Australian Journal of Botany Australian Journal of Botany Society
Southern hemisphere botanical ecosystems

Correlations between environmental factors, the biomass of exotic annual grasses and the frequency of native perennial grasses

Tanja I. Lenz A and José M. Facelli A B
+ Author Affiliations
- Author Affiliations

A Environmental Biology, School of Earth & Environmental Sciences, University of Adelaide, SA 5005, Australia.

B Corresponding author. Email:

Australian Journal of Botany 54(7) 655-667
Submitted: 9 May 2005  Accepted: 8 May 2006   Published: 19 October 2006


The species composition of temperate grasslands in the mid-north of South Australia has been radically altered from a system dominated by native perennial grasses to a system dominated by Mediterranean annual grasses. This study investigated the importance of chemical and physical soil characteristics, topographical features and climatic variables on the abundance of native and exotic grass species in nine ungrazed grasslands. Overall, climatic and other abiotic factors were highly variable. In addition, past management practices and original species composition are generally unknown, leading to further unexplained variation in the data. On a large spatial scale (among sites), the abundance of exotic annual grasses was positively correlated with mean annual rainfall, and on any scale, with finer soil textures and higher soil organic carbon levels. The most abundant annual grass, Avena barbata (Pott ex Link), was generally associated with soil factors denoting higher soil fertility. The abundance of native perennial grass species was not correlated with any environmental variables at any scale. The various native perennial grass species did not show clear associations with soil factors, although they tended to be associated with factors denoting lower soil fertility. However, at small spatial scales (within some sites) and among sites, the abundances of exotic annual and native perennial grasses were strongly negatively correlated. The results suggest that at the present time, rainfall and soil properties are important variables determining the abundance of annual grasses. The driving variables for the abundance of perennial grasses are less clear. They may be controlled by other factors or extreme rainfall events, which were not surveyed. In addition, they are likely to be controlled by competitive interactions with the annual grasses.


We thank T. Cammell, S. Gehrig and J. Prider for fieldwork assistance, M. Nicholls for assistance with study site identification, and G. Hastwell, J. Nicol, C. Rivers and A. Renfrey for assistance with laboratory work. The Burra Community School, R. & H. Bruce, F. & M. Nicholls, A. Michael and J. Trengrove; the Goyder Council; M. & B. Dare; the Northern Areas Council, R. Arthur and I. Falkenberg (NPWS) donated time, access to field sites and records. D. S. Whiting and J. Wurst supplied additional rainfall records. T. Cammell provided valuable comments on earlier drafts of this manuscript. The project was partly supported by the Native Vegetation Council and the National Heritage Trust.


Allison L (1965) Organic carbon. In ‘Methods of soil analysis. Part 2. Chemical and microbiological properties’. (Eds DD Evans, LE Ensminger, FE Clark, J White) pp. 1367–1378. (American Society of Agronomy: Madison, WI)

Austin AT, Sala OE (2002) Carbon and nitrogen dynamics across a natural precipitation gradient in Patagonia, Argentina. Journal of Vegetation Science 13, 351–360.
CrossRef |

Ayyad MAG, Dix RL (1964) An analysis of a vegetation–microenvironmental complex on prairie slopes in Saskatchewan. Ecological Monographs 34, 421–442.
CrossRef |

Bartolome JW, Stroud MC, Heady HF (1980) Influence of natural mulch on forage production on differing California range sites. Journal of Range Management 33, 4–8.

Burke IC, Lauenroth WK, Vinton MA, Hook PB, Kelly RH, Epstein HE, Aguiar MR, Robles MD, Aguilera MO, Murphy KL, Gill RA (1998) Plant-soil interactions in temperate grasslands. Biogeochemistry 42, 121–143.
CrossRef |

Claassen VP, Marler MJ (1998) Annual and perennial grass growth on nitrogen-depleted decomposed granite. Restoration Ecology 6, 175–180.
CrossRef |

Clarke KR , Warwick RM (1994) ‘Change in marine communities: an approach to statistical analysis and interpretation.’ (Plymouth Marine Laboratory: Plymouth, UK)

Day PR (1965) Particle fractionation and particle size analysis. In ‘Methods of soil analysis’. (Ed. CA Black) pp. 545–567. (Soil Science Society of America: Madison, WI)

Dowling PM, Garden DL, Eddy DA, Pickering DI (1996) Effect of soil pH on the distribution of Danthonia species on the tablelands of central and southern New South Wales. New Zealand Journal of Agricultural Research 39, 619–621.

