An especial method was applied for calculating the photosynthetic productivity of oak (Quercus robur L.) stand. The methodological basis is that the efficiency of photosynthetic utilization of intercepted PAR over the daylight period depends on environmental conditions and distribution of PAR within the canopy. This method was also used to determine the photosynthetic productivity of individual trees within the stand and to estimate the contribution of trees with various extents of growth retardment to the total photosynthetic productivity. For the oak stand in the forest-steppe region, the photosynthetic efficiency was expressed as a function of climatic variables such as solar irradiance day sum, day average temperature, air humidity, and water availability (quantified as the predawn leaf water potential, PLWP). This functional dependence differed for sun-exposed and shade leaves. Under optimum water availability (PLWP = −0.5 MPa), the photosynthetic productivity of a 60-year-old oak stand amounted 44.5 t C/(ha year) but it declined with the decrease in water availability. Under severe water deficit, when PLWP dropped to −2.1 MPa, the photosynthetic productivity decreased 17-fold and equaled 2.6 t C/(ha year). The strongest decline in photosynthetic productivity occurred on sunny days under moisture deficit in dominant and codominant trees belonging to growth classes I and II.
Russian Journal of Plant Physiology – Springer Journals
Published: Aug 9, 2005
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera