Ecological Observations Within the Remnant Red Tussock (Chionochloa rubra) Tussock Grasslands of Sandy Point Peninsula, Murihiku Southland

Jordon Trail & Yannick Dorsman

http://doi.org/10.34074/sitj.17106

Abstract

Sandy Point Peninsula, a unique coastal landform in Southland, New Zealand, supports threatened lowland red tussock (Chionochloa rubra) grasslands amidst a heavily modified landscape. This study provides a baseline ecological survey focused on vegetation assemblages and potential woody encroachment across remnant red tussock habitats. Thirty quadrats were sampled across dune hollows and flats, revealing a mosaic of native and exotic plant species. While exotic pasture grasses dominated, native hydrophytic species were also present, with red tussock hummocks providing microhabitats that were critical in supporting indigenous plant species. Notably, four indigenous taxa demonstrated an obligate association with C. rubra, highlighting the plants’ ecological role in retaining indigenous biodiversity in degraded habitats. Although woody weeds were observed, no recruitment was detected within the surveyed dune flats, suggesting limited encroachment. Incidental findings included a single matagouri/tūmatakuru (Discaria toumatou), potentially indicating a range extension, and the presence of South Island Fernbirds (Bowdleria puncata punctata), previously considered locally extirpated. This study highlights the conservation value of remnant tussock ecosystems in Sandy Point and underscores the importance of ongoing monitoring to assess future vegetation shifts and biodiversity resilience.

Keywords: tussockland; tussock grassland; regeneration; baseline survey; obligate associations.