Anales del Jardín Botánico de Madrid (Dec 2001)
Seed dimensions and volume as predictors of sed weight in herbaceous species in the centre of the Iberian Peninsula
Abstract
Although seed weight is a key factor in understanding the reproductive biology of plant species, its value is unknown for a large proportion of the herbaceous species in the Mediterranean basin. This paper presents data on seed weight, dimensions and volume for 1 18 herbaceous species in acidic Mediterranean scrub and grassland in the centre of the Iberian Peninsula. This information is used to design predictive models of seed weight using multiple regression models. taking into account the phylogenetic effect. Five groups of models were designed: one using Trifolium species. three. using the families represented by the largest number of species (Catyophyllaceae, Asteraceae and Poaceae); and finally a general model using one species from each of the families present in the sample. The models are rated according to the absorbed variante, their significance in relation to the previous in complexity and the effort required to obtain the data for each one. We also test the validity of seed dimension data taken from literature sources to predict seed weight. The 1-0 seed dimensions are excellent weight predictors in the case of Trifolium (Weight = - 24.55 + 0.10D1 + 3.38D2, r2 = 0.94) and Asteraceae (Weight = - 20.90 + 1.19D1 + 1.67D2, r2 = 0.91) and are quite satisfactory in the case of the general model (Weight = - 16.01 +0.56D1 + 1.6002, r2 = 0.69).
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