CAMELEON- Carbon Dynamics in Mountain Ecosystems: analyzing landscape-scale effects of anthropogenic changes (climate and land-use)

CArbon dynamics in Mountain Ecosystems: analyzing Landscape-scale

Effects Of aNthropogenic changes (climate and land use)

Main scientific question addressed

What are the impacts of changing land use and climate on the carbon cycle and grassland management of mountain landscapes?

CIRCLE MOUNTAIN final meeting, Barcelona 26 & 27 September 2013

project objectives

• Compile a unique database on climate, land cover, land use, carbon and ecological data for three contrasted mountain regions.

• Use information to improve representation of alpine systems in a DGVM model

• Use the improved model to attribute the role of climate, elevated CO2 and land use in past/present and future changes in mountain systems (focus on carbon cycle).

• Use the model to estimate possible adaptation of grassland systems to climate and land use change


challenges

• Synthesizing available data at plant, ecosystem and landscape level

• Upscaling process-based ecosystem information to larger spatial and temporal scales

• Implementing fine-scale grassland processes in global biogeochemical model (ORCHIDEE)

• Integrating natural sciences with stakeholder perceptions and disseminating scenarios of C dynamics across European mountain regions


5 partners

• LSCE (France)

• NOVELTIS (France)

• Zone Atelier Alpes (France)

• University of Innsbruck UIBK (Austria)

• CTFC (Spain)


3 regions

Stubai Valley

Alinya valley

Vercors Plateau


Data Synthesis


Land cover mapping

Historical period: based on photointerpretation of aerial and remote sensing data (3 to 5 dates been used).

Future: several scenarios, based on different climate change and local socio-economic constraints. Directly discussed with local stakeholders


• For future projection, available for Stubai and Vercors. Based on slighly different methods:

– Stubai: direct discussion with stakeholders presenting socio-economic and climate projection

– Vercors: automatic projection for past as basis for discussion with stakeholder to define the scenarios.

But conduct to similar kind of scenarios at the end

(i.e business as usual or reverse trend).

Land cover mapping: future


1. Partitioning 1692 available vegetation releves into k clusters

2. Listing the dominant plant species of each cluster

3. Checking trait availability in local or global DBs

4. Calculating Community Weighted Means and s.d. for key

traits

Synthesis and upscaling of functionnal diversity

5. Intra community s.d for key traits

Remote sensing

• Compilation of existing remote sensing data, MODIS, SPOT-VGT

• Processing and selection of the most relevant datasets


Climate data

combination between ERA-WATCH/ECHAM A1B scenario (0.25°, daily) and WORDCLIM (1km) climatology

1950 2100

Statistical downscaling

Era-watch +remo A1b 0.25°

1950

2100

Worldclim T,P 1km climatology

Eraworldc daily 1km data


• Mainly compilation of existing flux measurements from Alinya and Stubai + management data

In situ carbon data


Main results


Statistical model

of FI change FIij = a0i + a1i YEARij + eij

a0i = b00 + b01 ELEVi + u0i

a1i = b10 + b11 ELEVi + u1i


Modeling land cover dynamics

• In-situ flux measurement and remote sensing was used to evaluate and calibrate ORCHIDEE.

• Optimisation is based on 4D-VAR assimilation system of ORCHIDEE (ORCHIS).

• Assimilation based on:

- Remote sensing data to optimize phenological parameters

- Eddy fluxes for optimization of phosynthesis etc…

Calibration/evaluation of ORCHIDEE


Example anomaly of vegetation onset

Onset anomaly from remote sensing (Stubai)

Onset anomaly from ORCHIDEE (Stubai)


Improvement of anomaly estimation after assimilation

Correlation NDVI/model Stubai

Correlation NDVI/model Vercors

Prior Posterior


Comparison with eddy fluxes

Gross Primary production Ecosystem respiration Net carbon exchange

Stubai

Alinya


Obs

Model

Impact of functional diversity on carbon cycle

Vercors Stubai Alinya

Simuled variabiliy of net primary production for each vegetation class

Estimated community weighed mean and variation of Vcmax for each vegetation class

Vercors Stubai Alinya

• Series of Simulations at regional scale to understand role of climate and land use change in the past and for future projection.

• Some parameters fixed whereas others are varying

Attribution studies at regional scale


Climate change for the 3 sites Stubai Vercors Alinya

Temp.

Rainfall


Historical land use change for the 3 sites

Stubai Vercors Alinya

Bare soil

Grassland

Forest


Future land use change


Present net primary productivity

Alinya Stubai Vercors


GPP

Ecosystem respiration

Net carbon exchange

Evolution of carbon fluxes past/present/future

Stubai Vercors


Alinya

Attribution of carbon fluxes changes (present) GPP Ecosystem respiration Net carbon exchange


Attribution of carbon fluxes changes (future) GPP Ecosystem respiration Net carbon exchange

Alinya


• ORCHIDEE-GM is able to calculate an optimum animal density assuming a close system where grassland is separated between pure grazing/cut system, and autosufficient system

• Algorithm has been adapted to take into account for the 3 sites systems: – Stubai and Alinya: evaluation at the whole region

instead of pixel based assumption. – Vercors: take into account for transhumance: we

consider animal at Vercors in summer and in Crau during winter (i.e different climate change…)

Evolution of sustainable animal density


Evolution of mean sustainable animal density

Stubai Alinya

Large increase of animal density for Stubai, but stabilitation even small decrease after 2060 for Alinya


Attribution of climate and land use to change in animal density

Stubai Vercors

Change in fraction between int/ext grassland has a large impact on animal density for Stubai Limited productivity In Crau does not allow To fully benefit for Increase of grassland Surface in Vercors

• ORCHIDEE after calibration have shown a good ability to simulate the mountains ecosystems.

• Land use change: 3 sites shown a similar trend for reforestation for the past, the trend been more important for Vercors, contrasted response for future depending from the scenario

Main conclusions


• Climate change: – Increase of temperature (mainly after 1980)

– Contrasted response for precipitation between Stubai and Alinya

Consequence for production and carbon storage: – temperature is the main driver in contrast to plain

regions

– High increase for Stubai, Vercors, less for Alinya

Conclusion (2)


Consequence for grassland management: – possible increase of animal density, especially for Stubai.

But more limited even reversed for Alinya, limited by Crau production for Vercors

But could be too optimistic because:

– Two high response of ORCHIDEE to CO2 ?

– moderate A1B scenario used

– Increase of interannual variability

Conclusion (3)


The story is not finish ! CAMELEON created a momentun between the groups that will continue …..

CAMELEON- Carbon Dynamics in Mountain Ecosystems: analyzing landscape-scale effects of anthropogenic changes (climate and land-use)

Technology

mountain systems

mountain ecosystems

contrasted mountain

climate data combination

available data

climate projection vercors

management data

role of climate