The methods available for the determination of the botanical composition of grasslands are reviewed with reference to a range of objectives for which such a study may be carried out. Studies at the global, national/regional, farm, paddock and patch scale are discussed. While it is possible using GIS to scale up from detailed studies, it is not yet possible to scale down from global to detailed studies. Sampling strategies and sampling methods are described, including the determination of quadrat size. The use of transects and point quadrats is also discussed. Sections are provided on the properties of grassland vegetation, patterns, diversity and species richness, ground cover, plant density, presence/absence data, and the analysis of seed banks.

Three major pasture types probably occurred on the Northern Tablelands prior to European settlement. The dominants were probably Poa sieberana Spreng. and Themeda australis (R.Br.1 Stapf. at the higher elevations, T. australis, P. Sieberana and Sorghum leiocladum (Hack.) C.E. Hubbard on fine textured soils at lower elevations and T. australis, Aristida ramosa (R.Br.) and Cymbopogon refractus (R.Br.1 A. Camus. on coarse textured soils. The subsidiary species composition of these pasture types is also suggested, derived from fragmentary early accounts, earlier published work and observations on the behaviour under grazing of the different species involved. The characteristics of the important native and naturalised grass species are described. These species are classified into warm season perennials, warm season annuals, cool season perennials and cool season annuals. The native warm season perennials is the largest group of species at present on the Tablelands. The effects of grazing on the species composition of natural pastures is described. The grazing behaviour of merino sheep leads to a striking zonation of herbaceous species resulting from uneven grazing intensity and distribution of dung and urine. Data from an unreplicated stocking rate by superphosphate application rate trial at Shannon Vale are presented. This trial indicated that the proportion of white clover in the pasture depended on both stocking rate and superphosphate rate and that the proportion of Danthonia spp. increased when white clover decreased. Wool production data are also presented which show that high levels of pro- ductivity per hectare can be obtained from topdressed natural pastures. A number of different natural pasture types occur on the Tablelands. A schemeis presented showing the interrelationship$ between the original and the present pasture types as affected by grazing intensity and the addition or depletion of plant nutrients.

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Interest in native grasses is increasing in the US, Australia, Canada, and worldwide. We propose a model that can be used as a step-by-step guide for plant breeders, ecologists, seed producers, and others interested in developing expanded uses for native grasses. The following steps, with relevant examples from North America and Australia, are described in detail: 1) determine the need; 2) choose an appropriate species; 3) determine breeding system; 4) assess geographic and ecological range; 5) make a collection; 6) assess genetic diversity; 7) determine limitations of species; 8) develop appropriate breeding methods; 9) determine proper release strategy; 10) develop seed conditioning and establishment techniques; 11) develop management techniques; and 12) market development.

Summary. Four experiments were conducted to determine the effects of temperature, light and leaf extract solutions on the germination of Giant Parramatta grass [GPG, Sporobolus indicus (L.) R. Br. var. major (Buse) Baaijens] collected from a population on the North Coast of New South Wales. In the first experiment, seeds were subjected to one of a range of temperature combinations immediately after collection and again after 8 and 27 weeks. Germination was restricted to a narrow range of alternating temperatures with a peak at 35°C day/15°C night when seeds were tested immediately after collection. More seeds germinated when the samples had been stored, although germination remained depressed at constant temperatures. These data indicate that freshly collected GPG seeds are subject to primary dormancy and that few would germinate in the field immediately after seed fall. In a second experiment, seeds were buried beneath leaf litter in a pasture immediately after collection. After 7 months, the seeds were exhumed and subjected to either constant (20°C) or alternating (35/15°C) temperatures in either full light, reduced red:far-red (R : FR) light or dark treatments. Over 95% of GPG seeds germinated when subjected to alternating temperatures, regardless of light treatment. At constant temperatures, 97% of seeds germinated under full light, 59% at reduced R : FR light and <1% in dark treatments. A germination response to alternating temperatures and/or light treatments has been reported in pasture weeds and may be an adaptation to detecting gaps in the pasture canopy. Consequently, the germination of GPG in a pasture may be manipulated to some extent by altering the amount of pasture cover using grazing management, mowing and fertiliser applications. In experiment 3, leaves from a range of coastal grasses were mixed with water and the solutions were used to germinate GPG seeds. Solutions extracted from setaria (Setaria sphacelata) leaves completely inhibited GPG germination while 27% of GPG seeds germinated when imbibed with kikuyu leaf extract solution. Solution extracted from carpet grass (Axonopus affinis) leaves had the least effect on GPG germination. In experiment 4, the effects of solutions that had been leached from the leaves of either setaria or carpet grass on seed germination, and root and shoot lengths of GPG seedlings were compared. Germination was less inhibited by leachate solutions compared with the extract solutions used in experiment 3. Seedlings in setaria leachates had significantly shorter roots and shoots than both those germinated in carpet grass leachates and control seedlings. This may explain, at least in part, why carpet-grass-based pastures are readily infested with GPG while setaria-based pastures are relatively resistant to infestation. The potential for allelopathic interactions between GPG and setaria to be fully utilised to reduce the abundance of GPG in coastal New South Wales pastures is discussed.