Books by Anne-Gaelle Ausseil
Book chapter in "Ecosystem services in New Zealand", John R Dymond ed
Wetlands provide important and diverse benefi ts to people around the world, contributing provisi... more Wetlands provide important and diverse benefi ts to people around the world, contributing provisioning, regulating, habitat, and cultural services. Critical regulating services include water-quality improvement, fl ood abatement and carbon management, while key habitat services are provided by wetland biodiversity. However, about half of global wetland areas have been lost, and the condition of remaining wetlands is declining. In New Zealand more than 90% of wetland area has been removed in the last 150 years, a loss rate among the highest in the world. New Zealand Māori greatly valued wetlands for their spiritual and cultural signifi cance and as important sources of food and other materials closely linked to their identity. The remaining wetlands in New Zealand are under pressure from drainage, nutrient enrichment, invasive plants and animals, and encroachment from urban and agricultural development. In many countries, the degradation of wetlands and associated impairment of ecosystem services can lead to signifi cant loss of human well-being and biodiversity, and negative long-term impacts on economies, communities, and business. Protection and restoration of wetlands are essential for future sustainability of the planet, providing safety nets for emerging issues such as global climate change, food production for an increasing world population, disturbance regulation, clean water, and the overall well-being of society.
Biodiversity - The Dynamic Balance of the Planet,, 2014
Book chapter in: Ecosystem services in New Zealand, ed. John Dymond, Feb 2014
Human well-being depends on the ecosystem services provided by the landscape. The nature and magn... more Human well-being depends on the ecosystem services provided by the landscape. The nature and magnitude of these services depend on the interaction of a land use with its local and catchment environment, and consequently also on land management practices. In a landscape of spatially varying climate, soils, slope, and susceptibility to processes such as erosion, these services depend crucially on the location of the land use within the landscape. A land use may be detrimental or benign, depending on where it occurs in the landscape mosaic. Consequently, there is increasing interest in providing advice on precisely how land-use mosaics can be spatially configured to optimise ecosystem services. These complex spatial planning problems involving competing land uses and contradicting objectives can be tackled using an emerging set of tools for spatial optimisation. In this chapter we demonstrate how to optimise land-use configuration in order to maximise ecosystem services and land-use performance. First, we illustrate the impact of the spatial configuration of land use on ecosystem services. Then, we introduce the method of multi-objective spatial optimisation and its implementation in the Land-Use Management Support System (LUMASS). LUMASS allows for optimising a land-use configuration subject to multiple and possibly conflicting objectives and constraints. Using LUMASS in two different case study areas in New Zealand, we demonstrate how to reconfigure the land-use pattern to improve ecosystem services while maintaining agricultural production. In the first case study in the Waitaki catchment in the South Island, we used LUMASS in three different scenarios to maximise clean water provision, habitat provision, and water regulation. Dairying was not allocated to the shallow soils of the intermontane plains in the Mackenzie Basin in any of these scenarios. Optimising for water flow regulation produced a land-use pattern similar to the current land use. This suggested extensive sheep and beef farming should be kept
on tussock grasslands to maintain the Waitaki River flow. The second case study, in the central North Island, involved plantation forest, dairying, and sheep and beef farming. We optimised the land-use pattern to minimise nitrate leaching, soil erosion, and nitrate leaching and soil erosion concurrently. The results show that the current landscape configuration is suboptimal and point to a possible shift between dairying and forestry if we were to prioritise these criteria. The case studies demonstrate that spatial optimisation can be used to maximise the potential of the landscape in terms of its land use and ecosystem services performance. By testing different objectives and constraints to represent different stakeholder preferences, decision-makers can gain insight into the full spectrum of feasible solutions.
They can explore the opportunities that lie within the landscape, and critically assess the limits within which compromises need to be found.
Book chapter in: Dr JR Dymond ed, Ecosystem services in New Zealand.
This chapter reviews all stocks and fl uxes of carbon in New Zealand, and reviews biophysical reg... more This chapter reviews all stocks and fl uxes of carbon in New Zealand, and reviews biophysical regulation through surface albedo. The terrestrial environment provides a climate-regulation service by assimilating, transforming, and adjusting to emissions of greenhouse gases that could otherwise lead to undesirable changes in global climate. Quantifying this service requires accounting for both stocks and fl ows. While greenhouse gas emissions and removals are reported in the national inventory, this inventory accounts only for human-induced changes in greenhouse gases, and omits some natural processes and ecosystems; for example, indigenous forest and scrub are not included but represent the largest biomass carbon pool in New Zealand. Emissions are mainly attributed to the energy and agricultural sectors, while removals come from exotic forestry and natural shrubland regeneration. Erosion plays a role as a carbon sink through natural regeneration of soil carbon on slopes. Biophysical regulation occurs through absorption or refl ection of solar radiation (albedo). Forests tend to absorb more radiation than crops or pasture, thus contributing to a lesser extent to global warming. Government currently provides some mechanisms to incentivise sustainable land management in favour of increased forest area on lands unsuitable for agriculture. However, carbon stocks are also at risk of being lost through degradation of natural ecosystems, and this requires active management and mitigation strategies.
