Agricultural Land Fragmentation at Urban Fringes: An Application of Urban-To-Rural Gradient Analysis in Adelaide

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).One of the major consequences of expansive urban growth is the degradation and loss of productive agricultural land and agroecosystem functions. Four landscape metrics—Percentage of Land (PLAND), Mean Parcel Size (MPS), Parcel Density (PD), and Modified Simpson’s Diversity Index (MSDI)—were calculated for 1 km × 1 km cells along three 50 km-long transects that extend out from the Adelaide CBD, in order to analyze variations in landscape structures. Each transect has different land uses beyond the built-up area, and they differ in topography, soils, and rates of urban expansion. Our new findings are that zones of agricultural land fragmentation can be identified by the relationships between MPS and PD, that these occur in areas where PD ranges from 7 and 35, and that these occur regardless of distance along the transect, land use, topography, soils, or rates of urban growth. This suggests a geometry of fragmentation that may be consistent, and indicates that quantification of both land use and land-use change in zones of fragmentation is potentially important in planning

Reconfiguring an Irrigation Landscape to Improve Provision of Ecosystem Services

Over-allocation of fresh water resources to consumptive uses, coupled with recurring drought and the prospect of climate change, is compromising the stocks of natural capital in the world’s basins and reducing their ability to provide ecosystem services. To combat this, governments world wide are making significant investment in efforts to improve sharing of water between consumptive uses and the environment, with many investments centred on modernisation of inefficient irrigation delivery systems, and the purchase of water by government for environmental flows. In this study, spatial targeting was applied within a cost-benefit framework to reconfigure agricultural land use in an irrigation district to achieve a 20% reduction in agricultural water use to increase environmental flows and improve the provision of other ecosystem services. We demonstrate using spatial planning and optimisation models that a targeted land use reconfiguration policy approach could potentially increase the net present value of ecosystem services by up to AUS$463.7m. This provides a threshold level of investment that would be justified on the basis of benefits that the investment produces. The increase in ecosystem services include recovering 61 GL of water for environmental flows, the sequestration of 10.6m tonnes of CO2-e/yr, a 13 EC (?S/cm) reduction in river salinity, and an overall 24$68.7m in economic returns to agriculture which may be only marginally offset by the increased value of ecosystem services resulting from the return of 61 GL of water to the environment.landscape planning, geographic information systems, cost-benefit analysis, irrigation, climate change, water management, spatial targeting, environmental valuation

Aggregate effects on ecosystem services from certification of tea farming in the Upper Tana River basin, Kenya

Agriculture sustainability standards and certification are increasingly used by the private sector and civil society to incentivize and support environmental conservation and improved rural. However, evidence of impact is limited by methodological challenges that hamper the quantification of certification-induced changes, especially beyond farm level. This paper aims to explore the changes to soil and nutrient regulation ecosystem services from the adoption of Rainforest Alliance tea certification in the Kenyan Upper Tana River watershed. In this study we: i) apply ecosystem service models to simulate the effect of farm-level practices for before and after-certification scenarios, and; ii) evaluate the model applications for their ability to guide future decision making. Our scenario results indicate that a widespread adoption of agricultural practices prescribed in the certification standard reduces sediment export into watercourses. However, an increase in fertilizer use by certified farmers is estimated to result in greater nitrogen and phosphorous loads. Our scenario analyses are highly sensitive to input data and model choice, but show similar relative impacts of tea certification. Opportunities to improve spatial impact measurements to support decision making can be found in the systematic accounting of land management practices by certification organizations and increased remote sensing image accessibility

Space matters: the importance of amenity in planning metropolitan growth

Most Australian capital cities require many 100,000s of additional dwellings to accommodate demographic change and population pressures in the next two or three decades. Urban growth will come in the form of infill, consolidation and urban expansion. Plans to redevelop environmental amenities such as parks and open green spaces are regularly being put forward to local councils and State governments. Maintaining parks and reserves represents one of the largest costs to local councils. To aid in the evaluation of some of the different propositions, we report the results of a spatial hedonic pricing model with fixed effects for Adelaide, South Australia. The results indicate that the private benefits of a close proximity to golf courses, green space sporting facilities, or the coast, are in the order $0.54,$1.58, and $4.99 per metre closer (when evaluated at the median respectively). The historic Adelaide Parklands add$1.55 to a property’s value for each additional metre closer. We demonstrate how the estimated model could be used to calculate how local private benefits capitalized in property values change with changes in the configuration of a park

Reconfiguring an irrigation landscape to improve provision of ecosystem services

Over-allocation of fresh water resources to consumptive uses, coupled with recurring drought and the prospect of climate change, is compromising the stocks of natural capital in the world's basins and reducing their ability to provide water-dependent ecosystem services. To combat this, governments worldwide are making significant investment in efforts to improve the sharing of water between consumptive uses and the environment. Many investments are centred on the modernisation of inefficient irrigation delivery systems and the purchase of consumptive water for environmental flows. In this study, we applied spatial targeting within a cost-benefit framework to reconfigure agricultural land use in an irrigation district to achieve a 20% reduction in agricultural water use to increase environmental flows, and improve the provision of other ecosystem services. We demonstrate a targeted land use reconfiguration policy approach using spatial planning and optimisation models. Our model estimates a potential increase in the net present value of ecosystem services of up to $A 347 million. The increase in ecosystem services include recovering 62 GL of water for environmental flows, the sequestration of 10.6 million tonnes of CO2e/year, a 12 EC ([mu]S/cm) reduction in river salinity, and an overall 9$A 68.7 million in economic returns to agriculture which may be only marginally offset by the increased value of ecosystem services resulting from the return of 62 GL of water to the environment.Landscape planning Geographic information systems Cost-benefit analysis Irrigation Climate change Water management Spatial targeting Environmental valuation

Using mental-modelling to explore how irrigators in the Murray–Darling Basin make water-use decisions

Study region: Water stress and over-allocation are at the forefront of water management and policy challenges in Australia, especially in the Murray–Darling Basin (MDB). Because irrigated agriculture is a major social and economic component of the MDB, farmer decision-making plays a major role in water sustainability in the region. Study focus: This study used a fuzzy cognitive mapping methodology, ‘mental modeling’, to understand the perceived constraints of irrigator water-use decisions in the MDB, for two different types of irrigation: permanent and annual crops. The approach elicits and documents irrigator insights into the complex and networked nature of irrigation water use decisions in relation to farm-based dynamics. New hydrological insights for the region: Results suggest support for greater local and irrigator involvement in water management decisions. Many, if not most, of the irrigators understood the need for, or at least the inevitability of, governmental policies and regulations. However, a lack of accountability, predictability, and transparency has added to the uncertainty in farm-based water decision-making. Irrigators supported the concept of environmental sustainability, although they might not always agree with how the concept is implemented. The mental modelling approach facilitated knowledge sharing among stakeholders and can be used to identify common goals. Future research utilizing the mental modelling approach may encourage co-management and knowledge partnerships between irrigators, water managers and government officials