PLANT CLONALITY - BIOLOGY AND DIVERSITY

The current approaches to the study of clonal plants are reviewed. Mos t studies concentrate at the level of the ramet and clonal fragment ex ploring the ''microscopic'' view of clonal plants, dealing with the tr anslocation of resources, clonal integration, plasticity of growth etc . The information gained by this approach can be used in the understan ding of higher levels of organization within the clonal system either with the help of spatially explicit modelling techniques, or by using means and distributions of size within a population instead of studyin g individual ramets separately. Plant scientists use the term clone wi th two meanings, viz. (a) a set of physiologically connected, but pote ntially independent ramets, and (b) a set of genetically identical, bu t potentially physically separated individuals. The overlap of these t erms differs between individual plant species, depending on the extent of physical separation of the ramets and the degree of physiological integration between the ramets; the lower the frequency of ramet separ ation, the closer are the physiological and genetic concepts of the cl one. Three critical areas seem to be neglected in clonal plant researc h: (a) the interrelationship between hierarchical levels in clonal pla nts, (b) the particular spatial structure of their environment, and (c ) the importance of clonal plants in different ecological communities.