Papers by Anne-Gaelle Ausseil
Wetlands Ecology and Management, 2015
Freshwater wetlands provide a range of ecosystem services, one of which is climate regulation. Th... more Freshwater wetlands provide a range of ecosystem services, one of which is climate regulation. They are known to contain large pools of carbon (C) that can be affected by land-use change. In New Zealand, only 10 % of the original freshwater wetlands remain due to conversion into agriculture. This study presents the first national estimation of C stocks in freshwater wetlands based on the compilation of soil carbon data from 126 sites across the country. We estimated C stocks for two soil sample types (mineral and organic) in different classes of wetlands (fen, bog, swamp, marsh, pakihi and ephemeral), and extrapolated C stocks to national level using GIS. Bogs had high C content and low bulk densities, while ephemeral wetlands were the reverse. A regression between bulk density and C content showed a high influence of the soil type. Average C densities (average ± standard error) were 1,348 ± 184 t C ha -1 at full peat depth (average of 3.9 m) and 102 ± 5 t C ha -1 (0.3 m depth) for organic soils, and 121 ± 24 t C ha -1 (0.3 m depth) for mineral soils. At national level, C stocks were estimated at 11 ± 1 Mt (0.3 m depth) and 144 ± 17 Mt (full peat depth) in organic soils, and 23 ± 1 Mt (0.3 m depth) in mineral soils. Since European settlement, 146,000 ha of organic soils have been converted to agriculture, which could release between 0.5 and 2 Mt CO 2 year -1 , equivalent to 1-6 % of New Zealand's total agricultural greenhouse gas emissions.
Freshwater Biology, 2011
potential to protect a diverse range of wetland classes and a high proportion of the remaining ha... more potential to protect a diverse range of wetland classes and a high proportion of the remaining habitat.
Wetlands provide important and diverse benefi ts to people around the world, contributing provisi... more Wetlands provide important and diverse benefi ts to people around the world, contributing provisioning, regulating, habitat, and cultural services. Critical regulating services include water-quality improvement, fl ood abatement and carbon management, while key habitat services are provided by wetland biodiversity. However, about half of global wetland areas have been lost, and the condition of remaining wetlands is declining. In New Zealand more than 90% of wetland area has been removed in the last 150 years, a loss rate among the highest in the world. New Zealand Māori greatly valued wetlands for their spiritual and cultural signifi cance and as important sources of food and other materials closely linked to their identity. The remaining wetlands in New Zealand are under pressure from drainage, nutrient enrichment, invasive plants and animals, and encroachment from urban and agricultural development. In many countries, the degradation of wetlands and associated impairment of ecosystem services can lead to signifi cant loss of human well-being and biodiversity, and negative long-term impacts on economies, communities, and business. Protection and restoration of wetlands are essential for future sustainability of the planet, providing safety nets for emerging issues such as global climate change, food production for an increasing world population, disturbance regulation, clean water, and the overall well-being of society.
Abstract Measurement of nitrous oxide emission in the dairy farm is a time-consuming process. The... more Abstract Measurement of nitrous oxide emission in the dairy farm is a time-consuming process. The alternative approach is to run a realistic process-based model. The NZ-DNDC model is capable of generating reasonable results in a short time. The model is driven by weather and soil parameters that have a high degree of temporal (weather) and spatial (soil properties) variability. This variability in soil and weather parameters leads to uncertainty in the predicted nitrous oxide emissions. This paper examines the possibility of developing a ...
Environmental Science & Technology, 2016
Rivers and streams in New Zealand are natural with free access and used by many people for swimmi... more Rivers and streams in New Zealand are natural with free access and used by many people for swimming and fishing. However, pastoral farming with free grazing animals is a common land use in New Zealand and faecal microorganisms from them often end up in waterways. These microorganisms can seriously affect human and animal health if ingested. This paper describes spatial modeling using GIS of Escherichia coli sources in a large catchment (350 000 ha), the Ruamahanga. By examining the pathway of water over and through soils, it is possible to determine whether E. coli sources are connected to waterways or not. The map of E. coli sources connected to waterways provides useful context to those setting water quality limits. This approach avoids the complexity of modeling the fate and transport of E. coli in waterways, yet still permits the assessment of catchment-wide mitigation and best management practice. Fencing of waterways would minimize E. coli sources directly defecated to water and would reduce total E. coli sources by approximately 35%. Introduction of dung beetles would minimize sources connected to waterways by overland flow and would reduce total E. coli sources by approximately 35%. Construction of dairy effluent ponds would minimize sources connected to waterways through high bypass flow in soils and would reduce total E. coli sources by approximately 25%.
