UCL Department of Geography


David Downes

Research Title

Landscape-scale consequences of farmland pond restoration for aquatic macrophytes, macroinvertebrates and bats (Chiroptera).

More about David
  • 2018 – present, University College London: PhD Geography student: ‘Landscape-scale consequences of farmland pond restoration for aquatic macrophytes, macroinvertebrates and bats (Chiroptera)’
  • 2015 – 2017 University College London: MSc Aquatic Science (Distinction): Dissertation: ‘Return of the molluscs: recovery of freshwater Mollusca in Blakeney Freshes after seawater flooding’
  • 1998 – 1999 University of Essex: MA Sociological Research: Dissertation: ‘Drugs and youth crime: personal social networks and drug use’
  • 1988 – 1990 University of Leicester: MA Social Work (Distinction), CQSW: Dissertation: ‘Residential care: preparing children for long-term family placement’
  • 1978 – 1982 University of London, Chelmer Institute of Higher Education: BEd (Hons, 2:1) Environmental Studies: Dissertation: Ecological consequences of forestry in the UK
Research Interests

At the landscape level, ponds are the most species-rich aquatic habitat for macroinvertebrates and wetland plants, making a greater contribution than lakes, rivers, streams and ditches to regional (gamma) diversity. In particular, ponds have been shown to contribute significantly to biodiversity in agricultural areas, where they may be important ‘islands’ of heterogeneity in intensively farmed landscapes. Studies have also highlighted the vital role played by networks of ponds and their surrounding terrestrial habitat (‘pondscapes’) in aquatic landscape connectivity, for example by helping to support metapopulations of amphibians and some aquatic invertebrates.

Despite the ecological importance of farmland ponds, since the 1960s the majority of these ponds in lowland UK have become heavily overgrown, or have been deliberately filled-in, due to agricultural intensification and cessation of traditional management. Together with the destruction of other semi-natural features (such as hedgerows), this has been a significant cause of habitat loss and fragmentation in agricultural landscapes, with negative impacts on floral and faunal diversity.

Recent studies have demonstrated the effectiveness of restoration (clearance of scrub and sediment removal) and periodic management for enhancing the biodiversity of pond networks, with major increases in diversity for aquatic macrophytes, amphibians, invertebrates and birds. However, further research is needed to quantify the temporal changes in aquatic biodiversity on a landscape-scale following restoration and also to improve understanding of some of the underlying ecological processes.

The implications of farmland pond restoration for bats, and the potential of this approach to help support bat conservation in arable farmland, are under-researched. The limited research that has been undertaken in relation to bats’ use of ponds in temperate agricultural landscapes indicates that bats are influenced not only by the physical characteristics of individual ponds but also by the relationship between ponds and other landscape features. This project aims to compare bats’ use of managed, ‘open canopy’ ponds and unmanaged, overgrown ponds and to consider how patterns of usage are related to landscape connectivity in arable farmland. The mass hatching of aquatic insect prey is known to be a key factor explaining the greater diversity and foraging activity of farmland birds at restored ponds compared to overgrown ponds. Bat activity around farm ponds may also be related to patterns in the emergence of insect prey; this aspect of pond restoration is under-researched and would benefit from further exploration.


  1. Investigate the extent to which farmland ponds (in a typical lowland arable agricultural landscape) have become overgrown and quantify the amount of historic pond loss.
  2. Assess the potential for restoring farmland ponds and the potential consequences for landscape connectivity.
  3. Determine the effect of farmland pond restoration on the landscape-level (gamma) diversity of aquatic macrophytes and selected aquatic macroinvertebrates and quantify the temporal variation in gamma diversity for these taxa.
  4. Assess the implications of pond restoration and management for the conservation of bats in lowland arable agricultural landscapes.

This study aims to contribute to developing an evidence base for informing farmland pond conservation. The implications of the research findings will be considered in relation to landscape-scale restoration projects and future agri-environment schemes.