Current Events
Dr. Emily Alderton
Environmental Change Research Centre
Dept of Geography, UCL
London, England
"Ghost Ponds: Resurrecting lost ponds and species to assist aquatic biodiversity conservation."
Mark your calendar for the next NEBC Meeting on October 13, 2017, at Harvard University with lecture by Dr. Emily Alderton.
Abstract: Farmland ponds provide valuable oasis for aquatic and terrestrial wildlife, and contribute significantly to regional aquatic biodiversity. Good quality farm ponds support many rare and threatened species, which in our study region (north Norfolk, England), include the nationally rare tubular water-dropwort Oenanthe fistulosa, and holly-leaved naiad Najas marina. These islands of ecological diversity exist within an otherwise homogeneous sea of intensive agriculture, and are under constant threat from pollution, water abstraction, or simply being filled-in for land reclamation. Across the UK, it is estimated that around three quarters of farmland ponds have been filled-in during the last century, with similar levels of pond loss reported in Europe and parts of North America. Ponds lost in this way often leave behind a "ghostly" mark in the landscape – a damp depression, patch of poor crop cover, or change in vegetation, visible for many decades or even centuries after the pond was originally filled-in. We have recently found that these buried "ghost ponds" are not completely lost, but can be resurrected from the historic seed bank lying dormant underneath intensively cultivated fields. Even after burial for over 150 years, aquatic seeds and oospores are quick to germinate, and ghost ponds rapidly developed into species rich aquatic habitats. Taxa which are now uncommon in farmland due to nutrient enrichment, including several members of the Characeae (stoneworts), were particularly successful at re-colonising ghost ponds. Ghost ponds thus represent biological 'time capsules' whose restoration can facilitate the rapid return of wetland habitat and species to the landscape.
