The world's fastest growing herbaceous plant, papyrus, used to dominate natural African wetlands and their ecoystem services. Widespread in the Victoria Basin, in the Nile and in the Okavango, it supported livelihoods during ancient Egyptian civilisations as fuel, fibre, fodder, even food; in navigation and in the production of paper. Still today, papyrus is an appreciated source of provisional services. During ancient times, probably none understood the key regulatory services of tropical swamps, such as: provision of critical biotopes that are vital for the reproduction of insects, fishes and especially birds, carbon sequestration, control of nutrient balances, and climate mitigation by the control of extreme floods and droughts. Still today, few scientists are aware of these ecohydrological functions and the few field measurements that exist are yielding conflicting evidence. There is limited understanding of its physiological adaptations (C4 photosynthesis, resistance to vapour pressure deficit), which hint at its adaptation to the East African climate. We show how an inverse temperature gradient within papyrus swamps can be related to water retention capacity (lower water loss), while the shape of umbels could promote early morning condensation (more water gain). Papyrus swamps are degrading rapidly due to direct exploitation, to agricultural encroachment up to the water edge, and to damage by cattle. Agricultural drainage schemes are in the process of deliberately destroying papyrus swamps across East Africa. Papyrus restoration should thus be promoted as an ecohydrological biotechnology to improve water quality, to moderate local climate by regulating the water cycle, to provide base material for a variety of provisional ecosystem services, to enhance biotope structure and to support biodiversity. Small scale restoration attempts at lake Naivasha have included the creation of artificial floating islands and channel diversion for the enlargement of flooded swamps, which have succeeded.
The key role of papyrus in the ecohydrology of tropical swamps
Pacini N.
Writing – Original Draft Preparation
;
2017-01-01
Abstract
The world's fastest growing herbaceous plant, papyrus, used to dominate natural African wetlands and their ecoystem services. Widespread in the Victoria Basin, in the Nile and in the Okavango, it supported livelihoods during ancient Egyptian civilisations as fuel, fibre, fodder, even food; in navigation and in the production of paper. Still today, papyrus is an appreciated source of provisional services. During ancient times, probably none understood the key regulatory services of tropical swamps, such as: provision of critical biotopes that are vital for the reproduction of insects, fishes and especially birds, carbon sequestration, control of nutrient balances, and climate mitigation by the control of extreme floods and droughts. Still today, few scientists are aware of these ecohydrological functions and the few field measurements that exist are yielding conflicting evidence. There is limited understanding of its physiological adaptations (C4 photosynthesis, resistance to vapour pressure deficit), which hint at its adaptation to the East African climate. We show how an inverse temperature gradient within papyrus swamps can be related to water retention capacity (lower water loss), while the shape of umbels could promote early morning condensation (more water gain). Papyrus swamps are degrading rapidly due to direct exploitation, to agricultural encroachment up to the water edge, and to damage by cattle. Agricultural drainage schemes are in the process of deliberately destroying papyrus swamps across East Africa. Papyrus restoration should thus be promoted as an ecohydrological biotechnology to improve water quality, to moderate local climate by regulating the water cycle, to provide base material for a variety of provisional ecosystem services, to enhance biotope structure and to support biodiversity. Small scale restoration attempts at lake Naivasha have included the creation of artificial floating islands and channel diversion for the enlargement of flooded swamps, which have succeeded.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
