Annual biomass and production of epiphytes in three monospecific seagrass communities of Thalassia hemprichii (Ehrenb.) Aschers

Abstract

The biomass of epiphytes and seagrasses has been measured in relation to leaf age in three monospecific seagrass stands of Thalassia hemprichii (Ehrenb.) Aschers. in Papua New Guinea. From June 1981 through August 1982, biomass values for epiphytes at the three sites ranged from 5 to 70 g ADW m −2 sediment surface at site 1, from 5 to 14 g ADW m −2 at site 2, and from 3.5 to 7.0 g ADW m −2 at the site 3. Annual mean epiphyte biomass values for the different sites were 1.3 g ADW m −2 leaf surface at site 1, 1.7 g ADW m −2 leaf surface at site 2, and 1.5 g ADW m −2 leaf surface at site 3. The annual mean standing crop of T. hemprichii leaves was highest at site 1 (103 g ADW m −2. Values for site 2 and site 3 were 60 g ADW m −2 and 41 g ADW m −2, respectively. Production of epiphytes was calculated in three different ways: firstly, by using biomass values for each specific leaf-age group, with corrections for colonization; secondly, by fitting the biomass values with a specific growth curve; and thirdly, by estimated the rate of biomass accumulation. On an area basis, production of epiphytes on leaves of T. hemprichii ranged from 0.55 to 3.97 g ADW m −2 day −1 at site 1, from 0.17 to 0.73 g ADW m −2 day −1 at site 2, and from 0.24 to 0.68 g ADW m −2 day −1 at site 3.