Spatial agroecology: modelling multiple ecosystem services in periurban landscapes : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University

Abstract

Urban growth and agricultural intensification share a common trait of reducing landscapes' capacity of producing the critical ecosystem services (ES) on which they depend. The objective of the work described in this thesis was to develop a spatially explicit ES-based design method for the configuration of landscapes to generate regulating ES. Literature review, which is described in Chapter 2, identified a nexus of four research fields - Ecological Urbanism, Landscape Ecology, ES science and agroecology - as an unexplored framework for this ES-based design approach. The method used in this work is described in Chapter 3, where a key flaw in current ES modelling tools forms the basis for a Geographic Information Systems (GIS)-based conceptual model, ESMAX. Present models are characterised by 'the biophysical gap', an oversight of spatial interactions between ES-supplying landscape components. This inhibits their application to spatial design i.e., the configuration of those components to enhance ES performance. ESMAX is structured around the fundamental natural phenomena of distance-decay as exhibited by all regulating ES, enabling an original method of quantifying and visualising regulating ES produced by different configurations of landscape components. The results of Chapter 3 conceptually validated the model and provided the data for Chapter 4, which proposed a model for assessing landscape multifunctionality (or simultaneous supply of multiple ES) from different landscape configurations. Importantly, the results for different configuration options generate a solution space with which to negotiate specific ES demands and specific contextual spatial constraints. Chapter 5 applied ESMAX and the solution space in an agricultural context. This spatial agroecological approach determined that different configurations of the same total area of trees in a 1 ha paddock produce markedly different levels of ES performance, and that this approach may be useful in supporting an adaptive transition from conventional agriculture to agroecologically based farming systems. Chapter 6 applied spatial agroecology to a 190 ha periurban development site, demonstrating how the same apportioned area of agroecological systems, when subdivided and distributed differently across the site, has a significant bearing on multiple ES production. This suggests that urgent consideration should be given not only to placing trees on farm, but how trees should be placed on farm. Similarly, it supports not only the integration of agriculture with urban systems, but the specific spatial design of agroecological systems to address the regulating ES demands of the urban system. The spatial agricultural approach outlined in this thesis highlights the potential for agroecology in the Anthropocene as a spatially effective source of multiple regulating ES to surrounding communities at various scales.