Native Vegetation Condition Research Articles

Indices for ecological condition of native vegetation: A review, and introducing the HH2.0 method

SummaryThe concept of using a single index to encapsulate the ‘ecological condition’ or ‘quality’ of native vegetation is reviewed and critiqued, along with the history of the adoption of such indices by governments at the State and Federal levels in Australia. Despite the value judgements inherent in such a concept, these indices provide a currency that is useful for comparing sites for purposes such as to provide a nexus between vegetation proposed to be removed under permit and other vegetation that will be protected or improved as an ‘offset’. The oldest of the reviewed indices – Habitat Hectares, from the Victorian Government – has been the subject of more scrutiny than others but there has been negligible change to it in response to recommendations made. A recommendation of particular significance is for values of the index to respond smoothly to changes in continuously variable observables like foliage cover, rather than discretising the data into broad class intervals. The step‐wise jumps in index values that result from discretisation can have the effects of creating false indications of difference between sites or over time and masking actual differences. The index's value for monitoring change is thereby impaired. The Biodiversity Assessment Method of New South Wales is the only index reviewed here that avoids discretisation. However, many of the other recommendations that have been made for changes to Habitat Hectares were adopted in 2003 for a simplified variant of that method – the ‘Land manager self‐assessment method’. Therefore, this variant has been used as the basis for a new index – HH2.0 – that retains the simplifications but does not discretise continuous variables or allocate scores in a step‐wise manner. The process of translating field observations into scores is automated by a Microsoft Excel workbook, saving time and reducing human error. HH2.0 will suit landowners, land managers, local government and regional authorities, for non‐regulatory purposes such as determining what planning protection to apply to an area or prioritising vegetation management among different areas. It requires significantly less gathering of field data than Habitat Hectares, but like that method, it places weight on vegetation's similarity to a long‐undisturbed state. No restriction is made on whether it is applied to plots of specified size or shape. A pre‐existing set of observational data has been used to retrospectively determine scores under HH2.0 and compare them with Habitat Hectares scores. The data came from 37 sites spanning a range of vegetation types and ecological condition. The root‐mean‐square difference between the two methods' scores is 5.1 points (out of a theoretical maximum of 100). For reference, Tolsma and Newell (2003) concluded that a difference of 20 points between two Habitat Hectares assessments cannot be relied upon to indicate a genuine difference in ecological condition. A larger data set would be desirable but even if there were no comparison at all between indices (as normal for a new index), that would not invalidate the use of HH2.0 for its intended non‐regulatory purposes. HH2.0 is designed for use in Victoria but the changes that have been made compared with Habitat Hectares could be applied to create faster, simpler variants of indices used in other jurisdictions.

An assessment of potential herbivory impacts of a reintroduced marsupial in a predator‐free woodland sanctuary

SummaryFenced sanctuaries that exclude feral predators are critical for threatened species conservation. However, adaptive management of these sanctuaries requires careful consideration of the potential impact herbivore populations free from predation can have on the condition of native vegetation. The Mulligans Flat Woodland Sanctuary in the Australian Capital Territory comprises Critically Endangered box‐gum grassy woodland, threatened orchids, abundant macropods, and a reintroduced population of the Eastern Bettong (Bettongia gaimardi, hereafter “Ngaluda”). To understand how Ngaluda, along with other herbivores, may be potentially impacting vegetation across the sanctuary, we undertook an assessment of indicator plant species. We monitored 106 plots for 13 indicator species (10 species with tuberous roots that the burrowing Ngaluda would be preferentially targeting and three non‐tuberous species). We found that most floristic indicators we investigated – including richness of indicator species and the abundance of lilies – were higher in the Goorooyarroo area of the sanctuary (where Ngaluda are absent and wallabies are rare) compared to the Mulligans Flat area of the sanctuary (where Ngaluda are present and wallabies are abundant), suggesting a negative impact of the overall herbivore assemblage of Mulligans Flat. However, within just Mulligans Flat, some indicators, including the abundance of a common orchid, were significantly lower in areas associated with high Ngaluda activity irrespective of other herbivore densities. We found no instance of Ngaluda presence or higher activity being associated with higher values for any floristic indicator we investigated. These results are consistent with known impacts of abundant herbivores and reintroduced digging marsupials in other predator‐free sanctuaries in Australia. Our results highlight that Ngaluda herbivory may be outweighing any positive effect of their diggings on native vegetation and indicate the need for careful risk mitigation when deciding how critically endangered animals and vegetation communities are managed together in sanctuaries.

