Comparative Ecology of Rubus Species (Rosaceae) I. Ecological Distribution and Life History Characteristics of Three Species, R. palmatus var. coptophyllus, R. microphyllus and R. crataegifolius

Abstract The ecological distribution and life history characteristics of three Rubus species, i.e., R. palmatus Thunb. var. coptophyllus (A. Gray) O. Kuntze, R. microphyllus L.f. and R. crataegifolius Bunge were investigated, with particular emphasis on the seasonal growth cycles, modes of the alternation of aerial organs, and patterns of dry matter allocation, and these features were critically compared with one another. It was found that seasonal changes of aboveground biomass are strongly related to the modes of cane alternation, to underground branching producing stolons, and to their dry matter allocation patterns. The modes of cane alternation, underground branching and dry matter allocation patterns were very similar in R. microphyllus and R. crataegifolius , taking about five months from May to September. But R. palmatus var. coptophyllus showed much more gradual replacement of aerial organs, extending over seven months from May to December. These three Rubus species are often predominant in the early successional stages of pioneer communities which develop after cutting of forests in central Japan, and differentiations of the above-mentioned life history traits found in Rubus species seem to be related to the constraints inherent in their somewhat labile, changing environments, e.g., at the forest margin or clearings produced temporarily.