29.09.2014

Differentiated Disturbance Effects on Carbon Exchange of Forest

Ecosystems

- Estimated with LDNDC -

29.09.2014

Rüdiger Grote, Janina Hommeltenberg, Matthias Lindauer, Rainer Steinbrecher

Institute of Meteorology and Climate Research (IMK-IFU)

Garmisch-Partenkirchen, Germany

Introduction

Climate Change:

- Warming

- CO ₂ increase Indirect Changes - Drought

- (Species composition) - (Fire frequency)

 Carbon balance - Photosynthesis - Respiration

Friend et al. 2014 (PNAS)

Introduction

Other disturbances:

e.g. wind-throw Impact on carbon cycle not covered in models!

Reichstein et al. 2013 (Nature)

The Model

LandscapeDNDC - Site mode

- Disturbance

- Daily weather input

Haas et al. 2013 (Landscape Ecology)

The Model

LandscapeDNDC

- Modular process groups - Coupled ecosystem

processes

- Dynamic structure - Variable time steps

PSIM

DNDC

The Model

n

… 7

6

5

4

3

2

1

I ₀

Ic _n

Ia _n

Ic ₇

Ia ₇

Ic ₆

Ia ₆

Ic ₅

Ia ₅

Ic ₄

Ia ₄

Ic ₃ Ia ₃

Ic ₂

Ia ₂

Ic ₁ F _n

Grote et al. 2011 (ForestSystems)

- 2D canopy

(accounts for gaps!) - Vertically layered

(explicit species position) - Each layer with separate

pools, fluxes and properties

PSIM (forest model)

Species 1

Species 2

Species 3

Evaluations

Tharandt: spruce, thinned (Fluxnet site)

http://www.forst.tu-

dresden.de/ihm/projekte/vertiko/de/

messkamp/more1.html

Grote et al. 2011 (Agricultural and Forest Meteorology)

Evaluations

Schechenfilz:

open forest,

ground vegetation (TERENO site)

Measurements from: Hommeltenberg et al. 2014 (Biogeosciences)

http://www.icos-

infrastruktur.de/index.php?id=7992

The case study

2006 2009 Lackenberg,

Bavarian Alps wind-throw in Jan. 2007

- Measurements since 2009

- Original forest initialization estimated

- After disturbance

initialization from

inventory

Results

Measurements:

CO ₂ exchange (start 2009):

- Increase in gross primary productivity (GPP)

- Decrease in net

ecosystem exchange (NEE)

Lindauer et al. 2014 (Agricultural and Forest Meteorology)

Results

Simulations:

CO ₂ exchange (start 2006):

- High correlations to fluxes (R2 ~0.7)

- Problems in winter - Wind-throw induced

 decrease of GPP

 Increase in TER

 Net carbon release

Lindauer et al. 2014 (Agricultural and Forest Meteorology)

Wind-throw

+litter

Results

Lindauer et al. 2014 (Agricultural and Forest Meteorology)

Simulations:

CO ₂ exchange (start 2006):

- Higher grass contribution (decreasing)

- Higher soil respiration (decreasing)

Wind-throw

Uncertainties

• Species composition (‘grass’)

• Deadwood decomposition

• Microclimate

Disturbance Simulation

dead exported _

• Wind-throw: all trees none

• Clear cut: all trees stem wood

• Fire (severe): all trees aboveground

Outlook

• Regional application

Werner et al. 2013 (GCB-Bioenergy)

Thank you for your attention

Janina

Hommeltenberg Matthias Lindauer

Rainer Steinbrecher

Rüdiger Grote