No abstract

No abstract

The low-altitude parts of the UpperClutha have the nearest to a continental climate in New Zealand, with little-described vegetation comprising a mixture of native and exotic species. The vegetation ranges from remnants of Kunzea ericoides woodland to a"semi-desert" with bare soil between mats of scabweed (Raoulia australis). A vegetation survey was made, and the vegetation summarised for convenience by Cluster Analysis into eight major communities. The "Salix" community occurs in the wettest sites. Other wet sites had a variety of vegetation, and are categorised as "Wet Miscellaneous". "Dactylis/Cirsium pasture" includes agricultural pasture plants and weeds. Three drier communities can best be characterised overall by the presence of R umex acetosella and Vulpia megalura. The "Verbascum/ Thymus/Rumex" community tends to have present one or more of V. thapsus, T. vulgaris and R. acetosella. It tends to occur at lower altitude than the following two communities, and on east-facing aspects. The "Rosa~eucopogon" community occurs on steeper slopes where agricultural disturbance has been less intensive. The "Echium/ Verbascum" community is characterised by E. vulgare, V. virgatum and Bromus diandrus. The "Dry Bromus" community occurs on dry but relatively deep soils, quite flat sites, always with Bromus tectorum, often with Trifolium arvense and Bromus mollis, and with very few other species. The

No abstract

Spartina was first p}ant~d in th~ Waihopai River Estuary in 1913 and has spread to cover 15% of the mudflats. Tidal inundatIon was observed to determine possible further spread. Landward spread appears to be limited by the presence of Leptocarpus similis. The seaward edge corresponds to the low neap-tide level which appears to be close to the level of most of the mudflat area. Future colonisation seems to depend on the relationship between the neap-tide minimum level and the level of the mudflats. Spartina emerges during daylight hours for 887 .hr per annum (1~73 data) at its lower limit. This value is much lower than periods for marshes In England and IS probably the result of the Waihopai having clear estuarine waters.