the GlobalChangeBiology blog

Background. The implementation of hybrid Bt cotton unique to India has been heralded as a grand success by government agencies, seed companies and other proponents, and yet yields have stagnated at low levels and production costs have risen 2.5–3-fold. The low-yield hybrid cotton system of India contributes thousands of farmer suicides to the annual national toll. Conceptual and methodological barriers have hindered bioeconomic analysis of the ecological and social sustainability of such cross-scale agro-ecological problems in time and geographic space, under global technology and climate change. As a paradigm shift, we use conceptually simple, parameter-sparse, theoretically based, mechanistic, weather-driven physiologically based demographic models (PBDMs) to deconstruct the bio-economics of the Indian cotton system. Results. Our analysis of Indian hybrid cotton system explains some extant ecological and economic problems, and suggests a viable solution. Specifically, the model accur...

( This paper made cover story .) Of fruit crops, grape is the most largely cultivated and has the highest economic importance globally; it is part of the Mediterranean bio-cultural heritage that is threatened by climate change. However, the analysis of the climate effects on grape and other crop and natural ecosystems on a regional scale has been vexing. Here, we review how sparse physiologically based demographic models (PBDM) in the context of the geographic information system GRASS GIS can be used to examine the effects of the extant weather and climate change on the dynamics of the interaction between grape and European grapevine moth across the Euro-Mediterranean region. Further, by including management-relevant complexity in a mechanistic way, the PBDM/GIS system provides the basis for a regional bioeconomic analysis of the grape system and a template for similar analyses that require modest data and funding. Ponti L., Gutierrez A.P., Boggia A., Neteler M., 2018. Analysis of ...

Yellow starthistle ( Centaurea solstitialis L.) (YST) is an invasive weed native to the Mediterranean region with a geographical centre of diversity in Turkey. It is widely established in Chile, Australia, and western North America. It arrived in California as a contaminant in alfalfa seed in 1859 and, by 2002, had infested more than 7.7 million hectares in the U.S.A. Biological control of YST using capitula feeding weevils, picture wing flies and a foliar rust pathogen has been ongoing in the western U.S.A. for more than three decades with limited success. Modelling and field research suggest natural enemies that kill whole plants and/or reduce seed production of survivors are good candidates for successful biological control. A candidate species with some of these attributes is the rosette weevil Ceratapion basicorne (Illiger). In the present study, a model of the rosette weevil is added to an extant system model of YST and its capitula feeding natural enemies and, in a GIS context...

The workshop " When Space Meets Agriculture " aimed at promoting a better understanding of the significance and potential of Europe’s space systems (EGNOS/Galileo and Copernicus) for the agricultural sector. While introducing Rural Development Programmes of selected regions and exploring opportunities to set synergies for the development of space applications for the agriculture sector, it will present the main strands of the European Agriculture Policy and more generally link the space community to the agriculture community. Our contribution identified recent and prospective holistic analyses of climate change effects on crop-pest systems in the Mediterranean Basin. The approach used in the analyses involves using physiologically based demographic modeling (PBDM) of crop-pest-natural enemy interactions in the context of a geographic information system (GIS). A major goal is to link the PBDM/GIS technology with increasingly available biophysical datasets from global modeling ...

The polyphagous Asian vinegar fly Drosophila suzukii (spotted wing Drosophila) is a native of Eastern and Southeastern Asia. It emerged as an important invasive insect pest of berries and stone fruits in the Americas and Europe beginning in 2008. Species distribution models are commonly used for analyzing the extant and potential range expansion of invasive species. Previous modeling efforts for D. suzukii include a degree-day model, a MaxEnt ecological niche model, a demographic model incorporating the effects of temperature, and a preliminary mechanistic physiologically-based demographic model (PBDM). In the present analysis, we refine the PBDM for D. suzukii based on biological data reported in the literature. The PBDM is used to assess the effects of temperature and relative humidity from a recently published global climate dataset (AgMERRA) on the prospective geographic distribution and relative abundance of the pest in the USA and Mexico, and in Europe and the Mediterranean Ba...

Cotton with coevolving pests has been grown in India for more than 5000 years. Hybrid cotton was introduced in the 1970s with increases in fertilizer and in insecticide use against pink bollworm that caused outbreaks of bollworm. Hybrid Bt cotton, introduced in 2002 to control bollworm and other lepidopteran pests, is grown on more than 90 % of the cotton area. Despite initial declines, year 2013 insecticide use is at 2000 levels, yields plateaued nationally, and farmer suicides increased in some areas. Biological modeling of the pre-1970s cotton/pink bollworm system was used to examine the need for Bt cotton, conditions for its economic viability, and linkage to farmer suicides. Yields in rainfed cotton depend on timing, distribution, and quantity of monsoon rains. Pink bollworm causes damage in irrigated cotton, but not in rainfed cotton unless infested from irrigated fields. Use of Bt cotton seed and insecticide in rainfed cotton is questionable. Bt cotton may be economic in irrigat...

