In November 2015, MCMC reached a milestone in our Communities for Nature project to replenish the vulnerable Plains Yam Daisy, when monitoring showed at least 177 thriving new plants! These are the result of our largest round of direct sowing established six months ago. Over the last five years we have pieced together a jigsaw of facts about the Plains Yam Daisy and its reintroduction in the Merri Creek valley.
The most important lessons from this long-term project:
Establish from seed
Earlier unsuccessful attempts to plant Plains Yam Daisies into remnant grasslands using tube stock suggested that this plant needs to develop from seed, rather than transplanted seedlings. This allows the plants to develop a root system capable of withstanding harsh grassland conditions. Direct sowing was chosen as the preferred method for this project.
Understand Habitat and lifecycle of remnant plants
Between 2010 and 2014, several rounds of monitoring described the habitat and followed the lifecycle of nearly a hundred remnant plants at Kalkallo Common. This information was used to choose suitable reintroduction sites and the timing of planting and monitoring.
Know the population size
Methodical searches increased the mapped wild population of Yam Daisies in the Merri Creek valley from just a handful of plants at one site in 2010 to over 250 at three sites by 2015. The seed collection program has been expanded to capture the genetic variety of this larger population.
Confirm that habitat maintenance regimes suit the species
Repeat surveys have indicated that ecological burns and weed control has enhanced natural regeneration around remnant plants across a three year cycle. This confirms that re-established plants should thrive under an enhanced grassland management regime.
Access good quality seed source
Wild plants produce seed sparingly that is slow, and expensive to harvest. Lifecycle monitoring showed that seed production reaches a peak in the autumn following a late summer fire. This information improved seed collection efficiency and the genetic diversity of seed available for reintroductions.
Use a ‘Seed Orchard’ to increase seed for sowing
Direct sowing requires a large amount of seed. The precious wild-collected seed was grown up by the Victorian Indigenous Nurseries Cooperative and the potted plants used as a ‘Seed Orchard’ as these robust plants seeded far more prolifically than wild ones: supplying approximately 1,500 fresh seeds for this season’s sowing.
Create gaps among the grasses and disturb the soil
Studies in the 1990s confirmed that many grassland wildflower seedlings require a gap among grasses where competition and herbivore activity is reduced. Studies by researchers at Victoria University in the 2000s identified the importance of deep soil disturbance to improve establishment of grassland seedlings. Historically such areas of gaps and soil disturbance are thought to have resulted from digging by native Bettongs and Bandicoots as well as the food harvesting activities of Aboriginal people. This project has carefully re-created a combination of ‘gap and disturbance’ within Critically Endangered Grasslands to improve seedling establishment.
Protect from slugs and kangaroos
In a 2014 trial of direct sowing, seed germinated but most of the small seedlings soon disappeared. Paw prints suggested that Kangaroos like to hop on the bare soil of the gaps, trampling the seedings. Apparently they like to see where they put their feet! The introduced Grey field slug was observed to be very active during the peak germination period in early winter. So in 2015 direct sowing plots sported simple kangaroo cages and copper slug barriers. The copper strip barriers apparently work by reacting with the slime the slugs secrete, disrupting their nervous system. Bait stations with an environmentally ‘friendly’ slug killer were placed inside the barriers.
This species was once a staple food plant for the local Aboriginal people and members of the Wurundjeri tribe have been among the many community members contributing to this project. One vision for this project is that the daisies will be in sufficient number within remnant grasslands to be available for cultural renewal purposes. There are now hundreds of new Plains Yam Daisies at two Grasslands as a result of both protection and reintroduction activities. We also look forward to applying our new-found expertise to help other rare grassland plants.
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