ARTICLE : 2007 Otari-Wilton’s Bush BioBlitz

 Otari-Wilton’s Bush BioBlitz.

Ten teams of botanists headed for different tracks and gorges in Otari-Wilton’s Bush (OWB) just before 3 p.m. on Friday 23 March 2007 when Wellington’s Mayor, Kerry Prendergast, announced the start of BioBlitz.   Three hours later, as fading light forced them to return, many participants regretted the end of daylight saving one week earlier.   Nevertheless, the 24-hour challenge of identifying all the plants growing in OWB was well underway.

BioBlitz is a concept developed in the USA to promote urban biodiversity and public awareness of biodiversity.   The OWB BioBlitz was organised by Otari-Wilton’s Bush Trust and Wellington City Council, with the support of many other organisations as part of the Centenary celebrations (August 2006 - August 2007).   It was not just about plants; others surveyed birds, zooplankton, insects, fish, reptiles and fungi.

The preparation for the botanical surveys had started months before.   We knew from checks of previous species lists, herbarium specimens and some preliminary forays, that 608 plant species had been recorded in OWB at some time in the past (439 natives and 169 adventives).   What we couldn’t predict, however, was how many we’d find and identify in the next 24 hours.   We wondered if any of the weeds had been eradicated, or if new ones had arrived?   We knew we’d be lucky to find some of the orchids at this time of the year, for example, Pterostylis banksii and a caladenia.   Additions to the known mosses, liverworts and lichens were all possible.

Wellington is fortunate in having several institutions with botanists on staff.   This meant that the botanical teams included botanists from Te Papa, Victoria University, the Department of Conservation and Otari / Wellington City Council as well as BotSoc members.   In all, some 27 amateur and professional botanists took part.

Teams were back in the field early Saturday morning and in the 24 hours the botanical teams found and identified 497 species of plants – 343 indigenous and 154 adventives.   (BioBlitz and the species counts did not include species in the formal gardens / collections but did include non-Wellington species such as beech and kauri that were either self-introduced or planted in the bush areas).

Contributions from the specialists recording animals and other taxa brought the total number of species identified during the 24 hours of BioBlitz to 1345.

Twenty-seven adventive plants were added to the list during the BioBlitz including Phil Garnock-Jones’s find of Veronica javanica.   This is a new record for New Zealand.

Twenty-five native plant species were recorded at OWB for the first time during BioBlitz, and still more could be added later this year.   Barbara Polly, lichenologist from Te Papa, was confident of finding new records among the specimens she had collected but not formally identified during BioBlitz.   To date, only 70 lichens have been recorded from Otari-Wilton’s Bush though New Zealand has over 1700 species.   Barbara says it can take several hours to identify an unfamiliar lichen.

Ferns are an important component of plants at OWB.   Our pre-BioBlitz species list included 55 ferns and most were found again.   Leon Perrie added some Asplenium hybrids, and Patrick Brownsey confirmed Cyathea cunninghamii after some earlier detection work by Chris Horne.   Kidney fern (now called Hymenophyllum nephrophyllum) remained elusive for a long time but Barbara Mitcalfe and Chris Horne were eventually successful thanks to assistance from Dave Bidgood, one of the Otari staff.

At the end of the 24 hours of BioBlitz, there were also some surprises amongst the species still on the “missing” lists.   We could scarcely believe that no-one had found Blechnum fluviatile.   There is perhaps some good news in the fact that no one found cotoneaster, holly or boobialla / “Tasmanian ngaio”.

BioBlitz was not just a scientific inventory.   It also provided opportunities for the public to learn more about OWB through talks, guided walks and displays.   The Society produced several large posters to increase awareness of the plants and past changes in the vegetation of OWB and these will be offered to Otari for their use.