A triangular relationship between leaf size and seed size among woody species: allometry, ontogeny, ecology and taxonomy

A hypothesized relationship between seed weight and leaf size was investiga ted for 58 diverse British (semi-)woody species. Interspecific variation in leaf size of adult plants corresponded allometrically with interspecific v ariation in the weight of an infructescence (seed-bearing inflorescence). T he relationship between seed size and leaf size of adult plants was triangu lar. The corners of the triangle were interpreted in terms of ecological st rategy. Medium-sized infructescences, small seeds and large leaves were see n among medium-sized, fast-growing, earlier-successional, mostly deciduous shrubs and trees; small infructescences, small seeds and small leaves mostl y among low, slow-growing evergreens from stress-prone, proclimax habitats; and large infructescences, large seeds and large leaves among slow-growing , later-successional trees of potential competitive vigour. The hypothesis that the combination of large seeds and small leaves is allometrically unli kely was supported by the data. The roles of ontogeny and taxonomic related ness in the seed size-leaf size relationship were examined by correlative a nd taxonomic analyses of seed, plant and leaf size during the unfolding, of the life history from seed through two seedling phases to adulthood. Decid uous versus evergreen leaf habit was a source of deviation from the otherwi se linear allometric relationships during ontogenetic development, none of which were, individually, confounded significantly with taxonomy.