Territory Stories

Mary River Floodplain Vegetation

Details:

Title

Mary River Floodplain Vegetation

Creator

Lynch, D; Northern Territory. Department of Lands, Planning and Environment. Resource Capability Assessment Branch

Collection

E-Publications; E-Books; PublicationNT; Technical Report No. 08/2015

Date

1996

Location

Mary River

Description

The Mary River Flood Plains are approximately 100km east of Darwin and have a catchment area of about 7700 kn12 (Woodroffe 1993). The headwaters are approximately 18Skm inland. The southeast corner of the catchment includes Coronet Hill and a sandstone/siltstone plateau. Further to the south west in the Pine Creek region are undulating to rolling hills (includes strike ridges) of greywacke, sandstone and siltstone. The west side of the catchment includes undulating to rolling granite rises with some rugged hills. The McKinlay River joins the Mary River just south of the Arnhem Highway. From here the river divides into a series of streams and billabongs which are only connected in the Wet season.

Notes

Please replace the current item on the system with this report. This is the original report, produced in 1996 by the then Department of Lands, Planning and Environment. The report was resubmitted in order that it could be correctly filed with a Technical report number.

Table of contents

Introduction -- Climate -- Vegetation -- Method -- References

Language

English

Subject

Floodplains -- Northern Territory -- Mary River; Vegetation surveys -- Northern Territory -- Mary River Region; Floodplain plants -- Northern Territory -- Mary River Region; Mary River Floodplain Vegetation

Publisher name

Northern Territory Government

Place of publication

Palmerston

Series

Technical Report No. 08/2015

Format

1 volume (no pagings) : illustrations (some col.), maps ; 30 cm.

File type

application/pdf

Use

Attribution International 4.0 (CC BY 4.0)

Copyright owner

Northern Territory Government

License

https://creativecommons.org/licenses/by/4.0/

Parent handle

https://hdl.handle.net/10070/258435

Citation address

https://hdl.handle.net/10070/503313

Page content

Mary River Floodplain Vegetation Introduction: The Mary River Flood Plains are approximately 100km east of Darwin and have a catchment area of about 7700 kn12 (Woodroffe 1993). The headwaters are approximately 18Skm inland. The southeast corner of the catchment includes Coronet Hill and a sandstone/siltstone plateau. Further to the south west in the Pine Creek region are undulating to rolling hills (includes strike ridges) of greywacke, sandstone and siltstone. The west side of the catchment includes undulating to rolling granite rises with some rugged hills. The McKinlay River joins the Mary River just south of the Arnhem Highway. From here the river divides into a series of streams and billabongs which are only connected in the Wet season. The plains may be divided into three morphological provinces which are described and mapped by Woodroffe and Mulrennan (1993) . . 1. The coastal plain is generally at an elevation of 2.0m AHD with extensive lower areas. 2. The paleoestuarine plain begins at the transect between Alligator Head and Shady Canlp and extends down to Corroboree. The elevation is generally fr0l11 2.S111 AHD to 4.31TI AHD near Black Fella Island, including areas of lower elevation which fOrl11 swamps. 3. Alluvial plain which occurs upstream fronl the paleoestuarine plain. The main soils of the flood plains are Aquic Vertosols (Isbell 1996). These soils where previously classified as grey, brown and black cracking clays. These soils are poorly drained, with heavy clay textures and hard setting surfaces. They also exhibit extreITIe cracking when dry (FeU et al 1983). Also present are polygenetic soils found in floodout areas on the upper plains. Along the seaward edge of the coastal plain are tidal tlats of saline mud and relic sand dunes. The vegetation fringing the floodplain includes Melaleuca, Acacia auricliliformis, and Pandallus. On the adjacent upland are Eucalyptlls milliata, E. tetradollta open forest or woodlands, with SorghuJIl grassland understory. Towards the south the woodland nlerges with E. tectifica, E. latifolia woodland with Sorghum grassland and, Melalellca and E. papualla occurring in depressions and along drainage lines. For more detailed descriptions of these cOInmunities refer to "Vegetation Survey of the Northern Territory' Wilson et al (1990a), nlapping units 4 and IS. The 1100dplain is a complex of grasslands, sedgelands and Melalellca forests which are subject to some period of inundation during each year. Clilnate: The rainfall and temperature averages from weather stations nearest to Mary River plain are listed in Tables 1 and 2. The range in maxinlum tel11perature is 4.S degrees Celsius, and 9 c in the minimulll temperatures. The coolest average temperature being in June, IS c and the hottest is in October, 3S. 9 IIC.