Dyer AR, Rice KJ (1999) Effects of competition on resource availability and growth of a California bunchgrass. Ecology 80, 2697–2710.
CrossRef |

Ernst WHO, Tolsma DJ (1992) Growth of annual and perennial grasses in a savanna of Botswana under experimental conditions. Flora 186, 287–300.

Feral CJW, Epstein HE, Otter L, Aranibar JN, Shugart HH, Macko SA, Ramontsho J (2003) Carbon and nitrogen in the soil-plant system along rainfall and land-use gradients in southern Africa. Journal of Arid Environments 54, 327–343.
CrossRef |

Garden DL, Dowling PM, Eddy DA, Nicol HI (2001) The influence of climate, soil, and management on the composition of native grass pastures on the central, southern, and Monaro tablelands of New South Wales. Australian Journal of Agricultural Research 52, 925–936.
CrossRef |

Groves RH, Austin MP, Kaye PE (2003) Competition between Australian native and introduced grasses along a nutrient gradient. Austral Ecology 28, 491–498.
CrossRef |

Hamilton JG, Holzapfel C, Mahall BE (1999) Coexistence and interference between a native perennial grass and non-native annual grasses in California. Oecologia 121, 518–526.
CrossRef |

Harris GA (1967) Some competitive relationships between Agropyron spicatum and Bromus tectorum.  Ecological Monographs 37, 89–110.
CrossRef |

Heady HF , Bartolome JW , Pitt MD , Savelle GD , Stroud MC (1992) California prairie. In ‘Natural grasslands: introduction and western hemisphere’. (Ed. RT Coupland) pp. 313–335. (Elsevier: Amsterdam)

Hobbs RJ, Mooney HA (1991) Effects of rainfall variability and gopher disturbance on serpentine annual grassland dynamics. Ecology 72, 59–68.
CrossRef |

Hook PB, Burke IC, Lauenroth WK (1991) Heterogeneity of soil and plant nitrogen and carbon associated with individual plants and openings in North American shortgrass steppe. Plant and Soil 138, 247–256.
CrossRef |

Huenneke LF (1989) Distribution and regional patterns of California grasslands. In ‘Grassland structure and function: California annual grassland’. (Eds LF Huenneke, HA Mooney) pp. 1–12. (Kluwer Academic Publishers: Dordrecht, The Netherlands)

Huenneke LF, Hamburg SP, Koide RT, Mooney HA, Vitousek PM (1990) Effects of soil resources on plant invasion and community structure in Californian (USA) serpentine grassland. Ecology 71, 478–491.
CrossRef |

Hyde MK (1995) ‘The temperate grasslands of South Australia: their composition and conservation status.’ (World Wide Fund for Nature Australia: Sydney)

Hyde MK , Davies R , Steed Y , Reynolds T (2000) Mokota Conservation Park, Burra Hills, South Australia: a baseline biodiversity study. Nature Conservation Society of South Australia, Threatened Plant Action Group, Adelaide.

Jackson LE (1985) Ecological origins of California’s Mediterranean grasses. Journal of Biogeography 12, 349–361.
CrossRef |

Jacobs SWL, Everett J (1996) Austrostipa, a new genus, and new names for Australasian species formerly included in Stipa (Gramineae). Telopea 6, 579–595.

Jaramillo VJ, Detling JK (1992) Small-scale heterogeneity in semi-arid North American grassland: II. Cattle grazing of simulated urine patches. Journal of Applied Ecology 29, 9–13.
CrossRef |

Jessop JP , Toelken HR (Eds) (1986) ‘Flora of South Australia.’ (South Australian Government: Adelaide)

Kemp DR, Dowling PM (1991) Species distribution within improved pastures over central New South Wales (Australia) in relation to rainfall and altitude. Australian Journal of Agricultural Research 42, 647–660.
CrossRef |

Kolb A, Alpert P, Enters D, Holzapfel C (2002) Patterns of invasion within a grassland community. Journal of Ecology 90, 871–881.
CrossRef |

Lauenroth WK, Dodd JL (1978) The effects of water and nitrogen-induced stresses on plant community structure in a semiarid grassland. Oecologia 36, 211–222.
CrossRef |

Lenz TI, Facelli JM (2005) The role of seed limitation and resource availability in the recruitment of native perennial grasses and exotics in a South Australian grassland. Austral Ecology 30, 684–694.
CrossRef |

Lenz TI, Moyle-Croft JL, Facelli JM (2003) Direct and indirect effects of exotic annual grasses on species composition of a South Australian grassland. Austral Ecology 28, 23–32.
CrossRef |

Linder HP (1997) Nomenclatural corrections in the Rytidosperma complex (Danthonieae, Poaceae). Telopea 7, 269–274.