Vegetation quality assessment: A sampling-based loss-gain accounting framework for native, disturbed and reclaimed vegetation

Governments and society increasingly are demanding that industrial projects result in a net positive impact (NPI) on biodiversity. Impacts are commonly measured in terms of losses and gains of area and quality of vegetation, where quality refers to how closely a site matches the condition of native vegetation in its undisturbed state. Existing vegetation quality frameworks share a number of limitations, including little or no replication, uncertain scope of inference, vulnerability to bias, and inability to measure error. Here we present the Vegetation Quality Assessment (VQA) framework, a sampling-based extension of Quality Hectares that measures vegetation quality in terms of overlap between the probability distributions of ecological indicators at a project site and in undisturbed (benchmark) vegetation of the same kind. Distribution overlap incorporates natural variation at the landscape scale and provides an intuitive measure of quality that varies between 0 and 1. Indicators are measured using a stratified-random sampling design that minimizes bias and supports inference at the scale of the project landscape. Confidence limits of quality and quality hectares are determined by bootstrapping; power and minimum sample sizes are estimated by Monte Carlo simulation. Multiple assessments track losses and gains of quality hectares and enable accurate accounting of progress to NPI. The VQA framework can be implemented using a variety of vegetation sampling methods, allowing existing vegetation databases to be leveraged as sources of data. We conclude by demonstrating the application of VQA at several mining operations in the Elk Valley of southeastern British Columbia, Canada.

Influence of Long-Term Soil Management Practices on Carbon Emissions from Corn (Zea mays L.) Production in Northeast Croatia

Sustainable management of agricultural resources is needed to meet people’s increasing demands for food, fiber and energy while maintaining the quality of the environment and protecting natural resources. With the rapid growth of agriculture and the mechanization of farming, the agricultural sector has become one of the main contributors to the increase in CO2 emissions and other greenhouse gases in the world. Therefore, the aim of this study was to determine the effect, dependence and correlations of CO2 in soil with native vegetation (presence/absence, corn yield) and climatic conditions (soil temperature and moisture) during three years of measurements under different management practices in a classical conventional agroecosystem. This research contains four different treatments: control treatment (CT), dolomite/organic fertilization (DOL/OF), mineral fertilization (MF) and black fallow (BF). During the investigated period, the average overall C-CO2 flux ranged from 7.98 kg ha−1 day−1 on bare soil to 16.26 kg ha−1 day−1 on soil treated with mineral fertilization. No statistically significant difference was observed among different fertilization treatments, except in 2013 and 2015 when comparing different fertilization treatments to bare soil. In all three years, there was a positive correlation between average C-CO2 fluxes and soil temperature. Additionally, in 2013 and 2017, there was a positive correlation between average C-CO2 fluxes and soil moisture, while a negative correlation was observed in 2015. Obtained values of crop yield ranged from 0.89 t ha−1 in the control treatment (in 2015) to 14.81 t ha−1 in the treatment with mineral fertilization (in 2017). Growing global concern about the effects of climate change calls for intensive research on the carbon cycle, and these results will contribute to the understanding of carbon transformation in different crops and soil management practices.

Impacts of Vegetation Removal on Urban Mediterranean Stream Hydrology and Hydraulics

Given the widespread presence of non-native vegetation in urban and Mediterranean watersheds, it is important to evaluate how these sensitive ecosystems will respond to activities to manage and restore native vegetation conditions. This research focuses on Del Cerro, a tributary of the San Diego River in California, where non-native vegetation dominates the riparian zone, creating flooding and fire hazards. Field data were collected in 2018 to 2021 and consisted of water depth, streamflow, and stream temperature. Our data set also captured baseline conditions in the floodplain before and after the removal of burned non-native vegetation in November 2020. Observed changes in hydrologic and geomorphic conditions were used to parameterize and calibrate a two-dimensional hydraulic model to simulate urban floodplain hydraulics after vegetation removal. We utilized the U.S. Army Corps of Engineers’ Hydrologic Engineering Center River Assessment System (HEC-RAS) model to simulate the influence of canopy loss and vegetation disturbance and to assess the impacts of vegetation removal on stream restoration. We simulated streamflow, water depth, and flood extent for two scenarios: (1) 2019; pre-restoration where non-native vegetation dominated the riparian area, and (2) 2021; post-restoration following the removal of non-native vegetation and canopy. Flooding after restoration in 2021 was more frequent compared to 2019. We also observed similar flood extents and peak streamflow for storm events that accumulated half the amount of precipitation as pre-restoration conditions. Our results provide insight into the responses of small urban stream reaches to the removal of invasive vegetation and canopy cover.

