Assessment of management techniques
Ponds need to be managed; otherwise they fill in and disappear. Although widely applied, there is almost no information available on the effect of the various management techniques (such as clearing of water plants, sludge removal, deepening and re-profiling) on the composition and diversity of pond biota, or on ecosystem functions and pollutant dynamics in ponds. Management practices can set back the succession in the ponds and result in a serious disturbance of the pond system. This may create opportunities for new species, but may also lead to the disappearance of others. Management techniques are generally expected to have profound short-term effects on local diversity (by for instance restoring earlier succession stages), but their use as a tool for the management of regional biodiversity has hardly been explored. It is not known how different management techniques can be combined in a specific area in order to maximise gamma diversity at the regional scale. Similarly, it is not known whether reducing management efforts in favour of the creation of new ponds can be a more efficient strategy to preserve pond biodiversity. We will monitor the effects of several pond management actions in a large number of ponds. The data will be combined with the data obtained from WP1 and WP2 and computer simulations will be used in order to evaluate how local management techniques and the creation of new ponds can be applied to maximize biodiversity at the regional scale.