Caring for Hod hill

Cattle grazing on Hod Hill, Dorset, in June

This Iron Age Hillfort was constructed sometime around 500 BC and is one of a kind. Not only was it used by the local Durotriges tribe but, when taken over by them, the Romans decided to build a fort here as well.

While some of the flatter areas of the interior were ploughed in the past, parts that were more difficult to cultivate (and a small section of the interior that was never touched) are very important for the surviving flora and fauna. The downland turf supports a huge number of plant species, up to 50 per m2 on some sites, along with them comes a similarly varied mix of insects, most visible of these being the butterflies feeding on the nectar rich flowers growing here during the warmer months.

Chalk downland, largely a man-made habitat resulting from stone age forest clearance, is much reduced in extent throughout the UK with an estimated loss of 80% nationwide over the last 60 years. The majority of this was due to reduced grazing and increases in areas growing much needed arable crops, especially after World War Two. Without grazing or intervention the grassland will rapidly convert to scrub and eventually woodland so it is with this in mind that most of our downland sites are managed. The flowers growing here rely on low nutrient levels and being kept free of competition from scrub and the coarse agricultural grasses often used in most pastures where rapid growth of the grazing animals is the aim.

In conjunction with our tenants and graziers, we face a constant fight to balance the forces of change affecting sites such as this. Weather has a massive impact, too wet or too dry and we get damage from trampling hooves and visitors feet; a big problem on an archaeological site once the protective turf is broken. Too many or too few livestock or the wrong type alters how the site is grazed. Rabbits, moles and badgers all have the potential to cause massive archaeological damage with their digging, especially in places where no investigations have ever occurred. Nutrients whether from fertiliser, manure, not enough dog owners clearing up after their pet, even nitrogen dissolved in the rainfall can eventually change the makeup of the plant species growing here, as can something as simple as feeding hay to livestock if it brings in seeds from elsewhere.

Once the grazing is right though, the majority of the work is done, all we need to do then is keep control of the amount of scrub and this is usually one of the Rangers main autumn and winter jobs. It would be nice if the cattle and sheep could do it for us, but to do so we would need so many animals on the site that nothing would escape damage.

Hod Hill is really quite fertile compared to other chalk sites and grows scrub (hawthorn especially) for a pastime. As well as harbouring rabbits underneath it, the roots of mature scrub can cause a lot of damage to the buried remains, even more so if it gets big enough to get blown over in high wind. Over the course of the last five years or so with many days of help from contractors, other rangers and volunteers, we have gradually been removing and killing off the majority of the scrub inside the fort and on the ramparts as well. There is a long way to go yet and much crawling around on hands and knees to get the last seedling hangers on but the difference is already noticeable.

If you want to see something spectacular to get you going after a long winter, the carpet of cowslips nodding in the breeze in early spring is unmissable.