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VOICES FOR THE EARTH

Monitoring Bush Regeneration Projects

Monitoring of bush regeneration sites following the 2019-20 bushfires, as part of two NSW Environmental Trust funded weed eradication projects in the Clarence Valley, have shown mixed, but mostly positive results.

Both projects are aimed at enhancing endangered ecological communities, Lowland (Dry) Rainforest and Swamp Sclerophyll (Paperbark swamp) forest, both of which were heavily invaded by Lantana.

These are both multi-year projects, and being undertaken by the Clarence Environment Centre’s professional bush regeneration team. The first two years have focussed on the primary treatment of the Lantana using a mix of “splatter gun” chemical application, “cut and paint”, and hand pulling, depending on the circumstances.

The final stage of the project is focussed on follow-up work, removing Lantana seedlings, and any other exotic weeds whose seeds remained in the soil after the initial treatment.

Monitoring is a requirement, undertaken by the Centre’s volunteers as an in-kind contribution, to provide evidence of the benefits of weed removal. For this, six 50m long plots were established, stretching from areas of good quality forest, into degraded, weed infested areas on the forest edge, the idea being to determine if the endangered community was spreading into those degraded areas after the weed removal.

The first three years incorporated severe drought and heat, devastating fires and two floods, making data collection challenging. However, the results have been both encouraging and surprising. In fact, five of the six sites monitored are showing a marked improvement, while the sixth was so devastated by the fire that its Hoop Pine canopy has completely died and may never recover.

At one swamp site, the canopy was so depleted by fire that subsequent rain brought on a flush of ground-cover sedges, grasses and herbs, but the following year saw a massive growth of ferns which, along with the continued shrub growth shaded out many of the herbs, halving the number of native species recorded at the site.

These changes made the collection of meaningful data difficult, but the overall improvement in forest condition has dramatically demonstrated the benefits of weed removal.

– John Edwards

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