Re establishing grassland

Re establishing grassland

Its not easy!

Re-establishing grassland is not easy! After removal of wattle, one inevitably ends up with bare earth, somewhat rich in nitrogen from the legume effect of wattle, arguably still affected by Wattle’s allelopathic effect, and littered with woody debris. Going from this to dense grassland does not happen easily. In fact, it could be argued that this step is more difficult than the task of removing the trees themselves.

For one thing a fire may have gone through the landscape. This could be a natural occurrence, or a move by the landowner to “tidy up”. Burning is also not necessarily wrong. In fact one school of thought is to burn regularly, so as to trigger germination of the huge bank of wattle seed, as a means of ‘flushing it out’. There is real merit in this. But if the trash has been piled high, the fire will have been damagingly hot, and the earth will be baked and laid bare. The pulverised, baked earth is often best described as orange talcum powder. It has no structure, is hydrophobic, and nothing will grow in it. It represents a real erosion hazard!

Quite aside from burn areas, the ground is receptive to pioneer species, most of which are alien. Blackjacks (bidens pilosa), Khakhi bos, and other tall species grow. They have a poor basal cover, but are better than bare earth. The challenge is to get desirable species in before those weeds can predominate and shade out the species we would like to see. By all accounts, seeding a mix representative of highland sourveld is something that has never succeeded. Locally, a “summer veld mix” can be bought, and although it is not fully representative of the highland species mix, it comes as close as one can get. Initially we preferred a mix of Lovegrass and Teff (Eragrostis curvula and Eragrostis teff). Teff is indigenous to Ethiopia, but it is an annual and does not re-seed. Its advantage is that it germinates quickly to hold the soil, and will attract cattle, bearing other species in their dung. The curvula takes longer to germinate but does come away well in the end. The problem is that the teff does not germinate if merely scattered on the site: it must be raked in. It also will not germinate if there is a dry hot spell of weather. Also, the curvula tends to dominate and not allow the natural ingress of a diversity of species. So we use the “summer Veld Mix”, and we seem to be having success.

This quote from Grassland habitat restoration by Smith, Diaz and Winder , sums it up well:

“We conclude that there is no “quick fix” for the establishment of a grassland community; long-term monitoring provides useful information on the trajectory of community development; sowing gets you something ,but it may not be the target vegetation you want that is difficult to establish and regenerate; it is important to sow a diverse mix as subsequent recruitment opportunities are probably limited; post-establishment management should be explored further and carefully considered as part of a restoration project.”

and from Farmers Weekly:

“Effective restoration of encroached areas is not a short-term project, but a long-term commitment. “Chopping down a few trees and using a bit of poison here and there won’t solve the problem. There’s no quick-fix – you need a management plan as well as a budget if you want to succeed,” says Arnaud. “But,” he adds, “the rewards pay off as the land becomes more productive and animals can flourish.”

Our best summary of the way to do it, will follow in further posts…….