Past Events

Racemans Track

The last field trip of the winter is a trip to the Racemans Track at Whare flat, 20 minutes south of Dunedin. This is a chance to become familiar with using the Dunedin Fern Key to identify some of our local ferns. It will also provide an opportunity to work on those groups, the mosses, liverworts, and hornworts, plants which so enrich our environment yet are largely ignored. A checklist of species for the area will be provided and with the extra pairs of eyes hopefully added to. The start (and end) of the track involves crossing the Silverstream weir so if wet feet are to be avoided, boots will be needed. If water flow is high the start of the McLeans Falls track may be taken as far as the swing bridge which will avoid wet feet, but this track is not in a good state at the moment and its condition will be assessed nearer the time. Leave from Botany Department car park at 9.00 a.m.

The vegetation of some local volcanic domes

Mt Kettle (545m) and Mt Cutten (530m) are both phonolitic lava domes formed by the third eruption of the Dunedin volcanic massif. Mt Kettle is named after Charles Kettle, Otago’s first surveyor and Mt Cutten after William Cutten, MP and co-founder of the Otago Daily Times. The vegetation around both domes has been extensively modified by early twentieth century settlement when much of the area was divided up into small farms. In the early 1950s an area below Mt Kettle was dammed to form the Cedar Farm reservoir. A good patch of mature and regenerating cedars, Libocedrus bidwillii, can be seen from the summit of Mt Kettle. The trip will follow tracks recently restored by the WEA Walking Group. Meet 9am Botany Department carpark 464 Great King Street North. Rain day will be Sunday 25 July.

Almost an island - the remarkable flora and habitats of Banks Peninsula

Speaker: Melissa Hutchison. Banks Peninsula comprises approximately 100,000 hectares of volcanic hill country, rising to a height of 920 metres above sea level at its highest point (Mt Herbert-Te Ahu Pātiki). The vegetation pattern is influenced by varied altitudinal and climatic gradients, which have contributed to a unique and diverse indigenous flora (>550 vascular plant species and >200 lichen species), including a number of endemic species. Prior to human arrival in New Zealand, the Peninsula was largely covered in indigenous forest, but this was rapidly cleared following European colonisation, and by 1920 was reduced to relatively small, isolated fragments, mainly on steep slopes at higher altitudes. Indigenous woody vegetation cover has increased in recent years through natural succession, with primary forest, secondary growth forest and shrubland now covering about 15% of the Peninsula. More than 2200 hectares of land is currently protected in Department of Conservation and Christchurch City Council reserves, with a further 1500 hectares on private land protected through conservation covenants (>120 covenants). The vegetation and flora of the Peninsula has been by well-documented by legendary botanist Hugh Wilson, but recent ecological surveys have shown that there are still exciting botanical (and lichenological) discoveries waiting to be found!

Lichen Foray at Orokonui Ecosanctuary

Lichens are clever fungi that have discovered agriculture. They are very long-lived and fruit all year round, so there's a good chance of getting up close and personal with some of Orokonui's ‘hidden in full view’ wildlife. We will start at the top of the Ecosanctuary and wend our way down to the bottom gate. Copies of Allison Knight's Lichens of New Zealand: An Introductory Illustrated Guide will be for sale at the desk. A hand lens or magnifying glass would be helpful for appreciating the amazingly diverse structures, and a camera could help capture the fine detail. Photos can be entered into the Orokonui Photo Challenge or used to extend the indoor displays. Bring food and drink if you intend to stay the whole day, or take advantage of the yummy food at the Horopito Cafe at the Sanctuary. A koha to help carry on the impressive work at the Ecosanctuary would be appreciated. The Botanical Society recommends that passengers contribute 10c/km to their carpool drivers - it's a 42 km round trip from the Botany Department. Meet at Botany Department carpark, corner of Great King and Union St, at 10 am to carpool or at 10.30 am at the Ecosanctuary. The foray will end at 2 pm. Please contact Allison Knight 027 4878265, email: allison.knight.nz@gmail.co if you need a ride or can help provide transport.

Fungi at Orokonui Ecosanctuary

Speaker: David Orlovich, Department of Botany. I have had the privilege of collecting fungi at Orokonui Ecosanctuary on several occasions since it was established. The ecosanctuary hosts an interesting array of fungi, some of which are associated with particular plant species that grow there, and some that are not known from elsewhere in New Zealand. This informal talk will give an overview of the fungi at Orokonui and showcase some of the interesting finds.

