Vegetation of the Eden Region, South‐eastern Australia: Species composition, diversity and structure

Abstract

A classification of plant communities and land systems is presented for the Eden region to assist with the resolution of land use and management conflicts. Vegetation and environmental parameters were sampled at 369 sites and analysed with numerical techniques incorporating elements of the Braun-Blanquet approach.Land surfaces in the study area were described by means of a land systems analysis. A total of 41 plant communities, 3 with 2 subcommunities, were defined and described on the basis of floristic composition, structure and environmental variables. Descriptions of communities include information on habitat, structure, floristic composition of various strata, distribution and representation in reserves. The distributions of plant communities are interpreted in relation to characteristics of their land systems.Plant communities were grouped into 5 major floristic series: Rainforest, Moist Eucalypt Forest, Dry Grassy Eucalypt Woodland and Forest, Dry Shrubby Eucalypt Woodland and Forest and Heath and Swamp. These groupings are distinguished by their structure, physiognomic attributes, composition of their canopy and understorey strata and habitat. Plant communities are differentiated along gradients of moisture availability, soil properties and temperature. A hypothesis is proposed to explain floristic and structural variation in relation to interactions between moisture and soil fertility gradients. Where moisture is high, tall shrubby eucalypt forest, mesic eucalypt forest and rainforest are thought to be segregated along a gradient of increasing soil fertility. On drier sites, dry eucalypt communities with grassy understoreys are thought to inhabit more fertile soils than those with shrubby understoreys.The biogeographic relations and broad conservation values of the major floristic groupings are discussed. Vegetation patterns in the region are related to a latitudinal sequence which prevails in eastern Australia. A preliminary assessment of plant community distributions shows that the reserve system is not representative of the

A Forest Simulation Model for Predicting Eucalypt Dynamics and Habitat Quality for Arboreal Marsupials

“…This pattern is consistent with empirical work in the study area (Austin 1978, Fanning and Mills 1989, Austin et al 1990b. Lambert and Turner (1983) showed a close relationship between eucalypt species composition and soil nutrient status, whereas Keith and Sanders (1990) explained the vegetation in terms of soil moisture and soil fertility. Both studies were undertaken in the Eden region.…”

Influence of cattle grazing practices on forest understorey structure in north‐eastern New South Wales

“…The final model did not include geology as the model selection procedure indicated that the fit was better with it excluded. Others have noted that forest communities with grassy understories tend to occur on more fertile soils, and sclerophyll shrub understories predominate in communities © 2006 Ecological Society of Australia on poorer soils (Keith & Sanders 1990;York 1997;Clarke 2003;Keith 2004), although the mechanisms at play are still unclear. Clearly though, it is not possible to state with certainty whether it is time since wildfire or geology, or both, that are causing the observed pattern, and any separate effects could be determined only in a survey designed to distinguish them.…”

“…The understorey structure of forests is influenced by various environmental factors such as geology (Keith & Sanders 1990), elevation (Williams et al 1994), topographic position (Turner & Lambert 1988;Duncan & Brown 1995), aspect (Bale et al 1998), vegetation type (Newsome & Catling 1979), fire frequency and intensity (Gill 1981;Birk & Bridges 1989) and time since fire (Coops & Catling 2000;Catling et al 2001). It is also affected by anthropogenic activities, such as logging (Borg 1989), livestock grazing (Smith et al 1996;Bromham et al 1999) and modified fire regimes (Catling 1991).…”

Eucalypt dieback in eastern Australia: a simple model

“…The usual sequence is that tree crowns become thin, a thick ground litter layer develops, a dense shrub layer develops and bellbirds take control of the site. 'Bellbird dieback' on private land is particularly associated with two 'wet' vegetation types from a 'complex of grassy ecosystems' (Keith and Bedward 1999), previously described as a group of 'dry grassy eucalypt woodlands and forests' (Keith and Sanders 1990). These vegetation types, 'Brogo Wet Vine Forest' and 'Bega Wet Shrub Forest' (see Fig.…”