Header: A bare paddock – arguably the least preferable type of land to rehabilitate and the most vulnerable to soil erosion.
Now that I have your attention… If I just bought a block and want to rehabilitate it, would I prefer a cleared paddock or a paddock full of weeds? Depending on the type of weeds, I would prefer the latter.
Some weeds such as Cat’s Claw Creeper, Madeira Vine, Camphor Laurel and Chinese Celtis are a real problem, so I certainly would not want to inherit them. However, weeds do serve a purpose. In any rehabilitation project you first need to do a ‘weed triage’ and a cost/benefit analysis. At the core of this theory is the soil.
In an open, cleared paddock your land is more likely to be eroding and losing its precious topsoil. With no vegetative cover, be that weeds, wattles or grass, the top of the soil is fully exposed to sun, wind and rain. Any moisture that does happen to fall on your land will run straight off and not permeate into the soil.
Any plant that shades the earth has some benefits. Worms and other soil organisms will not come up to a baked surface. They need food, water and oxygen. They like it cool, preferably with leaf litter and some moisture. These organisms, like the humble but vital earthworm, recycles leaf litter and vastly improves the soil.
Plants have roots. These worm (sorry about that!) their way into compacted soil, breaking it up and allowing for penetration of moisture and oxygen. Soil organisms need access to oxygen via air spaces in the soil. Some roots, such as those of legumes and the under-rated wattle, have nitrogen nodules that fertilise the soil.
Another benefit is strata. This is the depth of plant material from the ground. In a healthy forest, I like to see grass/ ground cover; then small shrubs/small trees; then mature canopy trees. This is a healthy forest, with little kiddies coming through to replace the old, tired ones (like me!).
Another great benefit of strata is habitat – a place for critters to live and poo. Within some poo are seeds that can help aid natural regeneration. Strata includes dead material such as rocks, logs and branches. This material slows down waterpenetration, slows run off , creates shade and provides sanctuary for animals. Strata also reduces wind at ground level, resulting in less evaporation and less erosion. This all helps create a healthy piece of land.
To me, lantana, tobacco bush and all the annual weeds can be useful as part of a regeneration project. Lantana is a good example. It provides shade to the soil.
It restricts run-off in storms. It stops the impact from rain drops by breaking them up before they hit the earth. It reduces wind at ground level. It provides leaf litter as mulch. It provides habitat. Birds love the branches to perch. Butterflies love to feed on the nectar of lantana flowers.
The lesson for me is that any rehabilitation takes time. Plan for it taking time and work with nature. Rehabilitation to a healthy system is not neat. Neat is the opposite of good habitat.
Phil Moran Land for Wildlife member Cooran, Sunshine Coast Manager, Noosa and Districts Landcare
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