Key points are not available for this paper at this time.
Ola Inghe, Carl Olof Tamm, Survival and Flowering of Perennial Herbs. IV. The Behaviour of Hepatica Nobilis and Sanicula Europaea on Permanent Plots during 1943-1981, Oikos, Vol. 45, No. 3 (Dec., 1985), pp. 400-420
Inghe et al. (Sun,) studied this question.