OPERATING INSTITUTE: National Institute for Agricultural Research (INRA).
MAIN PURPOSE: Atmospheric exchanges, energy, water and C balances, nutrient cycles.
ECOSYSTEM TYPE: Maritime pine, Molinia, Ulex nanus.
EXPERIMENTAL TREATMENTS: Irrigation, fertilisation, forest management.
LOCALISATION: 44.72647389564197 -0.731048583984375
FACILITIES: The infrastructure is an experiment aimed at determining the carbon, water, energy and nutrient balances of short rotation forests dedicated to biomass and wood production. The infrastructure com-prises two sites located in Cestas and Salles. The Salles site (60ha plot of pine forest), has been fully operational since 2000 with an eddy flux tower (CO2, H2O, heat, radiation), wet and dry nitrogen deposition, soil moisture, micrometeorological and ancillary measurements. The site benefits from mains power and satellite data transmission.
The Cestas site installed in 2013 is composed of: (1) a set of 32 plots organised into complete randomised blocks where forest management alternatives are compared; (2) a set of four large plots (8-10ha) designed for carbon, nitrogen and water fluxes monitoring.
Quite recently, the Salles (ex “Bilos”) site (10 years old maritime pine plantation) has been monitored for dendrological and biomass growth, and for CO2 and water fluxes since 2001. New equipments has been installed to complete the measurement of GHG fluxes and micrometeorological measurements between terrestrial ecosystems and the atmosphere, according to ICOS standards.
In the INRA Bordeaux-Pierroton domain, 50ha of experimental plots were installed during the winter 2012-2013:
- Eight different options for dendrobiomass production including maritime pine, eucalyptus, nitrogen fixing species, and a mix of 6 tree species selected in the perspective of climate change, are tested at stand level in a randomised block trial (plots of 0.25ha, 4 replications);
- Four plots of 8-10ha, representing 4 sylvicultural options (maritime pine for biomass production, mixed plantation of eucalyptus and maritime pine, maritime pine plantation intercropped with nitrogen fixing species, comparative plantation of pure eucalyptus and maritime pine stand crossed with irrigation and fertilisation treatments) were planted and equipped with a set of automated measurement systems concerning the biophysical and biogeo-chemical functioning.
A biomass technical platform for manipulation of whole trees and root systems, 3D measurement of architecture and biomass for models calibration, wind stability studies, nutrient balance, and preparation of biomass and wood samples was set up at the INRA Pierroton in January 2014.
● Moreaux, V., A. P. O'Grady, N. Nguyen-The and D. Loustau (2013). Water use of young maritime pine and Eucalyptus stands in response to climatic drying in south-western France. Plant Ecology & Diversity 6 (1): 57–71.
● Dannoura, M., P. Maillard, C. Fresneau, C. Plain, D. Berveiller, D. Gerant, C. Chipeaux, A. Bosc, J. Ngao, C. Damesin, D. Loustau and D. Epron (2011). In situ assessment of the velocity of carbon transfer by tracing 13C in trunk CO(2) efflux after pulse labelling: variations among tree species and seasons. New Phytologist 190 (1): 181–192.
● Dannoura, M., P. Maillard, C. Fresneau, C. Plain, D. Berveiller, D. Gerant, C. Chipeaux, A. Bosc, J. Ngao, C. Damesin, D. Loustau and D. Epron (2011). In situ assessment of the velocity of carbon transfer by tracing 13C in trunk CO(2) efflux after pulse labelling: variations among tree species and seasons. New Phytologist 190(1): 181-192.
TA PROJECT: Water Limitation of Canopy and Understorey in a maritime pine forest.
TA User (visit): Tino Rau, Helmholtz Centre for Environmental Research UFZ, Dept. Of Computational Hydrosystems (CHS), GERMANY (September, 2011).
Project Description: The aim of the study is to analyze differences in water limitation between understorey and overstorey of a maritime pine stand.
Motivation: Low soil water content leads to a decrease in Gross Primary Production (GPP). This water stress can be characterized by a threshold value of Plant Available soil Water (PAWt). Soil moisture below PAWt leads to a reduction in GPP. PAWt can vary widely but a rather constant value of around 0.4 has been reported for a broad variety of European forest ecosystems. However, isohydric and anisohydric plants have different water use strategies and should therefore show different thresholds. We will examine water limitation of overstorey and understorey vegetation in a maritime pine stand at Le Bray/France, the precursor site of ECOSYLVE, since the understorey consists of isohydric grasses and overstorey of anisohydric trees.
Method: Latent heat (lE) and Net Ecosystem Exchange (NEE) will be measured at two 7m and 40m high towers with eddy covariance. Additionally soil moisture (Θ) will be measured throughout the root zone. The measurements will be combined together with simulations of the SVAT-scheme MuSICA of INRA-Epiphyse to understand water stress of over- and understorey in the maritime pine stand.
Hydraulic parameterization for MuSICA.
TA User (visit): Tamir Klein, The Weizmann Institute of Science, Rehovot, ISRAEL (October, 2011).
Project Description: The aim of the project is to integrate hydraulic parameters governing the timing and magnitude of forest hydrological fluxes into MuSICA, a multilayer, multileaf pine forest model. Hydraulic parameters include:
- transpirable water content, at specific soil depths;
- xylem sensitivity to embolism, from measurements of hydraulic conductivity in twigs;
- disequilibrium between leaf transpiration and xylem sap flow; and
- leaf water content changes.
The above parameters will be integrated into the parameterization phase of the MuSICA model, in scales ranging from diurnal to seasonal.
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