Characterizing plant attributes with particular emphasis on seeds in Tamaulipan thornscrub in semi-arid Mexico

Seed mass, dispersal syndromes and other plant attributes were investigated for 111 species native to north-eastern Mexico. We investigated whether se eds from Mexico conformed to patterns of seed size and dispersal syndrome s pectra found for floras in arid environments from around the world. The dis tribution of seed mass in the Mexican flora (0.03-598 mg) was generally sim ilar to that found elsewhere. All of the major seed dispersal syndromes pre viously found in arid environments were represented in Mexico, although ver tebrate dispersal (33 species) was unusually common. There were 31 species having wind-dispersed seeds, four ant-dispersed and 43 with no obvious disp ersal morphology. Woody species were more likely to have large seeds and he rbaceous species were more likely to have small seeds. Woody plants had pro portionally more wind-dispersed and less animal-dispersed species than did herbaceous plants. We did not find the expected relationship between time o f seed set of vertebrate-dispersed species and the presence of migratory bi rds or between time of seed set and optimum germination time. (C) 2001 Acad emic Press.