Neil MacLeod

Integrating Ecology into Natural Resource Management Policy

Traditional natural resource management policy has largely focused on implementing prescriptive solutions to maximize a production function. The fundamental assumptions of this approach were: (1) that ecosystems behaved in a linear, deterministic manner; (2) that there was general community agreement on the value of different ecosystem services; and (3) that land managers would accept and adopt the recommended technology. The result has generally been an unpredictable performance by ecosystems, conflicting expectations among users, and low adoption rates for the outputs of research and development (R&D). We propose that an approach that integrates the fundamentals of nonequilibrium ecology and “soft” systems methodologies to define options, make management decision recommendations, and implement programs will result in improved predictability of ecosystem response, more realistic expectations on the part of users of ecosystem services, and better uptake of technology by land managers.

An economic assessment of the impact of grazing land condition on livestock performance in tropical woodlands

Beef cattle grazing is the dominant economic use of the tropical woodlands of northern Australia. Land condition has declined over a large part of the region as a result of over-utilisation of pastures through poor management of grazing, fire and vegetation. While often assumed to be the case, there is little empirical evidence to support a link between deteriorating land condition and reduced economic outcomes for livestock production. A model of a representative livestock enterprise near Charters Towers in northern Queensland is used in conjunction with a simulation of 100 trials that is consistent with long-term rainfall in the region to examine the relationship between stocking rates, animal production and economic outcomes. The present study supports a view that ecological and economic outcomes of grazing management do have some general linkages. However, the linkages are less direct than suggested by common definitions of resource degradation and simple stocking rate models. Key economic parameters include the reproductive performance of breeding herds, the level and duration of supplementary feeding required to meet seasonal feed shortages under different land condition and stocking rate regimes, and additional capital invested in larger herds when stocking rates are increased. An overgrazing spiral is hypothesised whereby there is a short-term economic incentive to exploit the natural capital of land in good condition by grazing at relatively high stocking rates. Should land condition deteriorate, a much lower stocking rate is warranted. In an extreme case of a shift to very poor land condition, there is limited scope for profitable production. The 100 year mean values of many production variables for good and moderate condition land for the range of stocking rates trialled are similar. The inherent variation in climatic conditions in the woodlands region and the ability and skills of managers may lead to the actual differences in these measures passing un-noticed before major land resource problems become apparent.

A site-based approach to delivering rangeland ecosystem services

Rangeland ecosystems are capable of providing an array of ecosystem services important to the wellbeing of society. Some of these services (e.g. meat, fibre) are transported to markets and their quantity, quality and value are established via a set of widely accepted standards. Other services (e.g. climate mitigation, water quality, wildlife habitat) do not leave the land, but are, in fact, most valuable when they remain in situ. Determining their quantity, quality and value presents a challenge that must be met if there is to be a credible, accessible ecosystem services market for rangelands. In this paper we describe some of the ecosystem services that may be extracted from rangelands, discuss their unique ecological nature and relate those unique ecological properties to soil and vegetation attributes that can serve as a basis for measurement, both quality and quantity. We suggest the use of a soil/vegetation-based system in which similar climate, geomorphology and edaphic properties are grouped into ecological sites based on their response to disturbance. Within each ecological site, a unique state and transition model describes the dynamics of vegetation and soil surface properties, provides state indicators (vegetation structure, soil properties), predicts ecosystem services that may be derived at multiple scales, and organises information related to management to achieve ecosystem service objectives, including sustainability.

Scaling results up from a plot and paddock scale to a property - a case study from a long-term grazing experiment in northern Australia

Grazing experiments are usually used to quantify and demonstrate the biophysical impact of grazing strategies,withtheWambianagrazingexperimentbeingoneofthelongestrunningsuchexperimentsinnorthernAustralia. Previous economic analyses of this experiment suggest that there is a major advantage in stocking at a fixed, moderate stocking rate or in using decision rules allowing flexible stocking to match available feed supply. The present study developed and applied a modelling procedure to use data collected at the small plot, land type and paddock scales at the experimental site to simulate the property-level implications of a range of stocking rates for a breeding-finishing cattle enterprise. The greatest economic performance was achieved at a moderate stocking rate of 10.5 adult equivalents 100ha -1 . For the same stocking rate over time, the fixed stocking strategy gave a greater economic performance than strategies that involved moderate changes to stocking rates each year in response to feed supply. Model outcomes were consistent with previous economic analyses using experimental data. Further modelling of the experimental data is warranted and similar analyses could be applied to other major grazing experiments to allow the scaling of results to greater scales.

