Cassinia rugata: Translocation experiment
Cassinia rugata is our top priority threatened plant species.
Can Cassinia rugata seedlings be successfully translocated?
Does caging increase the vitality of the seedlings?
We obtained a permit from DPIPWE to trial the translocation of some Cassinia rugata seedlings to a new suitable habitat that was recently burnt. The seedlings had germinated and grown en masse near to adult plants after an ecological burn elsewhere. They were very close together and were unlikely to survive to adult plants based on the typical density of mature plants.
On 21 May 2014 20 seedlings of Cassinia rugata were transplanted to the new area. Half of them were caged with a cylinder of wire netting so that they could not be grazed by mammalian herbivores. Some translocated soil cores had more than one seedling resulting in the final count being 12 caged seedlings and 14 uncaged ones.
By 15 January 2015, all 12 of the translocated caged plants were still alive, but 9 of the 14 uncaged plants had disappeared or died. Using a χ2 test, this is a very significant difference (p<0.001).
Our experiment has shown that seedlings of Cassinia rugata that germinated after a fire can be successfully transplanted to suitable habitat. It is advisable to protect the seedlings from mammalian herbivores with a cage or fence.
Results to January 2015
Unprotected plants appear to have been subject to significant grazing pressure, which has either killed or weakened them. More than 70% of the uncaged translocated plants are dead, compared with only one (less than 10%) of the caged translocated plants that has died. The living uncaged plants are very significantly smaller than the caged plants, which potentially means that these plants will now struggle for light amongst surrounding vegetation. Grazing pressure is likely to be much reduced as the surrounding vegetation thickens, but the legacy of this early grazing is likely to remain.