Using long-term monitoring of fen hydrology and vegetation to underpin wetland restoration strategies

摘要

Question: How can long-term monitoring of hydrological and ecological parameters support management strategies aimed towards wetland restoration and re-creation in a complex hydrological system? Location: Newham Bog National Nature Reserve, Northumberland, UK, a site with a long history of active management, and recorded as drought-sensitive over the last 100 years. Methods: Water level readings are correlated with longer-term hydrological databases, and these data related to vegetation data collected intermittently over a 12 year period. Two analyses are undertaken: (1) a composite DCA analysis of 1993 and 2002 survey data to assess plant community transitions within the wetland and over time, and (2) analysis of recent vegetation data to explore wider vegetation gradients. This allows (3) communities to be classified using NVC classes and (4) integrated with revised Ellenberg F-values. Results: Drought impact and subsequent hydrological recovery over a 22-year period are quantified. Vegetation data display strong moisture and successional gradients. Analysis shows a shift from grassland communities toward mire communities across much of the site. Conclusion: The site is regionally unique in that it has a detailed long-term monitoring record. Hydrological data and vegetation survey have allowed the impact of the most recent 'groundwater' drought (1989-1997) to be quantified. This information on system resilience, combined with eco-hydro-logical analyses of plant community-water regime/quality relationships, provide a basis for recommendations concerning conservation and restoration.