Vegetative phenology of alpine plants at Tateyama Murodo-daira in central Japan

Abstract

The vegetative phenology of 29 alpine species, including herbaceous and woody summergreens and evergreens, was investigated. Summergreen species initiated and completed leaf growth earlier than evergreen species. The green period of leaves in summergreen plants was determined largely by the time of growth initiation. Early initiation of growth in summergreen plants contributes to the increase in photosynthetic carbon gain. Early cessation of growth in summergreens is advantageous for the growth in the following year because it leads to an increase in stored photosynthates. The growth period of leaves and stems in alpine plants correlated with the time of growth initiation more strongly than with the time of growth cessation, indicating the importance of early growth initiation for the increase in plant growth. The growth period of leaves was positively correlated with the sum of leaf lengths and the number of leaves. Herbs with a long growth period of more than 50 days had perennial shoot axes not terminated by inflorescences, suggesting a relationship between the growth period and shoot habit. Two summergreen species were completely dead by mid-September, before the air temperature decreased below 0 degrees C. The remaining summergreen species died immediately after the air temperature decreased to -1.4 degrees C in late September.

Effects of growth temperature and chilling duration on leaf phenology of Fauria crista-galli subsp. japonica, an alpine snowbed geophyte

“…(Yoshie 2008b). These herbs, including sedges and grasses, show late growth cessation and shallow dormancy compared with herbs having determinate growth habit in alpine regions (Bliss 1971;Yoshie 2008bYoshie , 2010 and in temperate regions (Yoshie and Yoshida 1989;Yoshie 1995). In the natural habitat of alpine plants, low summer temperatures may limit the leaf expansion period, and warm years may lengthen the leaf expansion period.…”

“…In the natural habitat of alpine plants, low summer temperatures may limit the leaf expansion period, and warm years may lengthen the leaf expansion period. Schizocodon soldanelloides f. alpinus, an alpine evergreen chamaephyte that develops inflorescences from the leaf axils (Yoshie 2008b), has a higher number of leaves and longer leaf expansion period in a warm year compared with a cool year (Yoshie 2010). Fauria crista-galli plants have aerial shoots that develop inflorescences from leaf axils (Yoshie 2008b).…”

“…Many alpine summergreen plants shed leaves immediately after the air temperature decreases below 0°C, indicating that they have been subjected to frost injury (Yoshie 2010). Therefore, warm temperatures in the late vegetative season lengthen the green period (the period from growth initiation to death in leaves) of these summergreen plants.…”

“…Some alpine summergreen forbs, such as F. crista-galli subsp. japonica and Veratrum stamineum, shed leaves completely before the air temperature decreases below 0°C, indicating that they are highly sensitive to chilling temperatures (Yoshie 2010). However, there remains a possibility that the early leaf senescence of these species is not dependent on temperature.…”

“…Some alpine plants start to grow while still beneath snow cover (Billings and Bliss 1959;Mooney and Billings 1960;Bliss 1962;Billings 1974;Kimball and Salisbury 1974;Hamerlynck and Smith 1994). F. crista-galli plants are considered as starting to grow while under snow cover because the effects of snow pressure damages have been observed in the leaves at a very early stage of growth in its natural snowbed habitat (Yoshie 2010). The objective of this study is to clarify how air temperature and chilling duration affect the expansion and green periods of F. crista-galli plants that have indeterminate growth habit.…”