The maturation ofPinus sylvestrisseeds in relation to temperature climate in Northern Finland
作者:
H. Henttonen,
M. Kanninen,
M. Nygren,
R. Ojansuu,
期刊:
Scandinavian Journal of Forest Research
(Taylor Available online 1986)
卷期:
Volume 1,
issue 1-4
页码: 243-249
ISSN:0282-7581
年代: 1986
DOI:10.1080/02827588609382415
出版商: Taylor & Francis Group
关键词: Pinus sylvestris L.;seed maturation;temperature regime;Northern Finland;polar timber line
数据来源: Taylor
摘要:
The probability of achieving an anatomically mature seed crop of Scots pine(Pinus sylvestrisL.) in Northern Finland has been studied on the basis of earlier data and meteorological observations. The meteorological data over the period of 1951–1980 was used to calculate the probability of having a mature seed crop in various parts of Northern Finland. The climatic variables used were: (a) June‐August mean temperature (b)June—September mean temperature, and (c) annual temperature sum (+5°C base temperature). A non‐linear relationship between the percentage of mature seeds in a seed crop and the annual temperature sum was detected, indicating that 50% mature seed crop was achieved at appr. 890 degree days. The results suggest that the probability of having 50% mature seed crop is approximately 0.02–0.03 near the polar timber line. The probability of the occurrence of such years is, however, considerably higher in lowlands and lake districts even near the timber line.
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