Deer and the environment

Deer and the Environment (2)

It has been said that the Isle of Wight has a unique rich ground flora due to the absence of deer, but is this really true?

This rich ground flora is an undeniable and welcome fact but is it truly unique? How does this relate to deer and what other factors may be involved? I decided to compare and contrast our island with other areas to help determine the truth.

The Isle of Man is an offshore island situated roughly in the middle of the Irish Sea. Geologically it is mainly made up of ancient rock from the Ordovician era.  With an area of around 221 square miles it is almost 1 1/2 x the size of the Isle of Wight. Wild deer are thought to be absent and it has around 127 ha of Ancient Woodland which was studied by the Manx Wildlife Trust in 2011.

They reported that the “woodland flora is in decline” and that compared to the rest of Great Britain the Manx “floral diversity is modest which is reflected in their woodland diversity.”

They attribute this to the levels of “shade cast by planted species and a lack of traditional woodland management with some species becoming rare or extinct as a result.”

Looking closer to home I drew a comparison with the Isle of Purbeck in Dorset.

Purbeck is a peninsular of around 156 square miles, slightly larger than the Isle of Wight with which it shares a similar varied geology and a favourably mild maritime climate. Like our island it is home to woodland bats including the rare Bechsteins, and though not numerous, both Dormice and Nightingales are also to be found there.

There is a substantial deer population in Purbeck which together with the adjoining Poole basin contains around 3000 – 4000 animals. Woodlands amount to around 710 ha of Semi-Natural Ancient Woodland and 674 ha of Plantations on the site of Ancient Woodlands, some of which has been fenced against deer.

Purbeck has many SSSI’s, nature reserves and designated special areas of conservation. Natural England has commented on the “biological diversity and richness” of the area and claims that Purbeck includes “the 10km2 square with the greatest diversity of plant species in the country”.

So what about the Isle of Wight where deer are rare?

The island has around 50km2 of woodland, nearly a third of is considered to be Ancient Woodland.  Within these woods are to be found relics of wood pasture which have deteriorated due to lack of grazing by creatures such as deer. This has also led to Lichens being threatened by shade cast by  vigorous growths of Brambles, whilst competition from aggressive plant species is said to pose the greatest threat to the Wood Calamint, the only native plant unique to the Isle of Wight.

Our rich floral heritage was commented on in the 18th century when deer were more abundant here.  Richard Worsley refers to the island as being the “Garden of England” , whilst the  historian John Albin remarks “Almost every species which are to be found in any other part of England are met with here, a circumstance which must be extremely agreeable to the philanthropic mind, and grateful to the botanist and man of science. They abound in quantity as well as variety.”

It would appear that a mild climate, a southerly latitude, a varied geology and land use, together with the presence of Ancient Woodland are amongst the prime factors influencing floral biodiversity.

It is notable that with a large resident deer population this rich flora is greater in Dorset than the Isle of Wight

If you have seen some deer on the island please take part in the Isle of Wight Deer Survey  locations will be treated with strictest confidence. For periodic updates please visit Isle of Wight Deer Conservation or email  deerwight@gmail.com

Thank you for your interest and support

For more photos of deer on the Isle of Wight please see the Isle of Wight Deer Album

 

Red Deer Hind

Red Deer Hind  Isle of Wight

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2 thoughts on “Deer and the environment

  1. Interesting findings that confirm unscientific observations made during a great deal of time spent out in the countryside of both Dorset and the Isle of Wight. Personally, I believe that higher populations of native deer on the Island would have a neutral to positive impact of floral diversity. However understory browsing would probably have a negative impact on Dormouse populations unless key areas of habitat are fenced. So far as other “British” species are concerned, we certainly don’t want Muntjack or Sika, and Fallow are, in my opinion, best left in fenced parkland settings. A couple of areas might support a few Chinese Water Deer but who needs them? Keep things native with a few more Reds and some Roe and the Island would be a better place than it already is.

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  2. Hi Steve,
    Many thanks for your comments.
    I certainly agree that it would be far more preferable to have well established populations of our native Red and Roe in the island’s woodlands at modest densities, rather than the Sika and Muntjac.
    Interestingly there may be some potential benefit to the Dormice in deer grazing if it slows down the progression to scrub and eventual canopy closure.
    Natural England in their Dormouse Conservation Handbook recommend keeping deer populations below 5/km2 and warn against grazing domestic stock in Dormouse habitats. It must be noted that Muntjac are particularly destructive to coppiced woods.
    To quote from “Impacts of woodland deer on small mammal ecology” by Flowerdew & Ellwood
    “ Not all deer impacts on small mammal communities are negative, the presence of some deer is a good thing, too many or too few deer are not.”
    Best wishes,
    Tim

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