Central Die-back of Monoclonal Stands of Reynoutria japonica in an Early Stage of Primary Succession on Mount Fuji

Reynoutria japonicais a common perennial pioneer species on Japanese volcanoes. In a volcanic desert (1500m above sea level) on Mount Fuji (3776m), central Japan, this species forms circular stands (patches). As a patch develops, shoot density decreases in its centre (‘central die-back’). The central die-back has been considered a key process in the early stages of primary succession, though its mechanism has been unknown. The pattern of patch development, population dynamics of aerial shoots, and growth patterns of below-ground organs were analysed in order to investigate the mechanism of die-back, and the following traits are clarified: (1) central die-back areas occur in most small patches (approx. 1m2) without later successional species; (2) shoot characteristics are dependent both on their position within a patch and on patch size; (3) despite the large differences in shoot density, neither time course of shoot growth nor their mortality differs between the centre and periphery of patches; and (4) rhizomes ofR. japonicagrow outwards with regular sympodial branching. From these results, it is concluded that neither interspecific nor intraspecific competition is likely to be a primary cause of the die-back phenomenon, but that central die-back is brought about intrinsically by the growth pattern of the rhizome systems. We also discuss the importance of the central die-back in facilitating establishment of later successional species in the early stages of primary succession.

[1]  D. Tilman.  The Resource-Ratio Hypothesis of Plant Succession , 1985, The American Naturalist.

[2]  Thomas J. Givnish,et al.  Adaptation to Sun and Shade: a Whole-Plant Perspective , 1988 .

[3]  A. Watt,et al.  Pattern and process in the plant community , 1947 .

[4]  F. Bazzaz.  Plant-plant interactions in successional environments. , 1990 .

[5]  E. Batschelet.  Circular statistics in biology , 1981 .

[6]  Thomas M. Smith,et al.  Plant Succession: Life History and Competition , 1987, The American Naturalist.

[7]  J. Connell,et al.  Mechanisms of Succession in Natural Communities and Their Role in Community Stability and Organization , 1977, The American Naturalist.

[8]  J. Harper.  Population Biology of Plants , 1979 .

[9]  L. Pitelka,et al.  Physiology and integration of ramets in clonal plants , 1985 .

[10]  D. Tilman.  Resource competition and community structure. , 1983, Monographs in population biology.

[11]  D. Tilman.  Plant Strategies and the Dynamics and Structure of Plant Communities. (MPB-26), Volume 26 , 1988 .

[12]  F. Stuart Chapin,et al.  Mechanisms of Primary Succession Following Deglaciation at Glacier Bay, Alaska , 1994 .

[13]  A. Bell,et al.  Branching patterns: the simulation of plant architecture. , 1979, Journal of theoretical biology.

[14]  A. Bell,et al.  Rhizome Growth and Clone Development in Anemone nemorosa L. , 1984 .

[15]  M. Hutchings.  Weight-Density Relationships in Ramet Populations of Clonal Perennial Herbs, with Special Reference to the -3/2 Power Law , 1979 .

[16]  T. Hirose,et al.  Nitrogen Acquisition and Use in Three Perennials in the Early Stage of Primary Succession , 1993 .

[17]  Henry S. Horn.  Some Causes of Variety in Patterns of Secondary Succession , 1981 .

[18]  E. Maruta.  SEEDLING ESTABLISHMENT OF POLYGONUM CUSPIDATUM ON MT. FUJI , 1976 .

[19]  M. Hutchings,et al.  Ecological Perspectives on Clonal Perennial HerbsWhen does it pay for individual clone modules to be functionally integrated or independent , 1986 .

[20]  O. T. Solbrig,et al.  Demographic factors in populations of plants. , 1980 .

[21]  Jacob Weiner,et al.  Size variability and competition in plant monocultures , 1986 .