Seed size in relation to phylogeny,growth form and longevity in a subalpine meadow on the east of the Tibetan plateau

This study examined seed size distribution, and seed size in relation to phylogeny, growth form and longevity, where seed size is expected to be approximately of a log-normal frequency distribution and correlate dwith phylogeny, growth form and longevity. We made use of a data set of 229 species from alpine meadow on the east of the Tibetan plateau. Species spanned 10⁴ range of seed size, and the frequency of seed mass classes on a logarithmic scale produced an approximately normal distribution, but largely shifted towards smaller-sized seeds compared to those of the temperate zone and the tropics. It was evident that seed size was strongly related to phylogeny, where order, family, genus and species accounted for 2%, 32.9%, 48.9% and 16.2% of total variation in log seed mass. However, both growth form and longevity did not account for variation in log seed mass, which was opposite to the previously reported patterns of trait correlation. The implications of our results are discussed.