Light distribution within forest edges in relation to forest regeneration
I. Schmid, K. Klumpp, M. Kazdahttps://doi.org/10.17221/4538-JFSCitation:Schmid I., Klumpp K., Kazda M. (2005): Light distribution within forest edges in relation to forest regeneration. J. For. Sci., 51: 1-5.
Light conditions were measured along six transects from 35 m inside of a mixed Norway spruce/Scots pine forest to an adjoining clear-cut in NW-Austria. Photosynthetic photon flux density (PFD) was recorded every minute of the day from 5:00 a.m. to 8:00 p.m. for three weeks in July. PFD decreases exponentially from the clear-cut to the interior of the forest following the gap fraction. Low light intensity classes (< 50 µmol photons m2/s) decrease from the stand towards the open, whereas the clear-cut receives light of higher intensities (> 200 µmol photons m2/s) for most of the day. PFD values assessed during the day were compared with photosynthetic light response curves measured on advanced planting of broadleaf species in the same stand. The high light compensation point of Quercus petraea enables carbon gain in deep shade for about 60% of the day. The other shade tolerant species Fagus sylvatica and Acer pseudoplatanus can perform net photosynthesis at 80% and 90% of the time, respectively. This reduces the possibility of advanced planting of light demanding species to the first few meters of the inner part of the forest edge. Keywords:
advanced planting; forest edge; light compensation point; photon flux density