Past Events

What’s cooking with kānuka?

Speaker: Matt McGlone, Manaaki Whenua-Landcare Research.

As a successional tree species after fire or other disturbance, kānuka plays a key ecological role in the lowland and montane landscapes of New Zealand. It is also highly variable, with some populations contributing to lowland forest canopies 25 m or more in height and others consisting of scattered, low-growing, multi-stemmed shrubs on gravelly soils in frosty basins. Until recently, two species and several varieties were formally recognized - along with a swag of tag names. In 2014, a comprehensive revision of the kānuka group attempted to rationalize the situation and expanded the number of species to 10. The revision has had a mixed reception with many of the species proving difficult to confidently identify whether in the field or herbarium. In this talk I will present the results of a recently published genetic study of nearly 900 kānuka specimens spanning the entire geographic range of the complex and all the current species. I will discuss the implications for kānuka taxonomy but also for how we decide what is and what is not a ‘species’.

NOTE: New meeting location! Talks are hosted by Manaaki Whenua Landcare Research in the Main Seminar room, 764 Cumberland Street, Dunedin

Mihiwaka.

Last winter we had a very successful trip to Mt Kettle and Mt Cutten. This year we will visit the neighbouring peak, Mihiwaka. Come prepared for an uphill walk on an uneven track and boggy conditions. We will see what we see. Contact Lydia Turley 021 062 3602

Looking for Shrubs in all the Wrong Places.

This talk will be held via zoom only due to due to Covid case numbers and the nasty weather forecast to continue into tomorrow.

Jess: A unique patch of land in Portobello is set to be the new study site for future ecology students. Jessica describes the process of documenting the plant species diversity and abundance in four different zones over summer, and the surprising discoveries she made along the way.

Shar: We know what climate change is, but it's harder to predict exactly what changes in temperature and precipitation will mean for species and ecosystems. During my Honours research I used statistical modelling techniques to show how future climate change will affect which parts of New Zealand contain suitable habitat for southern beech species and their associated fungi. This talk will describe some of what I found, and what these climate changes mean for New Zealand ecosystems as a whole.

Bull Creek Bush

We will explore around Bull Creek and its small attractive estuary. Southern rata dominated forest extends down the creek to the coast. There is potential to find turf communities in the estuary. We will follow a walking track up the creek to a small waterfall before returning to the coast to explore the turf communities and other coastal surprises. Grade: ~2km of walking on a well formed track, expect mud and uneven ground. Bring water, lunch, and warm clothing. Depart Botany car park at 9 am returning mid-afternoon.

Exploration of the functional significance of serrated leaves in New Zealand forest trees

Speaker: Bill Lee (with Jennifer Bannister and Tammo Reichgelt).

Many NZ trees have toothed/serrated leaf margins and diverse explanations exist for their functional significance, mostly derived from overseas studies on deciduous species. We survey the leaves of forest trees in NZ, investigating the presence/absence of serrations and any associated leaf pores or glands. We also compare the environmental distribution of species with either entire or serrated leaves. Serrated leaves are associated with leaf-margin and leaf-lamina hydathodes, permanent openings generally larger than stomata that are frequently attached to major veins. They may also have colletors, complex glands that appear to secrete fluid. Our previous study in New Zealand showed that trees with serrated leaves were commonly associated with high rainfall areas. The strong association between marginal hydathodes and toothed leaves supports the suggestion that serrated leaves may have a key function in regulating internal plant water pressure on regularly saturated soils.

NOTE: New meeting location: Talks are hosted by Manaaki Whenua Landcare Research in the Main Seminar room, 764 Cumberland Street, Dunedin.

BSO Annual General Meeting and Photographic Competition

The photographic competition is a popular and eagerly anticipated event for anyone interested in botanical photography. Enter your best photos and learn what makes a good photograph and how to improve your photographic skills from our panel of expert judges. Your photographs may be chosen for the BSO Calendar so this is your opportunity to have one month of fame. Start organising your entries now and don’t wait until the last minute.

NOTE: New meeting location! Talks are now held at the Otago Pioneer Women’s Memorial Assn., Inc., Building, 362 Moray Place, Dunedin Central.

108 years on – revisiting the great Dunedin-Waititi fire of 1914

This trip will look at the vegetation change 108 years after a large fire burned through Libocedrus bidwillii cloud forest near Leith Saddle. We will walk up Leith saddle track and look at the nature of vegetation on either side of the fire boundary and I’ll talk about some student projects that have been investigating the demographic effects of the fire; and the longer-term consequences of the fire on the flammability of plant communities in the area.

Field trip to Okia Reserve

Okia is a large coastal reserve on the Otago Peninsula that is jointly owned by the DCC and Yellow-eyed Penguin Trust. It comprises an old dune system that is rapidly changing from its dominant bracken fern cover to woody coastal species. There are also interesting hollows between the dunes that hold a variety of wetlands that include turf, bogs and ponds. On this trip we’ll focus on taking photos and making observations for iNaturalist https://inaturalist.nz/observations. The trip coincides with the iNaturalist City Nature Challenge where cities around the world compete to gather the most nature observations. Participants will find it helpful to download the iNaturalist app to their phone before the trip. Meet at Botany Department carpark at 9am or the Okia Reserve carpark at the end of Dick Road at 9.40 am. Bring lunch and expect to be back in Dunedin by 4 pm.

