REVIEW OF ADVANCES IN ECOLOGY OF SEED MASS
种子重量的生态学研究进展

Seed mass is a key attribute of plant species,and study of relationships between seed mass and other plant traits and ecological characteristics has become a practical problem and an interesting topic in evolutionary biology.Seed mass(or size)is related to other plant traits and community characteristics,including seed dispersal capacity,seed dispersal mode,plant growth form,leaf area index,abundance of seeds or plant individuals in a community,seed predation,seed dormancy and seed persistence in soil seed banks,net primary productivity,etc.Variations in seed mass have been related to latitude,longitude,altitude,temperature,precipitation,slope aspect,light environment,etc.Seed mass is thought to have evolved as a compromise between seed mass and number for a given amount of energy.Many studies support that seed mass has a closer relationship with plant growth types than other characteristics.Species that establish in shade have large seeds.Three patterns were found in the relationship between seed mass and seed predation.Four patterns were found in the relationship between seed mass and persistence in soil seed banks.During establishment,seedlings from larger-seeded species are better able to survive competition from established vegetation,deep shade,defoliation,mineral nutrient shortage,burial under soil or litter,drought,etc.Among species with seeds unspecialized for spatial dispersal,seed mass is unrelated to dormancy.However,in species with wind-or animal-dispersed seeds those with heavy seeds typically have less dormancy.This is consistent with heavy seeds having better establishment success and/or suffering higher levels of herbivory.Future research should focus on relationships between seed mass ecology and 1)plant phylogeny and plant taxonomy,2)latitude,longitude and altitude,3)community succession,4)number of plant individuals and seeds,5)microhabitats or microtopography such as forest gaps and slope aspect and 6)global climate changes.