Newhaven Sanctuary - Ecosystems / Plants
Newhaven Sanctuary
Newhaven Sanctuary sits on the eastern edge of the Great Sandy Desert Bioregion and contains elements of two other bioregions; MacDonnell Ranges and Burt Plain.
The property contains a diverse range of habitats and is considerably rich in plant species. A total of 631 plant species have been identified. Of these, 51 species of conservation significance were recorded to occur at Newhaven, including 3 that are considered rare from a national perspective and 15 that are classified as rare in the Northern Territory. Four species were classified as data deficient at a national level and 33 are poorly known and potentially rare within the Northern Territory.
Vegetation mapping has identified 23 broad plant communities on Newhaven ranging from communities associated with salt lakes, gypsum lakes and calcrete plains on the lower parts of the property to the Holly Grevillea and Ghost Gum communities on the quartzite ridges. Between these altitudinal extremes, a range of communities are distributed according to soil type (and therefore moisture availability) and fire history. Spinifex is a significant component in the understory of many of these communities.
Spinifex (Triodia spp) will burn fiercely and some species produce copious resins which encourages fire. Some Spinifex species can re-establish quickly after fire; where fire is frequent and or severe spinifex will replace fire sensitive communities. Spinifex which has itself escaped fire for many years, called old-growth Spinifex is an important habitat for a number of small mammals including the Desert Mouse (Pseudomys desertor), birds and reptiles which shelter beneath or within its spiky leaves. The distribution of spinifex in the landscape, and the time elapsed since each of its communities has been burnt, is an important determinant of the populations of many desert vertebrates.
All ecosystems/plants
Waterbodies
Waterbodies occupy 5.6% of Newhaven, and the lowest regions of support salt lakes. These lakes only hold water for any length of time after substantial rains. It is the smaller claypans, freshwater lakes and seasonal swamps that are most important for biodiversity. These smaller waterbodies generally occur in the upper saline areas and within the saltbush and calcrete communities. The understory vegetation of these wetlands varies considerably, depending on soil type, salinity and previous grazing and fire history. Most claypans are bare with vegetation such as Mulga being restricted to the fringes. Small freshwater lakes are fringed by Inland Teatree (Melaleuca glomerata) and as their beds dry they are colonised by sedges and herbs such as Nardoo (Marselia exerata). Semi-saline lakes usually support salt tolerant species such as samphire and Frankenia spp.
Open Saltbush Flats
This community is scattered over 5.6% of the reserve, mainly in the western half, and is characterised by scattered low shrubs of Bladder Saltbush (Atriplex vesicaria) and Reurrection Sedge (Fimbristylis dichotoma).
Semi-saline Spinifex plains
These grassy plains with scattered bushes occupy 13.2% of the reserve. This widespread community occurs on gently undulating sandy plains. Soft Spinifex (Triodia pungens) dominates the grass layer, while Needlebush (Hakea leucoptera), Inland Teatree (Melaleuca glomerata), Umbrella Bush (Acacia ligulata) and Beefwood (Grevillia striata) are common in the overstorey. This vegetation community is the preferred habitat for two nationally vulnerable species - the Great Desert Skink and the Brush-tailed Mulgara.
Watercourses
Some of the most species diverse communities on Newhaven occur along the banks of the dry watercourses, forming less than 1% of the area of the reserve. The Bean Tree (Erythrina vespertillio) is a common overstorey species in this community, and is easily damaged by feral camels which strip the lower branches for food.
Bloodwood sandplains
Covering 6% of Newhaven, this community is dominated by Bloodwood (Corymbia opaca) with an understory of Hard Spinifex (Triodia basedowi). Ghost Gum (Corymbia apperrerinja) replaces the Bloodwood in this community if fire is severe.
Blue Mallee sandplains
Blue Mallee (Eucalyptus gamophylla) is found over most sandy areas of Newhaven, but over about 15.9% of the reserve it is the dominant tree. A number of different Spinifex species form the understorey in different places.
Mixed Acacia sandplains
Up to ten species of Acacia make up this community which occupies 10.1% of Newahaven in areas where Mulga or Bloodwood communities have been affected by past fires.
