Saturday, July 14, 2007
Fenologisia laskentoja: Rentukka kukkii - Phenological computations: Marsh-manigold (Caltha palustris) in flower
Rentukka on Värriössä fenologisten havaintojen kannalta hieman pulmallinen seurattava. Varsinaisella fenologiareitillä se ei ole runsas, eivätkä reitillä kasvavat yksilöt näytä kukkivan kovin säännöllisesti. Niinpä rentukasta on saatu Värriön fenologiahavainnoista merkilliseltä tuntuva tulos: se kukkii nyt keskimäärin 8 päivää myöhemmin kuin 1980-luvun alussa.
Havainto voi olla sattuman satoa - tai voihan se tottakin olla. Rentukan kukintaa olisi pitänyt selvittää laajemmalla aineistolla kuin Värriön tukikohdan ympäristöstä löytyy, parhaiten Ylinuortin jokivarressa. Seurantaa kuitenkin jatketaan Värriön vähäisellä aineistolla.
Kukinnan (alun) ennuste ensi kesälle on 15. kesäkuuta.
By phenological observations Marsh-manigold (Caltha palustris) is a puzzling plant in Varrio. The occurrence of Marsh-manigold in the phenological track is scarce, and the few plants seem to behave irregularly. Based on observations 1981-2007 the onset of flowering seems to be delayed in the course of years. The average delay is as much as 8 days. This may be due to randomized error based on too few plants; or the observation may tell the truth as well.
Now it is understood that the observation series for Marsh-manigold ought to have been gathered in the Ylinuortti river valley where the occurrence of the plant is more frequent and regular than in the forest areas of Varrio. We will continue the observations of Marsh-manigold in the standard route, however.
The prediction for the next onset of flowering is 15 June 2008.
Havainto voi olla sattuman satoa - tai voihan se tottakin olla. Rentukan kukintaa olisi pitänyt selvittää laajemmalla aineistolla kuin Värriön tukikohdan ympäristöstä löytyy, parhaiten Ylinuortin jokivarressa. Seurantaa kuitenkin jatketaan Värriön vähäisellä aineistolla.
Kukinnan (alun) ennuste ensi kesälle on 15. kesäkuuta.
By phenological observations Marsh-manigold (Caltha palustris) is a puzzling plant in Varrio. The occurrence of Marsh-manigold in the phenological track is scarce, and the few plants seem to behave irregularly. Based on observations 1981-2007 the onset of flowering seems to be delayed in the course of years. The average delay is as much as 8 days. This may be due to randomized error based on too few plants; or the observation may tell the truth as well.
Now it is understood that the observation series for Marsh-manigold ought to have been gathered in the Ylinuortti river valley where the occurrence of the plant is more frequent and regular than in the forest areas of Varrio. We will continue the observations of Marsh-manigold in the standard route, however.The prediction for the next onset of flowering is 15 June 2008.
// posted by Veli Pohjonen @ 16:51 