Permanent removal of livestock grazing in riparian systems benefits native vegetation

Livestock grazing in riparian areas has significant impacts on waterway ecosystems. In Australia, livestock grazing is allowed on many public waterway frontages under long-term licences. Many barriers to removing or restricting grazing on riparian areas exist, including concerns that removing grazing from historically grazed sites may favour invasive plant species. We compared vegetation changes at 180 sites along three connected waterways in northern Victoria, Australia that had been extensively grazed by livestock under grazing licences. Some of these sites were permanently protected from grazing by the creation of a new public park and reserve system in 2002. We compared vegetation attributes between sites in the ungrazed reserves, to sites outside reserves that were either recently grazed or ungrazed in 2009. Importantly, we used a sampling design and statistical models that explicitly incorporated the proximity to the waterway to account for known resource and disturbance gradients. Broad site condition assessments that were conducted on the exact same sites prior to reservation provided an indication of pre-treatment condition attributes. Despite no clear evidence of having more or less native vegetation prior to reservation, reserved sites had more native vegetation cover across a range of different life-form types than unreserved sites. Reserved sites also had much less bare ground, and this effect was far greater closer to the waterway margin. Livestock grazing within reserves reduced these perceived benefits for native vegetation and bare ground. However, reserved sites also had a higher cover of exotic graminoids, but not herbs. This study suggests that reservation of stream frontages was beneficial to native vegetation condition within the study systems even if grazing persisted. Livestock grazing was effective at reducing exotic vegetation cover but at the cost of native vegetation and ground condition. Many factors may influence outcomes and we expect these responses to differ in more productive landscapes or in periods with greater rainfall, so quantitative monitoring is advisable. Evaluation of cost-benefit trade-offs for the environment, graziers, and social and cultural objectives will be important to guide reservation decisions. • Livestock grazing increases bare ground and reduces native vegetation cover. • Reservation decreases bare ground and increases native vegetation cover. • Removal of grazing increased exotic vegetation cover. • Bare ground and vegetation cover vary with proximity to a waterway. • Livestock grazing pressure and impacts vary with proximity to a waterway.

A new decision support tool for collaborative adaptive vegetation management in northern Great Plains national parks

National Park Service (NPS) units in the northern Great Plains (NGP) were established to preserve and interpret the history of America, protect and showcase unusual geology and paleontology, and provide a home for vanishing large wildlife. A unifying feature among these national parks, monuments, and historic sites is mixed-grass prairie, which not only provides background scenery but is the very foundation of many park missions. As recognition of the prairie’s importance to park fundamental resources and values has grown, so too has the realization that invasive plants threaten these values by reducing native species diversity, altering food webs, and marring the visitor experience. Parks manage invasive species despite uncertainties in treatment effectiveness because management cannot wait for research to provide definitive answers. Under these circumstances, adaptive management (AM) is an appropriate approach. In the NGP, we formed a collaborative adaptive vegetation management team to apply AM towards reducing invasive species (with a focus on exotic annual grasses) and improving native vegetation conditions. In our AM framework, the team uses a Bayesian model built from NPS Inventory & Monitoring and Fire Effects monitoring data and experimental results to predict the effects of management actions on park management units, according to those units’ vegetation condition and management history. These predictions inform management decisions, which are then applied.

Vegetation and Fluvial Geomorphology Dynamics after an Urban Fire

The goal of this research was to characterize the impact of invasive riparian vegetation on burn severity patterns and fluvial topographic change in an urban Mediterranean riverine system (Med-sys) after fire in San Diego, California. We assessed standard post-fire metrics under urban conditions with non-native vegetation and utilized field observations to quantify vegetation and fluvial geomorphic processes. Field observations noted both high vegetation loss in the riparian area and rapidly resprouting invasive grass species such as Arundo donax (Giant Reed) after fire. Satellite-based metrics that represent vegetation biomass underestimated the initial green canopy loss, as did volumetric data derived from three-dimensional terrestrial laser scanning data. Field measurements were limited to a small sample size but demonstrated that the absolute maximum topographic changes were highest in stands of Arundo donax (0.18 to 0.67 m). This work is the first quantification of geomorphic alterations promoted by non-native vegetation after fire and highlights potential grass–fire feedbacks that can contribute to geomorphic disruption. Our results support the need for ground-truthing or higher resolution when using standard satellite-based indices to assess post-fire conditions in urban open spaces, especially when productive invasive vegetation are present, and they also emphasize restoring urban waterways to native vegetation conditions.