Feathertop Spinifex sandy slopes
Feathertop Spinifex (Triodia shinzii) forms the dominant understory of this community which occupies gently sloping sandplains. Dogwood (Acacia coriacea) and Honey Grevillea (Grevillea eriostachya) are among the plants of the overstorey.
Feathertop Spinifex dunefields
7.1% of the Newhaven is covered by this vegetation type which has an understory of Feathertop Spinifex (Triodia shinzii) and Sandhill Bloodwood (Corymbia chippendalei) in the overstory.
Desert Oak dunefields
Desert Oak (Allocasuarina decasniana) is found on dunes and sandplains over 6% of Newhaven. Spinifex always forms the understory except immediately under the Desert Oak trees.
Mulga dunefields
This vegetation community is restricted to the south of Newhaven, covering 2.7% of the reserve. Mulga (Acacia anuera) is the principal canopy species with Native Fuchsia (Eremophila latrobei) dominating the shrub layer.
Blue Mallee dunefields
Blue Mallee (Eucalyptus gamophylla) is a minor component of the lower slopes of most dune communities on Newhaven, but in places becomes the dominant plant.
Lake edge dunes
The low dunes fringing salt lakes near the centre of Newhaven support a simple community of Soft Spinifex (Triodia pungens) and Umbrella Bush (Acacia ligulata).
Gypsum lakes
Covering 1.6% of Newhaven, this community occurs east of Lake Bennett and is dominated by Weeping Mulga (Acacia paraneura) or Ironwood (Acacia estrophiolata) in the overstorey.
Grassy calcrete plains
These grassy plains occur across 9.4% of Newhaven, and their species composition varies widely. The communities can include Mulga (Acacia aneura), Bluebush (Maireana triptera) and Witchetty bush (Acacia kempeana). Native Oatgrass (Enneapogon evanaceus) is the common grass.
Spinifex calcrete plains
This community replaces the grassy calcrete plains community after repeated hot fires. Shrubs are fewer and the grass layer is dominated by Soft Spinifex (Triodia pungens) or Hillside Spinifex (Triodia brizoides).
Mulga woodland
3.7% of Newhaven is occupied by communities dominated by a number of varieties of Mulga. They mostly occupy the non-hilly country and can merge with other sand plain communities.
Grassy open woodland
Black Gidgee (Acacia pruinocarpa), Mulga and Silver Witchetty (Acacia cuthbertsonii) dominate the overstorey of this community in the south west, with a grass layer occupied by Bunched Kerosene Grass (Aristida contorta), Woolybutt Grass (Eragostris eriopoda) and Woolly Oat Grass (Enneopogon polyphyllus). In the Mt Gurner area, Witchetty Bush (Acacia kempeana) dominates the overstorey of this community.
Hill communities
A wide variety of communities occupy the various parts of the quartzite range and granite hill country. Spinifex dominates the areas affected by frequent fires in the past..
Threatened ecosystems/plants
There are no plant communities listed as threatened in the Northern Territory, as the survey process is not yet complete, however seven communities, identified as rare in the Northern Territory, occur on Newhaven. Many of these communities are not resistant to repeated hot fires and their persistence depends on a fire regime that reduces the incidence of this type of fire.
- White Gidgee (Acacia calcicola) populations occur on conglomerate hills north east of Mount Gurner.
- Stands of the Newhaven Mallee (Eucalyptus aff. intertexta) are found on the upper slopes and scree slopes of the Yaripilangu Range.
- Conkerberry (Carissa lanceolata) communities are found on watercourse levee banks south of Yaripilangu Range
- The rare plant Frankenia punctata forms communities on the fringes of Lake Bennett
- Weeping Mulga (Acacia paraneura) is found on some sand plains and in association with salt bush communities
- Dune communities not dominated by Spinifex are uncommon, but dunes with the highest species diversity include stands of Aluta maisonneurii and Acacia ramulosa.
- The Desert Bloodwood (Corymbia deserticola) form hollows important for nesting birds in areas with very infrequent fires. Several stands occur on Newhaven.