Scientific knowledge

The following research projects have been completed under the NSW Salinity Strategy:

LIGULE - Low Input Grasses Useful in Limiting Environments

Native grasses could provide solutions to many of Australia's soil and water problems. Farmers will soon be able to choose from a wide range of native grasses that improve production and help stop land degradation.

LIGULE, or Low Input Grasses Useful in Limiting Environments, is an innovative native grass research project aimed at improving both the productivity and sustainability of less fertile hill lands in southeastern Australia. The project aims to find, develop and release cultivars (varieties of plants produced only under cultivation) of Australian native grasses that have applications in environments where the usual range of introduced pasture species fail, and, which have a role in preventing land and water degradation.

Native grasses and their response to salinity

Grasslands dominate the landscape of southeastern Australia. The spectrum of grasslands includes highly modified and simple communities of annual plants (including crops) to relatively undisturbed and diverse communities of various grass species mixed with trees and shrubs. The proportion of perennial plants, their growth patterns and the way they are managed impact on catchment hydrology and salinity.

The research paper 'Native grasses and salinity' presents an agronomic and catchment perspective of the links between salinity and the productivity and water use characteristics of native grasses.

Native Couch grasses for revegetating severely salinised sites on the inland slopes of NSW

This research paper by W. S. Semple, I. A. Cole and T. B. Koen, was published in The Rangelands Journal 26(1) (2004) and is available from CSIRO Publishing. The paper evaluates the performance of five native grass species planted on two scalded saline sites on the inland slopes of NSW. The grasses were evaluated for survival, vigour, groundcover and biomass. Further research will evaluate their performance under grazing and recreational uses.

Plant based solutions for dryland salinity management

Plant based options for the prevention and management of dryland salinity, particularly within recharge areas, is examined in this research paper. The use of deep-rooted perennial vegetation (trees and pastures) can increase water use within the landscape, helping to control the spread of dryland salinity. However, catchment characteristics can strongly influence the effectiveness of plant based options for controlling salinity, especially in the short term. Plant based options that reduce groundwater recharge are detailed and conditions that maximise their effectiveness described.

The economic benefits and costs of native vegetation management techniques in controlling salinity

This study reviewed case studies and research focussed on the issues of managing native vegetation, the problems of salinity and the relationship between the two. It addressed the economic feasibility of six tree planting configurations to reduce the impacts of salinity, showing the benefits and costs of each over a 30-year time span. The model, which is based on the characteristics of the Murrumbidgee catchment, can be used to assess the monetary net benefits/costs of reducing recharge of a vegetation management proposal. Inputs can be varied so the model can be tailored to different catchments. Even when applied to local groundwater systems, the impact on salinity in terms of land salinised, salt loads and dollars was small. These factors can represent major impediments to the implementation of tree planting and vegetation regeneration.

The effect of increasing salinity on freshwater ecosystems

A joint project between the DIPNR and the Murray Darling Freshwater Research Centre is investigating the relationship between increasing salinity and the structure of biological communities that develop from aquatic plant seeds and zooplankton eggs stored in the sediments of wetlands and rivers.

The preliminary results indicate that salinity above 1500 EC units reduces the diversity and abundance of aquatic plant and invertebrate communities. However, plant and animal communities from different wetlands responded to salinity in different ways and in plants the effects of increasing salinity were more obvious in edge communities than those more frequently flooded. Two journal papers and two fact sheets are available below.

Impacts of salinity on terrestrial biodiversity

A recent study has shown that woodland birds in Central Western NSW rely on the habitat found in bushland remnants. The area, condition and isolation of those remnants are important factors in the survival of bird populations, as is the total amount of habitat remaining in the landscape. Another study is investigating the effects of dryland salinity on the health of woodlands.

Page last updated: 26 February 2011