Town Belt Ecology

The loss of the emergent trees such as Rimu has been a major impact on the Town Belt

Flora

The predominant vegetation cover of the Town Belt is;

  • kanuka forest
  • moist broad-leaved forest
  • exotic coniferous-deciduous forest
  • mown grassland,
  • dry broadleaved forest
  • swamp forest
  • cliff vegetation
  • rough grassland
  • heathland vegetation

Stuart Street marks a major change in the overall composition and structure of the Town Belt, with native-dominant forest the predominant cover north of Stuart Street, and exotic-dominant forest and mown grassland the main vegetation south of Stuart Street. This change is also reflected in under-storey composition, with several native trees, shrubs, lianes, and monocot herbs being more common in the north of the Town Belt, while native dicot herbs are more common in the southern part.

The Town Belt forests are quite fragmented and disturbed. The Town Belt’s close proximity to residential housing is a key factor in  high levels of weed invasion. Competition with weeds such as Coprosma grandifolia, rangiora, sycamore, wandering jew, ivy, and aluminium plant are major factors reducing the diversity and frequency of locally native under-storey and ground cover plants.

Rare and Uncommon Plant Species

Three plant species recorded at the site are classified as nationally threatened, uncommon, or data deficient:

  • the tree Raukaua edgerleyi, listed as ‘Gradual Decline’
  • the fierce lancewood (Pseudopanax ferox), which is listed as ‘Sparse’
  • The sedge Carex raoulii, listed as ‘Data Deficient’

Most of the uncommon tree species are typically found as emergents in podocarp/broadleaved forest. These include kahikatea, pokaka, totara, and Hall’s totara.  Most of these species would have been removed by logging from the Town Belt in previous eras. Non-timber trees of fertile alluvial forest such as ribbonwood and narrow-leaved lacebark are also uncommon, reflecting the scarcity of this habitat within the Town Belt. There are a few larger emergent kahikatea in the Woodhaugh swamp forest remnant.

Serious Weed Threats to the Town Belt

 

The Bird life of the Town Belt

The Town Belt provides important habitat for native birds due to the presence of plant species that provide a seasonal food resource when other sources of food are less abundant. The Town Belt is also an important landscape link between the suburbs and wider forested landscape of the Leith Valley wooded slopes of Flagstaff. Sites such as Woodhaugh have the highest native diversity and include Shag, Kingfisher and Gull species due to the presence of the Leith (Owheo) stream. Pied and Variable Oystercatchers, Paradise Shelduck and Spur Winged Plovers will often roost and feed about the wetter open grassed playing field and amenity sites of the reserve, particularly during wet or stormy weather.

Common Native and Exotic Birds of the Dunedin Town Belt

Invertebrates

Much more scientific and monitoring work needs to be undertaken to give a better understanding of the invertebrates living within the Town Belt. This is even more important given the variety of habitat types in the site and their locations in relationship to other bush remnants and urban development. In broad terms Carabid beetles and large spider populations of the Clubionidae family are found in parts of the Town Belt which indicates relatively intact invertebrate food chains and generally habitat wellness. Both native types of forest and exotic forest reveal significant invertebrate numbers. Other species include Springtail, Amphipods, Isopoda, Millipedes and Harvestmen. There is some evidence that the Peripatus, or velvet worms may occupy niche areas of the Town Belt. These fascinating, but elusive hunters occupy the damp areas of leaf litter and the forest floor. They are called ‘living fossils’  and have remained unchanged from 500 million years ago. They can be considered a ‘missing link’ for their similarity to both worms and insects. However, they rare and difficult to find and identify.

Peripatus are rare and elusive

Advertisements