The standing live biomass of papyrus swamps is high compared with most other communities dominated by herbaceous vegetation. For the first time, measurements of below-ground rhizome and root biomass are reported here, in addition to measurements of shoot biomass, for a papyrus swamp located on Lake Naivasha, Kenya. The ratio of rhizome and root to shoot dry weight was 1.38: 1 and the total standing live biomass was 7.8 kg(dry weight) m−2. Detritus, formed from slowly decomposing papyrus, is normally the most important sink for carbon in this ecosystem. The amount of detritus retained by swamps varies but at L. Naivasha it contained almost 20 times the carbon found in living biomass. The net primary production of the swamp was calculated to be 6.28 kg(dry weight) m−2 y−1, which is amongst the highest recorded productivities for natural ecosystems. Model estimates of carbon input into the system from photosynthesis are incorporated into a carbon flow diagram for the swamp and this emphasises the importance of detritus as a sink for carbon in this ecosystem.
