An introduction to plant demography with special reference to New Zealand trees

Abstract

Abstract An outline of the scope and origins of plant demography emphasises the link between numerical and evolutionary approaches. The rules governing thinning in monocultures and some general features of plant competition in mixtures are described. Plant demography can be applied at several levels — that of the genetic individuals or that of the modular components of which plants are usually composed. This dual population structure puts a new emphasis on the morphological changes occurring in competing mixtures. Various approaches to the definition of strategies are discussed. Plants with short life cycles and abundant production of small seeds are contrasted with long-lived species producing fewer larger seeds. This ‘r-K’ continuum is used as a broad framework, although Grime's (1979) two dimensional strategy model may be more realistic. The concept of the ‘regeneration gap’ has been a persistent theme in forest ecology in New Zealand, and its explanation has generally been presumed to lie in past clim...