Wetlands in a Flood Pulsing Environment
Effects on and responses in biodiversity, ecosystem functioning and human society
This groundbreaking multidisciplinary symposium addresses the important effects of pulsing hydrologic cycles on the functioning of wetlands. The symposium focuses on inland wetlands with emphasis on the importance of flood pulses on wetland flooding and linked responses in chemistry, biological productivity, biodiversity and human livelihoods, history and culture.
The importance of flood pulses to the functioning of wetlands was first formulated by Junk and his co-workers in 1989. The concept has since been growing in importance: it is now time to make an update of the past 20 years of research. The flood pulse concept makes decisive causal links among climate events and the geological and vegetative features of a river catchment. The extent and duration of flooding in a downstream wetland is determined by climate and geomorphology. The relatively abrupt shift from terrestrial conditions to flooded wetland conditions has dramatic impacts on environmental chemistry, biological productivity and biodiversity, and many life forms have evolved specific adaptations to this dynamic environment. Not least, human beings have over centuries learnt to live and use these dry and wet phases to their benefit, reflected in their livelihood strategies and cultural expressions.
The flood pulse can easily be altered; it can be flattened out or removed completely or changed in periodicity by building of dams. It can be reduced in intensity by water diversions. In addition, the likelihood of rapid climate change has serious implications for larger variation in pulse magnitude and frequency than those to which ecological and economic systems are currently adapted. Such changes can have serious repercussions for flood pulse dependent wetlands. Understanding links between hydrological pulse and ecosystem and socio-economic processes is, therefore, of critical importance to sound and long-term management of such wetlands.
The symposium will be held in Maun, Botswana, at the edge of the Okavango Delta, one of the world's largest flood pulsed wetlands. Maun is a fitting venue for the symposium as many issues related to the flood pulse are visible. All inflow to the Delta emanates from the Angola highlands, passes through northern Namibia, arriving in Botswana as a distinct flood pulse where it covers many thousand square kilometres of grasslands with water. This process creates a dynamic, interlinked aquatic-terrestrial system with high biological productivity and biodiversity -- drivers of a flourishing tourism industry and the base for the development of local populations who have developed specific agricultural and livelihood strategies in response to the flood pulse.
However, newly formulated upstream interests are different, with ambitions for water developments such as irrigation and construction of dams for hydro-electrical production. To manage these changes in use and demand, the three riparian countries sharing the basin have established the Permanent Okavango Basin River Commission (OKACOM) with its secretariat in Maun. The Government of Botswana has developed the Okavango Delta Management Plan for the Ramsar site and the University of Botswana's Harry Oppenheimer Okavango Research Centre (HOORC), was established to specifically address natural resource management issues. A current UNDP-GEF funded project, BIOKAVANGO, aims to raise awareness and to involve local populations in the management of the Delta and its biodiversity.
The symposium will provide an opportunity to collect, summarize and synthesize the considerable multi-disciplinary knowledge that has been generated during the past 20 years, to give guidance to future research and to help incorporate the flood pulse concept into policy and management.