CEIP annual meeting, Poznan, Poland, Oct 2007 ADVEX overview paper summary: vertical advection positive during the nightzero Zero mean but large scatter

CEIP annual meeting, Poznan, Poland, Oct 2007 ADVEX overview paper summary: horizontal advection Positive during the night slightly negative during the day, trunk space Weak positive advection during the night trunk space Large negative advection during the night large scatter crown space

CEIP annual meeting, Poznan, Poland, Oct 2007 Direction of future scientific work ADVEX field campaigns Typology mechanisms at work Aubinet (2007) Model simulations (CFD, LES) in cooperation with INRA Exploring the “noise” Development of a robust correction scheme of EC-fluxes for advection Conference on advection July 2008 in Belgium

Spatial distribution of NBP of grasslands in Europe (data upscaling) Assuming a management similar to mean site management

How large is the grassland C sink?

Synthesis paper First draft will be discussed during grassland & wetland session Conclusions: grasslands are a strong C sink (ca. same as forests) Trade-off by N 2 O and CH 4 is relatively low (30 % reduction in NBP) Indirect emissions (e.g. indirect N 2 O, off site forage digestion) further reduce NBP by 15 % The C sink can be managed, but it is highly vulnerable to drought events and, hence, to climate change.

Uncertainty on Anthropogenic Carbon Emissions Up to 250 ppm IPCC SRES 2000; Friedlingstein et al Vulnerability of the Carbon Cycle in the 21 st century Up to 200 ppm Uncertainty of the Biospheric-Carbon-Climate Feedback Slide courtesy of Pep Canadell, GCP

Uncertainty in cropland & grassland SOC stock changes due to climate, NPP & technology change (HadCM3-A2) Climate Only Climate & NPPClimate & NPP & Tech Minimum Maximum J.U. Smith et al. (2005)

Organic soil restoration vs. mineral soil sequestration Data from: Smith et al. (2007a)

Part A - Eight different forests T = 8.3°C P = 730 mm Beech T = 5.5°C P = 527 mm Pine/Spruce T = 3.0°C P = 700 mm Pine T = -1.0°C P = 429 mm Pine T = 1.2°C P = 523 mm Spruce T = -0.9°C P = 305 mm Birch T = 3.4°C P = 738 mm Larch

.and after normalizing for LAI-dependence What about correlation with latitude? (reminding about Valentini et al., 2000)

.and after normalizing for LAI-dependence

After normalization for the LAI-dependency - no correlation with latitude!

Surprising finding by Annikki M. Estimates of site-specific LUE parameters β: for the European sites taken from the fitting of the variable-LUE model for the Ameriflux sites estimated with linear regression Measured GPP: eddy covariance GPP, mean of yearly totals Φ TOT : fAPAR times growing season sum of above-canopy PAR, mean of yearly totals Slope ≈ 0.45

Magnani et al (2007) Nature 447, 848 Not a temperature effect! 1g N→210gC

Tree rings show that carbon continues to accumulate, but often in an erratic manner! Scots pine, Glen Affric (Scotland), data of Teri Fish & Rob Wilson See Martinez-Vilalta, Vanderklein, Mencuccini (2007) on age-related decline; Ryan et al, (2006), Mencuccini & Grace (1996), Koch et al (2004).

Biomass accumulation in deciduous (●) and needle leaved (●) species

24/05/07 Long term period Forest C stock change (NBP)