Impact of climate change on economic components of Mediterranean olive orchards

Abstract

Combining an olive growth simulation model with a specific module for economic components—namely, net margin (NM) and irrigation water productivity (IWP)—resulted in the AdaptaOlive v2.0 model. This model, used with perturbed climate (PC) and impact response surfaces (IRS), provided a tool that enabled the assessment of the impact of climate change on economic components of Mediterranean olive groves in southern Spain. Under future mild winter conditions, reductions in NM and IWP are expected; negative NM values may even be registered, with water availability having a relatively small effect on the results. In the opposite case, under future cool winter conditions, NM and IWP will increase, except for rainfed olive groves under low rainfall conditions, with water availability playing a major role. In addition, the distance (in terms of changes in temperature and rainfall compared to baseline conditions) to critical thresholds such as negative NM or IWP lower than irrigation water cost was assessed, identifying changes depending on weather conditions, water cost and olive oil price. Thus, future temperature increases of around 3 ºC under mild winter conditions could generate negative values of NM. These economic results impact the performance of adaptation strategies for olive groves, even ruling out some strategies that were previously recommended when only agronomic components were taken into account (e.g., deficit irrigation under mild winter conditions). There is thus a need for site-specific recommendations related to the use of irrigation and olive orchard management to maintain or increase the sustainability of these cropping systems. Despite the utility of using PC and IRS to achieve a scientifically sound evaluation of Mediterranean olive groves under future weather conditions, the approach presents some limitations that can be overcome using climate model outputs.