Rapid assessment techniques are commonly used for measuring vegetation condition at sites. Techniques for measuring site condition need to be quantitative, repeatable, rapid and simple. The key challenge is achieving a balance between simple techniques and adequate discrimination of condition between sites. This study compared a grassland condition index with the existing BioMetric condition index and showed that (i) the grassland index provided a strong measure of the relationship of temperate montane grassland sites with disturbance level, and differentiated condition of sites to a high degree and (ii) the simpler BioMetric index provided a strong measure of the relationship of the grassland sites with disturbance and differentiated their condition to a moderate degree. The choice of index to assess grassland condition should depend on purpose, cost and capacity.

The need for public investment to address loss of biodiversity in agricultural landscapes is well recognised, yet there is little analysis of the likely benefits of land-use change for regional biodiversity or the cost effectiveness of different investment options. We estimated benefits for biodiversity and cost effectiveness of different investment scenarios over 50 years for a farming area in south-eastern Australia. Declines in biodiversity were predicted under status quo land use. Implementing actions in the investment scenarios improved biodiversity status only slightly, compared with status quo land use. Future biodiversity status differed little between biodiversity-focused investment and salinity-focused investment. Biodiversity status equalled or exceeded current status only for investment scenarios with much more extensive revegetation than in catchment targets. Cost effectiveness of biodiversity improvement varied greatly between investment strategies. Biodiversity improvement was more cost effective when investment to meet catchment targets was focused on revegetation for salinity management rather than on high conservation value areas, because of lower opportunity costs for salinity management. With enhanced investment, the cost effectiveness of biodiversity improvement was greater when actions were in high conservation areas. Although improvements in biodiversity were small under the changed farming system scenarios, their cost effectiveness was higher than the other investment scenarios. Regional scale improvements in biodiversity in farming areas will require increased stewardship payments or other economic incentives for landholders.

Agricultural production systems that also provide opportunities to conserve biodiversity will be a crucial component of integrated and sustainable land use in mixed farming landscapes and should be considered and evaluated. Alley farming is an innovative farming system that aims to increase farm profitability while also enhancing environmental outcomes. Alley farming incorporates belts of woody perennial plants such as trees or shrubs, interspersed with alleys of conventionally rotated cropping and livestock grazing land. In the present study, we assessed the impacts on terrestrial biodiversity of alley farming with the native perennial chenopod shrub old man saltbush (Atriplex nummularia Lindl.) in central western New South Wales. Terrestrial biodiversity conservation status was assessed by site surveys conducted in spring 2005, 2006 and 2007 at 15 old man salt bush alley farming sites (OMSB), 15 conventionally managed sites and three native woodland remnants in and around the Condobolin Agricultural Research and Advisory Station in the central western plains of New South Wales. Biodiversity surveys included an assessment of ‘site condition’ – a metric of biodiversity conservation status at the site scale based on measurement of 10 habitat and vegetation condition attributes, compared against benchmark values for the appropriate native ecosystems with relatively little recent anthropogenic modification. Bird surveys were also conducted to assess the diversity and abundance of birds in OMSB, conventional and remnant woodland sites in four functional response groups. Site condition was significantly higher at remnant woodland sites than at conventional farming and OMSB alley farming sites. Remnant woodland sites had greater native overstorey cover and native ground cover of forbs, more trees with hollows, presence of at least some overstorey regeneration and the presence of fallen logs. Site condition was also significantly higher at OMSB sites than at conventional sites and increased significantly across 3 years. By the third year after establishment, OMSB sites had higher native plant species richness and native mid-storey cover than did conventionally farmed sites. These attributes increased markedly over time at the OMSB sites whereas they did not increase at conventional or remnant woodland sites. Native grasses and forbs established under and around the saltbush plants, indicating that OMSB alley plantings can provide habitat for a wide range of native plant species, enhancing biodiversity values of these areas through improved structure and composition. Improved habitat condition at the OMSB sites after 3 years did not lead to a significantly higher diversity or to a higher overall abundance of birds at the OMSB than at conventional sites. Furthermore, diversity and abundance of birds at both OMSB and conventional sites remained significantly below those of remnant woodland sites. Some decliner bird species were observed using OMSB sites, but not conventional sites. Old man saltbush alley farming can provide direct on-site benefits for native biodiversity by improving the structure, function and composition of vegetation at the site or paddock scale. If proposed as a replacement to conventional crop–pasture rotation, OMSB alley farming can enhance biodiversity conservation values, and where production benefits are likely, could play an important role in the integration of production and conservation as a synergistic ‘win–win’ system in mixed farming enterprises.

