Cumberland Plain Woodland is different – the species richness is in the ground layer. This is in strong contrast to Hawkesbury Sandstone vegetation where the shrub diversity is very high. In Cumberland Plain Woodland, shrubs are not usually an identification problem as only one species, Bursaria spinosa, tends to dominate. Its dense localised thickets and its thorny branches provide shelter for small birds and animals, as well as protecting ground plants from grazing.
There are however two problem plant groups that are often important components of Cumberland Plain Woodland - exotic species and grasses.
Exotic species may give the appearance that they are predominating, either by their bulk or vigour, such as *Paspalum dilatatum or *Sida rhombifolia, or by their conspicuous and often pretty, flowers e.g. *Senecio madagascariensis, *Heliotropium amplexicaule, *Verbena rigida. This may give the impression that the woodland is not being looked after properly. However given the past disturbances that most sites have had, it is probably impossible to have exotic-free Cumberland Plain Woodland. What is important is to look past the weeds to the many, generally small, native species that will be there, and to work toward increasing their local populations. Certainly the major threatening weeds should be controlled, but many of the other exotics are a legacy of the rural management of sites and will gradually disappear as the longer-lived natives gradually spread.
Grass species are the main groundcover in most remnant sites and many species are difficult to identify when flowering, and impossible when they are not. This causes problems when a visitor asks 'What grass is that?' The times when they are likely to be flowering are often difficult to predict. That some are weeds and some are native adds to the problems.
Our long-term aim is to retain all native biodiversity
Our long-term aim in managing the Cumberland Plain Woodland remnants at the Australian Botanic Garden is to ensure that populations of all native plant species recorded in the woodland, as well as all the other components of natural biodiversity, such as the invertebrates, are maintained over the long-term. While plant and animal population numbers will fluctuate with seasons, and over dry and wet periods, and growth of saplings into canopy trees will alter the woodland structure in some areas, we hope that that visitors to the woodland in 2020, or 2070 will be able to experience the same breadth of woodland variety as we can now.
Our management program involves removal or control of exotic species, and maintenance of native species through bush regeneration. The scientific monitoring program, and other ecological studies provide input by highlighting potential problems, or suggesting actions that may benefit some species.
Parts of the woodland have been subject to ecological burns, though no areas will be burnt more frequently than at 10 year intervals (except for cases of localised trials or if found to be necessary to create particular habitat conditions), and some areas will be kept unburnt.
Asterisk * indicates exotic species naturalised at the Australian Botanic Garden.