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A comparative study of Geum rivale L. and G. urbanum L. to determine those factors controlling their altitudinal distribution
Author(s) -
Graves J. D.,
Taylor K.
Publication year - 1988
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.1988.tb00277.x
Subject(s) - germination , frost (temperature) , biology , botany , horticulture , environmental science , physics , meteorology
SUMMARY The control of germination by temperature was compared in Geum urbanum L. and G. rivale L. , two closely related species with contrasting altitudinal and latitudinal distributions. Under constant temperatures only slight differences were observed in the response of germination to temperature in the two species. A model was formulated to predict germination in field temperature conditions on the basis of rates of germination observed at constant temperatures. Comparison of observed and predicted germination under field temperature conditions revealed that the rate of germination was considerably higher than expected in G. urbanum at low temperatures. Calculations indicate that at altitudes above the altitudinal limit of G. urbanum this feature results in the germination of G. urbanum during the frost period of the year whilst seed of G. rivale remains dormant until the advent of milder climatic conditions.