Lunt ID , Barlow T , Ross J (1998) ‘Plains Wandering: exploring the grassy plains of south-eastern Australia.’ (Victorian National Parks Association and the Trust for Nature (Victoria): Melbourne)

Mack RN (1989) Temperate grasslands vulnerable to plant invasions: characteristics and consequences. In ‘Biological invasions: a global perspective’. (Eds JA Drake, HA Mooney, F Di Castri, RH Groves, FJ Kruger, M Rejmánek, M Williamson) pp. 155–179. (John Wiley and Sons: New York)

Marschner H (1995) ‘Mineral nutrition of higher plants.’ (Academic Press: London)

McCune B , Grace JB (2002) ‘Analysis of ecological communities.’ (MjM Software Design: Gleneden Beach, OR)

McCune B, Keon D (2002) Equations for potential annual direct incident radiation and heat load. Journal of Vegetation Science 13, 603–606.
CrossRef |

McCune B , Mefford MJ (1999) ‘PC-ORD.’ (MjM Software: Gleneden Beach, OR)

McIntosh PD, Allen RB (1998) Effect of exclosure on soils, biomass, plant nutrients, and vegetation, on unfertilised steeplands, Upper Waitaki District, South Island, New Zealand. New Zealand Journal of Ecology 22, 209–217.

Morgan JW (1998) Patterns of invasion of an urban remnant of a species-rich grassland in southeastern Australia by non-native plant species. Journal of Vegetation Science 9, 181–190.
CrossRef |

Morrow LA, Stahlman PW (1984) The history and distribution of downy brome (Bromus tectorum) in North America. Weed Science 32, 2–6.

Muller B, Garnier E (1990) Components of relative growth rate and sensitivity to nitrogen availability in annual and perennial species of Bromus.  Oecologia 84, 513–518.

Northcote KH (1960) ‘Atlas of Australian soils: sheet 1: Port Augusta—Adelaide–Hamilton area.’ (CSIRO, in association with Melbourne University Press: Canberra)

Paschke MW, McLendon T, Redente EF (2000) Nitrogen availability and old-field succession in a shortgrass steppe. Ecosystems 3, 144–158.
CrossRef |

Peco B, Ortega M, Levassor C (1998) Similarity between seed bank and vegetation in Mediterranean grassland: a predictive model. Journal of Vegetation Science 9, 815–828.
CrossRef |

Pettit NE, Ladd PG, Froend RH (1998) Passive clearing of native vegetation: livestock damage to remnant jarrah (Eucalyptus marginata) woodlands in western Australia. Journal of the Royal Society of Western Australia 81, 95–106.

Prober SM, Thiele KR, Lunt ID (2002) Identifying ecological barriers to restoration in temperate grassy woodlands: soil changes associated with different degradation states. Australian Journal of Botany 50, 699–712.
CrossRef |

Rayment GE , Higginson FR (1992) ‘Australian laboratory handbook of soil and water chemical methods.’ (Inkata Press: Melbourne)

Robertson MA (1998) A biological survey of grasslands and grassy woodlands of the Lofty Block Bioregion South Australia 1995–1996. Department of Environment, Heritage and Aboriginal Affairs, Adelaide.

Ross J (1999) Guide to best practice conservation of temperate native grasslands. World Wide Fund for Nature (Australia), Environment Australia.

Scott AW, Whalley RDB (1982) The distribution and abundance of species of Danthonia on the New England tablelands (Australia). Australian Journal of Ecology 7, 239–248.
CrossRef |

Singh JS, Milchunas DG, Lauenroth WK (1998) Soil water dynamics and vegetation patterns in a semiarid grassland. Plant Ecology 134, 77–89.
CrossRef |

Thompson LM , Troeh FR (1973) ‘Soils and soil fertility.’ (McGraw-Hill: New York)

Vinton MA, Burke IC (1995) Interactions between individual plant species and soil nutrient status in shortgrass steppe. Ecology 76, 1116–1133.
CrossRef |

Walsh NG , Entwistle TJ (1994) ‘Flora of Victoria.’ (Inkata Press: Melbourne)

Williams OB (1961) Studies in the ecology of the riverine plain. III. Phenology of a Danthonia caespitosa Gaudich. grassland. Australian Journal of Agricultural Research 12, 247–259.
CrossRef |

Williams OB, Roe R (1975) Management of arid grasslands for sheep: plant demography of six grasses in relation to climate and grazing. Proceedings of the Ecological Society of Australia 9, 143–156.

Rent Article (via Deepdyve) Supplementary MaterialSupplementary Material (228 KB) Export Citation Cited By (5)