Eating away at protected areas: Total grazing pressure is undermining public land conservation

Protected areas are critical for the long-term conservation of biodiversity globally. Across agricultural landscapes, protected areas serve as refuges for threatened and declining species and provide valuable ecosystem services that support broader landscape function. However, increasing pressure on protected areas from a range of sources is undermining their unique conservation values. Much of the native vegetation remaining in southern Australia is now protected from broad-scale clearing, but the management of threats within these areas could be inadequate to maintain their biodiversity. In particular, grazing by domestic and wild mammalian herbivores can have a significant impact on the condition of remnant native vegetation, even if it is formally protected. We evaluated the evidence for grazing-pressure trends in native vegetation in both protected and unprotected areas across an agricultural landscape covering c. 180 000 km2 of South Australia. Using total grazing pressure data from 1298 sites surveyed between 2004 and 2016, we employed Bayesian linear mixed-effects modelling to demonstrate increasing trends in grazing severity in four of five study regions, estimating that 45%–54% of grazed plants were heavily or severely grazed by 2016. Over the 12-year period, grazing severity in protected areas increased to levels closely matching those on private, unprotected land. Our results suggest that abundant native and/or introduced grazing animals are having an increasing impact on native vegetation across large areas of the agricultural zone of South Australia, with a disproportionate impact on protected areas. We recommend that: (1) research is needed to identify sustainable total-grazing-pressure thresholds; and (2) options should be considered for an adaptive, coordinated, and cross-tenure approach to maintaining total grazing pressure in protected areas below these thresholds.

Effects of Supplemental Feeding on Home Range Size and Survival of Northern Bobwhites in South Georgia

We studied the effects of supplemental feeding on fall-spring covey home range size and survival of radio-marked northern bobwhites (Colinus virginianus) for 3 years in southwest Georgia. A total of 372 radio-marked bobwhites were monitored on 2 separate study areas for 25 weeks from fall-spring each year from November 1993 through May 1996. The traditional supplemental feeding program of bi-weekly broadcast spreading of whole grains from November through May was discontinued on one of the study areas during 1993-1994 and 1994-1995. Supplemental feed was distributed on both areas during fall-spring 1995-1996. During the 2 years of no feeding, fall-spring covey home ranges were larger (P = 0.04) on the unfed study area. During the first of these 2 years (1993-1994), fall-spring survival of birds without supplemental feed (S = 0.127) was lower (P = 0.005) than that of fed birds (S = 0.432). During the 1994-1995 season while covey home ranges of birds without supplemental feed were still slightly larger (P = 0.04), there was no difference (P = 0.76) in survival between bobwhites on the sites with and without supplemental feed. Coveys seen per hour hunted was significantly lower (P = 0.007) on the treatment (unfed) area during 2 years. During the year supplemental feed was distributed on both sites, there was no difference in home range size (P = 0.87), survival (P = 0.90), or hunting success (P = 0.82) between the 2 study sites. Supplemental feeding may reduce bobwhite movements and home range size thereby enhancing survival because of less exposure to predation. However, such an effect will probably vary among years in relation to prevailing weather and native vegetation conditions. The specific mechanisms through which supplemental feeding may effect bobwhite population performance remain unknown and require additional study.

Using Optimal Land-Use Scenarios to Assess Trade-Offs between Conservation, Development, and Social Values

