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Silvi (Fach) / general (multi-storied) (Lektion)

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• How can a full-storied stand be described? How can this be simplified? What requirements have to be fulfilled? Diameter distribution four diameter classes (Dmax - Dmin / 4) stem number d1 smaller than d2! PLUS biggest tree at least 25cm...
• Height and diameter distribution? And in comparison (SS and FS)? FS: trees never stop growing in diameter but eventually level out (stop) growing in height. Diameter: bell shape (SS) to inverted J-shape (FS) Height: almost bell shape (SS) to a distinct hump (FS), because when the trees eventually stop growing all the big trees end up in the same diameter class (it then almost indicates a single storied stand).
• How are diameter classes spatially distributed over a stand? Impacts? - clustered (uneven distributed) - impacts are denser and less dense parts in the stand, this also means if something would be harvested (one diameter class) it would effect only a rather small part of the whole stand
• What components are discussed in basic stand dynamics? - tree growth (stem diameter, height, crown size etc.) - follows simple rules - tree mortality (trees lost through natural mortality or harvest) - different, since it is very stochastical. - ingrowth (small trees growing up past a specified lower size threshold) - follows simple rules
• Connection between "standing volume" and "annual volume increment"? What are conclussions? Annual volume increment increases with higher standing volume OR more like going to a maximum. --> if you leave a higher growing stock, you get a higher annual increment
• What is a simple guideline for the Connection between "standing volume" and "volume increment"? When does it deviate? the volume increment is roughly 3% of the standing volume, depending on the site index
• Standing volume over mean height, how is it influenced by different thinnings? 3 stages: 1. seen as normal forest because of enough standing volume to mean height; 2. seen and treated as shelterwood; 3. to less standing volume to mean height and, therefore, immediate planting requirement (seen as a CC) Thinning from below has no immediate effect on mean height (more increases it) and, therefore, it is a harder option in fulfilling legal requirements. Thinning from above decreases mean height a lot and is more suitable when it comes to fulfilling legal requirements. 
• What is MAI and CAI in full-storied stands? Both should be even over time.
• How can one compare SS and FS in growth? Difficulties? In level of increment between the different treatments (field plots) Simulation using growth models (problems with develop simulations equally good for both) compare with site productivity (FS less described)
• Differences in measuring? What characteristic is influenced by this? In FS stand the smallest trees are always excluded from measurements.  Ingrowth is influenced by this, because a threshold is established (e.g. 7cm). Only after trees are growing past this threshold they are beeing measured. 
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• What influences the level of ingrowth? Density, shelterwood (is beeing created by thinning from below) has higher ingrowth than FS stands.
• What is the average age for reaching BH (spruce, selection plot)? What is the typical height increment? - 50y. till BH - 2 to 4 cm per y. --> as a result only a few trees grow past ingrowth per y.
• What if plant extra seedling in FS stand? Can one speed things up? The ingrowth still stays low (around 10-15 trees/ha/y.), not influenced
• Why inverted J-curve? Diameter increment (first small increment (rings), larger the older the tree gets) FS: faster diameter growth with thicker trees SS: with thicker trees diameter growth slows down
• What is the real reason for the J-curve and its different diameter classes? Increasing diameter increment!! Not mortality, mortality is only essential in the highest diameter class (largest trees have highest self-thinning rate) --> also the reason for selection cuttings in highest class, because the lower classes are necassary to give enough upgrowth!
• Why FS stands? • mushrooms (more common in selection plots) • no effect to species • reindeers in selection cuttings (lichens) • more aestethic • root rot can be successively descreased • less wind fellings
• How can one establish a FS stand? Mistakes and difficulties? •start with CC, plant some trees •re-planting every 10y. • (-) shelter wood start is not suitable, shelters would have to endure approx. another 100y. • (-) no establishment of skid roads and thinning at the same time • (-) no pines

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