Reference conditions remain widely used as a benchmark for ecosystem management, but there remains conjecture about the definition of the reference state. Many techniques used to predict reference conditions are difficult to apply operationally because they are resource-intensive, subjective, or applicable for a limited suite of environmental variables or over a narrow range of environmental variation. We defined the reference state as variation in native vegetation exhibiting relatively little evidence of modification by humans since European settlement. Using data from 462 sites supporting native vegetation in a fragmented landscape in south-eastern Australia, we demonstrated a relatively quick and cost-effective way of objectively predicting reference conditions for various surrogates of biodiversity. We predicted reference values for several variables that are used as biodiversity surrogates (i.e., tree densities by diameter class, trees with hollows, tree regeneration, trees with mistletoe, fallen timber, vegetation cover by vertical stratum, litter cover, cryptogam cover and native plant species richness) using generalized additive models (GAMs) fitted with predictors representing measures of human modification since European settlement (exotic plant cover, number of stumps, evidence of firewood collection, evidence of rabbits, evidence of recent grazing by stock, surrounding land use) and measures of environmental variation (floristic composition, mean annual precipitation, mean annual temperature, solar insolation, aspect, slope). Reference values for each response variable were predicted from these models by holding the significant explanatory variables representing modification since European settlement at their minimum observed values, that is, our definition of the reference state. We demonstrated the importance of independently evaluating predictions of this type using generic ecological models and estimates of reference conditions derived from other sources.

We developed a methodology to objectively and transparently assess the impacts on terrestrial biodiversity of proposals to clear native vegetation in New South Wales (NSW), Australia. The methodology was developed to underpin a policy to permit land clearing only where it ‘improves or maintains environmental outcomes’. It was developed in the following steps: (1) operational requirements and resource constraints were defined. (2) Biodiversity surrogates and assessment techniques that matched these requirements and constraints were identified. (3) Sites were assessed locally, but also in the broader landscape, regional and national contexts. (4) Explicit rules and metrics were developed to facilitate transparent and consistent assessments. (5) These rules, metrics and the data that underpinned them were codified into a simple computer software tool. The tool did not permit clearing in vegetation communities or landscapes that were already over-cleared or listed as threatened, unless the vegetation was in ‘low condition’ (unlikely to persist in the long-term). Other native vegetation could be cleared if regional, landscape and site impacts could be offset. In the first year after the assessment methodology was implemented a net area of approximately 187ha of native vegetation was approved for clearing with offsets. Most approvals (68%) were for proposals to clear native vegetation with a low likelihood of persistence under the existing land use (predominantly scattered trees among cultivation) and offset these impacts by improving the condition and likelihood of persistence of native vegetation in comparable ecosystems. Remaining approvals were for clearing relatively small areas (mean=0.6ha) of partially modified native vegetation. Proposals to offset the impacts of clearing substantially intact native vegetation or larger areas of partially modified native vegetation were generally assessed as unlikely to ‘improve or maintain environmental outcomes’.

