Comparison of recovery processes between water categories (workpackage 6.4)
- to analyse and compare the processes and functional features of recovery from eutrophication, acidification or hydromorphological stress between water categories for four organism groups,
- to detect the antagonistic, neutral, additive or synergistic nature of the impact of multiple pressures between water categories,
- to detect commonalities among different recovery processes between water categories,
- to develop a method to combine recovery effects in a summarising 'catchment' metric.
Workpackage strongly depends on the data collected in Module 5 (Management and global/climate change) and additionally on those from the lake and coastal/transitional Modules 3 and 4, respectively. Furthermore, additional targeted data collecting will be done by the partners per water category on specific restoration projects and trait/functional data will be gathered from www.freshwaterecology.info. A literature metadata analysis helps gather existing knowledge on recovery processes in different water categories.
The influence of biological factors such as dispersal, connectivity and metapopulation dynamics on recovery processes was reviewed. Five restoration constraints were listed so far:
- Effects of barriers of colonization (dispersal and establishment)
- Introduction of non-native species
- Considerations of spatial and temporal scaling in restoration projects
- Accumulation effects and multiple stressors
- Unclear goals and insufficient monitoring
In conclusion, although the importance of establishing the suitable abiotics is stressed by a multitude of studies, the awareness that other factors should be considered as well is apparent in recent recommendations on freshwater restoration.
Relevance for end users
The comparison of responses along recovery trajectories between water categories will contribute to making existing assessment methods better comparable, and as such will add to the intercalibration of assessment methods presently carried out by the EU Member States. The published knowledge on biological processes on catchment scale, such as connectivity, dispersal and metapopulation dynamics will provide insights in the causes of negative restoration results when species did not return while the environmental conditions were fixed appropriately. Also knowledge will be provided on the impact of catchment scale processes and global change on recovery chains.