Development of land resources can contribute to increased economic productivity but can also negatively affect the extent and condition of native vegetation, jeopardize the persistence of native species, reduce water quality, and erode ecosystem services. Spatial planning must therefore balance outcomes for conservation, development, and social goals. One approach to evaluating these trade-offs is scenario planning. In this paper we demonstrate methods for incorporating stakeholder preferences into scenario planning through both defining scenario objectives and evaluating the scenarios that emerge. In this way, we aim to develop spatial plans capable of informing actual land-use decisions. We used a novel approach to scenario planning that couples optimal land-use design and social evaluation of environmental outcomes. Four land-use scenarios combined differences in total clearing levels (10% and 20%) in our study region, the Daly Catchment Australia, with the presence or absence of spatial precincts to concentrate irrigated agriculture. We used the systematic conservation planning tool Marxan with Zones to optimally plan for multiple land-uses that met objectives for both conservation and development. We assessed the performance of the scenarios in terms of the number of objectives met and the degree to which existing land-use policies were compromised (e.g., whether clearing limits in existing guidelines were exceeded or not). We also assessed the land-use scenarios using expected stakeholder satisfaction with changes in the catchment to explore how the scenarios performed against social preferences. There were a small fraction of conservation objectives with high conservation targets (100%) that could not be met due to current land uses; all other conservation and development objectives were met in all scenarios. Most scenarios adhered to the existing clearing guidelines with only marginal exceedances of limits, indicating that the scenario objectives were compatible with existing policy. We found that two key stakeholder groups, agricultural and Indigenous residents, had divergent satisfaction levels with the amount of clearing and agricultural development. Based on the range of benefits and potential adverse impacts of each scenario, we suggest that the 10% clearing scenarios are most aligned with stakeholder preferences and best balance preferences across stakeholder groups. Our approach to scenario planning is applicable generally to exploring the potential conflicts between goals for conservation and development. Our case study is particularly relevant to current discussion about increased agricultural and pastoral development in northern Australia.

Planning for metapopulation persistence using a multiple-component, cross-scale model of connectivity

Reducing fragmentation and habitat loss by restoring or maintaining connectivity has been promoted as a way to mitigate the negative impacts of human activities on biodiversity. This study is an example of collaboration between spatial researchers and on-ground practitioners, to deliver better informed management options for investment in connectivity and biodiversity outcomes. Using the Border Rivers-Gwydir catchment revegetation programmes in New South Wales, Australia, we describe a fit-for-purpose, cross-scale methodology consisting of multiple-component models, where each component reflected varying spatial scales. The methodology was based on the concepts of metapopulation ecology and landscape ecology and used least-cost paths analyses. At the wider scale, native vegetation extent and condition were used as a surrogate for all biodiversity; at the finer scale, landscape structure and generalised movement parameters related to a focal woodland species group were used to derive least-cost paths. The output from the analyses provided spatially explicit management action zones that were used to prioritise areas for revegetation investment. Combining local priority zones for linking habitat with regional-scale and broad-scale zones should increase access to resources for biota, increase dispersal potential and thereby enhance biodiversity persistence. Promoting connectivity is a global concern. Our approach could be relevant in other geographical settings where the implementation needs of NRM practitioners can be assisted through the application of scientific knowledge.

Estimating density-dependent impacts of European rabbits on Australian tree and shrub populations

Introduced European rabbits, Oryctolagus cuniculus, can severely damage Australian native vegetation but the problem is difficult to quantify because simple methods to estimate rabbit impacts are lacking. Management decision-making is often uncertain because of unknown relationships between rabbit density and damage. We tested simple quantitative sampling methods using belt transects to detect differences in critical characteristics of perennial vegetation communities affected by rabbit browsing: damage to individual juvenile shrubs and trees, and loss of recruitment cohorts. Rabbit density and relative abundance of larger herbivores were estimated from dung pellet density. The prevalence of identifiable rabbit browse on juvenile plants increased with increasing rabbit density and was higher for plant species considered by previous authors to be highly palatable than for moderately palatable or unpalatable species. At densities of ≥0.5 rabbits ha–1, highly palatable plant species were severely damaged as juveniles and cohorts in 0.3–1.0 m height classes and 5–20 mm basal diameter classes were missing. Similar damage became apparent in moderately palatable species at 2 rabbits ha–1 but was rarely seen in unpalatable species. Within species, size cohort evenness was inversely related to the proportion of surviving juveniles with identifiable rabbit damage. The effect of rabbits on native vegetation condition can be recorded in a simple manner suitable for identifying density-damage relationships and changes in vegetation condition over time. It is particularly useful in setting target densities below which rabbits must be managed to maintain natural plant recruitment and ecosystem function in conservation reserves and pastoral grazing properties of southern Australia.

