 5 6 7 8 9 10

Year

0

RothC DNDC DAISY ITE NCSOIL

CANDY CENTURY SOMM Verberne

INPUTS

CH 4 CO 2 NPP

CO 2

CH 4

LU Type

Soil

level

RPM

DPM

Model improvement

Methane

Oxidation

Water

level

Meth.

Oxid.

BIO Decomposition

HUM IOM

INPUTS

Max.Water

level

Rain,PET

Water

Module

Module Module Module Module

Temperature

Temperature

Temperature

Temperature

Temperature

Temperature

Temperature

Temperature

MoistureTexture

MoistureTexture

MoistureTexture

MoistureTexture

Decomposition

Drivers

Oxygen

Oxygen Oxygen Oxygen

Texture

Module

Oxygen Oxygen

Module Module

Oxygen Oxygen

Module Module

INPUTS

Soil

Parameters

INPUTS

Air Temp

pH

pH Module

DOC


Predicted changes in LL/SLA ratio

Evergreen Bleaf

Needleleaf

Dec B’leaf

C4

Dec N’leaf

C3


Wright et al 2004


Work Package 3

Wright et al 2004


Work Package 4

JULES modular structure

Unified Model IMOGEN Other driving data

snow

radiation

phenology

Surface exchange

Canopy conductance

Ocean and

sea ice

hydrology

soil

Dynamic vegetation

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