Analysis

Mediterranean-wide analysis of the olive-olive fly system

The Mediterranean Basin is expected to be particularly vulnerable to climate change including pronounced climate warming and desertification. Olive (Olea europaea) is of eco-social importance in the Mediterranean where it was domesticated, and it is also considered a sensitive climate indicator. This crop and its major pest, the olive fly Bactrocera oleae are a suitable model system to study Mediterranean climate. A weather-driven physiologically-based demographic model (PBDM) of olive and olive fly (http://cnr.berkeley.edu/casas/) is being used to analyze this plant-pest system in the Mediterranean region based on ERA-40 weather data (http://www.ecmwf.int/) downscaled via the regional climate model RegCM3 coupled to the MIT ocean model (the PROTHEUS system, see http://clima.casaccia.enea.it/PROTHEUS/). PBDM predictions are mapped with the open source GIS GRASS (http://grass.osgeo.org/).Ponti L., Gutierrez A.P., Ruti P.M., 2009. The olive–Bactrocera oleae system in the Mediterranean Basin: a physiologically based analysis driven by the ERA-40 climate data. 5th Study days “Models for Plant Protection”, Piacenza, Italy, 27-29 May 2009.

http://www.grimpp.it/v_giornate_di_studio.htm

Can climate change influence olive pests and diseases?

Climate change will make the Mediterranean Basin vulnerable to desertification, and this will affect many species such as olive in largely unknown ways. Olive is the base of a tri-trophic food web that includes pest, disease and their natural enemy species, each of which will be affected differently by climate change. The effects of extant weather and climate change scenarios on the tri-trophic interactions can be examined using biologically-rich physiologically-based demographic models developed from field and laboratory data. Studies from Sardinia, Italy and California show how the same model can be applied to these areas, and by inference, to other areas of the Mediterranean basin and elsewhere globally. Specifically, the model enables the examination of climate change on the range of olive and olive fly. The effect of climate change on natural enemies are illustrated using the olive scale/parasitoid interactions. The same system can also be used to examine the distribution and abundance of diseases. No model is complete, and required improvements can serve as a basis for interdisciplinary regional IPM research.Gutierrez A.P., Ponti, L., 2009. Can climate change have an influence on the occurrence and management of olive pests and diseases? 4th European Meeting of the IOBC/WPRS Working Group “Integrated Protection of Olive Crops”, Córdoba, Spain, 1-4 June 2009. (Keynote address)

Sardinia olive systems in a warmer climate

In the Mediterranean Basin, major islands including Sardinia are considered particularly vulnerable to global warming and desertification. We used a physiologically based demographic model (PBDM) of olive and olive fly to analyze in detail this plant-pest system in Sardinia under observed weather (ten years of daily data from 48 locations), three climate warming scenarios (increases of 1, 2 and 3 °C in average daily temperature), and a 105-year climate model scenario for the Alghero (e.g. 1951-2055). GRASS GIS was used to map model predictions, and model calibration with field bloom date data was performed to increase simulation accuracy of olive flowering predictions under climate change. As climate warms, the range of olive is predicted to expand to higher altitudes and consolidate elsewhere, especially in coastal areas. The range of olive fly will extend into previously unfavorable cold areas, but will contract in warm inland lowlands where temperatures approach its upper thermal limits. Consequently, many areas of current high risk are predicted to have decreased risk of fly damage with climate warming. Simulation using a 105 year climate model scenario for Alghero, Sardinia predicts changes in the olive-olive fly system expected to occur if climate continued to warm at the low rate observed during in the past half century.Ponti L., Cossu Q.A., Gutierrez A.P., 2009. Climate warming effects on the Olea europaea–Bactrocera oleae system in Mediterranean islands: Sardinia as an example. Global Change Biology, 15: 2874–2884.

http://dx.doi.org/10.1111/j.1365-2486.2009.01938.x

Agroecosystems and climate change

In a chapter to appear in the Handbook of Climate Change and Agroecosystems, four approaches used to estimate the potential distribution of native and invasive species in agricultural, natural and medical/veterinary vector/disease systems in the face of climate change are reviewed: (1) time-series observations to document biological responses to changes in climatic variables; (2) remote sensing analysis of data; (3) climate envelope approaches (statistically-based ecological niche models and physiologically-based ecological niche models); (4) physiologically based demographic models. The bases and relative merits of the approaches are discussed. The chapter emphasizes physiologically based demographic models that may be used at the individual, population and regional scales. Such models easily include multiple trophic levels as demonstrated for the olive/olive scale system. The olive/olive-fly system embedded in a geographic information system (GIS) is used to illustrate the utility of the physiologically based demographic approach for climate change research. Applications to other crop/pest/natural enemy systems are also discussed. The use of marginal analysis to summarize regional simulation data is introduced.Gutierrez A.P., Ponti L., Gilioli G., 2010. Climate change effects on plant-pest-natural enemy interactions. In: Hillel D., Rosenzweig, C. (eds.), Handbook of Climate Change and Agroecosystems: Impacts, Adaptation, and Mitigation. World Scientific Publishing, Singapore (in press).

http://www.icpress.co.uk/environsci/p755.html