Note that sections of this article were written for the Australian Plants Society Alice Springs Inc. and the Alice Springs Field Naturalists Club as part of a joint walk of Olive Pink Botanic Garden the groups ran at the end of April.
Regular visitors to Olive Pink Botanic Garden over the years will have noticed a big change taking place as Buffel Grass (Cenchrus ciliaris) has been progressively removed from sections of the garden and the species regeneration is remarkable! The Land for Wildlife team joined Constance Spencer and the Olive Pink Botanic Garden curator, Ian Coleman, on a walk and talk to learn more. Olive Pink Botanic Garden are a long-time Land for Wildlife member, having signed up to the program in 2007, so we thought it would be a good opportunity to see how far they’ve come.
The property was gazetted in 1956 as the Australian Arid Regions Flora Reserve, established by Olive Muriel Pink (affectionately known as ’Miss Pink’) and her gardener, Johnny Jambijimba Yannarilyi. Prior to this the land was unoccupied and grazed by feral Goat, Rabbit, and Cattle populations. Miss Pink lived within the garden until her death in 1975, regenerating the vegetation on the property throughout her time there.
Following her death, the early 1980’s saw increased development with the establishment of irrigation and the construction of a visitor centre. Consequently the garden opened to the public in 1985 as the Olive Pink Flora Reserve. Olive Pink Botanic Garden was listed on the Register of the National Estate in 1995 and the garden was renamed Olive Pink Botanic Garden in 1996.
The garden has been worked on over the years by many hands, including Francis and Clary Smith, but is currently curated by Ian Coleman. Other permanent staff include Doug McDougall and Cyd Holden. In addition to the staff on ground, the Garden is managed by a voluntary Board of Trustees. Recent times have seen the garden undergo a process of consultation with the public and a new master plan has been released, which outlines some changes to come to advance the garden and visitor experience. Olive Pink Botanic Garden successfully hosted four Green Army programs, who which had a hard task of getting Buffel under control over the site, though others have chipped away on it over the years.
The property itself is 16.1 Ha of land that sits adjacent to the Todd River, with Annie Meyers Hill to the north on the property and Nurses Hill to the south-east of the block. Annie Meyers Hill is a very important sacred site as it is the location of one of the Ntyarlke caterpillars Ntarlkarle Tyaneme, which is located at the Barrett Drive T-junction.
The property encompasses two major land units—drainage floor (which makes up the majority of the garden area) and gneiss hills (which surround the garden). The landscape is an erosional landscape, hence the drainage floor land unit, and controlling floods resulting from heavy rains will be a perennial issue. Several control methods, including recent attempts to slow water flow down the gully with shrub and tree pruning waste, have been used and are quite effective.
There is also one mapped vegetation type, which is Witchetty Bush and/or Mulga on rocky hills of granite, gneiss or schist, and the remainder of the property hasn’t been mapped, though much of the unmapped garden has been deliberately planted. It is likely that this zone is composed of a secondary vegetation type Ironwood and Fork-leaved Corkwood on alluvial flats.
Since the property became established, controlling Buffel Grass has been a challenge of an ongoing nature. As for feral species, traps have been loaned out to the garden to control Cats (Felis catus) and Spotted Turtle-doves (Streptopelia (Spilopelia) chinensis) over the years with fluctuating trap rates. Rabbits have also been observed and controlled in the past but numbers have decreased over the years and are rarely seen now.
Olive Pink Botanic Garden joined the Land for Wildlife team as a member as they were keen to provide support towards the aims of Land For Wildlife, space for workshops and demonstrations, and to encourage community interest in the Land For Wildlife scheme. Land for Wildlife have in turn helped provide information resources to the curators and workshops for four of their Green Army teams, as well as ongoing support in the form of trap loans and ecological advice.
So how have they been going of late?
The APS / Field Nats walk and talk began at the entrance to OPBG and ran along the outside of the fence line abutting the Todd River to demonstrate the work that the OPBG Landcare group have been undertaking. The Landcare group are relatively new to establish, but with some hard work and muscle power, Buffel is starting to make way for some native grasses such as Purple Plumegrass (Triraphis mollis), Erect Kerosene Grass (Aristida holathera var. holathera), and Woolly Oat-grass (Enneapogon polyphyllus), among others. Some species have been planted and are doing well, including Dense Cassia (Senna artemisioides nothosubsp. sturtii) and Bluebush (Maireana sp.).
The walk continued into the formal gardens. One of the hills to go under the mattock was Annie Meyers Hill, which has been cleared of Buffel until half way up the slope (marked with some pegs and flagging tape) and the area has been allowed to naturally regenerate with grasses such as Wanderie (Eriachne sp.) and forbs such as Crimson Foxtail (Ptilotus sessilifolius).
Further up the slope, some Kangaroo Grass (Themeda triandra) is holding on in patches amongst the Buffel and plans to clear selected areas to allow natives to expand their range is in the works. Some management of Buffel Grass around selected trees (ie. Common Rock Fig, Ficus brachypoda) has taken place as a fire management tool. Selected shrubs do well among the rocks, with some hardy Native Fuchsia (Eremophila latrobei) staking a claim for space.
We continued back down the hill after a moment of soaking in the view to see the impact of Euro’s (Macropus robustus) on the native forbs in the low-lying areas. A few individuals stuck around to demonstrate their ability to eat the soft succulent grasses and forbs. We then continued on over to Nurses Hill, which has also gone under the mattock. The native species present on Nurses Hill is testament to the hard work of the Green Army teams and OPBG staff. We paid a quick visit to the sand dune and heath areas on our way out, where we interrupted a pigeon party and spied a Painted Lady (Vanessa kershawi) butterfly feeding on Salty Heath (Frankenia cordata) inflorescences.
While Buffel Grass control is an ongoing concern for many, OPBG are certainly on the right track and are making a considerable impact on the regeneration of native plants on the site.
Thanks to Connie Spencer and Ian Coleman for showing the Land for Wildlife team and others around Olive Pink Botanic Garden—the hill climbs were a great way to get the blood pumping early on a Sunday morning!
You can also view this article in the Land for Wildlife May 2018 Newsletter.
Want to know more about Olive Pink Botanic Garden? Check out the OPBG website!