Update on restoration project to fix accidental damage

Case Study By Sean Altern – Consultant: Biodiversity Conservation Services

The Team during the initial restoration phase late last year.

About 12 months ago a vehicle accident caused considerable damage to a small area of fynbos and NCC was contracted to restore the impacted area. The team returned to the site in September this year for a follow up visit.

Following good winter rainfall, the site received 264mm of rainfall since the initial rehabilitation; with 32mm in one occurrence. This means that although the site was well watered, which is great for plant growth, the erosion potential was still very high. The silt nets and soil saver cloth did however hold the soil in place and a wide variety of plant species, both shrubs and grasses, have naturally colonised the site (a process greatly assisted by these interventions).

Rainfall figures for the region since the implementation of rehabilitation measures.

At this early stage in the sites recovery, the emerging plant density is, as expected, still below that of the surrounding veld. NCC used a minimal intervention approach: preparing the soil and better enabling the areas natural vegetation drivers to repair the site. Although this does take more time for a fuller soil vegetation cover to be achieved, NCC believes it to be a more ecologically appropriate method and the diversity of indigenous plants present appear to attests to this.

A variety of shrubs and grasses have emerged through natural colonisation which has been assisted by the installation of biodegradable silt nets and soil preparation. No foreign seeding or replanting was done.
Barren areas covered by protective soil saver cloth have held the soil in place whilst naturally occurring indigenous shrubs and grasses emerge through it.
Seeds have germinated under the protection of lightly spread organic matter which traps moisture and creates a more favourable microclimate.

Whilst full site recovery will take time all the necessary elements are present for this to now occur and the initial signs of this recovery are well evident.

The biodegradable silt nets used have held up well despite their exposure and rainfall. Often permanent plastic based materials are utilised for silt nets however this then becomes a part of the environment which eventually becomes litter and must then be removed. The biodegradable silt nets, which never have to be removed, have proven just as effective at holding the soil in place and by the time they break down the areas will have recovered enough to no longer require them.

The theory behind this rehabilitation project has been an understanding of what causes the vegetation of the area to exist in the first place and then applying interventions that better assist these natural vegetation drivers to re-colonise the site with appropriate, naturally occurring species rather than trying to force a rapid ‘greening’ of the area. So far the results are positive and NCC is enthusiastically monitoring the recovery of the site.

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