Lessons Learnt
Impact Monitoring and Management
At Wicken and Great Fen there is a major monitoring programme for both sites together – including hydrology (groundwater levels and surface water levels and quality); soil, vegetation, invertebrates, mammals, birds, fixed-point photography. See link in 1. above.
Water table data is the most useful.
This monitoring shows that vertebrates return most rapidly to restoration areas (see Lakenheath birds in 2. above for example). Macro-invertebrates return rapidly and then plateau. Plants are slowest.
Ecosystem services are being monitored, and economic implications of farming changes (see ref under 7 below).
Data collection will need to continue for a long time (even after 100 yrs a meta-anlysis of wetland restoration sites shows taxa and soil nutrients to be different from reference sites).
At Lakenheath, every compartment is nest-searched (in/out) for bittern and marsh harrier. For other species, territories are mapped. Water levels are monitored once a fortnight from fixed sluices. There are many other survey and monitoring activities.
Participants' Reactions
"The ambitious guiding principle for these large scale nature conservation projects is to initiate and support the return of nature to areas from which it has long been lost. The ecological transformation of the landscape and related ecosystem services should mitigate the impacts of climate change." (Eva Jürgens, NABU)
"Water needs to be allocated more fairly, with more going to ecosystem services other than agriculture. We need a carbon trading and payment scheme. Indications are that this would tip the economic balance towards peatland restoration." (N.N., National Trust)
Examples of Best Pratice
Best practice is shown here in the scale and ambition of the projects, and the fact that they are linked throughout the fens. In terms of motivation, all sites are best practice sites.
Lakenheath Fen is a prime example of best practice in that it has fulfilled and exceeded its targets and is an exceptionally rich site for fen birds. It has the advantage that the whole site is owned and managed in-hand. It is also largely independent of the surrounding water system to fulfill its own needs.
Wicken and Great Fen by contrast are largely dependent on rainwater and winter-abstraction of eutrophic water, and the only viable option left then is to create large sites with enough surface level differences to cope with drought and inundation. Because this type of hydrological regime is very different from the reference fen-hydrology, together with the altered physical and chemical soil condition, the outcome of habitat restoration/creation is uncertain. It may be difficult to combine:
- Creating areas with high nature value robust enough for species with a low ability to colonise new area
- Immediate reduction of CO2 emissions and new carbon storage
The reason is the amount of phosphorus in the top soil. High quality sites may require phosphorus removal, for relatively fast results, but with huge CO2 costs. Alternatively an adequate layer of growing mesotrophic (as opposed to eutrophic) peat will take hundreds of years, if the climate is suitable, but will cost no CO2 cost at all.A choice has to be made in each site on how to reach both goals.
Participants' Reactions
"The differences are in the process of enlarging and linking nature conservation sites as a survival strategy for the future. In the Netherlands this process started a few decades ago and is now coming to an end largely due to the lack of government funding. We are now exploring other types of funding which are more common practice in England." (N.N., Natuurmonumenten)
The project started in 2010 and was finished in 2012.