4.5 Restoring Vegetation

Where the natural landscape and fragile habitats have been damaged by upland path use the eroded areas are restored by encouraging natural re-vegetation.

Illustration

FUNCTION

The objective is to return the vegetation as closely as possible to its natural state prior to erosion. This includes minimising the visual impact of the path on the surrounding landscape. Vegetation may need restoring on:

Bill of Quantities (example)

Turf eroded areas to blend in with surrounding undamaged ground. All turf edges and joins should look natural. Turf cover of bare ground should be at least 75%. Apply seed and fertiliser with stone scatter to areas with less than 50% turf cover.

METHODS

Revegetation of damaged areas can be achieved by using the following methods:

The methods used are dependant on the size of the area to be restored and the availability of materials.

Materials

The following materials are used to restore and encourage revegetation:

These materials and the general principles for using them are detailed in Materials and Use.

Procedure

Turfing

Blanket turfing is labour intensive but it provides an instant effect of full revegetation, and the success rate is high. The availability of turf is a key consideration. Restrictions will be placed on some sites due to conservation designations and fragile habitats.

Illustration

Spot turfing can be used to give partial coverage. The turfs will also act as a nurse crop either for the natural seed source, or in conjunction with seeding, and fertilising. By providing shelter and better conditions turfs encourage seed germination and growth. Total revegetation cover will be slower than blanket turfing, particularly if growing conditions are poor.

Seeding

Seeding is a slower and less reliable way of restoring vegetation. If the site has a favourable climate and soil conditions, recovery can be successful. Most upland sites have low fertility soils, and a colder climate which slows down the growth and recovery rate of a seeded site. Applications of fertiliser will help to address this. Over-grazing of new shoots by sheep or deer can dramatically hinder the success of seeding. Temporary fencing to exclude stock and deer may be needed - this will also prevent physical damage from trampling by both animals and people.

Stone Scatter

Problems can also arise from walkers trampling over seeded areas, if they stray from the path line. Random stone scatter will deter this and will also aid germination and growth by providing small moisture retaining pockets.

Spoil

Spoil from excavations can be used to spread over areas where the soil has been totally eroded. If the spoil is organic and nutrient rich, it will provide more fertile and stable growing conditions. If not, fertilisers can be added. Only the top 100mm or so of soil is "active" and will immediately boost plant growth. Soil from below this level, particularly dark wet peat, will not on its own support successful plant re-establishment.

Geotextile

Where no turf is available or slopes are too steep, natural fibre matting can be used in conjunction with spoil, for soil and water retention. This will provide a more stable base for seeding, or for turf transplants.

TROUBLE-SHOOTING

Key points to watch:

MAINTENANCE TASKS

The following maintenance may be required:

ENVIRONMENTAL SENSITIVITIES

  • do not use seed mixes that will introduce "alien" species to the area
  • be cautious in the use of fertilisers - over-green vegetation is unnatural in an upland landscape
  • don't use fertilisers where water run-off or leaching may affect natural or fragile vegetation
  • geotextiles can be intrusive on steep slopes - use only where they can be effectively hidden

HEALTH AND SAFETY HAZARDS

  • wear gloves if handling seed or fertilisers
  • remove excess fertiliser from the site, on completion of work

TAKE CARE

  • not all areas will require revegetation - a certain amount of erosion is acceptable in an upland landscape.
  • developments in site restoration are happening all the time - consult an expert, or other pathworkers, to find out latest developments and the success of other techniques