Managing ecosystem services in broadacre landscapes: what are the appropriate spatial scales?

Abstract

Over the past 200 years agriculture has expanded throughout Australia. The culmination of clearing and cultivating land at the farm scale has resulted in highly modified landscapes and a perceived loss of ecosystem services from pest control and pollination. We examine the literature: (i) to identify the appropriate spatial scale for managing pests, natural enemies and pollinators; and (ii) for evidence that farm-scale changes (due to agricultural intensification) across a landscape have resulted in a tipping point favouring pests and hindering pollinators. Although there is limited information to draw firm conclusions, the evidence suggests that actions undertaken on individual farms have an impact both on their neighbours and regionally, and that the culmination of these actions can lead to changes in population dynamics of pests, natural enemies and pollinators. For major pest species, there is reasonable evidence that grain growers may benefit from improved management and higher yields by implementing area-wide pest management strategies on a landscape scale in collaboration with growers of other crops that also share these pests. As yet, for natural enemies and pollinators there is little direct evidence that similar area-wide initiatives will have a greater effect than management strategies aimed at the field and farm level. Managing pests, natural enemies and pollinators beyond the scale of the field or farm is technically and socially challenging and will required a well defined research agenda, as well as compromise, balance and trading among stakeholders. We highlight critical knowledge gaps and suggest approaches for designing and managing landscapes for ecosystem services.