The conservation and enhancement of biodiversity is one of the principal aims of the Group. Biodiversity describes the biological wealth of a region, at both the habitat level and the species level. The region around Farnham is underlain by a finely-scaled geology, and hence has a surprisingly varied mosaic of habitats, so has an unusually high biodiversity. Although The Bourne is extensively built over, it still has many types of habitat. Gardens and mixed woodland cover the greatest proportion of its area, but there are remnants of heathland, a few open fields, small patches of wetland along the seasonal streams. The group is seeking to conserve these remnants and enhance the biodiversity throughout our local wildlife.
Here are illustrations of a very small subset of wildlife that occurs in The Bourne.
These are comfrey, lesser celandine, germander speedwell and greater stitchwort. Our surveys have identified 200 species growing in Compton Field, 169 in the Middle Bourne Lane Garden and 122 in
the Bourne Old Churchyard. This rich diversity of plants supports an equally rich diversity of animal life.
A brimstone butterfly feeds on knapweed, a peacock sunning on nettles, a small copper feeding on fleabane and a small skipper on tufted vetch al take in Compton Field. Many of our butterflies are in
decline. We have recorded 19 species in Compton Field, 22 in Middle Bourne Lane and 18 in the Old churchyard.
An angle shades feeds on ivy blossom in the Old Churchyard, a rosy footman feeds on ling on Farnham Heath, a six-striped rustic on purple loosestrife in the Old Churchyard and a figure-of-eighty
on feeds on bugle in Compton Field. We have recorded 390 species in Compton Field, 213 species in Middle Bourne Lane, 432 species in the Old Churchyard and 650 species in a garden. In all we have
recorded over 750 species in The Bourne which is a quarter of all moths ever recorded in Britain.
A fox, a grey squirrel, a wood mouse and a couple of badgers all photographed in a garden in The Bourne. All these are common animals. Other mammal species that are often seen are roe deer,
brown rats and bank voles, and there have been rare sightings of hedgehogs and dormice.
A female blackbird, a robin, a green woodpecker and the ubiquitous wood pigeon photographed in a garden. Most of the birds in The Bourne are common garden and woodland species and can be
attracted to feeders. In winter there are good numbers of winter migrants especially redwings which are attracted to the abundant holly berries. For seeing less common birds like wood larks, Dartford warblers and nightjars, a visit to the Farnham Heath Reserve is a must.
Reptiles and Amphibians
A common frog, a slow worm, a smooth newt and a common toad photographed in a garden and in the pond we created in the Old Churchyard. Grass snakes are occasionally spotted, and adders are
quite common in Sable Wood. Common lizards occur on the Farnham Heath Reserve, where the much rarer sand lizards have been re-introduced.
Grasshoppers and crickets
An earwig couple, a dusky cockroach a field grasshopper and an oak bush cricket from four different locations in The Bourne. Earwigs and the native cockroach are abundant in gardens. The oak bush cricket was photographed at night in the Old Churchyard. The richest fauna of this group has been recorded in Compton Field.
Bees and wasps
A common wasp is the main pollinator of figwort, a honey bee collecting pollen from a bluebell, a red banded sand wasp excavating its nest hole in a sandy bank, and a queen hornet feeding on ivy
nectar in late autumn before hibernating. There are numerous other bee and wasp species to be found in The Bourne. Some are important pollinators and others like the common wasp and the hornet perform a valuable ecological service by controlling many pests.
A stag beetle that flew into the moth trap in the garden and the beginning of June, a hazel leaf roller, a pair of summer chafers and a pair of wasp beetles. 45 species of beetle have been recorded in
Compton Field, 33 in the Old Churchyard, and 28 in Middle Bourne Lane. These are gross underestimates because we lack anyone with the ability to identify this highly diverse group of insects.
An emperor dragonfly resting on bramble in Compton Field, a common blue damselfly, a large red damselfly and a broad-bodied chaser all take in Middle Bourne Lane. The greatest diversity of this
charismatic ancient group of insects can be seen in greatest diversity in the wetlands on Thursley Common, but can be attracted into gardens by digging even quite small garden ponds.
There are over 7000 species of fly in Britain so the 93 species we have recorded in Compton Field is just the tip of the iceberg. The beefly photographed here on a lesser celandine is a harbinger of Spring And its larvae live in the nests of bumblebees. Many hoverflies like the Seriocomya silentis on bramble and the narcissus fly on knapweed mimic bees or wasps and are important pollinators. The robberfly is just one of the many predatory species.
Few spiders have been given common names. The male Amaurobius ferox was photographed on a tree trunk in the Old Churchyard, the crab spider on ragwort, the green Areniella cucurbitina and the
wasp spider wee all in Compton Field. These predatory species are important as they keep down the numbers of pest species.
There are many important species of invertebrate that are associated with soils and rotting vegetation. Here is a flat-backed millipede, two species of woodlouse and a centipede, all from the Old Churchyard. The millipede and the rough woodlice recycle dead plant material. The small blind white woodlice live in ant nestsm and the centipede is a ferocious predator.
Invasive alien plants
A small percentage of the plants introduced into Britain become invasive and pose environmental problems. In The Bourne. Checkerberry grows in Bourne and Sable Woods; we have found floating pennywort together with New Zealand pygmy weed in a garden pond; the group has expended much time and effort into removing Himalayan balsam from the valley of the Bourne Stream, and found Japanese knotweed flourishing along the stream in Compton Field.
Since we started monitoring wildlife in 2006, we have observed the arrival of the tree bumblebee in Farnham in 2009 (first UK record 2001), the harlequin ladybird in 2010 (first UK record 2004), the
boxwood moth in 2015 (first UK record 2008) and the ivy bee in 2013 (first UK record 2001). Some get introduced accidentally, others arrive apparently unaided. So, our fauna is in a state of flux, but
while additions are easy to record, losses may go unrecognised for decades. Nationally there is clear evidence that many of our ‘common or garden’ species are showing clear signs of major decline.
Our wildlife recording has been limited; for example, we have no identification skills for mosses and liverworts, fungi, and molluscs, and limited skills for several of the groups illustrated. Even so, we are making useful contributions to both local and national monitoring, and our toad watches along Boundary Road have succeeded in rescuing several hundreds of amphibians.
What is the Importance of local biodiversity?
Probably most of the population of The Bourne is unaware of the wildlife around them, yet they avidly watch natural history programmes on television, and make appreciative remarks about the
differences we are making to the appearance of the village at The Bourne Crossroads. Many enjoy walking through Bourne Woods and the network of footpaths that criss-cross the village. This
enjoyment is based on the diversity of natural world they encounter. So, biodiversity is contributing extensively to the health and well-being of our community and to the pride we take in our
Most householders in The Bourne have gardens where they grow flowers and apple trees, and have bird-feeders. Some grow vegetables on allotments and wage wars on the pests that their efforts unwittingly encourage. Unwittingly they depend on the soil fertility being maintained and their plants being pollinated – ecological services being provided by the biodiversity.
The trees that are a major feature of The Bourne not only contribute to the landscape and provide habitat for our birds, but filter out pollutants from the atmosphere and muffle the traffic noise. The seasonal changes in the deciduous trees give use a feel for the changing seasons. These are benefits that far outweigh the downside of having to tidy up the autumn leaf-fall, but the fallen leaves help to maintain the soil fertility and moisture especially of the sandy soils of The Bourne.
By caring for the biodiversity in our patch, we are contributing to maintaining the biodiversity nationally, counteracting the effects of environmental degradation resulting from urbanisation,
pollution and climate change. We should all be alarmed by the marked decline in the populations of so many of our wildlife species.