Description:

A wide variety of wetland types including a low turf ephemeral tarn, a medium turf ephemeral tarn, Purei wetlands, pools, bogs and moist red tussock (Chionochloa rubra) grasslands in a relatively small area on the upper slope and ridge crests of the Rolling Hills land system. ¹

Type/Class:

Swamps. ²

Size:

67.0 ha.

Altitude:

480 - 600 m above sea level.

Approximate location:

4.8 km East of the intersection of Nenthorn Road and Ramrock Road, Nenthorn.
NZTM (centre point): E1396010 N4962740.

Regional Plan:

Water for Otago.
Schedule 9 Regionally Significant Wetland, no.112, Map F59.

Territorial Authority:

Waitaki District Council.

Other Information:

• Listed as an Area of Significant Indigenous Vegetation and Habitat of Indigenous Fauna in the Waitaki District Plan. ¹²
  
  
• Seven main habitat/vegetation types have been recorded in the Nenthorn Ridge Wetland Management Area in a report for the Department of Conservation prepared by P. Johnson of Landcare Research. ⁴⁷
  
  
• Red tussock grassland (Chionochloa rubra) occupies gently sloping stream head basins on moist mineral soil. The main associated plants are browntop (Agrostis capillaries), tall Juncus sp. species, occasional sedge tussock (Schoenus pauciflorus), and Oreobolus strictus. Much of the ground cover is of the mosses Hypnum cupressiforme and Polystrichum sp. and the lichens Stereocaulon ramulosum and Cladia aggregata.
  
  
• Turf depressions that are seasonally inundated hollows without surface outlets. Turf plants form an almost complete and uniform cover in each depression. Plant composition is variable, but the common dominants are Carex gaudichaudiana and creeping bent (Agrostis stolonifera). Other species which contribute 10% or more of the cover are Hypsela rivalis, Gratiola concinna (classified as nationally vulnerable), Isolepis aucklandica, toad rush (Juncus bufonius), Lachnagrostis sp., Polytrichum sp. and Drepanocladus sp. In an upper zone of turf the dominant plants become dichondra (Dichondra brevifolia), piripiri (Gonocarpus micranthus) and dwarf bedstraw (Galium perpusillum).
  
  
• Pools contain common aquatics: common water milfoil (Myriophyllum propinquum), blue sweet grass (Glyceria declinata), kneed foxtail (Alopecurus geniculatus), jointed rush (Juncus articulatus) and Ranunculus glabrifolius.
  
  
• Juncus sp.-Carex sp. swamp, where pūkio (Carex secta) is found on shallow peat. Patches are dominated by one or more of the tall rushes leafless rush/wīwī (Juncus gregiflorus) and leafless rush (Juncus conglomeratus), makura (Carex diandra) and red tussock (Chionochloa rubra).
  
  
• Sphagnum sp. bog with patches 10-15m across. Orange-brown cushions of Sphagnum cristatum grows with Carex gaudichaudiana. Sphagnum falcatulum grows within watery hollows.
  
  
• Narrow-leaved snow tussock grassland. Narrow-leaved snow tussock (Chionochloa rigida) and fescue tussock (Festuca novae-zelandiae) are the main cover on soils drier than those under red tussock (Chionochloa rubra). Browntop (Agrostis capillaries) and mouse-ear hawkweed (Hieracium pilosella) are also common.
  
  
• Dry land turf. On sunny slopes mouse-ear hawkweed (Hieracium pilosella) is the predominant plant cover, with Carex riparia scattered. Other native plants that are abundant are Leptinella serrulata with a threat status of naturally uncommon, dwarf mingimingi/Pātōtara (Leucopogon fraseri) and turf mat daisy (Raoulia subsericea).
  
  
• Tors. These provide are range of different habitats such as sunny ledges, shaded clefts, and small caves. A diverse range of shrubs are found including Carmichaelia virgata, Carmichaelia crassicaulis with a threat status of declining, leafy coprosma (Coprosma parviflora), mountain korokio/korokio (Corokia cotoneaster), prickly mingimingi/hukihuki (Cyathodes juniperina), turpentine scrub (Dracophyllum uniflorum) with a threat status of naturally uncommon, bush snowberry/koropuka (Gaultheria antipoda), poataniwha (Melicope simplex), porcupine shrub (Melicytus alpinus), small-leaved pohuehue/pōhuehue (Muehlenbeckia complexa) and weeping matipo (Myrsine divaricata).
  
  
• This area is of interest to the Department of Conservation as it is habitat to 7 lizard species. ⁴⁷
  
  
• Gratiola concinna has a threat status of nationally vulnerable and is in gradual decline. ⁴⁸