Future Events

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.

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.

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.

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

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.

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

Cyanobacteria

Speaker: Nicole Heaton. Cyanobacterial blooms pose a significant threat to freshwater ecosystems globally, fuelled by eutrophication and warming temperatures. More recent studies have shown that the associated heterotrophic bacteria community may have an influential role in cyanobacterial bloom dynamics. Are these interactions affecting blooms in the Ōtākou region?

Flowers of Annapurna

Speaker: Mike Small. The Annapurna Circuit is one of the great hikes of the world. More than 150 kms of trails pass from an altitude of 80m with subtropical rainforest to as high as 5500m high-alpine/ subarctic areas near the world's highest mountain pass at Thorung La. Culturally diverse, it is also a biodiversity hotspot as a result of the intersection of several floristic regions and extremes of precipitation and altitude. Floral diversity also results from numerous geological uplifts that formed the Himalaya and the monsoon after India collided with Asia 50 million years ago. This talk follows the trail and the flowers during the monsoon flowering season of 2024.