Creative erosion control

The Cape Flats Nature Reserve is a 32ha area containing endangered Dune Strandveld and critically endangered Sand Fynbos.   Due to the importance of this, keeping the area as natural as possible, we became very creative in our management practices.  Erosion control is a continuous problem during winter at any nature reserve.  Through a series of trial and error, we have found our solution. 

The soil type in the reserve is sandy and erodes away quite easily if left unmanaged.  Unfortunately due to the status of the vegetation we have had to experiment with natural materials.  Our solution came in the form of mulch.   However, this is not any mulch; this is the result of laborious field work removing dead and overgrown vegetation from the reserve.   Now why are we removing vegetation from the reserve in the first place you ask?  Well, let me first give you some quick background information on how we came to our mulch decision for a better understanding. 

Generally natural fires would solve the problem of dead and overgrown vegetation which, if left to its own devices, would result in a monoculture (dominance of one plant species) and a hazard to the soil if an accidental fire did occur.  The soil hazard occurs because fire cannot pass through the vegetation quickly enough to stimulate new growth but instead causes a more intense fire which sterilizes the soil.  Unfortunately we have no such luck with natural fires due to it being on a tertiary institute and surrounded by an urban area. This has led to the laborious task of physically removing dead and overgrown vegetation in the reserve; the results are still being monitored.

At this point we had removed so much dead and overgrown vegetation, but at the same time, did not want to add to the landfill site; we are into conservation after all.  We then had the vegetation chipped and used in our gardens on campus and at our Outreach Greening schools which saved on purchasing mulch for this purpose.   We went one step further by applying the mulch in the reserve as an erosion control method for potholes for our service roads as part of an experiment.  We realized we could not bring in any foreign soils for erosion control due to the impact it would have on the endangered vegetation.  This was the perfect solution.  It is vegetation removed from the reserve and placed back in a clever way.  It was the most environmentally creative management practice we could come up with and has proven quite successful over the past few winters.