Modified debarking heads
Pilot-Projekt: Rückbau des Erschließungssystems im Nationalpark Bayerischer Wald
In der 2015 neu ausgewiesenen Kernzone des Nationalparks werden die Erschließungsdaten und –fakten intensiv überprüft. Darauf aufbauend werden Möglichkeiten des Rückbaus der Erschließung in diesem Gebiet aufgezeigt. Abschließend soll eine Empfehlung zum weiteren Vorgehen im Bereich der „Renaturierungs-/Rückbaumaßnahmen“ erarbeitet werden.
Aufbauend auf eine Übersicht über die Ausgangsbedingungen folgt die Beschreibung und Einordnung der zu planenden Rückführungsmaßnahmen in dieser intensiv erschlossenen Zone. Situationsbeschreibungen der natürlichen und technischen Bedingungen sowie Ziele der zu planenden Rück- und Umbaumaßnahmen bilden je nach Widmung und Nutzungsart die Planungsgrundlagen für Umbaumaßnahmen. Methodik, Kostenanalyse und eine Wirtschaftlichkeitsbetrachtung gehören dazu.
Das Ergebnis liefert Grundlagen für Entwürfe und Umsetzung der Maßnahmen. Unsere Hinweise sollen u.a. Grundlagen und Argumentationshilfe für die Öffentlichkeitsarbeit liefern.
Productivity of a single-grip TimberPro 620 harvester with a LogMax 7000 harvesting head in a beech dominated stand
The forest conversion from spruce dominated forests to close-to-nature stands with considerable shares of broad-leaved tree species is of high importance in Germany. For mechanized harvesting operations, the complex tree architecture and high wood density of broad-leaved tree species, in particular of beech, pose a challenge during the processing phase. Usually more powerful machinery is required than for softwood stands of comparable age and tree dimensions. This pilot-study assessed the productivity of a TimberPro 620 single-grip harvester with a LogMax 7000 harvesting head in a mature mixed-wood stand located in southern Germany. A total of 82 trees previously inventoried were harvested using one of two silvicultural treatments (clear-cut in plot A or selective-cut in plot B). A conventional time and motion study was performed on the selected trees using a handheld computer with the UMT Plus software. Results demonstrate considerable differences in percent distribution of the work cycle elements between the two tested silvicultural treatments, particularly with machine movement. Based on single-tree volume estimations, average harvesting productivity was determined to be 32.2 m3/PMH for spruce and 28.9 m3/PMH for beech, irrespective of silvicultural treatment.
The effect of quality bucking and automatic bucking on harvesting productivity and product recovery in a pine dominated stand under Bavarian conditions
On-board computers of harvesting machines can now provide optimized bucking (task of cutting stems into different log lengths) by relying on value and demand matrices. Despite existing benefits of these systems in certain countries, they remain largely under-utilized and generally poorly understood in German mechanized forest operations. The study aimed to compare and quantify the differences in value recovery and machine productivity between two treatments (quality bucking (OFF) and automatic bucking (ON)). A mature forest stand with a high proportion of Scots pine (Pinus sylvestris L.) was divided into (30 m x 100 m) plots where both treatments were randomly distributed and replicated 10 times. Pre-harvest inventory was performed on each tree targeted for removal via a commercial thinning operation. Mechanized harvesting was performed with an excavator based Atlas Kern T23 Königstiger harvester. The same assortment specifications and prices were used for both treatments but on-board bucking solutions were applied in the ON plots whereas the operator had full control of the products to be recovered in the OFF plots. During harvesting operations, continuous time and motion was done within all tested plots. Harvesting productivity was very similar between both treatments when isolating pine trees, while spruce trees showed more differences, especially as dbh increased. A higher product recovery and revenue per cubic meter when using automatic bucking for spruce trees but the opposite for pine trees was also found.