BSO Fungal Foray to Waikaia Forest

Change of Date! Please contact David Orlovich by 11th May if you wish to come (david.orlovich@otago.ac.nz)!

Waikaia Forest at Piano Flat is an isolated remnant of the mixed beech forests (red beech - Nothofagus fusca, mountain beech - Nothofagus cliffortioides and silver beech – Nothofagus menziesii) that once covered much of the area. The area supports a unique invertebrate fauna with several rare species being found there. Beech trees are dependent on various mycorrhizal fungi for their survival and growth. We plan to look at the fungal diversity of this forest in conjunction with Assoc. Prof. David Orlovich of the Otago University Botany Department as part of his ongoing research. For further details and to arrange carpooling contact David Orlovich (david.orlovich@otago.ac.nz).

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.

Seaweed communities – Responses to invasion, climate change and nutrients

Speakers: Gaby Keeler-May, Isla Twigg, Ben Williams, and Nam Chand. This month we have a series of short talks from four Marine Science PhD students.

Gaby Keeler-May is assessing the impacts of the invasive kelp, Undaria pinnatifida, in the subtidal rocky reefs of southern New Zealand. Her focuses are to compare invasive and native seaweed contributions to the total biomass of kelp forest ecosystems, to evaluate the distribution and expansion of Undaria at sites of past and recent introductions, and to determine the impact of Undaria on native kelp abundance and its ability to resettle after large-scale removal.

Isla Twigg’s research revolves around the microbial communities of kelp forests. She is interested in how the productivity of different microbial communities changes with environmental conditions, and between species of macroalgae. This involves tracking seasonal patterns in environmental conditions and bacterial productivity, as well as experiments exposing these microbial communities to different types of stress. Nam Chand will discuss her research on the community habitat and ecophysiology of soft sediment red macroalgal communities in Otago Harbour, with a focus on the red endemic macroalgae Adamsiella chauvinii. Specifically the research investigates the algal habitat community and epifauna composition within A. chauvinii meadows. Moreover, it will also assess the nitrogen uptake by A. chauvinii and other dominant algae within its meadows.

Ben Williams’ will talk about the trends in kelp forest decline in New Zealand driven by climate change and anthropogenic stressors. He will also discuss the future for kelp forest reseeding and how this can be used to rebuild degraded fisheries.

Quoin Point

Quoin Point. This trip offers another opportunity (a previous field trip has been to the mouth of the Akatore River) to look at the distinctive plant communities defined as coastal turfs. These salt tolerant (halophytic) plants are made up of low growing (generally less than 50mm in height), herbs, sedges and grasses, and are well adapted to living in the exposed marine shoreline locations, like this one on the southern Otago coast. Contact Robyn Bridges 021 235 8997.

Weekend Field Trip to Mahu Whenua

27-28th March 2021: Weekend Field Trip to Mahu Whenua. This trip will allow us to explore the flora of a spectacular part of Central Otago not typically accessible to the public. The Mahu Whenua landscape is in the midst of a huge transformation from farmland to conservation land and supports a number of interesting remnant and transitional vegetation types as well as a many rare species including Olearia lineata, Alepis flavida, Sonchus novae-zelandiae, Pachycladon cheesemanii, Carmichaelia crassicaulis ssp. crassicaulis, Azorella exigua, Carex lachenalii ssp. parkeri and Carex enysii. There will be a number of options associated with this trip which will suit all interests and abilities. We will depart Dunedin at 07:00 on Saturday, arriving at the hut where we will have lunch at ~13:30. In the afternoon we will explore the beech forest and shrublands up Highland Creek. Depending on interest a group may also head up above the bushline.

Sunday options include:

• remaining at Highland Creek hut to continue exploring that area,
• heading up the expansive Motatapu Valley via 4WD to explore beech patches, tussock and shrublands,
• and visiting a spectacular high alpine patterned wetland. This last option includes helicopter flights, which will need to be paid for in advance. There will be a maximum of four people + guide (Cara-Lisa) and the cost will be $260 for the return flight.

We will be leaving at 13:00 and will stop for afternoon tea in Alexandra on our way back to Dunedin. The trip will be taking a maximum of 20 people (you must be a BSO member). You will need to provide your own breakfast, lunch and snacks. Dinner will be a potluck/BBQ. We will be camping next to a hut with toilet and cooking facilities, so you will need to BYO sleeping arrangements (tent/mat/bag etc.). Please register your interest with Matt Larcombe (matt.larcombe@otago.ac.nz, 027 919 9709) by the 22nd March.

