Past Events

Andersons Lagoon

Wrap up for an easy winter walk to Andersons Lagoon. This little known gem close to Palmerston (last BSO trip in November 2019) is accessed via a planted area along a grass pathway which opens onto a small but interesting saltmarsh and marginal plant communities at the closed mouth of Stony Creek. Contact Maia Mistral-Armour 027 2388498

Losing our edges: adjacent land-use intensification facilitates plant invasions into indigenous shrubland fragments

Speaker: Gretchen Brownstein.

Native shrublands were once common across the Canterbury Plains, but over time, conversion of land to other uses including irrigated pasture have contributed to their gradual decline. In this talk I will be discussing a study we recently published which found that spillover of nutrients and water from adjacent intensive agriculture is facilitating invasions by exotic plants into reserves set up to protect the last remnants of these native shrublands. We show that nitrogen enrichment, likely from irrigated animal effluent, is detectable 10 m inside reserve boundary fences. And we observed increases in exotic herbs and grasses, along with declines in native species, up to 30–40 m in from irrigated boundaries. These distances are significant as some of these reserves are only 100 m across, meaning that more than 60% of these reserves can be affected.

The ongoing effects of more intensive land use adjacent to the reserves could be managed with better rules around buffers. However, our study highlights the larger problem of establishing representative reserves that are too small. To maintain viable indigenous populations in other landscapes will require protection of blocks in the 100s of ha to avoid past mistakes in reserve design made on the Canterbury Plains.

AGM and photo competition

At the AGM we will vote on a new constitution.

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

BSO Fungal Foray, Piano Flat, Waikaia Forest

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. It has proved to be a regional hotspot of fungal diversity with many species of mycorrhizal fungi associated with the beech. It is suggested that anyone wishing to participate travel down on Friday evening so they can get an early start on Saturday morning. People can either travel back on Saturday evening or on Sunday. Accommodation is available at the DOC Campsite at Piano Flat or the Waikaia Motor Camp. You will need to bring your own tents, food cooking gear etc if you wish to stay overnight. Contact David Lyttle 027 654 5470 for further details.

Field trip to Bungtown Conservation Area and Lake Mahinerangi

The Bungtown Conservation Area is a small (c. 3.5 ha) reserve in the headwaters of the Waitahuna River. It's a great example of an upland copper tussock bog with stands of bog pine (Halocarpus bidwillii). There's also a population of the declining Carex tenuiculmis sedge. After exploring this area we'll visit the nearby shore of Lake Mahinerangi where some lake shore turfs have tiny herbs such as the nationally vulnerable Gratiola concinna, mudwort (Limosella australis) and declining Maniototo button daisy (Leptinella maniototo). Meet at the Botany department car park at 9 am. Return by 4 pm. Leader John Barkla 027 326 7917.

A Samoan Sojourn

Join John and Marilyn Barkla on their cycle-tour perspective of the amazing nature and people of Savai’i, the largest island of Western Samoa. There’ll be a glimpse of the bewildering array of tropical plants, along with plenty of beaches, fales and much more.

Truby King Reserve, Seacliff

A day trip to explore the diverse botanical features of the Truby King Reserve (TBK). The TBK once formed part of the grounds of the Seacliff Hospital. It is now administered by the Dunedin City Council. There are survivals of the original - mostly introduced - tree plantings (which are currently being mapped). There are many more trees that have spread from the original plantings, many - native and introduced tree and shrub species - that have arrived spontaneously, and there are also ongoing informal plantings of - mostly - native trees. Some of the species present, such as sycamore, require ongoing control. The TKR has a good network of tracks, and it is a good place to visit if you like tall trees. We will investigate the different stands of TKR to see what mosses, liverworts, fungi and lichens are present, and what is happening to the woody debris that has been left in situ following cutting and pruning. Bring good walking shoes, something to eat and drink, and clothing for the weather on the day. Meet at the Botany Department car park at 9 am and return time 3 p.m. Contact Alex, 0210510014.

Re-evaluating some common and rare Cortinarius species

Speaker: Andy Nilsen. Work by Andy Nilsen and David Orlovich.

Herbaria hold invaluable biodiversity data, but many collections, particularly historical ones, lack DNA barcodes necessary for accurate identification. This is especially problematic for type collections, which serve as a taxonomic reference for a species. Older specimens are often degraded, making successful DNA barcoding challenging with traditional methods. We applied both traditional and modern sequencing techniques to type and non-type collections from the New Zealand Fungarium (PDD) and the State Herbarium of South Australia (AD), successfully retrieving DNA from specimens over 100 years old.