Site-based and remote sensing methods for monitoring indicators of vegetation condition: An Australian review

Native vegetation around the world is under threat from historical and ongoing clearance, overgrazing, invasive species, increasing soil and water salinity, altered fire regimes, poor land management and other factors, resulting in a degradation of natural ecosystem services. Consequently, maintaining and improving native vegetation condition is a target frequently adopted by natural resource managers and government agencies world-wide. Adequate monitoring of vegetation condition remains a prerequisite for environmental decision-making and for tracking progress towards management goals. Throughout we consider vegetation condition to include the compositional, structural and functional attributes of vegetation relative to undisturbed vegetation of the same type.Site-based methods have long been used to assess compositional, structural and functional attributes as indicators of vegetation condition, and these methods continue to be used widely today. With developing technologies, remote sensing methods are being employed increasingly for monitoring a range of remotely detectable properties of vegetation, and there is now a growing demand to explicitly integrate the two approaches for mapping and monitoring vegetation condition across a range of scales.Here we review the attributes of vegetation identified as important for monitoring vegetation condition, those indicators that are best measured using traditional site-based methods and those that are more readily detectable using remote sensing methods, including their application in operational programmes within Australia. Further to this we review recent literature on the integration of the two approaches for monitoring indicators of vegetation condition.We find that remote sensing methods have the advantage of offering broad scale automated and repeatable methods for monitoring indicators of vegetation condition, but when combined with detailed ecological site-based data, together can improve monitoring for answering ecological questions across a range of scales. Further work, however, is required to effectively integrate the two approaches for mapping and monitoring vegetation condition.

Effectiveness of Exotic Plant Treatments on National Park Service Lands in the United States

AbstractThe United States created national parks to conserve indigenous species, ecological processes, and cultural resources unimpaired for future generations. Curtailing impacts of exotic species is important to meeting this mission. This synthesis identified 56 studies reported in 60 publications that evaluated effects of exotic plant treatments on National Park Service lands. Studies encompassed 35 parks in 20 states and one U.S. territory and included 157 exotic plant species. Eighty-seven percent of studies reported that at least one treatment reduced focal exotic species. Of 30 studies evaluating response of native vegetation, 53% reported that natives increased, 40% reported neutral responses, and 7% reported that natives decreased. For at least some of the neutral cases, neutrality was consistent with management objectives. In other cases, insufficient time may have elapsed to thoroughly characterize responses, or restoration might be needed. Nonfocal exotic species increased in 44% of the 16 studies evaluating them, but the other 56% of studies reported no increase. Results suggest that: (1) a range of exotic species spanning annual forbs to trees have been effectively treated; (2) developing effective treatments often required extensive experimentation and balancing nontarget impacts; (3) presence of multiple exotic species complicated treatment efforts, highlighting importance of preventing invasions; and (4) placing treatment objectives and outcomes in context, such as pretreatment condition of native vegetation, is important to evaluating effectiveness. Attaining the goal in national parks of conserving native species and ecological processes minimally influenced by exotic species will likely require comprehensive management strategies inclusive of treatment interactions with focal exotic species, other potential invaders, and native species.

The role of private conservation in saving biodiversity in Australia

The role of private conservation in saving biodiversity in Australia

A rapid survey method for estimating population density of European rabbits living in native vegetation

European rabbits are severe environmental pests in Australia but reporting of density-damage relationships has been hindered by a lack of simple methods to estimate the density of rabbit populations in native vegetation. A methodology for quantifying rabbit densities suitable for use in sparse populations of rabbits in conjunction with surveys of the condition of native vegetation is proposed. Dung pellets were counted in 11 629 regularly-spaced quadrats of 0.1 m2 in semiarid, coastal and cool-temperate areas of southern Australia. Mean pellet counts in latrines and the relationship between dung counts outside of latrines and the proportion of quadrats falling on latrines were quantified. This allowed density of dung pellets to be estimated by using a correction factor for latrines instead of attempting to count all pellets within quadrats that included parts of latrines. Rabbit density was calculated from pellet density based on mean pellet size, pellet breakdown rate and estimates of rabbits’ dry matter intake and digestive efficiency. Results were validated against estimates of rabbit density from long-term studies using a combination of spotlight transect counts and burrow entrance counts. The proposed methodology allows estimates of rabbit density in native vegetation to be obtained from just a few hours work and can be used in conjunction with surveys of the condition of native vegetation to quantify rabbit impacts. This methodology is seen as particularly useful in providing a tool to allow rabbit densities to be estimated and then compared with the thresholds, determined separately, at which damage occurs for given ecosystems.