Resting pastures to improve land condition in northern Australia: guidelines based on the literature and simulation modelling

Pasture rest is a possible strategy for improving land condition in the extensive grazing lands of northern Australia. If pastures currently in poor condition could be improved, then overall animal productivity and the sustainability of grazing could be increased. The scientific literature is examined to assess the strength of the experimental information to support and guide the use of pasture rest, and simulation modelling is undertaken to extend this information to a broader range of resting practices, growing conditions and initial pasture condition. From this, guidelines are developed that can be applied in the management of northern Australia’s grazing lands and also serve as hypotheses for further field experiments. The literature on pasture rest is diverse but there is a paucity of data from much of northern Australia as most experiments have been conducted in southern and central parts of Queensland. Despite this, the limited experimental information and the results from modelling were used to formulate the following guidelines. Rest during the growing season gives the most rapid improvement in the proportion of perennial grasses in pastures; rest during the dormant winter period is ineffective in increasing perennial grasses in a pasture but may have other benefits. Appropriate stocking rates are essential to gain the greatest benefit from rest: if stocking rates are too high, then pasture rest will not lead to improvement; if stocking rates are low, pastures will tend to improve without rest. The lower the initial percentage of perennial grasses, the more frequent the rests should be to give a major improvement within a reasonable management timeframe. Conditions during the growing season also have an impact on responses with the greatest improvement likely to be in years of good growing conditions. The duration and frequency of rest periods can be combined into a single value expressed as the proportion of time during which resting occurs; when this is done the modelling suggests the greater the proportion of time that a pasture is rested, the greater is the improvement but this needs to be tested experimentally. These guidelines should assist land managers to use pasture resting but the challenge remains to integrate pasture rest with other pasture and animal management practices at the whole-property scale.

Integrated shrub management in semi-arid woodlands of eastern Australia: ground and aerial application of defoliant to shrubs regenerating after disturbance

This paper describes experiments undertaken at several sites in semi-arid woodlands of eastern Australia to determine if chemicals applied either on the ground or from the air reduce the density of shrubs regenerating after disturbance. Ground-spraying of Roundup® in the autumn was more effective than spring application in defoliating shrubs, especially 2-year-old coppice growth. Spraying of Roundup with a hand-held boom at 0.5 up to 2.5 kg glyphosate/ha identified rates to be used for boom spraying. Aerial spraying experiments were then undertaken across several sites and involved several target species. The location of sufficiently large areas where shrub regeneration was of an optimum age (i.e. about 2–3 years) proved to be extremely difficult due to prevailing drought conditions precluding the use of prescribed fire as a preliminary treatment. Nonetheless in one experiment, young (1-year-old) regrowth of firebush (Senna pleurocarpa) exhibited increased sensitivity to Roundup with significant shoot mortality recorded after it had been applied at 0.5 kg glyphosate/ha. Aerial spraying based on an ultra-low volume application of 10 L/ha further enhanced cost-effectiveness on this occasion. Economic analyses structured around 20-year partial budgeting and determination of net present value (NPV) suggested a profitable return could be expected where treatment was based on Roundup applied at this threshold rate 2 years after a prescribed fire, especially when the rehabilitation costs were spread over an entire paddock that had been only partially sprayed. Finally, operational aspects involving aerial spraying in these semi-arid woodlands are also discussed.

An economic assessment of forage options to improve the profitability of smallholder beef cattle enterprises in the Red Soils region of China

Beef cattle numbers in the People’s Republic of China have expanded dramatically in the past two decades. Most of this enlarged herd is carried as small numbers of animals on smallholder farms whose production focus has traditionally been on cropping, with very limited emphasis on the planting and use of forages and nutritious feed supplements. Limited plantings of specialised forages combined with a poor knowledge of appropriate feeding and husbandry practices for beef cattle by smallholder farmers remains a serious challenge to establishing genuinely sustainable beef enterprises for this sector. Public policy to further raise the level of beef cattle production on smallholder farms is focussing on encouraging the planting and use of new forage species and also on promoting research and extension for improved feeding practices that are centred on these forage species. The paper presents some results from the economic component of an Australian Centre for International Agricultural Research (ACIAR) project that is exploring options for integrating the planting and feeding of improved forages within existing smallholder farming systems in the Red Soils region of south-central China. An economic model is used to examine these options using a synthetic case example of a smallholder farm enterprise located in Hunan Province. The impact of changing values for several critical profit drivers are reviewed along with the implications of these findings for the management of cattle feeding systems on smallholder farms in the Red Soils region. The model results identify the potential for cattle rearing activities based on producing and feeding improved forages to increase the economic welfare of smallholder households. Where cattle rearing is based on diets of poor quality feedstuffs, economic returns are negative, although positive net cash incomes may support continued commitment of resources to this activity in the short-term.

