Portchester Common is part of the Portsdown Hill site of special scientific interest (SSSI) for its rich chalk grassland flora and interesting fauna. The species-rich habitat gives it a high conservation, and educational value.
The unique topography and south facing aspect encourage a wide variety of plants and invertebrates that are at the northern extent of their range so uncommon in the rest of Britain. The vascular plant species-list exceeds 200 and is increasing as new species are found. Notable plants include Knapweed broomrape, bee orchid, rock-rose, horseshoe & kidney vetch and autumn lady's tresses. The site is also known to be of interest for its lower plants such as lichens and bryophytes.
Much of its scientific interest stems from its invertebrate community. The diversity of food plants and microclimate supports a considerable range of invertebrates. As well as many more common butterflies, there are healthy populations of chalkhill blue plus brown argus and dark green fritillary. There is a rich bee and wasp population, including mutilla europaea, mellitta tricincta and the blue carpenter bee.
Many birds can be seen on the hill as it provides a variety of habitats, food and shelter. These include the chiff-chaff, willow warbler, whitethroat and lesser whitethroat, the stonechat, yellowhammer, skylark and meadow pipit. The abundant hawthorn berries and ivy provide winter food and the hill's value is increased as it is on a migratory route for many species.
Healthy populations of wood mouse, field vole and common shrew exist while rabbits are common on the site. Roe deer, badgers, stoats and weasels can also be seen at certain times of the year.
The site offers panoramic views across Portsmouth Harbour and the Solent. However, the sensitivity and fragility of a number of the species within it means we ask anyone using it to respect the countryside code of practice. If you see anyone causing damage to the site, please report it to our countryside service on 01329 824843.
We manage the habitat (scrub clearance and reintroduction of grazing) to meet the long-term site objectives of reduced scrub cover and increased diversity of grassland. Our main objective is to maintain all habitat types and increase the proportion of species-rich calcareous grassland at the expense of scrub and coarse grassland.
The main entrance to the common is on Skew Road, approximately 100m from the junction with Portsdown Hill Road (B2177). There is a narrow lay-by next to the entrance gate with parking for two vehicles. A viewing point a little further down the hill has better parking facilities. On foot, you can reach the common from Anson Grove. A steep footpath up the side and over the M27 includes two flights of steps (not suitable for wheelchairs, buggies or pushchairs) onto the lower section of the common.
For more information about the common or any other countryside site please contact our countryside service on 01329 824843 or by email at firstname.lastname@example.org
If you know of any faults, such as damaged signs, fences, fly tipping, excessive litter or obstructions on footpaths you can let us know by using the online form for reporting problems with parks and open spaces.