In Brief New Zealand is highly dependent on ecosystems for a range of services. Since the arrival... more In Brief New Zealand is highly dependent on ecosystems for a range of services. Since the arrival of Europeans in the 19 th century, many natural ecosystems have been converted to managed ecosystems. This conversion has been accompanied by biological invasions. Managing the balance between natural and managed ecosystems is crucial. In this article, we review the conditions and trends of ecosystem services in New Zealand. We find that natural resource management is maintaining services, but there are several opportunities for enhancement. These include better matching of land use to soil capacity and improved management of riparian zones for water quality. A more systematic approach to evaluating trade-offs among invasive species and native biodiversity would also be helpful. Landcare Research
The New Zealand Government purchased the lease of St James in 2008 as public conservation land fo... more The New Zealand Government purchased the lease of St James in 2008 as public conservation land for ecosystem services, public recreation, and biodiversity protection purposes. In this chapter, the ecosystem services and biodiversity provided by St James are reviewed. In the future, climate regulation, erosion control, clean water provision, and recreation services are all likely to increase. Habitat provision, food provision, and biodiversity are likely to be maintained. Water yield is the one service which is likely to decrease. We discuss how an ecosystem services framework can best benefi t conservation.
Spatial optimisation has been widely used in scientific studies for land-use pattern optimisation... more Spatial optimisation has been widely used in scientific studies for land-use pattern optimisation and resource allocation, often to maximise ecosystem services and/or land use performances. Such use implies its applicability in real-world spatial planning and policy development. But how suitable is spatial optimisation, especially in the context of uncertain input data and stakeholder expectations? For example, what is the impact of uncertainty associated with modelled nitrate leaching rates on land-use pattern optimisation with the objective to minimise nitrate leaching? Since spatial optimisation problems are usually constrained by stakeholder expectations or preferences, it is equally important to know how sensitive optimal land-use pattern are to changes in those expectations and preferences.
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Books by Anne-Gaelle Ausseil
on tussock grasslands to maintain the Waitaki River flow. The second case study, in the central North Island, involved plantation forest, dairying, and sheep and beef farming. We optimised the land-use pattern to minimise nitrate leaching, soil erosion, and nitrate leaching and soil erosion concurrently. The results show that the current landscape configuration is suboptimal and point to a possible shift between dairying and forestry if we were to prioritise these criteria. The case studies demonstrate that spatial optimisation can be used to maximise the potential of the landscape in terms of its land use and ecosystem services performance. By testing different objectives and constraints to represent different stakeholder preferences, decision-makers can gain insight into the full spectrum of feasible solutions.
They can explore the opportunities that lie within the landscape, and critically assess the limits within which compromises need to be found.
Papers by Anne-Gaelle Ausseil
on tussock grasslands to maintain the Waitaki River flow. The second case study, in the central North Island, involved plantation forest, dairying, and sheep and beef farming. We optimised the land-use pattern to minimise nitrate leaching, soil erosion, and nitrate leaching and soil erosion concurrently. The results show that the current landscape configuration is suboptimal and point to a possible shift between dairying and forestry if we were to prioritise these criteria. The case studies demonstrate that spatial optimisation can be used to maximise the potential of the landscape in terms of its land use and ecosystem services performance. By testing different objectives and constraints to represent different stakeholder preferences, decision-makers can gain insight into the full spectrum of feasible solutions.
They can explore the opportunities that lie within the landscape, and critically assess the limits within which compromises need to be found.
the balance between natural and managed ecosystems, and to ensure the sustainability of human development and equity in resource use. We use the ecosystem services approach to help resource managers achieve that balance. In this paper we combine several critical ecosystem services (provision of food and fibre, provision of clean water, regulation of water-flow, provision of natural habitat) into a framework for land-use optimisation, LUMASS. We developed spatial explicit models of these services based on process-based models upscaled to national level using look-up tables. Quantification depends on land use, climate, and soil, and can be used to analyse trade-offs and the optimal configuration of the landscape that would maximise the benefits for humans. The Waitaki catchment is
subject to such trade-offs with the conversion of natural areas (mainly tussock grasslands) into dairy farming, which, while increasing the provisioning of food, will impact on water quality and quantity, and reduce habitat provision. We applied the
LUMASS optimisation algorithm with an objective function designed to maximise regulating services (clean water provision, water-flow regulation) while still maintaining provisioning services (food). The land-use options are managed agro-ecosystems (dairy, sheep, and beef) and natural ecosystems (conservation land). We explain differences between the current land-use pattern and the optimal land-use pattern.