With the exception of its spectacular rock formations, when Organ Pipes National Park was declared in 1972, it was a depressing sight. Head-high artichoke thistles blanketed the creek flats and slopes, horehound had spread everywhere, boxthorn bushes crowded the slopes and plains, and other weed species filled the gaps. Erosion gullies scarred the steep slopes. Rubbish was piled haphazardly.
The National Parks Service aimed to restore the area's vegetation to its original condition as much as possible. Considerable progress has been made towards this goal, and many valuable lessons have been learnt, which have helped revegetation schemes elsewhere in Victoria.
“Revegetation” here is the process of changing a disturbed ecosystem to an indigenous one (indigenous species are those native to a particular area).
The strategies used can be both direct and indirect: direct strategies include direct seeding and planting of indigenous species as seedlings; indirect strategies may involve weed and vermin control, or the use of fire to stimulate germination of preferred indigenous species and to suppress exotic plants.
A successful revegetation plan relies on indigenous plant seed being available.
In 1972, there were few undisturbed remnant sites of indigenous vegetation in the park. A group of interested people started a series of working days to clear rubbish and eradicate weeds. They also surveyed the remaining native vegetation, both in the park and in similar areas nearby, collecting seed and striking cuttings to raise young plants.
There is Australia-wide and even worldwide interest in the Organ Pipes project, and the work of volunteers has been vital to its success.
Records have also been kept of all planting and direct seeding trials. It is important to monitor the progress of the revegetation program, as the rate of ecological change is very slow.
In 1990, a seed bank and seed safe were established in the Park to provide a seed source for revegetation. The Park's seed bank and nursery provided tube stock for planting out seedlings and for direct seeding, which involves scattering a mix of seed over a suitable area and limiting negative growth factors such as rabbits and weeds. Direct seeding is cheaper than growing and later planting tube stock.
It is particularly important to have a seed bank because many of the remaining indigenous sites near the park are under threat from development, which may lead to a reduction in the genetic diversity of rare grassland species.
Unfortunately the Park’s nursery is no longer in use.
Watch these videos to learn about the revegetation process: