Friday 11 October 2019
The results of the most recent Habitat Survey of Guernsey, Herm & Jethou has been published.
A Habitat Survey was conducted in the Spring and Summer of 2018, in order to establish the extent of change in the habitat composition in the last decade. The results of the survey give a mix of good and bad news for the Bailiwick's habitats and the wildlife they support.
The most significant findings are:
- Woodland cover has more than doubled since 1999 (up to 498ha from 217ha). This is mostly due to an increase in planted woodland under various schemes, including the free tree planting scheme that ran from 1992 to 2006, to offset losses to Dutch elm disease and which is now continued by Guernsey Trees for Life.
- A 90% loss of Semi-improved Grasslands and a complete loss of Unimproved Grasslands since 1999. These two habitats are and were providers of some of the richest diversity of life on the Island. These dramatic declines have mainly resulted from changes in land management; either too little management, for example allowing land to revert to scrub; or too much management, for example, through the application of fertilisers, herbicides and ploughing plus the conversion of fields to regularly mown "garden" lawns.
- Marshy grasslands, another valuable group of habitats, have declined by 37% since 1999.
- The area of the invasive non-native Sour fig, which represents just one example of several invasive non-native species found in Guernsey, has more than doubled since 2010, from four to nearly ten hectares. This is despite continual efforts by local conservation charities to clear land of the plant. Much of the land now dominated by Sour fig was previously classified as either Cliff, Coastal Grassland or Dune Grassland. All of these internationally important habitats are being eroded by the spread of this one single invasive non-native plant.
- The amount of land managed as gardens and "Parklands" has increased since 1999. Parkland has increased by 155% and Amenity Grassland (which supports very few species) by 33%. The latest survey also reveals that 187ha of land which was originally available for agriculture has now become subsumed into domestic curtilage.
- Twenty nine kilometres of Earthbanks are now regarded as being 'gardened' i.e. planted with non-native species or covered with artificial grass or plastic membrane.
- Scrub has increased by 64% since 1999, mostly due to a lack of management of marginal land such as along the south coast cliffs. The rate of increase of scrub has also increased over the 19 year survey period.
- Between 1999 and 2010 there was a significant decline in Coastal Heathland whilst Dune Heathland was lost from Guernsey. Since 2010, both habitats have begun to recover due to the introduction of appropriate management techniques, which demonstrate the effectiveness of conservation measures.
The data compiled during the survey has been analysed and the findings are available in both a Summary Report and Full Technical version online at www.gov.gg/habitatsurvey. Paper copies can also be made available on request, by emailing aclms@gov.gg. It will also be made available as a digital map online at www.digimap.gg/environmental by the end of this month.
Julia Henney, Biodiversity Education Officer said:-
"The results of this Island-wide Habitat Survey are stark and concerning. The decline in natural habitats is likely to indicate an associated decline in Guernsey's biodiversity.
"Many of the losses identified are due to changes in land management, which illustrates that our natural land does need managing, simply designating nature reserves is not enough.
"The survey does highlight some positive trends, such as an increase in the area of heathland since 2010, and an increase in the area of woodland. These positive trends demonstrate that it is possible to restore habitats through hard work and the implementation of sound conservation measures.
"For some habitats, new conservation measures cannot come soon enough. With 90% of our species rich dry grasslands having disappeared, we are on the brink of losing it from our Island and potentially the species it supports.
"I hope that these alarming results can mark a turning point, at which we see an increased investment in nature conservation and the introduction of policies and strategies which focus on protecting our natural word."
