Objectif FOREST AND WOOD INDUSTRIES TRADITIONALLY HAVE USED ONLY BETWEEN 60 AND 70% OF THE TOTAL BIOMASS PRODUCED BY OUR FORESTS. WITH TRADITIONAL HARVESTING SYSTEMS THE HARVESTING OF VERY SMALL TREES AS WELL AS OF BRANCHES IS POSSIBLE ONLY WITH LOW PRODUCTIVITY AND THAT MEANS HIGH COSTS. A POSSIBLE WAY TO USE A GREATER PART OF THE FOREST BIOMASS IN A MORE ECONOMICAL WAY MIGHT BE THE CHIPPING TEHNIQUE. IN NORTH AMERICA AND TO A LESSER EXTENT SCANDINAVIA (FINLAND) CHIPPING-SYSTEMS HAVE BEEN INTRODUCED DURING THE LAST YEARS. UNDER MIDDLE EUROPEAN CONDITIONS CHIP-HARVESTING SYSTEMS HAVE BEEN WIDELY UNKNOWN UP TO NOW. THE RESEARCH PROGRAM AIMS - TO DESIGN A HARVESTING SYSTEM, - TO QUANTIFY A SURPLUS OF BIOMASS WHICH CAN BE OBTAINED BY CHIPPING, - TO DETERMINE THE COMPOSITION AND QUALITY OF THE CHIPS OBTAINED BY CHIP-HARVESTING, - TO PROVIDE ECONOMIC FIGURES AS WELL AS INFORMATION ON THE ECOLOGICAL PROBLEMS OF HARVESTING SYSTEMS. THE METHODOLOGICAL WAY TO ANSWER THESE MAIN QUESTIONS IS A) TO ANALYZE THE FOREST BIOMASS UNDER LABORATORY CONDITIONS AND B) TO MAKE EXTENSIVE TRIALS WITH TIME STUDIES UNDER CONDITIONS WHICH ARE SIMILAR TO PRACTICAL SITUATIONS. INITIAL RESULTS OF RESEARCH HAVE SHOWN THAT THERE ARE PRINCIPALLY 4 SYSTEMS TO ORGANISE CHIP-HARVESTING: 1. THE USE OF SMALL, TRACTOR-DRIVEN CHIPPERS IN THE STAND OR ON STRIP ROADS. 2. THE USE OF MEDIUM SIZE CHIPPERS WITH MECHANIZED FEEDING ON FOREST ROADS OR ON UPPER LANDINGS. 3. THE USE OF BIGGER, TRUCK-MOUNTED CHIPPERS ON LOWVER LANDINGD. 4. THE USE OF STATIONARY CHIPPERS, TO WHICH THE TREES OR PART OF THE TREES TO BE CHIPPED ARE TRANSPORTED OVER LONG DISTANCES. IT IS PLANNED TO MAKE PRACTICAL EXPERIMENTS ON THESE FOUR SYSTEMS. THE FOLLOWING TYPE OF FOREST OPERATIONS SEEM TO HAVE BEEN SUCCESSFULLY COMBINED WITH CHIP-HARVESTING: A) FULL-TREE CHIPPING OF SMALL MATERIAL COMING OUT OF FIRST THINNINGS, B) FULL-TREE CHIPPING OF MEDIUM SIZED, BADLY SHAPED TREES AND OF COPPICE FORESTS, C) CHIPPING OF THE CROWNS AND OTHER LOGGING RESIDUES IN COMBINATION WITH TRADITIONAL HARVESTING OPERATIONS. THE CHIPS PRODUCED IN EACH OF THESE CHARACTERISTIC TYPES OF OPERATIONS SHALL BE EXAMINED UNDER LABORATORY CONDITIONS TO ASCERTAIN THE MOST IMPORTANT CHARACTERISTICS OF THE CHIPS PRODUCED SUCH AS MOISTURE CONTENT, DIMENSIONS, SHAPE, PERCENTAGE OF THE GREEN PARTS (NEEDLES, LEAVES) AND PERCENTAGE OF BARK AND OF STONES, SAND, ETC. THESE QUALITY ANALYSES SHOULD PROVIDE A GUIDELINE AS TO WHICH WOOD INDUSTRY (PULP AND PAPER, CHIPBOARD ETC.) COULD MOST ECONOMICALLY USE THE CHIPS PRODUCED. ALL THE DATA OBTAINED IN THE DIFFERENT TRIALS AND TESTS SHOULD ALLOW THE CALCULATION OF COSTS AND BENEFITS OF THE DIFFERENT CHIPPING-SYSTEMS IN TERMS OF MONEY AND OF LONG TERM EFFECTS ON THE ECOSYSTEMS. Programme(s) PRE-RAWMAT 2C - Research and development programme (EEC) in the raw materials sector, 1982-1985 Thème(s) Data not available Appel à propositions Data not available Régime de financement Data not available Coordinateur Albert-Ludwigs-Universität Freiburg Contribution de l’UE Aucune donnée Adresse Holzmarkplatz 4 7800 Freiburg Allemagne Voir sur la carte Coût total Aucune donnée
