Archive for the ‘multitrophic interactions’ Category

Analysis of invasive insects: links to climate change

September 12, 2014 Leave a comment

Climate change is expected to alter the geographic distribution and abundance of many species, to increase the invasion of new areas by exotic species and, in some cases, to lead to extinction of species. This chapter reviews some of the links between invasive insects and climate change. The effects of climate change on insect pest populations can be direct, through impacts on their physiology and behaviour, or indirect, through biotic interactions (i.e. bottom-up and top-down eff ects). Anthropogenic climate and global change is expected to be a major driver in the introduction, establishment, distribution, impact and changes in the efficacy of mitigation strategies for invasive species. To address these problems, we must be able to predict climate change impacts on species distribution and abundance. Commonly used ecological niche modelling approaches have implicit assumptions about the biology of the target species and attempt to characterize the ecological niche using aggregate weather and other factors in the area of recorded distribution. More holistic physiologically based demographic modelling approaches explicitly describe the biological and physiological responses of species to weather and the species they interact with on fine temporal and spatial scales. The geographic distribution and relative abundance of four invasive insect pests are reviewed under observed and +2°C weather scenarios across the USA and Mexico: the tropical New World screwworm, the pink bollworm, the Mediterranean fruit fly (i.e. medfly) and the olive fly. The distribution of the olive fly is examined across the Mediterranean basin to illustrate the transferability of the model to analyses of new regions and climate change scenarios.

Gutierrez A.P., Ponti L., 2014. Analysis of invasive insects: links to climate change. In: Ziska L.H., Dukes J.S., (eds.), Invasive Species and Global Climate Change. CABI Publishing, Wallingford, UK. ISBN: 978-1780641645.

Dry matter partitioning in a ladybeetle PBDM.

Olive bioeconomics under climate warming

March 25, 2014 Leave a comment

Inability to determine reliably the direction and magnitude of change in natural and agro-ecosystems due to climate change poses considerable challenge to their management. Olive is an ancient ubiquitous crop having considerable ecological and socioeconomic importance in the Mediterranean Basin. We assess the ecological and economic impact of projected 1.8 °C climate warming on olive and its obligate pest, the olive fly. This level of climate warming will have varying impact on olive yield and fly infestation levels across the Mediterranean Basin, and result in economic winners and losers. The analysis predicts areas of decreased profitability that will increase the risk of abandonment of small farms in marginal areas critical to soil and biodiversity conservation and to fire risk reduction.

Ponti L., Gutierrez A.P., Ruti P.M., Dell’Aquila A., 2014. Fine scale ecological and economic assessment of climate change on olive in the Mediterranean Basin reveals winners and losers. Proceedings of the National Academy of Sciences, USA,

Sardinia olive systems in a warmer climate

February 23, 2010 Leave a comment

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.

Mediterranean-wide analysis of the olive-olive fly system

August 6, 2009 Leave a comment

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 ( is being used to analyze this plant-pest system in the Mediterranean region based on ERA-40 weather data ( downscaled via the regional climate model RegCM3 coupled to the MIT ocean model. PBDM predictions are mapped with the open source GIS GRASS (

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.