THE BIOLOGICAL AND PHYSICAL DETERMINANTS LEADING TO A HIGH PRIMARY PRODUCTIVITY IN SHORT ROTATION INTENSIVE CULTURE SYSTEM (SRIC), BEING IDENTIFIED FOR EACH OF THE POPLAR TEST CLONE SHOULD NOW PROVIDE THE FUNDAMENTAL BASIS FOR THE CLONE-SPECIFIC PHOTOSYNTHETIC POTENTIAL AND ENERGY CONVERSION EFFICIENCY. A MATHEMATICAL DESCRIPTION OF EACH CLONE DEPENDENT PRODUCTION SYSTEM WILL BE TRIED IN TERMS OF FUNDAMENTAL SYSTEM PROCESSES AND SYSTEM STRUCTURE ANALYZED IN THIS STUDY. MODEL SENSITIVITY ANALYSES SHOULD THEN YIELD THE DOMINANT GUIDELINES FOR CLONE SELECTION CRITERIA IN VIEW OF OBTAINING HIGH BIOMASS PRODUCTIVITY.
Dry mass productivity of 5 poplar clones (2 Populus (P) trichocarpa, 1 P x euramericana and 2 P trichocarpa x P deltoides), grown under intensive culture and high plantation density, was related to leaf area index and duration, solar radiation extinction coefficient and conversion efficiency. Significant clonal differences in photosynthetic capacity, leaf orientation, leaf area index and duration, extinction coefficient and above ground dry mass production were observed. Accumulated stem dry mass was linearly related to accumulated intercepted solar radiation in all 5 clones. Seasonal average conversion efficiencies for total above ground dry mass (stem, branches, leaves) were 0.72 g/MJ for euramerican clone Robusta and 1.10 g/MJ for interamerican clone Beaupre. Clone Beaupre also had highest leaf area index and duration, highest photosynthetic capacity and lowest solar radiation extinction coefficient.
THE OBJECTIVES OF THIS PROJECT ARE THE IDENTIFICATION AND ANALYSIS OF FUNDAMENTAL DETERMINANTS LEADING TO A HIGH PRIMARY PRODUCTIVITY ON A SHORT TIME PERIOD AND THIS AT DIFFERENT ORGANIZATIONAL LEVELS OF THE VEGETATIVE PRODUCTION SYSTEM. STUDIES WILL BE MADE AT THE LEAF LEVEL TO DETERMINE THE BIOLOGICAL (GAS EXCHANGE) AND ARCHITECTURAL (STRUCTURAL) DETERMINANTS AND AT THE PLANT CANOPY LEVEL (BIOMASS ACCUMULATION) TO EVALUATE CARBON ALLOCATION PATTERNS.
SHORT ROTATION, HIGH DENSITY (0.8 X 0.8 M) EXPERIMENTAL PLOTS WITH 5 POPLAR CLONES WILL BE ESTABLISHED AT GENT (BELGIUM), ORSAY AND MONTPELLIER (FRANCE) TO STUDY THE BIOLOGICAL PRODUCTION POTENTIAL AND THE EXTERNAL CONSTRAINTS UNDER A RANGE OF ENVIRONMENTAL CONDITIONS. EXPERIMENTS (BELGIUM, G.B., FRANCE) UNDER CONTROLLED CONDITIONS WILL BE AN ADDITIONAL SOURCE OF INFORMATION. DATA OBTAINED WILL LEAD TO A MATHEMATICAL DESCRIPTION OF A CLONE SPECIFIC BIOMASS PRODUCTION SYSTEM. SENSITIVITY ANALYSIS SHOULD YIELD DOMINANT GUIDELINES FOR CLONE SELECTION CRITERIA.
Funding SchemeCSC - Cost-sharing contracts