Horsnell Gully Project yearly report March 2023

 

We continued with our regular habitat restoration events this year.  The project has become more complex over time, with our work split between three locations.

• The original project area in the valley adjacent to the car park.
• The grassland flat along the Rockdale Hill track and
• The “good bush” at the top of garden gully

Working on the Orninthogalum.  The Park Rangers have been very supportive of our work in Horsnell.

All locations have their priorities.

 

• The original project site represents hundreds of hours of volunteer work over decades and needs maintenance to ensure weeds don’t once again overwhelm the area.
• The grassland flat is a significant grassland that needs protection and contains the active weedfront of Ornithogalum that we are working on. We undertook several ad hoc events to supplement the scheduled work program. Over 115 kg of bulbs, flowers and seeds were removed this season. We are successfully pushing the weedfront back in this location.
• The “good bush” at the top of garden gully is of excellent integrity and from a bushcare perspective provides the best value for return in terms of hours expended as the weed front is well defined and the ecosystem is largely in tact. Unfortunately the Ornithogalum has found its way down to the creek line. While work was done on it this year (10 kg of plant material removed), the full seed set could not be removed.

Working in the main project area.

Robert Lawrence from the Native Orchid Society SA did several site searches for the bell-flowered hyacinth orchid: an orchid of significance in the site of which we have reported on in previous newsletters.  He found several more occurrences of the orchid in the park and mapped their locations for future reference. This may also become a factor in prioritising future work in the park.

 

In December 2021, the Friends of Black Hill and Morialta were awarded a Friends of Parks ‘On-park’ small grant at the value of $5,000. These funds were used to employ two contractors in spring 2022 to work in high quality native vegetation of the park using sensitive bush care techniques. The contractor Environmental Weed Control and Revegetation (EWC&R) performed woody weed control by systematically traversing the targeted area and removed Boneseed, Erica, Blackberry, English and Montpellier broom.

 

Restore Environmental Services performed follow up Chincherinchee control that was chemically treated in July 2022 with Green Adelaide Landscape Board funds. Work started in the priority one area where small, isolated patches of 10-20 flowering plants were found, dug up and bagged. Work continued along the Rockdale Hill walking trail where denser infestations of Chincherinchee were found. Chincherinchee was dug up and bagged within a 2 metre buffer either side of the trail to deter bushwalkers from picking the flowers. Opportunistic control of Boneseed, Olives and Watsonia was also undertaken as they were encountered.

 

The result of this work has increased the quality of native vegetation in Horsnell Gully Conservation Park. This will continue to contribute to the protection and conservation of a number of the regions’ significant flora and fauna species, in particular the chestnut-rumped heathwren, yellow-footed antechinus and yellow-tailed black cockatoo.

Working in the good bush at the top of Garden Gully

Goals/follow up work to be considered for Horsnell Gully Conservation Park:

• Chemically treating Chincherinchee patches in priority one and two areas in Winter 2023.
• Follow up control of Chincherinchee patches in priority one and along Rockdale Hill trail in spring 2023.
• Treat isolated Watsonia patches in high quality native vegetation.
• Continue to survey and control woody weeds in high quality vegetation.

 

Report compiled by Grace Porter-Dabrowksi and John Fleming

Special mention of Grace for her work organizing and reporting on the grant and contractor work.