Conservation and grazing in Australia’s north-east: the bridled nailtail wallaby

Australia’s vast continent is dominated by semi-arid and arid landscapes that have been modified to support the development of an extensive livestock grazing industry. Historically, this development has come at great environmental cost, with wide-scale landscape degradation and loss of biodiversity, including small macropods. With the growing appreciation of environmental values and ecological services provided by grazing landscapes, the engagement of pastoral landholders is now central to contemporary conservation efforts. In this paper we explore the spluttering recovery of Australia’s critically endangered bridled nailtail wallaby Onychogalea fraenata, once presumed extinct but now subject to a limited rehabilitation program in Queensland. We explore the ‘fit’ between management units and the scale of conservation challenges for the bridled nailtail wallaby, and then use this to frame the role of the private grazing industry in the governance of conservation actions. A centralised state conservation program has largely failed to stop the decline of the species, which remains critically endangered. We argue that non-state (privately) managed grazing properties working within a multi-level governance system that includes the state have a greater chance of conservation success because their actions can more appropriately match the scale of the problem at the implementation level. If the species recovers, the balance of management focus will need to shift towards broader scale actions such that localised disconnected sub-populations can successfully interbreed. By analysing the institutional failures that surround the bridled nailtail wallaby, we provide recommendations on how public institutions or policies can successfully catalyse private sector action at regional scales. These include avoiding economic incentives that may crowd out local stewardship, avoiding overly-authoritative state control (i.e. mono-centricity), and developing a multilevel governance structure that can strategically adapt its focus to the scale of various and shifting targets.

An ecosystem services filter for rangeland restoration

Rangeland restoration ecology and practice have profited from an emphasis on research and development that emphasises technical tools for monitoring and altering ecological processes. However, this approach has not been particularly effective in conveying the potential value of restoration projects to both an interested public and funding institutions. Rangelands, by their nature, are extensive in both land area and ecological process, and the ecosystem services derived from them reflects that diversity of resources. Without explicit links to specific ecological process outputs (i.e. commodity production, pollution reduction), it is difficult to capture and convey the values that may be achieved through rangeland restoration efforts. In this paper, we review the intersection of the practice of rangeland restoration ecology and ecosystem service provision as a basis for better evaluating and communicating potential projects. We also suggest that rangeland restoration projects pay more attention to explicitly defining the spatial and temporal extent of projects as a way to enhance communication with land owners, policy-makers and the concerned public.

Comparing fixed and flexible stocking as adaptations to inter-annual rainfall variability in the extensive beef industry of northern Australia

Many beef producers within the extensive cattle industry of northern Australia attempt to maintain a constant herd size from year-to-year (fixed stocking), whereas others adjust stock numbers to varying degrees annually in response to changes in forage supply. The effects of these strategies on pasture condition and cattle productivity cannot easily be assessed by grazing trials. Simulation studies, which include feedbacks of changes to pasture condition on cattle liveweight gain, can extend the results of grazing trials both spatially and temporally. They can compare a large number of strategies, over long periods of time, for a range of climate periods, at locations which differ markedly in climate. This simulation study compared the pasture condition and cattle productivity achieved by fixed stocking at the long-term carrying capacity with that of 55 flexible stocking strategies at 28 locations across Queensland and the Northern Territory. Flexible stocking strategies differed markedly in the degree they increased or decreased cattle stocking rates after good and poor pasture growing seasons, respectively. The 28 locations covered the full range in average annual rainfall and inter-annual rainfall variability experienced across northern Australia. Constrained flexibility, which limited increases in stocking rates after good growing seasons to 10% but decreased them by up to 20% after poor growing seasons, provides sustainable productivity gains for cattle producers in northern Australia. This strategy can improve pasture condition and increase cattle productivity relative to fixed stocking at the long-term carrying capacity, and its capacity to do this was greatest in the semiarid rangeland regions that contain the majority of beef cattle in northern Australia. More flexible stocking strategies, which also increased stocking rates after good growing seasons by only half as much as they decreased them after poor growing seasons, were equally sustainable and more productive than constrained flexibility, but are often impractical at property and industry scales. Strategies with the highest limits (e.g. 70%) for both annual increases and decreases in stocking rates could achieve higher cattle productivity, but this was at the expense of pasture condition and was not sustainable. Constrained flexible stocking, with a 10% limit for increases and a 20% limit for decreases in stocking rates annually, is a risk-averse adaptation to high and unpredictable rainfall variability for the extensive beef industry of northern Australia.