Dryland salinity is considered a significant and increasing threat to sustainable land management and biodiversity across large parts of temperate Australia. However, there is little information on the extent of this threat to terrestrial ecosystems in south-eastern Australia. This paper provides a quantitative assessment of the extent of dryland salinity in remnant native woody vegetation in the agriculture-dominated landscape of the Boorowa Shire located in the South West Slopes bioregion of south-eastern Australia. The amount and type of native woody vegetation in the Boorowa Shire affected by dryland salinity was assessed by analysing the extent of overlap between the following three spatial data layers: (1) woody vegetation mapping derived from high-resolution satellite imagery, (2) existing vegetation community mapping predicted from field data and expert opinion and (3) existing dryland salinity outbreak mapping derived from air photo interpretation and filed verification. There were more than 6000 patches of salt outbreak in woody vegetation in the Boorowa Shire, 383 (6%) of which were 1 ha or larger in area. Almost 2000 ha of woody vegetation were affected by dryland salinity, representing ~3% of the extant native woody vegetation in the Boorowa Shire. The vegetation type with the largest total area affected by dryland salinity was yellow box (Eucalyptus melliodora Cunn. Ex Schauer)–Blakely’s red gum (E. Blakelyi Maiden) woodland. As a proportion of their current extent, vegetation communities lower in the landscape were significantly more affected than those higher up the topographic sequence, with 14% of riparian communities and nearly 6% of yellow box–Blakely’s red gum woodland exhibiting symptoms of dryland salinity. About 1% of white box (E. albens Benth) woodland, and of hill communities which are on mid- and upper slopes, were affected. The pattern of salinity outbreaks in relation to landscape position and vegetation type is significant for biodiversity conservation because the vegetation communities most affected by salinisation are those most heavily cleared and modified post-European settlement. Throughout the South West Slopes of New South Wales, remnants of riparian communities and yellow box–Blakely’s red gum woodland are highly cleared, fragmented and degraded. Dryland salinity represents an additional threat to these vegetation communities and their component species. Salinisation of woodland ecosystems poses significant problems for land managers. The long-term viability of these woodland remnants needs to be considered when allocating limited public funds for woodland conservation, whether on private land or in formal reserves.

Landscapes are often shaped by decisions taken at the scale of individual stands or patches. In this chapter we make the following points. Biodiversity assessments at the scale of individual stands or patches must be undertaken in the landscape context. Landscape measures only inform land-use decisions when they can be interpreted at the scale in which land-use decisions are taken. In a management context, landscape units must be surrogates for multiple species and ecological processes, although no single unit will suffice as a surrogate for biodiversity generally, so risk-spreading strategies such as defining landscapes at multiple scales should be employed. Vegetation cover, pattern and patch content are measures often used to assess the biodiversity value of landscapes and impacts of change in landscapes. Vegetation cover and pattern are often assessed as though vegetation or habitat is binary (present or absent) and therefore the patches are uniformly good and the matrix uniformly hostile. Patch content is rarely assessed in a landscape context. We discuss how patch content can be interpolated at landscape scales and how this information can inform the way landscapes are defined and how cover and pattern are assessed. We suggest that spatial data on habitat attributes will enable us to view and assess landscapes as continua of habitats rather than discrete patches in a hostile matrix. From this discussion, six landscape principles are derived.

Summary The assessment of vegetation condition is seen as an increasingly important requirement for effective biodiversity conservation in Australia. Condition assessments that operate at the scale of the site are well established. However, there is a need for mapped representations of vegetation condition at regional scales to: (i) assist with regional planning and target setting; (ii) provide regional context for site‐based assessment; and (iii) monitor the change in vegetation condition at multiple scales. This paper describes a methodology for converting site condition data collected in plots into maps of vegetation condition across entire regions using a predictive statistical modelling framework (Generalized Additive Modelling) combined with a GIS. The research demonstrates how explanatory variables including topographic position, terrain roughness, landscape connectivity and remote sensing derived indices can be used to map the condition of native vegetation at the scale of a subcatchment. The inclusion of indices derived from remotely sensed imagery (SPOT4) as explanatory variables in the modelling is a novel component of this research. Although the methodology generates statistically and ecologically plausible models of vegetation condition, there are nevertheless limitations associated with the way plot data were collected and some of the explanatory variables, which impacts upon model utility. We discuss how these problems can be minimized when embarking upon studies of this type. We demonstrate how maps produced from exercises such as this could be used for conservation planning and discuss the limitations of these data for monitoring.

Building a flexible system is difficult, particularly if each instance of the system will be highly customised. This paper describes how an ERTMS Railway Simulator and Test Environment system was designed using abstractions, components and purpose specific languages. The use of components and modularisation provides the basis for reliability and testability, whereas the use of languages provides for flexibility to match the generic simulation environment to the problem in hand. The challenge of using Commercial Off The Shelf (COTS) hardware and software for large real-time systems is also discussed.