The Mediterranean Basin is a climate change and biological invasion hotspot where recent warming is facilitating the establishment and spread of invasive species, one of which is the highly destructive South American tomato leafminer ( Tuta absoluta ). This pest recently invaded the Mediterranean Basin where it threatens solanaceous crops. Holistic approaches are required to project the potential geographic distribution and relative abundance of invasive species and hence are pivotal to developing sound policy for their management. This need is increasing dramatically in the face of a surge in biological invasions and climate change. However, while holistic analyses of invasive species are often advocated, they are rarely implemented. We propose that physiologically-based demographic models (PBDMs) in the context of a geographic information system (GIS) can provide the appropriate level of synthesis required to capture the complex interactions basic to manage invasive species such as T...

The new world screwworm Cochliomyia hominivorax (Coquerel) was eradicated in North America, Libya and other locations using the sterile insect technique (SIT). To examine the role of weather in its eradication, a physiologically-based demographic model (PBDM) was developed and used to characterize its range of year-round persistence. Winter temperature and rainfall are shown to have a strong influence on screwworm outbreaks and in facilitating eradication in North America and Libya. Prospective analysis for the Mediterranean Basin suggests eastern areas are most favorable for screwworm establishment (e.g., the Nile River area of Egypt). The SIT eradication programme and its possible extension into South America are discussed. Expected +2°C climate warming is predicted to increase the potential year-round range of screwworm in the SE USA. Gutierrez A.P., Ponti L., 2014. The new world screwworm: prospective distribution and role of weather in eradication. Agricultural and Forest Entom...

The invasive Asian citrus psyllid Diaphorina citri Kuwayama vectors the bacterial pathogen ‘Candidatus Liberibacter asiaticus’ that is the putative causal agent of citrus greening disease (Huanglongbing disease) in citrus in many areas of the world. The capacity to predict the potential geographic distribution, phenology and relative abundance of the pest and disease is pivotal to developing sound policy for their management. A weather-driven physiologically based demographic model (PBDM) system is developed that summarizes the available data in the literature, and used to assess prospectively the geographic distribution and relative abundance of citrus, the psyllid, its parasitoid ( Tamarixia radiata Waterston), and citrus greening disease in North America and the Mediterranean Basin. The potential for natural and biological control of citrus psyllid is examined prospectively. Gutierrez A.P., Ponti L., 2013. Prospective analysis of the geographic distribution and relative abundance...

Control of insect pests and other taxa may be due to many factors that are difficult to separate and quantify as was the case for the control of the spotted alfalfa aphid (SAA, Therioaphis maculata Monell) in California and elsewhere. Introduced parasitoids, host plant resistance, pathogens and native predators led to its successful control, but the relative contribution of each factor remained largely unknown. The relative contribution of each control factor was estimated using a weather-driven physiologically-based demographic system model consisting of alfalfa, SAA (a), its three exotic parasitoids [ Trioxys complanatus (Quilis) (b), Praon palitans Muesebeck (c), and Aphelinus semiflavus Howard (d)], a native coccinellid beetle [ Hippodamia convergens (Guérin-Menéville)], a fungal pathogen [ Erynia neoaphidis Remaudière & Hennebert (Zygomycetes: Entomophthorales) (g)], and host plant resistance (HPR) (h). Alone, each factor failed to control SAA, as did combinations of the ...

The ENEA Technical Unit for Sustainable Development and Agro-industrial Innovation ( UTAGRI ) organized a course on "Using open source software for remote sensing and GIS applications" sponsored by the GlobalChangeBiology project and taught by Dr. Markus Neteler, head of the GIS and Remote Sensing Unit at Fondazione Edmund Mach (Trento, Italy). The course was held at the ENEA Casaccia Research Center and spanned two days of intensive work (17-18 January 2012). After an introduction to open source GIS, the course moved to practical issues such as software installation, data import and a simple analysis. The remote sensing part started with a review of available data sets, followed by an overview on data import and processing (analysis of time series and classification). Database management was also covered with a focus on SQL, which introduced vector data editing. Last, the GRASS-R interface was illustrated. Even though the course was targeted to ENEA researchers, it attra...

