Swap the weed for an indigenous plant

Pam Golding is to run a series of articles on being aware of the aliens in the plant life which should be eradicated and are a threat to our gardens and environment, giving you some tips on managing the newly experienced burned areas, etc.

First step though is knowledge about how to control and know how to manage the areas where so many trees/shrubs have succumbed to the fires. SOIL STABILISATION

First rule of thumb: do no harm, observe and let nature take the lead. Where plants are starting to emerge, don’t go trampling in these areas. These plants are fire-adapted hardy pioneers whose roots will be helping to stabilise the soil, while some also help to fix nitrogen and improve soil quality so that other more sensitive species can start to grow. Best to leave these areas to naturally regenerate. Obviously, if in these areas there are sites where some erosion is already evident (it may be pre-fire erosion), keep an eye on this – you may need to lend a helping hand.

Second principle: work with what you have. On steep or steepish slopes where erosion is going to be a problem, where there is very little, if anything, growing and there are burnt trees that are still standing but are just trunks and branches with no leaves, then you could use these to create log terraces that provide a barrier to runoff from heavy rainstorms. CONTOUR LOG TERRACES (using material that is on site) Begin at the top of the slope and work down. It is easier to see how the water might flow by looking down on an area and you will be better able to visualise the alternating spacing of the logs. Fell and de-limb the dead trees (make sure you have someone trained in the felling of trees and use of chainsaws to do this).

Many trees still have foliage on them due to the speed with which the fire moved. Do not fell these trees – even though the leaves are burned and dry, they will still help to slow water flow and the tree could still recover. Even if they are alien trees, for now erosion is the most serious concern.

Best to tackle these trees a few months down the line when you can assess whether erosion remains an issue and this will then determine the best method for dealing with the trees. It may be you rather frill or ring-bark them as opposed to felling them, to ensure their root system stabilises the soil for some time .

Place the logs on the contour, perpendicular to the direction of the slope, i.e. across the slope. This is critically important or else you will simply speed up water flow. Place logs in an alternating pattern so that the runoff doesn’t have a straight downslope path to follow.

This forces water to meander back and forth between logs, reducing the speed of flow and giving time to percolate/infiltrate into the soil. The steeper the slope, the closer the rows should be to each other. On a steep slope, they should be only 1m apart. On a less steep slope, this can be extended to 5m apart. Logs should be 15 to 20cm in diameter and 3m to 9m long.

Smaller-diameter logs can be used but will not hold back as much water and should rather be stacked one on top of the other, and staked to form something of a barrier that will trap soil.

Logs should be bedded a third of their diameter (i.e.. 5 to 10cm) into the soil for the entire log length and backfilled with soil so that water cannot run underneath (backfill should be tamped down).

Logs can be secured and prevented from rolling by driving stakes on the downhill side or simply using the remaining stump to hold the log in place. –