Science
- Evolutionary ecology research
- Australian rain forest community assembly
- Australian rain forest through time
- Ecology of Cumberland Plain Woodland
- Bicentenary Plant Diversity Program
- Biodiversity Adaptation Transect
- Botany of Botany Bay
- Conservation genetics
- DNA studies of Elaeocarpaceae
- Ecology of Isopogon prostratus
- Floristic Lists of NSW
- Habitat fragmentation
- Lomatia (Proteaceae)
- Molecular phylogeny of the Australian Lauraceae
- Promiscuous Lomatia
- Promiscuous Proteaceae
- Native plants of Sydney Harbour NP
- Newnes Plateau Shrub Swamps
- Next Generation Sequencing
- Nickel hyperaccumulation in Stackhousia
- NSW Vegetation Classification & Assessment Project
- Plants of the Newnes Plateau
- Plants, vegetation, landscape, country
- Phylogenetic relationships of Ceratopetalum
- Podocarpus elatus
- Rainforest conifer - Podocarpus elatus
- Speciation in Proteaceae
- Testing speciation models
- Horticultural research
- Plant diversity research
- Plant pathology research
- Herbarium & resources
- Scientific publications
Plant interactions - between native and exotic plantsOf the 200 or so plant species in the woodland, about 35% are naturalised exotic species. Our conservation management aim is to improve conditions for the native species component of the woodland over the long-term. Detrimental impacts by exotic species on native species are to be reduced, and ideally all exotic species should be eradicated. However it is unrealistic to expect that all exotics can be removed, and priority should be given to those which clearly impact on the long-term viability of native species. The most threatening exotic species are large perennials that outcompete natives by shading e.g. the shrub African Olive *Olea europaea subsp. cuspidata, or vigorous growth e.g. Chilean Needle Grass *Nasella neesiana, St Johns Wort *Hypericum perforatum and Heliotrope *Heliotropium amplexicaule. These, like most native species, can survive fire and drought particularly well. These threatening species however, make up only a small proportion of the total exotic flora. A greater proportion of the exotic species are short-lived species (see Lifespans), that are able to respond and grow in changed environmental conditions by way of soil-stored seedbanks or wind-dispersed seeds from adjacent sites. In contrast a greater proportion of the native species have relatively stable long-lived above-ground populations. Following the cessation of grazing and mowing in 1988 the majority of exotic species have generally decreased in abundance in the woodland. For example, comparing numbers of species present in 1988 and 15 years later (2003) at five undisturbed sites (Table ), we found that:
Table: Number and percentage of species showing changes in frequency (increased, stable or decreased) after 15 years in the 10 ha Conservation Research Woodland , the Australian Botanic Garden
Asterisk * indicates exotic species naturalised at the Australian Botanic Garden. |
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