After a couple of weeks in the field, Jennie and Nick have provided the following update on their botanical findings:
Azorella macquariensis dieback
Azorella dieback is continuing to be active across the island, with almost no area completely free of dieback. However, the SMAs (Special Management Area) have good populations of healthy Azorella. We have completed 80% of the Azorella photo monitoring plots.
Vegetation recovery in the absence of rabbits
The 30 year vegetation/rabbit plots and exclosure plots have all been scored and photographed. Initial impressions are that there is amazingly rapid recovery in some of the most palatable and visible species (Stilbocarpa — Macquarie cabbage, Pleurophyllum and Poa foliosa — tussock grass). The shield fern, Polystichum vestitum, is showing good recovery in the exclosures constructed to conserve a 'seed' population, as well as in scattered locations across the island. Acaena minor also appears to be more common (although this might also be because we are earlier in the season). The introduced species Poa annua forms thick lawns in places.
Huperzia australiana populations
The enthusiasm and intense scrutiny of the vegetation by the MIPEP team has resulted in several new populations of Huperzia australiana being identified on the island. Previous inspections of populations has revealed that many of the plants were unhealthy and appeared to show signs of chlorosis. However, new populations with as many as 20 individual clumps per site, have been identified and inspected. Many of these appear quite healthy. These new populations mean a significant range extension, with the most southerly population being at Lusitania Bay (previously it was in Green Gorge basin). Kelly currently holds the record of most Huperzia found and Dave holds the record for the most southerly extension of the range.
The distribution and health of Sphagnum moss has varied over the 25 years that it has been monitored. Currently, the Sphagnum moss appears to be in good health and expanding at monitoring sites. A new population ofSphagnum moss was found just north of Pyramid Peak, extending southwards the previous known range of Green Gorge basin.
The most unexpected and exciting find of our visit has been the re-location of Galium antarcticum on the northern shore of Skua Lake. We found a total of 35 individuals spread over 15 metres in the general vicinity of the original collection. The plants appeared to be in good health, with one or two flowers evident. It is possible that additional individuals may exist in the area, but snow, hail and pending hypothermia curtailed our enthusiastic searching and celebrating.
We are wondering whether the initial recovery of the ecosystem in the absence of rabbits and rodents has resulted in an expansion in numbers and distribution of some species, particularly the Galium and Huperzia.
Jennie and Nick