Long-term study of dry matter allocation and rhizome growth in Anemone nemorosa

Abstract

The rhizome system of Anemone nemorosa in a beech forest in Denmark was studied to determine how resources (dry matter) are allocated to segments of different age, and how rhizome growth is influenced by temperature and precipitation in the spring. The allocation pattern was studied by regular sampling and by experiments. In early spring, almost all movable resources in 1-4-year-old rhizome segments are used for development of leaves and flowers. Later, photosynthetic products from the above-ground parts are used for the growth of new segments (one-third to one-quarter of the resources allocated to the rhizome) or stored in segments from previous years (two-thirds to three-quarters of the resources). Thus, A. nemorosa uses the rhizome tissue for storage several times. Maximum and minimum dry weight per unit length (DWUL) was remarkably constant in 1-4-year-old rhizome segments. The DWUL of the current year's segments was half as high as that of the older segments. The differences in dry matter production across years were expressed in differences in segment length and branching, not in the DWUL of rhizomes. Unusually severe drought in the spring had a negative effect on rhizome growth, although a significant correlation between spring precipitation and rhizome growth was not detected. We found a negative correlation between the length of the growing period in spring and segment length, suggesting that a future increase in winter temperatures may cause an increase in rhizome growth. © 2007 The Authors; Journal compilation © 2007 The Society for the Study of Species Biology.