Description:
Drainage ditches are main aquatic structures in Dutch arable land which have been largely ignored studies of ecology, biodiversity and conservation and corresponding policy. However, because of their significance, expressed in total length of ditches, they could be major landscape-scale carriers and determinants of aquatic biodiversity.
The question is how and why do macrophytes control the distribution, structure and dynamics of macroinvertebrate communities found in ditch ecosystems?
Research objectives:
The objectives are:
1. to establish the key factors that decide the biodiversity in Dutch drainage ditches
2. to describe and explain the effects of water quality (in terms of nutrients, oxygen and temperature) on the functional biodiversity of macroinvertebrates
3. to indicate measures to optimise ditch biodiversity.
Results and products:
In 2007 an extensive literature survey was conducted. This provided the theoretical basis for further experimental hypothesis testing. Based on a full factorial field experiment (2007 and 2008) using artificial substrates it can be concluded that microhabitat characteristics (plant structure surface area and structural complexity) influenced the numbers of crawling detriti-herbivore and crawling predatory macroinvertebrates and thereby likely influence the rate and magnitude of ecosystem processes. Total abundance and taxon richness was not determined by microhabitat but on ditch scale, which indicated that local environmental conditions, e.g. dissolved oxygen level, or even processes on landscape scale (dispersal from other water bodies) determine ditch biodiversity Based on these results we are going to study the relationships between:
- macroinvertebrate community composition and/or dynamics and ditch ecosystem functioning
- ditch biodiversity on landscape scale: where are the hotspots of biodiversity and why? |
