In recent weeks a contractor has been working on the Furth stream to remove wattle branches and logs from the stream. The work was co-funded by the WWF and the NFFC. The work is now done, and the stream is looking great  from the perspective of a fisherman.

But here’s the thing:

“Soil pH and carbon were significantly different (p < 0.05) in the soils collected from under and outside [wattle] canopies . Soil pH was acidic (3.1) on soils collected from under canopies while soil from outside tree canopies was less acidic (5.5) “.

Quote from:   EFFECTS OF REMOVING ACACIA MEARNSII ON THE WATER TABLE, SOIL AND VEGETATION PROPERTIES IN THE TSOMO VALLEY OF THE EASTERN CAPE PROVINCE, SOUTH AFRICA
2010 University Thesis By
Hloniphani Peter Mthunzi Moyo

In recent days we also heard that a downstream farmer’s galvanised irrigation suction pipes had rusted through just two years after he replaced them.

We also read of Frank Sawyer, years ago in the UK, discovering that all the leaf matter in the chalk streams, from bankside trees that did not naturally belong there, had “soured the water” and made it acidic.

In  the KZN midlands, our soils are naturally acidic, and farmers spend a great deal of money putting down lime to counter this, and to make their fertilisers more available to plants in a more pH neutral environment.

Could it just be that removal of wattle trees on river banks, after the initial soil disturbance, could have a long term benefit to farmer’s soil management.

Modern thinking in environmental circles revolves round finding “Eco System services”, or as the Director of the Wild Trout Trust in the UK enlightened me to the more modern term,  “natural capital accounting”. This concept, in layman’s terms, involves finding an economic value to a restored environment, so that someone will pay to get it done.

Anyone out there want to attempt the calculation……what is the value in bought lime, of a cleared hectare of wattle upstream from your irrigation pump…..?

DCIM100MEDIADJI_0010.JPGJoe Gwamanda’s team working on the Furth Stream in late May 2019