His research focuses on the effects of disturbance regimes and methods for managing and restoring endangered grassy ecosystems. Ian Cole is an Ecologist in theSummary Temperate grassy ecosystems are amongst Australia's most endangered ecosystems. Most remnants are small, fragmented and highly degraded. Practical methods for restoring native understorey species are urgently required. Dominant native grasses such as Kangaroo Grass ( Themeda triandra Forssk.) and Tussock-grasses ( Poa species) have been eliminated from many remnants by heavy grazing in the past. The reintroduction of these grasses is a critical step for understorey restoration. This paper (i) reviews the literature on Themeda seed biology and seedling establishment; (ii) summarizes the lessons learnt from three major attempts to establish Themeda stands in south-east Australia; and (iii) identifies the research needed to enhance Themeda restoration. Considerable information is available on Themeda seed and establishment biology, and restoration exercises have shown that Themeda stands can be readily established by surface-spreading awned seeds in seed-bearing hay. However, many practical challenges remain, including the need to identify optimal sowing periods, create better seedbed conditions, develop practical mulching techniques, and improve weed control. The use of seed-bearing hay has constrained restoration to relatively small areas in the past. Future trials may benefit by using more concentrated seed products such as seedbearing florets and pure seeds which permit larger areas to be restored at one time.

Control of exotic annuals is often a priority when restoring degraded grasslands or shrublands. This study evaluated combinations of nutrient-depleting (carbon addition) and seed bank-depleting approaches for controlling exotic annuals, and compared the seed bank depletion technique of spring burning with the more easily applied technique of pulse grazing. Treatments were applied in two Box Gum woodlands over 4 years. Consistent with earlier studies, carbon addition dramatically reduced exotic annuals and available nutrients in all 3 years at both sites. Exotic annual grass abundance was significantly reduced in burnt plots following the first year and in grazed plots following the second year of application. Spring burning or grazing did not reduce available nutrients or exotic annual broadleaf abundance at either site. The effect of carbon addition on exotic annuals and available nutrients was so powerful that no additional benefit of the combination treatments was found, although at one site burning and grazing slightly reduced the effectiveness of carbon addition in suppressing broadleaf exotic annuals. We conclude that nutrient-depleting approaches are most effective because they control both exotic annual grasses and broadleaf exotics annuals, but given their expense seed bank-depleting approaches may be more practical where exotic annual grasses dominate. In particular, pulse grazing is readily applied across large areas, offering a relatively simple tool that if appropriately implemented could enhance outcomes of restoration investments in vegetation communities invaded by exotic annual grasses.

Cultivars of Australian native grasses released in the 1990s are potentially useful for improving the composition of degraded pastures, roadside revegetation and sowing in low-care amenity situations. Over 20 selections or cultivars have been identified and progressed to the stage of commercial seed increase. This review focuses on the challenge of producing high-yielding seed crops for this range of promising Australian native grasses with the aim of fostering commercial-scale seed production operations. Commercialisation of the current suite of native grass cultivars has been difficult, which is often the case for new herbage species. There are a variety of reasons for this including: (i) that experience gained in breeder’s nurseries was not directly transferable to commercial seed growers; (ii) that knowledge of the biology of many species was incomplete; (iii) a lack of basic management information for these new species; and (iv) failure to rigorously apply what is known about the seed increase of new species. Success of new cultivars as seed crops depends on addressing seed production issues as part of the overall cultivar development program, and on breeders maintaining close links with innovative commercial seed growers until the major seed production barriers are overcome and commercial seed becomes available.

This paper presents a case for the selection and development of a wider range of perennial grasses for pastoral use in the higher rainfall (annual rainfall >500 mm) zone of southern Australia, especially the southern sector of the Murray–Darling Basin. There is also a need to reconsider the use of ‘high-input’ pastures on hill lands by developing more appropriate recommendations for managing existing native grass pastures productively. Past experiments which compared native grass based pastures with sown pastures promoted the view that indigenous grasses were inferior in most respects to exotic improved species. Even though many of the findings were confounded with fertiliser, stocking rate, and other treatment effects, they reinforced the general direction of cultivar development programs which in the temperate zone have been based mainly on the 4 exotic C3 species Phalaris aquatica L., Dactylis glomerata L., Lolium L. spp., and Festuca elatior var. arundinacea (Schreb.) Hackel (syn. Festuca arundinacea Schreb). This has led to an imbalance in the adaptability and range of species available to be sown in pastures, particularly for sowing on less productive landscapes where stony, shallow, infertile, acid soils limit the persistence of current cultivars. The pre-European vegetation of temperate Australia comprised species with a capacity for active growth and transpiration during summer. The water use pattern resulted in soil moisture being near capacity in late winter and spring, and exhausted by summer’s end. Replacement of this vegetation with annual-growing and summer-dormant C3 species has changed the water use pattern so that soils are drier in spring and wetter in autumn. This has reduced the pre-winter soil moisture deficit, which in turn has increased rates of deep drainage in winter. Land degradation in southern Australia is a consequence of this changed water use pattern. Deep drainage of water beyond the reach of plant roots has mobilised salts stored in the landscape and caused watertables to rise, which has led to large areas becoming saline. Lack of growth in summer in pastures consisting of senescent annual-growing species and dormant C3 perennial grasses limits utilisation of the products of nitrogen mineralisation, which allows nitrate nitrogen to accumulate in summer and be readily leached by rainfall in autumn. This increases rates of soil acidification. Although there may be scope to reduce deep drainage by increasing pasture growth in spring in areas where there is little likelihood of summer rainfall, this is not the case in south-eastern Australia where significant falls of rain occur during summer and autumn.

Thirty perennial grass accessions were evaluated for emergence, growth and persistence at 6 severely salinised seepage scalds on the western slopes of New South Wales. Warm-season accessions were sown or planted in spring 1996 and 1997, and cool-season types in autumn 1996 and 1997. Control species, tall wheat grass (Thinopyrum ponticum) and puccinellia (Puccinellia ciliata) were sown in spring and autumn. Plants were monitored over 2 growing seasons. None of the accessions, including the controls, performed well at all sites. Of the accessions established from seed, tall wheat grass was the most reliable in terms of the number of successful establishments but its growth potential was only achieved at a few sites. Some warm-season species (Panicum coloratum, Chloris gayana and Cynodon dactylon) approached their growth potential at some sites but overall rates of establishment were very low. The performance of puccinellia appeared to be adversely affected by low pH. It was concluded that on severely scalded sites, vegetative propagation of stoloniferous–rhizomatous plants, e.g. Pennisetum clandestinum, Paspalum vaginatum and C. gayana, may be the best option.