End Peak wetlands

End Peak wetlands. Speaker: Cara-Lisa Schloots, Masters student, Botany Department. The End Peak wetland complex is situated within the Mahu Whenua covenants near Wanaka at approximately 1800 m a.s.l. in a south facing basin. It has a variety of vegetation types including uncommon species and a number of plants not typically found at such high altitudes. It is a fine example of a southern hemisphere patterned wetland, and a unique system about which very little is known. My Masters project was carried out over the five months of summer 2018-19 when the wetland complex was free of snow. Cameras were set up at six locations to record water level throughout the growing season from mid-December 2018 until mid-May 2019. Water level patterns were found to vary largely within the wetland complex, although some seasonal changes were observed across all sites. Transects were used to investigate standing vegetation and the seed bank. Plant assemblages also varied across the wetland, although some species were present at all locations. These patterns were related to water level regimes at respective sites. From this we can see that even relatively small wetland areas can contain a remarkable variety of environments and communities, and it is unlikely that such an area will respond as one unit to the climatic changes that are taking place. There will be specific areas and communities within the system which are more threatened, in particular those sites which currently experience more stable conditions and are not adapted to as extreme environmental fluctuations.

Weekend Field Trip to the Oteake Conservation Park

Weekend Field Trip to the Oteake Conservation Park. We plan to stay at the DOC Homestead Camp Site, Hawkdun Runs Road. The camp site has stunning views of the Hawkdun Range. The facilities are basic so you will need to bring a tent. You are responsible for providing your own food but plan to bring a meal for Saturday evening to share with the group. There are a number of tracks accessible from the Homestead Camp Site giving access to the Hawkdun Range, the St Bathans Range and the East and West branches of the Manuherikia River. The vegetation of the Oteake Conservation Park is diverse and very interesting especially in the alpine zone. There are well-developed screes which have their own specialised flora and a number of species reach their southern limit in the region. Final details will depend on the number of people attending and the number of 4WD vehicles available. We will leave Dunedin on Friday evening and return Sunday afternoon. If you wish to go on this trip please contact David Lyttle (03) 454 5470 email djl1yttle@gmail.com

Petrified Forests of Zealandia

Petrified Forests of Zealandia. Speaker: Mathew Vanner, Department of Geology. This talk explores the history of Zealandia’s forest tree flora from a palaeontological perspective. Forests are our oldest and most persistent ecosystems and New Zealand, the Chathams and Auckland Islands have all yielded identifiable fossil wood from a range of ages and families. The fossils reveal an unbroken line of conifers, including Araucariaceae and Podocarpaceae, from the Jurassic (~170 Ma) to the Miocene (~10 Ma). New records of angiosperms, (Araliaceae, Myrtaceae, and Legumes), appear in the Eocene (~50 Ma) and other taxa (Casuarinaceae) disappear from New Zealand in the Miocene. Wood characters can be used to investigate palaeoclimate and show when key features developed in New Zealand lineages. My talk illustrates the exquisite preservation of fossil wood, the range of information that can be derived from wood features, and the history of many of the distinctive trees currently growing in New Zealand.

The ‘other half’ of New Zealand’s flora: how distinct are the non-native plants from the native?

Speaker: Dr. Angela Brandt, Ecologist, Manaaki Whenua – Landcare Research. Non-native species make up about half of New Zealand’s plant species, and those that have naturalised have added 68 families and 650 genera to the New Zealand flora. Non-native plants that are introduced and then naturalise are not a random subset of the global flora, but how distinct are these species from the native flora as a whole? I will give an overview of recent inventories of native and non-native plant species in New Zealand and the challenges involved in documenting the ever-changing composition and distribution of the ‘other half’ of New Zealand’s flora.

Weekend Field trip to the Hokonui Hills, Southland

Cancelled

Weekend Field trip to the Hokonui Hills, Southland. We plan to stay at the Dunsdale Recreation Reserve, which is near the township of Hedgehope southwest of Gore. The facilities are basic so you will need to bring a tent. You are responsible for providing your own food but plan to bring a meal for Saturday evening to share with the group. A track from the campground gives access to the Hokonui Forest where there is some interesting riparian forest along the Dunsdale Stream. Expect to see several species of orchid and some impressive specimens of the rare Coprosma, Coprosma wallii. Other places that we can visit are Forest Hill Scenic Reserve and Croydon Bush Scenic Reserve. We will leave Dunedin on Friday evening and return Sunday afternoon. If you wish to go on this trip please contact David Lyttle (03) 454 5470 email djl1yttle@gmail.com