By Brian Rance, Technical Advisor – Ecology and Ecosystem
I was involved in establishing some vegetation monitoring during the November 2014 trip to the Antipodes.
There was no existing vegetation monitoring on the Antipodes Islands. This vegetation monitoring is in part to monitor the recovery of the vegetation following the mouse eradication and in part to monitor longer term vegetation change including succession on the numerous peat slips and changes due to climate change.
The monitoring involved the establishment of more than thirty 10 metre x 10 metre recce plots and assessing some potentially sensitive/susceptible plant species – notable Lepidium oligodontum.
Lepidium oligodontum is a rare (Nationally Vulnerable) coastal cress that is known from both Antipodes and Chatham Islands. It was previously known from a single site on the Antipodes Island. A particular highlight was the discovery of a new population of Lepidium oligodontum towards the western end of Anchorage Bay. This discovery was made by Jo Hiscock and Denise Fastier while undertaking penguin monitoring. This new population consisted of c. 586 plants at two sites (483 & 103 plants). This population is much larger than the previously recorded Reef Point population. The plants in the Anchorage Bay site were healthy and tended to be larger (both in height and diameter) than those at the Reef Point site. A survey of the Reef Point population recorded a total of c. 177 plants from 8 sites, the largest sub-population has 144 plants. The new population adds to the security for the species.
Our other main task was to survey the flora of the island and to assess the abundance. Prior to this survey the published flora (Godley, 1989) listed flora of 73 taxa. The current survey (along with the earlier August trip) recorded a total of 72 taxa including 4 potentially new additions to the flora. These new additions include a fern, a small herb (Colobanthus muelleri), the sow thistle and a grass. This brings the total known flora to 75 taxa, consisting of 3 lycopodes, 18 ferns, 3 shrubs, 30 herbaceous plants, 8 grasses, 7 sedges, 4 orchids and 2 other monocots.
I also assisted with mouse impact monitoring, including putting out and recovering tracking tunnels on both Antipodes and Bollons Island; putting out and recovering invertebrate pitfall traps and collecting litter samples for invertebrate presence and helping with the penguin survey.
It was a privilege to get to these remote islands and have the opportunity to study the flora and ecology of the islands. It was great to know that I was contributing in a small way to the mouse eradication programme.
It was exciting to be able to land on Bollons Islands – twice, to monitor for mice; so few people have been there once! This island is difficult to land on and because of its pest free status is only infrequently visited. The landings were challenging and reinforced the remoteness and ruggedness of the islands.
While I have been fortunate to have previously been to Auckland, Campbell and Snares Island groups, I had not previously been to the Antipodes. This trip reinforced the distinct characteristics of each of these different island groups.
A highlight was to see the wildlife, especially the penguins, albatross, parakeets and snipe in their natural surroundings.