One key application of this work has been revisiting New Zealand sequestrate Cortinarius species and the elegant blue webcap, Cortinarius rotundisporus. The true identity of these species has long been difficult to establish due to morphological similarities and a lack of molecular data from type collections. Here we discuss current progress in establishing these species phylogenetic placements and some of the difficulties arising from this research

Maukaatua track

The walk starts from Woodside Glen, crosses Lee Creek, and heads up through mixed podocarp and beech forest. The low-alpine and rocky summit provides a great lunch spot, lots of lichen and bryophytes to observe, with stunning views. The 2.7 km return walk reaches around 895m and is a steep climb in places. Bring tramping shoes, lunch/snacks and lots of water. You may get wet feet crossing the creek. If the creek is too high to cross due to heavy rain, we can enjoy a shorter walk through Woodside Glen’s lush undergrowth. Meet at the Botany Department at 8:30am, or Woodside Glen at 9:10 am. Returning to Dunedin late afternoon. Contact Jo, 021 026 13580

The Hikaroroa Mt Watkin Conservation Group

Speaker: Jamie Hickling. The Hikaroroa/ Mt Watkin Scenic Reserve is a 660ha DCC reserve containing one of the best examples of remnant lowland podocarp and kowhai dominant forest in the region. Hikaroroa is also culturally significant as being the mauka tipuna for Kati Huirapa Ki Puketeraki. The Hikaroroa Mt Watkin Conservation Group is a community conservation group established in 2023 whose primary object is to protect the ecological values of the area. This talk will detail the conservation work the group has been doing and their plans moving into the future.

Catlins Weekend

This is an adventurous weekend trip up the Tautuku River in the Catlins. We will follow local experts along trapline routes through mixed old growth and regenerating podocarp forest to investigate some interesting nooks. There is potential for exciting plant sightings. This trip requires a high level of fitness; we will be covering up to 10km of very rough routes through dense forest. Bring tramping boots, wet weather gear, food, water, and first aid kit. Contact Gretchen Brownstein (brownsteing@landcareresearch.co.nz) to book a spot (drive time: 2hrs one way, ~300kms return trip). Leaving Friday evening, returning Sunday.

Quarantine Island exploration and picnic lunch

Join us for a day exploring Quarantine Island Kamau Taurua, a public Recreation Reserve and an Historic Area in Otago Harbour. Wander the trails to check out the regenerating forest and the interesting human history. Bring a pair of work gloves if you feel like doing some volunteer weeding. Tools are provided. To book a place contact Gretchen by Wednesday 20th Nov. as we need to book the boat in advance (boat cost will be covered by the BSO). Bring appropriate clothing, water and lunch.

The Sequoioideae: What can extant lineages tell us about evolution?

Speaker: Jess Paull. In ages bygone, gymnosperms were at the height of their diversity. In the modern age, many face extinction due to the looming threat of climate change. What can this group (and others) tell us about our past and our future?

An Exploration of the Flora of Western Australia

The flora of Western Australia (WA) contains over 10,000 species of vascular plants and that, together with the huge area that the State encompasses, means that the visitor will only experience a tiny fraction of the floristic diversity that WA has to offer. In late August 2023 David Lyttle, together with his wife Belinda, embarked on a two-week camper van trip round the State. After collecting the camper van in Perth they drove north to Kalbarri National Park and then South to the Stirling Range stopping at various points on the way before returning to Perth. Although the spectacular great swathes of wildflowers for which WA is known were not in evidence due to an unfavourable season, they found plenty of botanical interest including a wealth of Banksias, Grevilleas, orchids and sundews. The talk will provide an introduction to the flora of WA as well as covering the journey, the landscapes, aspects of the photography and will be illustrated with a collection of wild flower images taken during the trip.
Artwork from the Botanical Art competition will be displayed at this meeting, and prizes awarded. There may also be an art auction, depending on interest.

Field trip to Mahaka Katia Scientific Reserve (Pisa Flats)

Mahaka Katia Scientific Reserve (Pisa Flats) is situated on an elevated terrace above Lake Dunstan just north of Cromwell. It is a unique example of Central Otago dryland habitat that has mostly been lost to agricultural development and residential subdivision. Pisa Flats is one of the few remaining places where populations of a number of rare, native, dryland endemic species can still be found. These include Raoulia monroi, Lepidium solandri, Convolvulus verecundus, Myosotis uniflora and Craspedia argentea. Myosotis uniflora is classified as At Risk – Naturally Uncommon and the yellow-flowered form is more or less confined to the Pisa Flats. We are timing our visit to hopefully coincide with its spring flowering. Craspedia argentea is known only from this location and is considered Threatened – Nationally Critical. If we have time, we will possibly visit the saline sites at Springvale Scientific Reserve or the Chapman Road Reserve both near Alexandra to look at Central Otago spring annuals, a suite of dryland species that includes Myosotis brevis, and the tiny buttercup relatives, Ceratocephala pungens and Myosurus minimus.
We will meet at the Botany Department carpark at 8.00 am and travel to Cromwell and then on to the Reserve. Bring lunch, warm clothing, rain gear and suitable footwear. Travel time from Dunedin to Cromwell is approximately 3 hrs. Contact David Lyttle | djl1yttle@gmail.com | 027 654 5470