Juniper not only provides dense cover for nesting birds on the commons, it's also the food plant for many different types of caterpillar moths. When the berries appear, they provide birds with vital food to help them through the colder months.
Juniper thrives on chalk downlands. Although it can grow to a height of 10 metres and live for up to 200 years, juniper on the commons is more scrub like.
Juniper leaves are like needles that curve to a sharp, prickly point. Its bark is grey-brown and peels with age. The twigs are reddish-brown. Juniper stems are fragrant throughout.
Unusually the male and female flowers grow on seperate trees. Male flowers are small and yellow while the female ones are green. Once pollinated by the wind, the green female flowers develop into berries. The fleshy, purple berries are eaten and distributed by birds.
It's important we look after the juniper on the commons. It's been in decline throughout the country and is now a national conservation priority.
Getting the balance right so that juniper thrives on the commons is difficult. Excessive grazing prevents seedlings from developing, whereas no grazing leads to the development of scrub. This creates shade that will slowly kill the juniper.
Juniper is very slow growing, and can take up to seven years to reach a height of just 20cm. While the plants are so small they are vulnerable to being eaten by the cattle or being trampled on.