
Lars Eklundh
Professor

Net primary production and light use efficiency in a mixed coniferous forest in Sweden
Author
Summary, in English
Simple light use efficiency (epsilon) models of net primary production (NPP) have recently been given great attention (NPP = epsilon x absorbed photosynthetically active radiation). The underlying relationships have, however, not been much studied on a time step less than a month. In this study daily NPP was estimated as the sum of net ecosystem exchange (NEE) and heterotrophic respiration (R-h) of a mixed pine and spruce forest in Sweden. NEE was measured by eddy correlation technique and R-h was estimated from measurements of forest floor respiration (R-f) and the root share of R-f. The total yearly NPP was on average 810 g C m(-2) year(-1) for 3 years and yearly epsilon was between 0.58 and 0.71 g C MJ(-1), which is high in comparison with other studies. There was a seasonal trend in epsilon with a relatively constant level of approximately 0.90 g C MJ(-1) from April to September Daily NPP did not increase for daily intercepted radiation above 6 MJ m(-2) d(-1), indicating that between-years variation in NPP is not directly dependent on total Q(i). The light was most efficiently used at an average daytime temperature of around 15 degreesC. At daytime vapour pressure deficit above 1400 Pa epsilon was reduced by approximately 50%.
Department/s
- Dept of Physical Geography and Ecosystem Science
Publishing year
2005
Language
English
Pages
412-423
Publication/Series
Plant, Cell and Environment
Volume
28
Issue
3
Links
Document type
Journal article
Publisher
Wiley-Blackwell
Topic
- Physical Geography
Keywords
- Norway spruce
- light saturation
- meteorological dependency
- Scots pine
- seasonal variation
Status
Published
ISBN/ISSN/Other
- ISSN: 0140-7791