Woods & Trees
Our region of England - the Sussex Weald - is one of the most densely wooded in the country and about 12% of Knepp is woodland. This does not include the thousands of trees on our field edges, the open-grown trees in the Repton Park, and emerging scrub and saplings in the rewilded area.
Plantations & Ancient Woodland
Much of Knepp's conventional woodland is made up of small plantations of mainly non-native species (Douglas fir, Corsican pine, European poplar) planted between the turn of the 20th century and the 1960's as commercial crops.
However, after the collapse of the timber industry in the 1990's we were compelled to close the commercial forestry department on the Estate. Our focus is now primarily on conservation.
In 2006 we carried out a major thinning of the estate's conifers, felling over 1,000 tonnes of low grade softwoods and poplars. In the absence of much Scots pine on the Estate our Advisory Board for the rewilding project has advised us to keep some non-native pines and firs for the benefit of bird species like gold-crest.
In 2015 we engaged Jamie Simpson, an arboriculturalist trained at Kew and Richmond, to manage the veteran oaks and young trees in the Repton Park, and the plantations that lie mainly outside the rewilding project.
For both plantations and ancient woodland our policy is now to leave dead trees standing and dead wood on the ground, providing habitat for saproxylic beetles and fungi, and roosting places for bats and birds. We create and maintain glades and rides, providing light for woodland flora like bluebells, anenomes, violets and spurges, and butterflies like the speckled wood and silver-washed fritillary.
Restoration of the Repton Park & Pleasure Grounds
As part of the Repton Park Restoration around the castle we have been opening up vistas and removing commercial species in the Pleasure Grounds - an arboretum that was partially underplanted in the 1960's with nothofagus and larch. We have also planted hundreds of individual trees out in the open - oaks, limes, crab apples, Scots pine and beech - where they require tree-guard protection from the grazing animals. These will become our next generation of open-grown parkland trees.
In 2016 Jamie surveyed the Estate’s lime trees. He is also involved with veteran tree conservationists Ted Green and Jill Butler, protecting rare tree fungi and relieving compaction around some of the ancient oaks in the park.
Natural Wood Pasture
In the 1,100-acre Southern Block within the rewilding project where, between 2000-6, our arable fields were simply left fallow after their last harvest and not re-seeded with grass, thorny scrub has spontaneously regenerated over large areas. With no free-roaming grazing animals introduced here until 2008, blackthorn, hawthorn, dog-rose and bramble have had a proper chance to establish. They now provide extremely effective protection for saplings from browsing by our herds of cattle, horses, pigs, and red and fallow deer - nature's barbed wire.
We've been astonished by the diversity of trees and shrubs that have appeared of their own accord in this wildest part of the Estate - including wild service, crab apple, hornbeam and sallow (a naturally-occurring hybrid willow, habitat of the rare purple emperor butterfly). Thousands of jay-planted oaks have also taken root, and those that have found protection in the thorny scrub are now up to 14 feet tall - a height they have reached in little more than a decade. Any saplings that germinate outside this thorny protection are soon browsed off.
Eventually, as the protected trees mature, we expect they will shade out the underlying thorny scrub that nursed them, creating an open, park-like landscape characterized by groves and free-standing trees.
The success of natural tree recruitment in this area is a useful demonstration of an alternative, low-cost way of establishing woodland - a system that was common practice in medieval times when thorny scrub was protected by law. Allowing thorny scrub to do the job of tree-guards is not only infinitely cheaper since it involves no human labour, it is more successful at establishing vigorous, disease-free plants and it is environmentally sound - avoiding the pollution involved in the use of carbon-intensive polypropylene cylinders and tanalized wooden stakes.
In the Northern Block, which was either permanent pasture already or sown with grass after coming out of conventional farming in 2003, thorny scrub has been much slower to establish. Fists of gorse are only just beginning to punch up through the sward, and blackthorn is very slowly creeping out from the hedgerows. But eventually we expect that this area, too, will be colonized, at least in part, by thorny scrub which will provide a nursery for new trees as well as myriad forms of wildlife, including - hopefully - nightingales and turtle doves.
New Conservation Woodland
In some areas of the rewilding project we have felt that intervention is necessary to kick-start the regeneration of species - like black poplar - that are entirely missing from our landscape. Riparian habitat - the natural environment of black poplar - has declined dramatically in England over the past decades. In 2007, as part of the Otters and Rivers Project, under the auspices of Fran Southgate and her team of volunteers, we planted a 0.7-hactars floodplain at Tenchford in the Southern Block with black poplar, x, y and z.
In the Middle Block of the rewilding project, in the extended Repton park landscape where there is no thorny scrub to encourage the natural regeneration of trees, we have planted and fenced small copses of riparian species beside our restoration of the River Adur [hyperlink]. This planting, carried out in 2016 by volunteers from 'Trees for Trout', will, it is hoped, provide shade to cool the river, encouraging fish.
There is a pressing need in our industrialized landscape to connect isolated pockets of nature. Creating wildlife 'corridors' and 'stepping-stones' helps wildlife - both flora and fauna- to move about the landscape, encouraging genetic diversity and allowing populations to respond to pressures brought about by pollution and climate change. In 2007/8, at Swallows Farm, we created Lack's Link - a half a hectare plantation named in memory of our much-loved farm foreman, connecting an ancient oak wood with a 1990's plantation.
Over the next few years we will be planting up the earth banks created against the A24 with new copses and woods of native shrubs and oaks, and scrubland, as wildlife habitat and visual screening from the road.
Eucalyptus plantation for biomass
In 2017 we planted 7 hectares of ex-arable land outside the rewilding project with eucalyptus - an experimental crop designed to feed our biomass boilers in the future. Eucalyptus is fast growing, has a high calorific value and, we hope, can be coppiced on an 8-15 year cycle. In time, this should make the Estate entirely self-sufficient in biomass heat supply, allowing our native woods to be managed for conservation and wildlife.