The ENEA Technical Unit for Sustainable Development and Agro-industrial Innovation ( UTAGRI ) organized a seminar on "Geographic Free and Open Source Software for remote sensing and GIS: a toolbox for the GlobalChangeBiology project " by Dr. Markus Neteler, head of the GIS and Remote Sensing Unit at Fondazione Edmund Mach (Trento, Italy). The seminar highlighted a wide range of applications implemented via open source software such as remote sensing of biophysical parameters, landscape analysis, environmental modeling, geostatistics, geomorphology, machine learning, management of emerging infectious diseases, and others. Thanks to the GlobalChangeBiology project , ENEA deploys a unique technology in Europe that provides a sound scientific platform for laying out effective response strategies to global change in agriculture. Open source geospatial software is key to achieving a major goal of the GlobalChangeBiology project , namely to link agroecosystem analysis with remote...

The polyphagous European grapevine moth Lobesia botrana (Den. & Schiff.) is the principal native pest of grape berries in the Palearctic region. It was found in Napa County, California, in 2009, and it has subsequently been recorded in an additional nine counties, despite an ongoing eradication program. A holistic physiologically-based demographic model for L. botrana linked to an extant mechanistic model of grapevine was run using observed daily weather data to simulate and map (via GRASS GIS ) the potential distribution of the moth in California and the continental U.S.A. The model predicts L. botrana can spread statewide with the highest populations expected in the hotter regions of southern California and the lower half of the Central Valley. In the U.S.A., areas of highest favorability include south Texas, and much of the southeast U.S.A. With climate warming, L. botrana abundance is expected to increase in northern California and in the agriculturally rich Central Valley ...

The capacity to predict the geographic distribution and relative abundance of invasive species is pivotal to developing policy for eradication or control and management. An example is the glassy-winged sharpshooter Homalodisca vitripennis (Germar) (GWSS) in California which vectors the bacterial pathogen Xylella fastidiosa (Wells) that causes Pierce’s disease in grape and scorch-like diseases in other plants. A weather driven demographic model of grape, GWSS, its two parasitoids ( Gonatocerus ashmeadi Girault and G. triguttatus Girault) and the pathogen was developed to show how the geographic distribution and abundance of GWSS as affected by weather and natural enemies in California can be easily assessed. The distribution of X. fastidiosa is limited to the warm inland areas of southern California. Biological control of GWSS further decreases the pathogen's relative range. Two climate warming scenarios show that increasing temperatures will increase GWSS severity in the agric...

Since being detected in California in 1975, the polyphagous tropical Mediterranean fruit fly ( Ceratitis capitata Weid. (medfly)) has been the subject of a large-scale eradication campaign in the absence of sound knowledge of its invasive potential. We use a weather-driven physiologically-based demographic system model ( CASAS ) embedded in a GIS based on GRASS to examine medfly's potential distribution across Arizona-California (AZ-CA), and Italy where its establishment is documented. AZ is unfavorable for medfly because of high summer temperatures, while much of CA, including many frost-free areas, is too cold during winter. Only the south near coastal region of CA is predicted to be potentially favorable for medfly, but in the absence of consistent measurable populations, we cannot say if medfly is established there. Medfly has been established in Italy for decades, and our model predicts a wide distribution in the southern and western regions of the country. Gutierrez A.P.,...

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 o...

The highly polyphagous light brown apple moth (LBAM) ( Epiphyas postvittana (Walk.): Tortricidae) is indigenous to Australia and was first found in California in 2006. It is currently found in 15 coastal counties in California, but nowhere has it reached outbreak status. The USDA projects the geographic range of LBAM will include much of Arizona and California and the southern half of the U.S., which together with economic estimates of potential crop losses have been used as the rationale for an eradication program in California. We report a temperature-driven demographic model to predict the likely distribution and relative abundance of LBAM using the detailed biology reported by W. Danthanarayana and colleagues, and climate data from 151 locations in California and Arizona for the period 1995 to 2006. The predictions of our model suggest that the near coastal regions of California are most favorable for LBAM, the northern Central Valley of California being less favorable, and the de...

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 li...

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. 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...

Maps obtained using the integrated models/GIS tool developed and implemented by the GlobalChangeBiology (GCB) project are under display at OSGeo Gallery , the showcase website of theOpen Source Geospatial Foundation. Please, visit our OSGeo Gallery page to see what it looks like. The Open Source Geospatial Foundation, or OSGeo, is a not-for-profit organization whose mission is to support and promote the collaborative development of open geospatial technologies and data. An official project of OSGeo, GRASS is the GIS platform used by the GCB project.