Transplanting tussocky vegetation, shrubs and small trees can be useful for the following reasons:
- They can act as a barrier and discourage trampling.
- The canopy intercepts rainfall, and so reduces direct run-off on slopes.
- The roots help bind the soil and prevent erosion.
- Transpiration draws up water through the root system, so lessening subsurface flow which contributes to slope instability.
- The canopy softens and disguises the appearance of damaged slopes.
Clodding
This term is used to describe the movement by excavator of large ‘clods’ of vegetation, which may include grasses, small shrubs, seedling trees and so on, as well as 500mm or more depth of soil with all the organisms it contains. In effect, this is relocation of habitat, and has been successfully done on development sites, and routes of pipelines. Success rates for establishment are high, but the technique depends on having a suitable source site, and access for machinery.
Bracken
This grows from a dense mat of rhizomes, and can be used to stabilise ground and discourage trampling. It is not easy to dig up as the rhizomes grow very deep in the soil, but it can be moved in winter, when the plant is dormant. Only use where successful establishment will not itself become a problem, as bracken is difficult to eradicate.
Gorse
This is a useful plant for discouraging access, and young plants can be moved successfully, preferably during the winter or early spring.
Hawthorn and blackthorn
Young plants can be transplanted and should survive even in poor stony soils and in exposed situations.
Heather
Young heather plants can easily be transplanted, preferably in early spring. Heather growth is very slow however, and young plants are vulnerable to being destroyed by trampling or grazing, or being smothered by mobile peat or stony material. Planted areas need fencing against trampling or grazing. Brashings can be laid down, or a nurse grass seed mix sown, to protect the bare soil between heather plants whilst they establish.
Clumps containing mature plants which have flowered can be transplanted. The mature plants won’t survive, but they will shed their seed, and with associated micro- organisms in the soil, provide the right micro-environment for germination and establishment.
Sedges and rushes
Clumps of sedges and rushes make useful barriers, as they are uncomfortable to walk over, and further discourage by being associated in people’s minds with wet ground. This technique was used at Cwm Idwal and succeeded in keeping people to the path where fences and barriers had failed.
Willow
Willow roots very easily from cuttings taken in the winter. Almost any size of branch can be used, up to the size of a fencing stake or larger. A traditional technique for slope stabilisation is to use bundles or ‘fascines’ of willow partly buried horizontally across the slope. These give some immediate stabilisation, and then root to provide shrubby willow growth.
Nursery grown stock
In some situations it may be worth using nursery-grown plants for barriers and slope stabilisation.
Species chosen should be native to the area. Useful characteristics include prickly growth to deter browsing and trampling, a deep tap root for anchorage on unstable slopes, and the ability to withstand water and nutrient stress. Use transplant size stock, that establishes quickly and does not need staking.
Planting should only be considered if fencing against sheep, rabbits and trampling can be provided. Provide explanatory notices as necessary. Some weeding and trimming will be necessary, as well as periodic checking of fences.
Planting can be successful even in very poor, rocky areas with little soil. One such area which has been successfully planted is on the slopes above the New Dungeon Ghyll, Langdale, in the Lake District. Five plots of about half an acre each were fenced against sheep and walkers. They were planted with a variety of species including Scot’s pine, birch, juniper, holly, oak, larch and hawthorn. The transplants were simply planted into crowbarred holes in rocky scree. No fertiliser, topsoil or other treatments were used. Within five years or so the trees were well established, and other native species such as heather spread naturally. The dark grey stable scree within the plots is in marked contrast to the pale mobile scree along the trampled lines outside the plots. Most walkers however keep to the pitched path, and the whole slope is well on the way to recovery. Another example of simple restoration techniques succeeding because trampling has been contained.