Why monitoring often fails to inform adaptive management: a case study

SummaryMonitoring that facilitates adaptive management requires us to link observed changes in resource condition with management actions. Here, we present a case study to discuss how monitoring should be undertaken so it can facilitate adaptive management. Drawing on monitoring data collected by landholders as part of an incentive programme for native vegetation conservation on private land, we examined whether it was possible to determine to what extent changes in native vegetation condition were affected by funded management actions. Using a simple statistical technique (linear regression), we were unable to find strong links between the intended natural resource management (NRM) outcomes and funded management actions because (i) we could only use data from 22% of the 55 monitored sites as most data sheets were incomplete; (ii) sampling was undertaken in different seasons making it difficult to distinguish change due to management from change due to natural variability; and (iii) management actions were recorded in a generic way only, and not monitored through time, thus making it difficult to link observed changes in vegetation condition to on‐ground management. We suggest that monitoring programmes will only inform adaptive management where NRM bodies can prosecute (i) sampling designs that enable change as a result of management to be distinguished from change due to natural variability, and (ii) protocols that provide consistent data capture between sites and through time.

The challenge of integrating science for landscape management

‘Ecosystem restoration is now a global priority’ announced a recent editorial (Aronsen and Alexander 2013), reporting on the outcomes of the 11th Conference of the Parties (in Oct 2012) of the Convention on Biological Diversity. Large-scale programs to restore, or more sustainably manage, ecosystems exist in many countries and landscape ecologists often are at the forefront of those actively contributing their expertise. In Australia, for example, the Federal Government has invested some $6.5 billion since 1990 in a series of natural resource management and restoration programs (Hajkowicz 2009), primarily in agricultural environments to respond to the consequences of excessive clearing of native vegetation. But how do we know whether such management interventions are effective? How do we measure their impact? Is the environment in a better condition as a result of these investments? Could these restoration actions be carried out in a more effective and efficient way? These kinds of challenging questions were the stimulus for a research project in southern Australia, documented in this volume. ‘Landscape Logic’ was a four-year, nationally funded project, which set out to ‘measure the effects of past human intervention on the environment using a combination of biophysical and social evidence, and the experience of land and water managers’. It was large in scale, scope and ambition: personnel were drawn from four Universities, three state agencies, and six catchment management organisations. From the outset, the project was planned to be interdisciplinary and participatory, with scientists working alongside managers. The structure of the book reflects the priority issues identified in consultation with land managers in two study areas. Thus, Part 1. ‘Managing water quality in agricultural catchments’ relates to project components undertaken in the state of Tasmania (Chaps. 2–9), where the issue of water quality was of greatest concern. Part 2, ‘Vegetation change in rural landscapes’, relates to components in Victoria (Chaps. 10–17), where the effects of management intervention on the condition and quality of native vegetation was a priority. Part 3, ‘Integrating science and practice’, includes four chaps. (18–21) that synthesize aspects of the overall project. Two questions kept recurring as I read this book: ‘who is this written for?’ and ‘what is its purpose?’. My initial expectation was that the book would provide an array of new scientific evidence evaluating ecological outcomes of the extensive restoration and management activities undertaken in Australia over the last two decades. However, while the bulk of the chapters are centred on various research components of the project, communication of research findings is not the sole intention of the book. Rather, it documents the ‘anatomy’ of a major project, including what it set A. F. Bennett (&) School of Life & Environmental Sciences, Deakin University, 221 Burwood Highway, Burwood, VIC 3125, Australia e-mail: Andrew.Bennett@deakin.edu.au

The Effects of a Rotational Cattle Grazing System on Elk Diets in Arizona Piñon–Juniper Rangeland

I t is not uncommon to hear statements such as these in the western United States. Dietary overlap between cattle and wild herbivores such as elk or deer has been 1 reported in various regions, seasons, and ecosystems. Competition between two species occurs when a shared resource is in limited supply or when the presence of one species disturbs the other. The simple fact that space and forage resources are shared might or might not, however, constitute a negative interaction between cattle and elk. 1 Studies in central Arizona 2 found that although diet similarity was high in certain years and seasons, there was actually little inter-specific competition between cattle and elk overall. Factors such as scale, season, and forage availability influ- ence the likelihood and degree of competition. Overgrazing isdetrimentaltosustainedlivestockandwildlifeproductivity. Livestock grazing can, however, be applied to positively manipulate habitat for wildlife. A review by Krausman et al. 3 cites a Montana case study in which a rotational cattle graz- ing system “maintained productive cover and forage for elk while enhancing native vegetation condition on all of the managed areas.” DOI: 10.2458/azu_rangelands_v34i1_t olleson