article id 461, category Commentary
Boreal forest and climate change – from processes and transport to trees, ecosystems and atmosphere. Silva Fennica vol. 43 no. 4 article id 461. https://doi.org/10.14214/sf.461
Book review: Hari, P. & Kulmala, L. (eds.). 2008. Boreal Forest and Climate Change. Advances in Global Change Research 34. Springer. 582 p. ISBN 978-1-4020-8717-2.
article id 673, category Research article
Utilizing a multipoint measuring system of photosynthetically active radiation in photosynthetic studies within canopies. Silva Fennica vol. 32 no. 4 article id 673. https://doi.org/10.14214/sf.673
A novel multipoint measuring system of photosynthetically active radiation (PAR) has been constructed and operated within a Scots pine canopy. A regular grid of 800 measuring points has been incorporated into a cuvette to observe the spatial and temporal distribution of PAR incident on the needles of a twig along with simultaneous measurements of the CO2 exchange in order to determine the dependence of photosynthesis on PAR. It was shown that large errors can result if the photosynthetic rate is estimated using the mean value of PAR instead of the instantaneous values of PAR detected at given points in the region of the needles. The results demonstrate that the obtained regression between the CO2 exchange rate estimated using the multipoint PAR measuring system and the measured CO2 exchange rate is as good within a canopy as in unshaded conditions.