Botanical Quiz

Instead of a talk, this month we are hosting a botanically themed quiz! It’s about more than just identifying plants, so brush up on your general (planty) knowledge and come have some fun. Come as a team, or join one on the night.

Dune Slacks species check Kaikai Beach, Heyward’s Point

The Botanical Society has been approached to help with species identification in an area of dune slacks which border Kaikai Beach near Heyward’s Point. Sue Chapman, the landowner, wants to place a covenant on the area adjacent to the beach. To do this she requires an idea of what species are growing there and in particular if there are any threatened species. We have permission to drive to the headland above Kaikai where we will park, and then it’s a shortish walk down through the farm to the dunes. Of interest to those who have not visited this area before is a large cave with historical links to early Otago whalers and that is still in use today. Meet 9am, Botany Department carpark. Rain date Sunday 13 March.

Tautuku weekend field trip

Join us for a weekend exploring the varied vegetation around the Lenz Reserve and Tautuku. The reserve is 550 hectares of conservation land owned and managed by Forest and Bird. There is something for everyone here: old growth podocarp forests, beech forests, peat bogs, and estuaries. In February the ratas should be flowering, the fungi popping up and, if it happens to drizzle, the lichens and bryophytes will be at their best. There are numerous adventurous tracks or easy paths to ramble along and, for the aquatically inclined, a kayak option to explore the estuary. Gavin White, trapper for the reserve, will be our guide for the weekend. Gavin will show us the hidden gems he had found over many years of working the reserve. There are options for all fitness levels: from well-formed tracks on level ground to rough routes up the hills. We will stay at the Forest and Bird Lodge on Saturday night (costs $22 pp). BYO bedding, towels, etc. (more information about the lodge here: https://www.forestandbird.org.nz/our-community/lodges/tautuku-forest-cabins). You will need to bring your own breakfast, lunch and snacks. Bring a dish to share at the Saturday night potluck dinner. Space in the lodge is limited to 14 people, so book your spot early! Contact Gretchen Brownstein brownsteing@landcareresearch.co.nz for more information and to book.

A Vegetation Map for Dunedin City

Speaker: Richard Ewans, Biodiversity Advisor, Dunedin City Council.

In 2019, Dunedin City Council commissioned a vegetation cover map for Dunedin City which was completed in 2020. The map provides a detailed picture of vegetation cover across Dunedin City that compliments and enhances data sets from regional and national agencies. Together this information will be used to identify priority areas for ecological restoration and protection, and for district-wide monitoring of the extent of indigenous ecosystems to support improved outcomes for indigenous biodiversity in the city. I will give an overview of the map and its potential utility for a range of users, show how the map is an improvement on what was previously available, and describe some of the limitations to be aware of when interpreting or using the map and underlying data.

NOTE: New meeting location! Talks are now held at the Otago Pioneer Women’s Memorial Assn., Inc., Building, 362 Moray Place, Dunedin Central.

Truby King Recreation Reserve, Seacliff – tree mapping

The Truby King Recreation Reserve comprises much of the landscaped grounds of the former Seacliff Psychiatric Hospital. The Reserve is made up open grassed areas, mixed plantings of exotic deciduous and coniferous species, along with elements of the original coastal forest, and contains many great examples of significant specimen trees. The earliest plantings have been added to through successive plantings and, as such, provide a living record of changes in horticultural fashions spanning from the 1890s to the 1960s when the last major plantings were made. In 1991, a map and DBH measurements of the significant trees was made by Euan Cadzow. His map was partially updated in 2004 by Chuck Landis to include plantings post-dating those included in the original map. On this BSO trip we will be working with Truby King Reserve Committee to begin re-mapping and measuring the significant trees and assessing tree health. This will be a great trip to use and/or gain skills in tree measurement and GPS / mapping. The information we gather will be used by Truby King Reserve Committee to assist with the ongoing maintenance and management of this wonderful reserve. The reserve has a number of well formed grass walking tracks on slopes. Only part of the tree collection is bordering relatively flat ground; some of the mapping will be of trees off track and on uneven terrain. Moderate fitness required. For more details, contact Maia Mistral mistral.maia@gmail.com. The trip will depart from the Botany Department Carpark at 9am. Bring lunch.

Modelling Niches and Phylogeny in Celmisiinae (Asteraceae)

Speaker: Duncan Nicol. This research is part of ongoing systematic, biogeographic, and ecological studies aiming to deepen the understanding of biodiversity. The subtribe Celmisiinae Saldivia (Asteraceae: Astereae) is a hypothesis of relationships between a number of unresolved genera in the Tasman region and contains ca. 159 species. These genera have a range from New Guinea through Australia and New Zealand. Celmisiinae has a number of interesting features making it useful as a study group to investigate questions with implications for biodiversity more broadly.

Full day field trip to Herbert Forest

Please note new date

Herbert Forest is a predominantly exotic plantation forest in north Otago managed by Blakely Pacific Limited. Within its matrix, however, are significant native forest remnants that include some magnificent podocarp stands. We will do a loop track of about 10 km that links together these varied and interesting blocks of native forest. The tracks are well maintained by the North Otago Tramping & Mountaineering Club, but be prepared for numerous stream crossings. Meet at Botany Department carpark at 9am.